Next Article in Journal
Probing the Activity Enhancement of Carbocatalyst with the Anchoring of Atomic Metal
Next Article in Special Issue
Controllable Synthesis and Growth Mechanism of Interlayer-Coupled Multilayer Graphene
Previous Article in Journal
Sol–Gel-Processed Y2O3 Multilevel Resistive Random-Access Memory Cells for Neural Networks
Previous Article in Special Issue
Controlling the Surface Morphology of Two-Dimensional Nano-Materials upon Molecule-Mediated Crystal Growth
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Nanomaterials
Volume 13
Issue 17
10.3390/nano13172433
nanomaterials-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Transition Metal Dichalcogenides Nanoscrolls: Preparation and Applications

by
Shilong Yu
,
Pinyi Wang
,
Huihui Ye
,
Hailun Tang
,
Siyuan Wang
,
Zhikang Wu
,
Chengjie Pei
,
Junhui Lu
and
Hai Li
*
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing 211816, China
*
Author to whom correspondence should be addressed.
Nanomaterials 2023, 13(17), 2433; https://doi.org/10.3390/nano13172433
Submission received: 20 July 2023 / Revised: 21 August 2023 / Accepted: 25 August 2023 / Published: 27 August 2023
(This article belongs to the Special Issue 2D Structured Materials: Synthesis, Properties and Applications)
Browse Figures
Versions Notes

Abstract

:
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) nanosheets have shown extensive applications due to their excellent physical and chemical properties. However, the low light absorption efficiency limits their application in optoelectronics. By rolling up 2D TMDCs nanosheets, the one-dimensional (1D) TMDCs nanoscrolls are formed with spiral tubular structure, tunable interlayer spacing, and opening ends. Due to the increased thickness of the scroll structure, the light absorption is enhanced. Meanwhile, the rapid electron transportation is confined along the 1D structure. Therefore, the TMDCs nanoscrolls show improved optoelectronic performance compared to 2D nanosheets. In addition, the high specific surface area and active edge site from the bending strain of the basal plane make them promising materials for catalytic reaction. Thus, the TMDCs nanoscrolls have attracted intensive attention in recent years. In this review, the structure of TMDCs nanoscrolls is first demonstrated and followed by various preparation methods of the TMDCs nanoscrolls. Afterwards, the applications of TMDCs nanoscrolls in the fields of photodetection, hydrogen evolution reaction, and gas sensing are discussed.

1. Introduction

As representative two-dimensional (2D) materials, the transition metal dichalcogenides (TMDCs) nanosheets have been successfully applied in the fields of photodetection [1,2,3,4,5,6], energy storage [7,8,9,10,11], catalysis [12,13,14,15,16], and so on. Although the monolayer TMDCs nanosheets have shown excellent optoelectronic performance, their low light absorption efficiency hinders the applications in photodetection [17], because of their ultrathin thickness.
A great deal of effort has been developed to improve the light absorption of TMDCs nanosheets, such as plasma treatment, formation of van der Waals heterojunction, utilization of plasmonic effect, integration of quantum dots [18,19,20,21,22], etc. Recently, rolling up the monolayer TMDCs nanosheet to form the TMDCs nanoscroll (TMDCs-NS) has been reported as a promising method to improve their optoelectronic performance [19]. With the aid of volatile organic solvents or alkaline solution [19,23,24,25,26,27], the monolayer TMDCs nanosheets can be transformed into one-dimensional (1D) nanoscrolls with tubular and spiral structures [23,28,29]. The as-obtained TMDCs nanoscroll (TMDCs-NS) showed enhanced light absorption due to the increased cross-section. In addition, the TMDCs-NS also inherits the excellent properties from the monolayer TMDCs nanosheet [21,30,31,32,33,34,35]. Furthermore, the curved structure of the nanoscroll exhibits strain, which can modulate the band gap of TMDCs nanosheet [33]. Moreover, its scrolled structure has tunable interlayer space with open ends, in which other functional nanomaterials can be encapsulated [35,36]. Therefore, the TMDCs-NS have attracted great attention in optoelectronics in recent years.
In this review, we introduce the structure, fabrication, and applications of TMDCs-NS. Firstly, the structure of nanoscrolls is demonstrated. Secondly, the preparation methods of nanoscrolls are discussed in detail. We then present the applications of TMDCs-NS in the photodetection, sensing, and hydrogen evolution reaction.

2. Structure of TMDCs-NS

Different from other 1D nanomaterials, the nanoscrolls have spiral tubular structure with weak van der Waals (vdW) interaction between adjacent layers, which are transformed from 2D nanosheet, exhibiting open ends and side edges without fusion as shown in Figure 1b, To date, various 2D nanosheets can be transformed into nanoscrolls, such as graphene, TMDCs, black phosphorus and h-BN [37,38,39,40,41,42]. The graphene nanoscroll was discovered in the arc discharge experiment of graphite electrode [43], and confirmed by transmission electron microscopy (TEM) [44]. The large-scale preparation of graphene nanoscroll was proposed in 2003 and then received much attention [45,46].
Similar to graphene nanoscroll, the TMDCs-NS is also composed of monolayer TMDCs nanosheets scrolled up into Archimedean helical structure (Figure 1c) [37,47]. These TMDCs-NS have unique physical and chemical properties due to their nanoscale dimensions and high surface area-to-volume ratio, which make them useful in a variety of applications, such as energy storage, catalysis, and optoelectronics [19,27,48,49,50,51,52].
The structure of TMDCs-NS is illustrated by taking MoS2 nanoscroll as an example. By scrolling a monolayer MoS2 nanosheet (Figure 1a), the MoS2 nanoscroll is formed with an inner layer radius of Rin, an outer layer radius of Rout, and a interlayer spacing of h, as shown in Figure 1c [53,54,55]. The scrolling direction is usually along the armchair or zigzag orientation of the MoS2 nanosheet (Figure 1d) [53]. A molecular dynamics (MD) simulation was performed to understand the scrolling direction of MoS2 at the molecular level (Figure 1e). The results indicate that the energy per atom of nanoscrolls along the armchair orientation is lower than those of nanoscrolls through the zigzag and chiral orientations (Figure 1f). As a consequence, the armchair orientation (Mo-S bond direction) is the dominant trend to roll up the MoS2 nanosheet into MoS2 nanoscrolls [56]. The spacing between adjacent layers of MoS2 nanoscroll also plays an important role in determining its stability. As the interlayer spacing increases from 4 to 5.5 Å, the energy of each atom decreases quickly (Figure 1g). While it increases continuously as the interlayer spacing increases from 5.5 to 10 Å. The MoS2 nanoscroll is in an energy-favorable state when the interlayer spacing is in the range of 4.7~6.5 Å [47,53].
Nanomaterials 13 02433 g001
Figure 1. (a). Monolayer MoS2 nanosheet. (b) Schematic structure of the TMDCs nanoscroll with open ends and side edges. (c) The MoS2 nanoscroll with inter-core radius Rin, in outer radius Rout and interlayer spacing h. (d) The formation of the MoS2 nanoscrolls are always along the armchair direction (Mo–S bond direction) [56]. (e) The MoS2 sheets of the same size roll through the armchair (left) and zigzag (right) orientation molecular dynamics (MD) simulations before (upper) and after (lower) structural relaxation [53]. (f) The relationship between unit atomic energy and simulation time of MoS2 nanoscrolls with armchair, zigzag, and chiral orientation [53]. (g) The atomic energy is a function of MoS2 nanoscroll spacing. The red area indicates the energy-favorable interlayer distance [53].
Figure 1. (a). Monolayer MoS2 nanosheet. (b) Schematic structure of the TMDCs nanoscroll with open ends and side edges. (c) The MoS2 nanoscroll with inter-core radius Rin, in outer radius Rout and interlayer spacing h. (d) The formation of the MoS2 nanoscrolls are always along the armchair direction (Mo–S bond direction) [56]. (e) The MoS2 sheets of the same size roll through the armchair (left) and zigzag (right) orientation molecular dynamics (MD) simulations before (upper) and after (lower) structural relaxation [53]. (f) The relationship between unit atomic energy and simulation time of MoS2 nanoscrolls with armchair, zigzag, and chiral orientation [53]. (g) The atomic energy is a function of MoS2 nanoscroll spacing. The red area indicates the energy-favorable interlayer distance [53].
Nanomaterials 13 02433 g001

3. Preparation of TMDCs Nanoscrolls

In recent years, many TMDCs nanosheets have been reported to form TMDCs-NS, including MoS2, WS2, MoSe2, MoS2/WS2, etc. [3,9,17,18,19,20,29,33,51,52,53,57,58,59,60,61,62,63,64,65,66,67,68]. Several methods have been successfully developed to prepare TMDCs-NS, such as strain-induced scrolling [17], argon plasma-assisted scrolling [18], supercritical fluid-assisted scrolling [68,69], volatile organic solvent-induced scrolling [23,24,25,33,70], alkaline droplet assisted scrolling [19,21,26,27,35], and vortex flow device (VFD) induced continuous flow [50].
Theoretical investigation indicates that there is an energy barrier between the nanosheet and nanoscroll [71,72,73]. A driving activation energy is required to initialize the scrolling automatically [74]. By scrolling or folding the nanosheet into a nanoscroll, the lowest energy form is presented [74]. The barrier can be overcome with the help of external force in liquid or in air, where the TMDCs-NS is formed.

3.1. Fabrication of TMDCs Nanoscrolls in Liquid

3.1.1. Solvent Evaporation to Make Nanoscrolls

Many organic solvents are liquid at ambient conditions with large volatility, which can be used to assist or induce the scrolling of TMDCs nanosheets [23,33,35,75,76,77], such as acetone, ethanol, and isopropanol [24,78,79,80]. In 2018, we proposed the preparation of MoS2 nanoscroll by dropping an ethanol or acetone droplet on monolayer MoS2 nanosheet [23], as shown in Figure 2. Monolayer MoS2 nanosheets were first obtained by chemical vapor deposition (CVD) on SiO2/Si (Figure 2a,b), and a drop of ethanol was deposited on the MoS2 nanosheets (Figure 2c). Due to its low surface tension, the ethanol can wet MoS2 and SiO2/Si substrates easily. During the evaporation process, a thin ethanol layer is formed near the contact line (Figure 2d). With the rapid evaporation of ethanol, a temperature gradient is generated near the contact line, creating a surface tension gradient to induce fluid flow. Such kind of fluid flow could roll up the edge of MoS2. As the contact line moves, the MoS2 nanosheet continues to be rolled up until a complete MoS2 nanoscroll is formed (Figure 2e) [23].
By dropping the mixture of ethanol and water on CVD-grown monolayer MoS2 nanosheet, Jian Zheng et al. also successfully prepared MoS2 nanoscrolls, as shown in Figure 3 [24]. Large-area monolayer MoS2 nanosheets were obtained firstly by CVD (Figure 3a). MoS2 nanoscrolls were then fabricated in a short time in a mixture solution of ethanol and water with a volume ratio of 2:1 (ethanol:water = 2:1).
Due to the high temperature-causing mismatch between the MoS2 nanosheet and substrate during CVD growth (Figure 3a), a strain equilibrium is balanced between them when the temperature decreases to room temperature (Figure 3b). When the mixture solution is dropped onto the MoS2 nanosheet, the ethanol intercalates between the MoS2 and substrate, and the upper part of MoS2 is detached from the substrate. In this case, the strain balance is broken (Figure 3c), and the released portion curls into a roll (Figure 3d). Due to the adhesion from the substrate, the left portion remains intact [24]. With the evaporation of ethanol, the surface tension at the air-solvent-MoS2 interface is greater than that between MoS2 and the substrate. As a result, the strain-adhesion balance is broken continuously, generating MoS2 nanoscroll finally (Figure 3e).

3.1.2. Alkaline Droplet-Assisted Fabrication of Nanoscrolls

For bilayer and multilayer nanosheets, it is difficult to roll them up effectively due to the strong adhesion force from the substrate. Since TMDCs nanosheets are usually grown on SiO2/Si substrate, etching the SiO2 layer beneath them could eliminate the strong adhesion from the substrate. Therefore, alkaline solution has been used to etch the SiO2 layer, and thus break the adhesion energy between the nanosheet and substrate (Figure 4). As a result, the strain equilibrium is broken, rolling up the TMDCs nanosheet from edges to form spiral nanoscrolls [19,51].
The materials for fabricating nanoscrolls are derived from 2D nanosheets produced by mechanical stripping [78] or CVD. The experiments were dominated by CVD-prepared nanosheets, but the nanosheets prepared by CVD in most cases are accompanied by the production of defects, homojunctions, and heterojunctions [81]. Therefore, we successfully fabricated nanoscrolls using CVD-prepared heterojunction nanosheets. In 2020, we proposed a method to scroll the MoS2/WS2 heterostructures nanosheet by using an alkaline solution. Firstly, large-area MoS2/WS2 heterostructure nanosheets were grown on SiO2/Si substrate by CVD (Figure 4a) [19,81]. Afterwards, 50 μL of alkaline aqueous solution (0.1 M KOH or NaHCO3) was dropped on the nanosheets. The SiO2 layer was etched by the alkaline solution, allowing penetration of the alkaline solution into the interface of the nanosheet and SiO2/Si substrate (Figure 4b), which could further etch the SiO2 layer to release the edge of the nanosheet. To decrease the energy form, the released edge of the nanosheet tends to be scrolled (Figure 4c). With the further etching of the SiO2 layer, more portions of the nanosheet were released and continuously scrolled till forming nanoscroll (Figure 4c,d) [19]. The as-obtained nanoscroll was then rinsed with deionized (DI) water and dried with N2 for characterization and device fabrication (Figure 4d). Furthermore MoS2/WS2 heterostructures nanosheet, we found that the silver nanoparticles decorated monolayer MoS2 and WS2 nanosheets could also be rolled up effectively by using an alkaline solution [35].
Duan et al. found that 80% of the bilayer and trilayer TMDCs heterostructure nanosheets could be transformed into 1D nanoscrolls by using a mixture of ethanol and water. However, many scrolls are incompletely rolled up with tightly pinned edges, indicating the mixed solvent does not work well to completely delaminate the edges of a thick 2D nanosheet. The yield of the nanoscroll increased to 90% by adding 5% ammonia into the mixed solvent, with 60% of them showing a closely stacked scroll structure. The result indicated that the etching of the SiO2 layer by alkaline solution played an important role in peeling off the 2D nanosheet from the substrate even the existence of strong edge-substrate interaction [21,24].
Similarly, alkaline solution was also employed to roll up PbI2/MoS2 and BaTiO3/MoS2 nanosheets into complete nanoscroll, further confirming the importance of alkaline solution in preparation of TMDCs-NS [3,27,51].

3.1.3. Fabrication of TMDCs Nanoscrolls by Dragging Water Droplets

Due to the low surface tension of organic solvent, it is easily adsorbed on TMDCs nanosheets. Thus, it is inevitable to trap organic solvent in the TMDCs-NS during the scrolling process. It is known that the adsorbed organic solvent could greatly influence the properties and device performance of TMDCs nanosheets. Therefore, it is desirable to fabricate TMDCs-NS without using organic solvent. Recently, we reported an organic solvent-free method to fabricate tightly-packed TMDCs-NS [52]. Firstly, CVD-grown monolayer MoS2 nanosheets were heated at 100 °C, as shown in Figure 5a,b. After 3 µL of deionized (DI) water droplet was dropped on the MoS2 nanosheets (Figure 5c), The coverslips were dragged from one end to the other at a speed of 3 mm/s (Figure 5d). Afterwards, large scale closely packed MoS2 nanoscrolls were fabricated (Figure 5e).
The detailed mechanism for the formation of nanoscrolls could be explained as follows, as shown in Figure 5f. When the monolayer MoS2 nanosheets on SiO2/Si substrate were heated at 100 °C, the adhesion force between the nanosheets and substrate was weakened. Therefore, with the movement of water droplets, the scrolling occurs first at the edges of MoS2 nanosheets. Due to the hydrophobicity of MoS2 nanosheets, the low friction between water and MoS2 and the high surface tension of water contribute to the following scrolling of MoS2 nanosheets. More importantly, due to the hydrophobicity of MoS2, the water molecules were difficult to trap in the nanoscrolls, obtaining solvent-free and closely packed nanoscrolls [52].

3.1.4. Amine-Functional Amphiphilic Molecule Assisted Fabrication of TMDCs Nanoscrolls

The involvement of amphiphilic molecules in the preparation of MoS2, MoSe2, and MoTe2 nanoscrolls has also been investigated [48,49,82,83]. By mixing N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide (LCA) and exfoliated TMDCs nanosheets in orthodichlorobenzene (ODCB) for 24 h at room temperature, TMDCs-NS was obtained in large scale (Figure 6a). The formation of MoS2 nanoscrolls with the help of LCA could be explained as follows. Firstly, the LCA molecules were self-assembled into fibers in ODCB. The amine group of LCA fiber has a stronger interaction with the edges of TMDCs nanosheets than the entire plane. Thus, the edges start scrolling around the LCA fibers. With the gradual self-assembly of LCA fiber, the interaction of fiber with the edges of TMDCs nanosheets is enhanced. In this case, the original equilibrium state of TMDCs nanosheets is broken and the nanosheet scrolls spontaneously. Therefore, TMDCs-NS was formed. By using this method, MoS2 nanoscrolls, MoS2-Ag nanoparticles nanoscrolls, and MoS2-Au nanoparticles nanoscrolls have been successfully prepared [49,83].

3.1.5. Supercritical Fluid-Assisted Fabrication of Nanoscrolls

Supercritical fluids (SCFs) are fluids with much more space and are highly compressible than ordinary fluids above their critical temperatures and pressure [84,85]. By controlling the temperature or pressure, the density and solvent strength of SCFs can be tuned from gas-like to solid-like [49,83,86,87]. SCF has unique properties such as gas diffusivity, liquid solubility, low interfacial tension, excellent surface wettability, and high diffusion coefficient [88,89,90]. Thus, SCFs processing has been used as a promising and effective route to exfoliate layered materials into 2D nanosheets, such as graphene, BN, and MoS2 due to their simplicity, rapidity, and short reaction time [68,69,88,91]. It has been reported that the as-exfoliated 2D nanosheets can be rolled up into nanoscrolls in order to minimize their surface energy. Therefore, MoS2 and WS2 nanoscrolls can be formed by using SCF processing of MoS2 nanosheets in 30 min, as shown in Figure 7a–g [68,88]. The X-ray diffraction (XRD) patterns of the MoS2 nanoscrolls clearly show that the surfaces of the MoS2 nanosheets are not oxidized and are free of impurities [68]. Meanwhile, the lattice structure of the SCF-prepared MoS2 is essentially unchanged, making this method a convenient and efficient way to prepare nanoscrolls.

3.1.6. Shear Force Assisted Fabrication of Nanoscrolls

By using a vortex flow device (VFD), MoS2 nanosheets have been successfully transformed into nanoscrolls under continuous flow [50]. In a tilted quartz tube with rapid rotation, a dynamic thin film was generated in VFD, providing mechano-energy as high shear stress during intense micro-mixing. Therefore, the MoS2 nanosheets were firstly exfoliated from bulk material due to the strong shear stress. Simultaneously, the as-exfoliated MoS2 nanosheets were rolled up in-situ to form scrolls with high yield (Figure 8a,b). At low-speed rotation (4000 rpm), the shear stress is mainly governed by the Typhoon-like toroidal flow, generating centrifugal forces on the tube wall. As a result, the MoS2 nanosheets were exfoliated first and then scrolled as the toroidal flow moved upwards (Figure 8c,d) [50,92,93]. As the rotation speed increased to 8000 rpm, the dominated double-helical twisted Faraday wave vortex flow cannot curl and roll up MoS2 nanosheets effectively. The morphology of MoS2 nanostructure can be changed from lamellae to scroll, by controlling the solvent selection, concentration of bulk material, and the processing parameters of VFD, including rotation speed and rotation angle. The VFD has been widely used to synthesize nanoscrolls from 2D nanosheets, such as graphite, graphene oxide, and hexagonal boron nitride [92,93,94].

3.2. Fabrication of TMDCs Nanoscrolls in Air

3.2.1. Plasma-Assisted Fabrication of MoS2 Nanoscrolls

In 2016, Zhang et al. proposed the preparation of MoS2 nanoscrolls by treating CVD-grown monolayer MoS2 nanosheets in a weak Ar plasma environment, as shown in Figure 9 [18]. Upon plasma bombardment, the top layer sulfur atoms of the MoS2 nanosheets are partially removed as the kinetic energy of Ar+ is larger than the binding energy of the Mo-S bond. As a result, the MoS2 lattice is disrupted and unsaturated dangling bonds are left, leading to out-of-plane strain. Such kind of strain induces out-of-plane distortion, which rolls up the edge of the MoS2 nanosheet to form nanoscrolls [18,58]. The optimum power for fabricating nanoscrolls was 25 W. If the power was too strong, short nanoscrolls were obtained. While a longer time was needed to trigger the scrolling when the power was too weak. When the adjacent edges of MoS2 nanosheets are not parallel, a kink will be formed, preventing the formation of a long scroll [18]. In addition, WS2 and WSe2 nanoscrolls were also prepared by treating the monolayer WS2 and WSe2 nanosheets in Ar plasma.

3.2.2. Strain-Assisted Fabrication of TMDCs Nanoscrolls

Because of the different thermal expansion coefficients of the MoS2 and SiO2, there are thermal strain gradients between the interface of CVD-grown MoS2 nanosheets and SiO2/Si substrate [58,75,95]. Upon quenching, the orientation-specific fractures are formed on CVD-grown MoS2 nanosheets due to the existing S vacancies (Figure 10a,b). Since the cooling rate of the top MoS2 layer is greater than the bottom SiO2 layer, strong lattice contraction of the MoS2 layer is observed due to the temperature difference, which induces self-curling at the fractures of the MoS2 layer (Figure 10c). Afterwards, the curled edge continues to form a scroll in order to minimize the surface energy (Figure 10d).
Table 1 summarizes the preparation methods of TMDCs nanoscrolls to show the advantages and disadvantages in detail. To date, the TMDCs nanoscrolls have been prepared mainly from CVD-grown monolayer nanosheets or film in large-area. It is known that large-area TMDCs nanosheets can also be obtained by using molecular beam epitaxial (MBE) method and mechanical exfoliation (ME). Therefore, TMDCs nanosheets prepared by the MBE or ME method provide an alternative way for fabricating TMDCs nanoscrolls. Currently, it is difficult to control the geometry of nanoscrolls by using organic or alkaline droplets to directly treat CVD-grown large-area monolayer TMDCs films. In this case, TMDCs nanoscrolls with lengths of several tens to hundreds of micrometers were obtained in random orientation. By using a focused ion beam (FIB), the large-area monolayer TMDCs film can be shaped as long parallel ribbons with controlled width and direction. After dropping the mixture of ethanol and water on these ribbons, long straight TMDCs nanoscrolls can be obtained in array form [24]. The diameter of TMDCs nanoscroll could be tuned by controlling the width of the original ribbon. By using FIB to cut the long TMDCs nanoscrolls, the TMDCs nanoscrolls were patterned into arrays with controlled lengths and locations. By etching the large-area monolayer TMDCs films along the crystalline orientation, TMDCs nanoscrolls arrays with controlled chirality could also be prepared.

4. Applications of TMDCs-NS

4.1. Photodetector Based on TMDCs-NS

Compared to monolayer TMDCs nanosheet, the TMDCs-NS shows much better light absorption efficiency due to its increased thickness of spirally scrolled structure. Thus, the TMDCs-NS should exhibit excellent optoelectronic performance. Recently, the photodetection performance of TMDCs-NS has been investigated [51,98]. Photosensitivity, described by the ratio of photocurrent to dark current (PDR), is one of the most important parameters to evaluate the performance of a photodetector [19,23,35]. Figure 11a shows the PDRs of MoS2 nanosheet and nanoscroll-based photodetectors under blue light irradiation with a bias voltage of 0.1 V. The PDR of a nanoscroll-based photodetector is about 400, which is about 100 times higher than that of a nanosheet-based one [23]. In addition, the response and recovery time of a nanoscroll-based photodetector is less than the nanosheet-based photodetector. Similar enhanced PDR was also observed in the MoSe2 nanoscroll-based device [17]. These results indicate that the TMDCs-NS shows much better photodetection performance than the TMDCs nanosheet, which should be attributed to the enhanced light absorption and rapid electron transportation along the 1D structure [24,52]. The photodetection enhancement of TMDCs nanoscrolls could be explained in detail as follows. Firstly, the increased thickness of TMDCs nanoscroll increases the light absorption as the light permeates each layer of the nanoscroll. Although each layer shows low light absorption, the total light absorption of the nanoscroll has increased. Therefore, increased photocurrent is obtained in nanoscroll. In addition, the one-dimensional structure of the nanoscroll confines the electron transportation along the axis direction, and thus rapid electron movement is realized in the nanoscroll compared to that in a 2D nanosheet. Moreover, due to the large surface-to-volume ratio of the MoS2 nanosheet, the adsorbates, such as O2 and H2O molecules, greatly reduce the photoresponse of the MoS2 nanosheet-based device. The MoS2 nanoscroll has a much smaller surface-to-volume ratio than the nanosheet, which can decrease the influence of adsorbates on the photoresponse.
Compared to the MoS2 nanoscroll prepared by ethanol droplet (MoS2 NS-ethanol), the MoS2 nanoscroll prepared by water droplet (MoS2 NS-water) shows higher PDR (Figure 11b) [52]. The ethanol molecules trapped in MoS2 NS-ethanol reduce the light absorption and hinder the interlayer transport of photogenerated carriers, and thus decrease the photoresponse. In addition, the ethanol can donate an electron to MoS2 and thus increase the dark current of MoS2 NS-ethanol, which in turn decreases the PDR. Moreover, the MoS2 NS-water shows a slightly higher photocurrent than MoS2 NS-ethanol.

4.2. Photodetector Based on TMDCs-NS Composite

In bilayer WS2/MoS2 heterostructure, the carriers can be transferred from MoS2 to WS2 within 50 fs under illumination, indicating the important role of interface. However, there is only one interface in the bilayer WS2/MoS2 heterostructure. The photoresponse performance of WS2/MoS2 heterostructure could be further improved if multiple interfaces can be established. By scrolling the bilayer WS2/MoS2 heterostructure into WS2/MoS2 heterostructure nanoscroll, multiple hetero-interfaces are formed, which could show better photoresponse than the bilayer WS2/MoS2 heterostructure with one hetero-interface. After the bilayer WS2/MoS2 heterostructure was grown by CVD, the alkaline droplet was dropped on it to roll up the bilayer heterostructure into a nanoscroll [19]. As shown in Figure 12a, the PDR of bilayer WS2/MoS2 heterostructure-based photodetector is ~180 under a blue laser, which is much higher than that of monolayer MoS2 or WS2 nanosheets. The PDR of WS2/MoS2 heterostructure nanoscroll-based photodetector is 2700, about an order of magnitude higher than that of bilayer WS2/MoS2 heterostructure-based photodetector.
By encapsulating photoactive PbI2 nanocrystals into MoS2 nanoscroll, the PDR of MoS2 nanoscroll can be enhanced by two orders of magnitude (Figure 12b) [51]. Similarly, the PDRs of MoS2 and WS2 nanoscrolls also increased by two orders of magnitude after Ag nanoparticles were trapped in a nanoscroll (Figure 12c) [35]. Moreover, the photoresponsivity of the MoS2 nanoscroll was also enhanced by about two orders of magnitude when BaTiO3 nanoparticles were encapsulated into it [27]. By doping the WS2 nanoscroll with CdSe–ZnS quantum dots, the photosensitivity can be enhanced 3000-fold (Figure 12d) [79]. Compared to single TMDCs nanoscrolls, the nanoscroll composite shows excellent photodetection performance [24,70], indicating it could be a promising candidate for high-performance optoelectronics.

4.3. Hydrogen Evolution Reaction

The conductivity and effective active site of the catalyst are two key factors in improving the hydrogen precipitation reaction (HER) [99,100,101]. TMDCs are considered promising candidates after noble metals for catalytic hydrogen precipitation due to their good electrical conductivity and abundant active edges [66,102,103]. The introduction of a small amount of MoSx greatly enhanced the HER activity of NbS2 nanoflakes [100]. The theoretical calculation indicates that Mo edge sites are identified as the catalytically active site for HER [104,105].
A number of efforts have been employed to increase the active sites and conductivity of TMDCs materials [106,107,108]. Among them, transforming the TMDCs nanosheets into nanoscrolls with active edges is of great interest in electrocatalytic HER [50]. By curling the TMDCs nanosheets to form nanoscrolls, the curled edges provide highly active edge sites for efficient catalysis. Meanwhile, the bending strain of the basal plane also provides more active sites due to the scrolled structure [50,109,110,111]. In addition, the specific surface area of the nanoscroll increases, converting the solution contact from single-sided contact of the nanosheet to multi-layer contact [112]. As a result, the TMDCs-NS provides higher catalytic activity and better conductivity. Thus, the HER activity of TMDCs-NS is greatly enhanced. Figure 13a shows the polarization curves of metallic WSe2 (M-WSe2) and 2H-WSe2 nanoscrolls compared to the commercial Pt/C catalyst. The M-WSe2 nanoscroll exhibits higher HER activity, smaller overpotential, and larger current densities than the 2H-WSe2 nanoscroll, attributed to its good conductivity and enhanced catalytic activity from the scrolled structure [103]. Figure 13b shows the linear scanning voltammogram curves of current density and potential for Pt electrode, MoS2 sheet, MoS2 nanoscroll, MoS2 nanoscrolls@Pt, MoS2@Pt sheet, and MoS2@Pt nanoscroll [48]. The MoS2 nanosheet shows overpotential over 400 mV, while that of the MoS2 nanoscroll decreases. The overpotential of MoS2 nanoscroll decorated by Pt nanoparticles (NPs) greatly decreases, indicating the important role of Pt NPs in enhancing the HER activity. By decorating Pt NPs on MoS2 nanosheet (MoS2@Pt sheet), the overpotential further decreases to around 300 mV. After the MoS2@Pt sheet was rolled up to form a MoS2@Pt scroll, the overpotential was reduced to 200 mV, implying the basal plane bending of the nanoscroll can further improve the HER activity.

4.4. Gas Sensor

In recent years, TMDCs nanosheets have attracted great attention for gas sensing because of their large surface-to-volume ratio and good electrical properties [113,114,115,116]. The TMDCs nanosheet-based gas sensors show high sensitivity for trace gas molecules and good selectivity at room temperature [60,117,118,119]. However, they suffer from incomplete recovery and poor stability [120], which limit their practical applications. The TMDCs-NS has good conductivity due to its 1D structure and specific surface area from the tubular structure. Meanwhile, the nanoscroll structure also provides tunable space to encapsulate functional nanomaterials for further enhanced performance. Therefore, the TMDCs-NS has been considered to present promising performance in the field of gas sensing [121].
By electrochemically exfoliating InSe crystal in electrolytes containing cetyltrimethylammonium bromide (CTAB), the CTAB-functionalized InSe nanosheets (C-InSe) were obtained [120]. With the aid of solvent evaporation, the C-InSe nanosheets rolled up to form C-InSe nanoscroll. After the as-obtained C-InSe nanoscrolls were deposited on interdigitated electrodes (Figure 14b), they were placed into a chamber with a fixed concentration of NO2 gas. An LED lamp illuminates light into the chamber through a glass cover (Figure 14a). The response of the C-InSe nanoscrolls-based sensor increases under light illumination (Figure 14c). The enhanced response has arisen from the increased adsorption of NO2 molecules favored by photogenerated electrons. While desorption of NO2 is observed as the light intensity increases further, which decreases the response of the sensor. As the concentration of NO2 increases from 100 ppb to 25 ppm, the response of C-InSe nanosheets and nanoscrolls-based sensors largely increases (Figure 14d). However, the C-InSe nanoscrolls-based sensor exhibits a much better response than the C-InSe nanosheets-based sensor, indicating the superiority of nanoscrolls in gas sensing.

5. Conclusions

In this review, we summarize a series of fabrication methods of TMDCs nanoscrolls, and briefly demonstrate their applications in photodetection, HER, and gas sensing (Figure 15). Compared to the 2D TMDCs nanosheet, the 1D TMDCs nanoscroll presents higher light absorption efficiency and faster electron transport because of the scrolled structure. Due to their higher specific surface area and active edges, the TMDCs nanoscrolls have shown excellent performance in catalytic reactions. In conclusion, the TMDCs nanoscrolls are emerging materials with many novel physical and chemical properties that are promising for optoelectronics, catalysis, energy storage, and sensing.

Author Contributions

Conceptualization, H.L.; supervision and project administration, H.L.; methodology, H.L., S.Y., P.W. and C.P.; formal analysis, S.Y., P.W., C.P., H.Y., S.W., J.L., H.T. and Z.W.; investigation, S.Y. and P.W.; writing—original draft preparation, H.L., S.Y. and P.W.; revision of the manuscript, H.L. and S.Y. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the National Natural Science Foundation of China (Grant No. 51832001 and 21571101), the Natural Science Foundation of Jiangsu Province in China (Grant No. BK20161543), and the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 15KJB430016).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data can be available upon request from the authors.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Youngblood, N.; Chen, C.; Koester, S.J.; Li, M. Waveguide-integrated black phosphorus photodetector with high responsivity and low dark current. Nat. Photonics 2015, 9, 247–252. [Google Scholar] [CrossRef]
  2. Wang, F.; Zhang, Y.; Gao, Y.; Luo, P.; Su, J.; Han, W.; Liu, K.; Li, H.; Zhai, T. 2D metal chalcogenides for ir photodetection. Small 2019, 15, 1901347–1901365. [Google Scholar] [CrossRef]
  3. Wu, Z.; Li, F.; Li, X.; Yang, Y.; Huang, X.; Li, H. Direct synthesis of MoS2 nanosheets in reduced graphene oxide nanoscroll for enhanced photodetection. Nanomaterials 2022, 12, 1581. [Google Scholar] [CrossRef]
  4. Andleeb, S.; Wang, X.; Dong, H.; Valligatla, S.; Saggau, C.N.; Ma, L.; Schmidt, O.G.; Zhu, F. Fast-response micro-phototransistor based on MoS2/organic molecule heterojunction. Nanomaterials 2023, 13, 1491. [Google Scholar] [CrossRef]
  5. Al Qaydi, M.; Kotbi, A.; Rajput, N.S.; Bouchalkha, A.; El Marssi, M.; Matras, G.; Kasmi, C.; Jouiad, M. Photodetectionproperties of MoS2, WS2 and MoxW1-xS2 heterostructure: A comparative study. Nanomaterials 2022, 13, 24. [Google Scholar] [CrossRef]
  6. Yu, X.; Yu, P.; Wu, D.; Singh, B.; Zeng, Q.; Lin, H.; Zhou, W.; Lin, J.; Suenaga, K.; Liu, Z.; et al. Atomically thin noble metal dichalcogenide: A broadband mid-infrared semiconductor. Nat. Commun. 2018, 9, 1545–1554. [Google Scholar] [CrossRef] [PubMed]
  7. Sun, D.; Huang, D.; Wang, H.; Xu, G.-L.; Zhang, X.; Zhang, R.; Tang, Y.; Abd Ei-Hady, D.; Alshitari, W.; Saad Al-Bogami, A.; et al. 1T MoS2 nanosheets with extraordinary sodium storage properties via thermal-driven ion intercalation assisted exfoliation of bulky MoS2. Nano Energy 2019, 61, 361–369. [Google Scholar] [CrossRef]
  8. Wang, X.; Li, B.; Bell, D.R.; Li, W.; Zhou, R. Hydrogen and methane storage and release by MoS2 nanotubes for energy storage. J. Mater. Chem. A 2017, 5, 23020–23027. [Google Scholar] [CrossRef]
  9. Jiao, Y.; Hafez, A.M.; Cao, D.; Mukhopadhyay, A.; Ma, Y.; Zhu, H. Metallic MoS2 for high performance energy storage and energy conversion. Small 2018, 14, 1800640–1800660. [Google Scholar] [CrossRef]
  10. Abdolrazzaghian, E.; Zhu, J.; Kim, J.; Yanilmaz, M. MoS2-decorated graphene@porous carbon nanofiber anodes via centrifugal spinning. Nanomaterials 2022, 12, 2505. [Google Scholar] [CrossRef]
  11. Ali, L.; Subhan, F.; Ayaz, M.; Hassan SS, U.; Byeon, C.C.; Kim, J.S.; Bungau, S. Exfoliation of MoS2 quantum dots recent progress and challenges. Nanomaterials 2022, 12, 3465. [Google Scholar] [CrossRef] [PubMed]
  12. Anjum, M.A.R.; Jeong, H.Y.; Lee, M.H.; Shin, H.S.; Lee, J.S. Efficient hydrogen evolution reaction catalysis in alkaline media by all-in-one MoS2 with multifunctional active sites. Adv. Mater. 2018, 30, 1707105–1707114. [Google Scholar] [CrossRef]
  13. Duan, H.; Wang, C.; Li, G.; Tan, H.; Hu, W.; Cai, L.; Liu, W.; Li, N.; Ji, Q.; Wang, Y.; et al. Single-atom-layer catalysis in a MoS2 monolayer activated by long-range ferromagnetism for the hydrogen evolution reaction: Beyond single-atom catalysis. Angew. Chem. Int. Ed. 2021, 60, 7251–7258. [Google Scholar] [CrossRef]
  14. Li, G.; Zhang, D.; Yu, Y.; Huang, S.; Yang, W.; Cao, L. Activating MoS2 for pH-universal hydrogen evolution catalysis. J. Am. Chem. Soc. 2017, 139, 16194–16200. [Google Scholar] [CrossRef]
  15. Pan, Y.; Gong, L.; Cheng, X.; Zhou, Y.; Fu, Y.; Feng, J.; Ahmed, H.; Zhang, H. Layer-spacing-enlarged MoS2 superstructural nanotubes with further enhanced catalysis and immobilization for Li–S batteries. ACS Nano 2020, 14, 5917–5925. [Google Scholar] [CrossRef]
  16. Lunardon, M.; Ran, J.; Mosconi, D.; Marega, C.; Wang, Z.; Xia, H.; Agnoli, S.; Granozzi, G. Hybrid transition metal dichalcogenide/graphene microspheres for hydrogen evolution reaction. Nanomaterials 2020, 10, 2376. [Google Scholar] [CrossRef] [PubMed]
  17. Zhou, X.; Tian, Z.; Kim, H.J.; Wang, Y.; Xu, B.; Pan, R.; Chang, Y.J.; Di, Z.; Zhou, P.; Mei, Y. Rolling up MoSe2 nanomembranes as a sensitive tubular photodetector. Small 2019, 15, 1902528–1902535. [Google Scholar] [CrossRef]
  18. Meng, J.; Wang, G.; Li, X.; Lu, X.; Zhang, J.; Yu, H.; Chen, W.; Du, L.; Liao, M.; Zhao, J.; et al. Rolling up a monolayer MoS2 Sheet. Small 2016, 12, 3770–3774. [Google Scholar] [CrossRef] [PubMed]
  19. Wang, L.; Yue, Q.; Pei, C.; Fan, H.; Dai, J.; Huang, X.; Li, H.; Huang, W. Scrolling bilayer WS2/MoS2 heterostructures for high-performance photo-detection. Nano Res. 2020, 13, 959–966. [Google Scholar] [CrossRef]
  20. Chu, X.S.; Li, D.O.; Green, A.A.; Wang, Q.H. Formation of MoO3 and WO3 nanoscrolls from MoS2 and WS2 with atmospheric air plasma. J. Mater. Chem. C 2017, 5, 11301–11309. [Google Scholar] [CrossRef]
  21. Zhao, B.; Wan, Z.; Liu, Y.; Xu, J.; Yang, X.; Shen, D.; Zhang, Z.; Guo, C.; Qian, Q.; Li, J.; et al. High-order superlattices by rolling up van der Waals heterostructures. Nature 2021, 591, 385–390. [Google Scholar] [CrossRef] [PubMed]
  22. Ghosh, R.; Lin, H.-I.; Chen, Y.-S.; Hofmann, M.; Hsieh, Y.-P.; Chen, Y.-F. Efficient light-confinement in heterostructured transition metal dichalcogenide-based nanoscrolls for high-performance photonic devices. J. Mater. Res. 2022, 37, 660–669. [Google Scholar] [CrossRef]
  23. Fang, X.; Wei, P.; Wang, L.; Wang, X.; Chen, B.; He, Q.; Yue, Q.; Zhang, J.; Zhao, W.; Wang, J.; et al. Transforming monolayer transition-metal dichalcogenide nanosheets into one-dimensional nanoscrolls with high photosensitivity. ACS Appl. Mater. Interfaces 2018, 10, 13011–13018. [Google Scholar] [CrossRef]
  24. Cui, X.; Kong, Z.; Gao, E.; Huang, D.; Hao, Y.; Shen, H.; Di, C.A.; Xu, Z.; Zheng, J.; Zhu, D. Rolling up transition metal dichalcogenide nanoscrolls via one drop of ethanol. Nat. Commun. 2018, 9, 1301–1308. [Google Scholar] [CrossRef] [PubMed]
  25. Deng, W.; You, C.; Chen, X.; Wang, Y.; Li, Y.; Feng, B.; Shi, K.; Chen, Y.; Sun, L.; Zhang, Y. High-performance photodiode based on atomically thin WSe2 /MoS2 nanoscroll integration. Small 2019, 15, 1901544–1901550. [Google Scholar] [CrossRef] [PubMed]
  26. Ji, E.; Son, J.; Kim, J.H.; Lee, G.-H. Rolling up two-dimensional sheets into nanoscrolls. FlatChem 2018, 7, 26–33. [Google Scholar] [CrossRef]
  27. Su, J.; Li, X.; Xu, M.; Zhang, J.; Liu, X.; Zheng, X.; Shi, Y.; Zhang, Q. Enhancing photodetection ability of MoS2 nanoscrolls via interface engineering. ACS Appl. Mater. Interfaces 2023, 15, 3307–3316. [Google Scholar] [CrossRef]
  28. Du, L.; Hasan, T.; Castellanos-Gomez, A.; Liu, G.-B.; Yao, Y.; Lau, C.N.; Sun, Z. Engineering symmetry breaking in 2D layered materials. Nat. Rev. Phys. 2021, 3, 193–206. [Google Scholar] [CrossRef]
  29. Lai, Z.; Chen, Y.; Tan, C.; Zhang, X.; Zhang, H. Self-assembly of two-dimensional nanosheets into one-dimensional nanostructures. Chem 2016, 1, 59–77. [Google Scholar] [CrossRef]
  30. Koppens, F.H.; Mueller, T.; Avouris, P.; Ferrari, A.C.; Vitiello, M.S.; Polini, M. Photodetectors based on graphene, other two-dimensional materials and hybrid systems. Nat. Nanotechnol. 2014, 9, 780–793. [Google Scholar] [CrossRef]
  31. Long, M.; Wang, P.; Fang, H.; Hu, W. Progress, challenges, and opportunities for 2D material based photodetectors. Adv. Funct. Mater. 2018, 29, 1803807–1803835. [Google Scholar] [CrossRef]
  32. Huo, N.; Konstantatos, G. Recent progress and future prospects of 2D-based photodetectors. Adv. Mater. 2018, 30, 1801164. [Google Scholar] [CrossRef]
  33. Deng, W.; Chen, X.; Li, Y.; You, C.; Chu, F.; Li, S.; An, B.; Ma, Y.; Liao, L.; Zhang, Y. Strain effect enhanced ultrasensitive MoS2 nanoscroll avalanche photodetector. J. Phys. Chem. Lett. 2020, 11, 4490–4497. [Google Scholar] [CrossRef] [PubMed]
  34. Tan, C.; Cao, X.; Wu, X.J.; He, Q.; Yang, J.; Zhang, X.; Chen, J.; Zhao, W.; Han, S.; Zhang, H.; et al. Recent advances in ultrathin two-dimensional nanomaterials. Chem. Rev. 2017, 117, 6225–6331. [Google Scholar] [CrossRef] [PubMed]
  35. Yue, Q.; Wang, L.; Fan, H.; Zhao, Y.; Wei, C.; Pei, C.; Song, Q.; Huang, X.; Li, H. Wrapping plasmonic silver nanoparticles inside one-dimensional nanoscrolls of transition-metal dichalcogenides for enhanced photoresponse. Inorg. Chem. 2021, 60, 4226–4235. [Google Scholar] [CrossRef]
  36. Hwang, D.Y.; Suh, D.H. Universal surface modification of transition metal dichalcogenide decorated with metal nanoparticles for surface enhanced Raman scattering. Mater. Res. Bull. 2017, 90, 73–80. [Google Scholar] [CrossRef]
  37. Perim, E.; Machado, L.D.; Galvao, D.S. A brief review on syntheses, structures, and applications of nanoscrolls. Front. Mater. 2014, 1, 31–38. [Google Scholar] [CrossRef]
  38. Costa, M.C.F.; Ng, P.R.; Grebenchuck, S.; Tan, J.Y.; Koon, G.K.W.; Tan, H.L.; Woods, C.R.; Donato, R.K.; Novoselov, K.S.; Neto, A.H.C. Colossal enhancement of electrical and mechanical properties of graphene nanoscrolls. Carbon 2023, 208, 140–147. [Google Scholar] [CrossRef]
  39. Muschi, M.; Lalitha, A.; Sene, S.; Aureau, D.; Fregnaux, M.; Esteve, I.; Rivier, L.; Ramsahye, N.; Devautour-Vinot, S.; Sicard, C.; et al. Formation of a single-crystal aluminum-based MOF nanowire with graphene oxide nanoscrolls as structure-directing agents. Angew. Chem. Int. Ed. Engl. 2020, 59, 10353–10358. [Google Scholar] [CrossRef] [PubMed]
  40. Wang, Y.; Jiang, C.; Chen, Q.; Zhou, Q.; Wang, H.; Wan, J.; Ma, L.; Wang, J. Highly promoted carrier mobility and intrinsic stability by rolling up monolayer black phosphorus into nanoscrolls. J. Phys. Chem. Lett. 2018, 9, 6847–6852. [Google Scholar] [CrossRef]
  41. Wang, Y.; Tang, X.; Zhou, Q.; Chen, X.; Chen, Q.; Xu, Y. Blue phosphorus nanoscrolls. Phys. Rev. B 2020, 102, 165428–165434. [Google Scholar] [CrossRef]
  42. Miranti, R.; Qayyum, M.S.; Sharma, A.; Einarsrud, M.-A.; Mestres, N.; Benelmekki, M. Spectroscopic study of partially oxidized BN nanoscrolls induced by low frequency ultrasonic irradiation. Appl. Surf. Sci. 2020, 515, 146055–146062. [Google Scholar] [CrossRef]
  43. Bacon, R. Growth, ctructure, and properties of graphite whiskers. J. Appl. Phys. 1960, 31, 283–290. [Google Scholar] [CrossRef]
  44. Dravid, V.P.; Lin, X.; Wang, Y.; Wang, X.K.; Yee, A.; Ketterson, J.B.; Chang, R.P.H. Buckytubes and derivatives their growth and implications for buckyball formation. Science 1993, 259, 1601–1604. [Google Scholar] [CrossRef] [PubMed]
  45. Shioyama, H.; Akita, T. A new route to carbon nanotubes. Carbon 2003, 41, 179–198. [Google Scholar] [CrossRef]
  46. Viculis, L.M.; Mack, J.J.; Kaner, R.B. A chemical route to carbon nanoscrolls. Science 2003, 299, 1361. [Google Scholar] [CrossRef]
  47. Braga, S.F.; Coluci, V.R.; Legoas, S.B.; Giro, R.; Galvão, D.S.; Baughman, R.H. Structure and dynamics of carbon nanoscrolls. Nano Lett. 2004, 4, 881–884. [Google Scholar] [CrossRef]
  48. Hwang, D.Y.; Choi, K.H.; Park, J.E.; Suh, D.H. Highly efficient hydrogen evolution reaction by strain and phase engineering in composites of Pt and MoS2 nano-scrolls. Phys. Chem. Chem. Phys. 2017, 19, 18356–18365. [Google Scholar] [CrossRef]
  49. Hwang, D.Y.; Choi, K.H.; Park, J.E.; Suh, D.H. Highly thermal-stable paramagnetism by rolling up MoS2 nanosheets. Nanoscale 2017, 9, 503–508. [Google Scholar] [CrossRef] [PubMed]
  50. Alharbi, T.M.D.; Elmas, S.; Alotabi, A.S.; Andersson, M.R.; Raston, C.L. Continuous flow fabrication of MoS2 scrolls for electrocatalytic hydrogen evolution. ACS Sustain. Chem. Eng. 2022, 10, 9325–9333. [Google Scholar] [CrossRef]
  51. Wu, Z.; Li, F.; Ye, H.; Huang, X.; Li, H. Decorating MoS2 nanoscrolls with solution-processed PbI2 nanocrystals for improved photosensitivity. ACS Appl. Nano Mater. 2022, 5, 15892–15901. [Google Scholar] [CrossRef]
  52. Zhao, Y.; You, H.; Li, X.; Pei, C.; Huang, X.; Li, H. Solvent-free preparation of closely packed MoS2 nanoscrolls for improved photosensitivity. ACS Appl. Mater. Interfaces 2022, 14, 9515–9524. [Google Scholar] [CrossRef]
  53. Wang, Z.; Wu, H.H.; Li, Q.; Besenbacher, F.; Zeng, X.C.; Dong, M. Self-scrolling MoS2 metallic wires. Nanoscale 2018, 10, 18178–18185. [Google Scholar] [CrossRef] [PubMed]
  54. Liu, Z.; Gao, J.; Zhang, G.; Cheng, Y.; Zhang, Y.W. From two-dimensional nano-sheets to roll-up structures: Expanding the family of nanoscroll. Nanotechnology 2017, 28, 385704. [Google Scholar] [CrossRef]
  55. Taghinejad, H.; Rehn, D.A.; Muccianti, C.; Eftekhar, A.A.; Tian, M.; Fan, T.; Zhang, X.; Meng, Y.; Chen, Y.; Nguyen, T.V.; et al. Defect-mediated alloying of monolayer transition-metal dichalcogenides. ACS Nano 2018, 12, 12795–12804. [Google Scholar] [CrossRef] [PubMed]
  56. Wang, R.; Guo, S.; Li, Z.; Weller, D.; Quan, S.; Yu, J.; Wu, M.; Jiang, J.; Wang, Y.; Liu, R. Strong anisotropic optical properties by rolling up MoS2 nanoflake. J. Phys. Chem. Lett. 2022, 13, 8409–8415. [Google Scholar] [CrossRef]
  57. Chithaiah, P.; Ghosh, S.; Idelevich, A.; Rovinsky, L.; Livneh, T.; Zak, A. Solving the "MoS2 nanotubes" synthetic enigma and elucidating the route for their catalyst-free and scalable production. ACS Nano 2020, 14, 3004–3016. [Google Scholar] [CrossRef]
  58. Han, Y.; Zhou, J.; Dong, J. Electronic and magnetic properties of MoS2 nanoribbons with sulfur line vacancy defects. Appl. Surf. Sci. 2015, 346, 470–476. [Google Scholar] [CrossRef]
  59. Kotekar-Patil, D.; Deng, J.; Wong, S.L.; Lau, C.S.; Goh, K.E.J. Single layer MoS2 nanoribbon field effect transistor. Appl. Phys. Lett. 2019, 114, 13508–13513. [Google Scholar] [CrossRef]
  60. Li, H.; Yin, Z.; He, Q.; Li, H.; Huang, X.; Lu, G.; Fam, D.W.; Tok, A.I.; Zhang, Q.; Zhang, H. Fabrication of single- and multilayer MoS2 film-based field-effect transistors for sensing NO at room temperature. Small 2012, 8, 63–67. [Google Scholar] [CrossRef] [PubMed]
  61. Mehdizadeh, A.; Zeynali, M.; Karimi, M. Engineering of MoS2 nanoribbons as high-performance materials for biosensing applications. Appl. Surf. Sci. 2021, 540, 148349–148359. [Google Scholar] [CrossRef]
  62. Seravalli, L.; Bosi, M.; Fiorenza, P.; Panasci, S.E.; Orsi, D.; Rotunno, E.; Cristofolini, L.; Rossi, F.; Giannazzo, F.; Fabbri, F. Gold nanoparticle assisted synthesis of MoS2 monolayers by chemical vapor deposition. Nanoscale Adv. 2021, 3, 4826–4833. [Google Scholar] [CrossRef] [PubMed]
  63. Wang, Q.; Sang, P.; Wei, W.; Li, Y.; Chen, J. Functionalized MoS2 nanoribbons for intrinsic cold-source transistors: A computational study. ACS Appl. Nano Mater. 2022, 5, 1178–1184. [Google Scholar] [CrossRef]
  64. Yi, J.-D.; Liu, T.-T.; Huang, Y.-B.; Cao, R. Solid-state synthesis of MoS2 nanorod from molybdenum-organic framework for efficient hydrogen evolution reaction. Sci. China Mater. 2019, 62, 965–972. [Google Scholar] [CrossRef]
  65. Jeong, Y.; Shin, J.; Hong, Y.; Wu, M.; Hong, S.; Kwon, K.C.; Choi, S.; Lee, T.; Jang, H.W.; Lee, J.-H. Gas sensing characteristics of the FET-type gas sensor having inkjet-printed WS2 sensing layer. Solid State Electron. 2019, 153, 27–32. [Google Scholar] [CrossRef]
  66. Woods, J.M.; Jung, Y.; Xie, Y.; Liu, W.; Liu, Y.; Wang, H.; Cha, J.J. One-step synthesis of MoS2/WS2 layered heterostructures and catalytic activity of defective transition metal dichalcogenide films. ACS Nano 2016, 10, 2004–2009. [Google Scholar] [CrossRef] [PubMed]
  67. Lin, C.; Cai, L.; Fu, J.H.; Sattar, S.; Wang, Q.X.; Wan, Y.; Tseng, C.C.; Yang, C.W.; Aljarb, A.; Jiang, K.; et al. Direct band gap in multilayer transition metal dichalcogenide nanoscrolls with enhanced photoluminescence. ACS Mater. Lett. 2022, 4, 1547–1555. [Google Scholar] [CrossRef]
  68. Thangasamy, P.; Raj, J.A.; Sathish, M. Transformation of multilayer WS2 nanosheets to 1D luminescent WS2 nanostructures by one-pot supercritical fluid processing for hydrogen evolution reaction. Mater. Sci. Semicond. Process. 2020, 119, 105167–105174. [Google Scholar] [CrossRef]
  69. Sathish, M.; Mitani, S.; Tomai, T.; Honma, I. Supercritical fluid assisted synthesis of N-doped graphene nanosheets and their capacitance behavior in ionic liquid and aqueous electrolytes. J. Mater. Chem. A 2014, 2, 4731–4738. [Google Scholar] [CrossRef]
  70. Zhang, S.; Gao, F.; Feng, W.; Yang, H.; Hu, Y.; Zhang, J.; Xiao, H.; Li, Z.; Hu, P. High-responsivity photodetector based on scrolling monolayer MoS2 hybridized with carbon quantum dots. Nanotechnology 2021, 33, 105301–105309. [Google Scholar] [CrossRef]
  71. Xu, J.; Jiang, H.; Shen, Y.; Li, X.Z.; Wang, E.G.; Meng, S. Transparent proton transport through a two-dimensional nanomesh material. Nat. Commun. 2019, 10, 3971–3979. [Google Scholar] [CrossRef]
  72. Graba, M.; Mamala, J.; Bieniek, A.; Sroka, Z. Impact of the acceleration intensity of a passenger car in a road test on energy consumption. Energy 2021, 226, 120429–120445. [Google Scholar] [CrossRef]
  73. Yang, J.; Zeng, Z.; Kang, J.; Betzler, S.; Czarnik, C.; Zhang, X.; Ophus, C.; Yu, C.; Bustillo, K.; Pan, M.; et al. Formation of two-dimensional transition metal oxide nanosheets with nanoparticles as intermediates. Nat. Mater. 2019, 18, 970–976. [Google Scholar] [CrossRef]
  74. Gentile, P.; Cuoco, M.; Volkov, O.M.; Ying, Z.-J.; Vera-Marun, I.J.; Makarov, D.; Ortix, C. Electronic materials with nanoscale curved geometries. Nat. Electron. 2022, 5, 551–563. [Google Scholar] [CrossRef]
  75. Xu, C.; Wu, X.; Huang, G.; Mei, Y. Rolled-up nanotechnology: Materials issue and geometry capability. Adv. Mater. Technol. 2018, 4, 1800486–1800512. [Google Scholar] [CrossRef]
  76. Cho, J.H.; Azam, A.; Gracias, D.H. Three dimensional nanofabrication using surface forces. Langmuir 2010, 26, 16534–16539. [Google Scholar] [CrossRef]
  77. Li, J.; Zhang, J.; Gao, W.; Huang, G.; Di, Z.; Liu, R.; Wang, J.; Mei, Y. Dry-released nanotubes and nanoengines by particle-assisted rolling. Adv. Mater. 2013, 25, 3715–3721. [Google Scholar] [CrossRef] [PubMed]
  78. Huang, X.; Huang, Z.; Liu, Q.; Zhou, A.a.; Ma, Y.; Wang, J.; Qiu, H.; Bai, H. Organic solvent-assisted lyophilization: A universal method of preparing two-dimensional material nanoscrolls. ACS Omega 2019, 4, 7420–7427. [Google Scholar] [CrossRef]
  79. Ghosh, R.; Lin, H.I.; Chen, Y.S.; Singh, M.; Yen, Z.L.; Chiu, S.; Lin, H.Y.; Bera, K.P.; Liao, Y.M.; Hofmann, M.; et al. QD/2D hybrid nanoscrolls: A new class of materials for high-performance polarized photodetection and ultralow threshold laser action. Small 2020, 16, 2003944–2003953. [Google Scholar] [CrossRef]
  80. Na, J.; Park, C.; Lee, C.H.; Choi, W.R.; Choi, S.; Lee, J.-U.; Yang, W.; Cheong, H.; Campbell, E.E.B.; Jhang, S.H. Indirect band gap in scrolled MoS2 monolayers. Nanomaterials 2022, 12, 3353. [Google Scholar] [CrossRef]
  81. Taghinejad, H.; Eftekhar, A.A.; Adibi, A. Lateral and vertical heterostructures in twodimensional transition-metal dichalcogenides. Opt. Mater. Express 2019, 9, 1590–1607. [Google Scholar] [CrossRef]
  82. Hwang, D.Y.; Choi, K.H.; Suh, D.H. A vacancy-driven phase transition in MoX2 (X: S, Se and Te) nanoscrolls. Nanoscale 2018, 10, 7918–7926. [Google Scholar] [CrossRef] [PubMed]
  83. Hwang, D.Y.; Suh, D.H. Evolution of a high local strain in rolling up MoS2 sheets decorated with Ag and Au nanoparticles for surface-enhanced Raman scattering. Nanotechnology 2017, 28, 25603–25614. [Google Scholar] [CrossRef] [PubMed]
  84. Reddy, J.; Basha, H.G.; Narayanan, N.S.V. Heat flow visualization of a chemical compound isobutane (C4H10) past a vertical cylinder in the subcritical, near critical and supercritical regions. J. Mol. Struct. 2018, 259, 209–219. [Google Scholar] [CrossRef]
  85. El Khouri, L.; Carle`s, P. Supercritical fluids as experimental models for geophysical flows. Int. J. Thermophys. 2003, 24, 683–693. [Google Scholar] [CrossRef]
  86. Shah, P.S.; Hanrath, T.; Johnston, K.P.; Korgel, B.A. Nanocrystal and nanowire synthesis and dispersibility in supercritical fluids. J. Phys. Chem. B 2004, 108, 9574–9587. [Google Scholar] [CrossRef]
  87. Schienbein, P.; Marx, D. Assessing the properties of supercritical water in terms of structural dynamics and electronic polarization effects. Phys. Chem. Chem. Phys. 2020, 22, 10462–10479. [Google Scholar] [CrossRef]
  88. Thangasamy, P.; Sathish, M. Rapid, one-pot synthesis of luminescent MoS2 nanoscrolls using supercritical fluid processing. J. Mater. Chem. C 2016, 4, 1165–1169. [Google Scholar] [CrossRef]
  89. Thangasamy, P.; Sathish, M. Supercritical fluid processing: A rapid, one-pot exfoliation process for the production of surfactant-free hexagonal boron nitride nanosheets. CrystEngComm 2015, 17, 5895–5899. [Google Scholar] [CrossRef]
  90. Wang, W.; Gai, Y.; Xiao, D.; Zhao, Y. A facile and general approach for production of nanoscrolls with high-yield from two-dimensional nanosheets. Sci. Rep. 2018, 8, 15262–15268. [Google Scholar] [CrossRef]
  91. Rangappa, D.; Sone, K.; Wang, M.; Gautam, U.K.; Golberg, D.; Itoh, H.; Ichihara, M.; Honma, I. Rapid and direct conversion of graphite crystals into high-yielding, good-quality graphene by supercritical fluid exfoliation. Chem. Eur. J. 2010, 16, 6488–6494. [Google Scholar] [CrossRef]
  92. Alharbi, T.M.D.; Jellicoe, M.; Luo, X.; Vimalanathan, K.; Alsulami, I.K.; Al Harbi, B.S.; Igder, A.; Alrashaidi, F.A.J.; Chen, X.; Stubbs, K.A.; et al. Sub-micron moulding topological mass transport regimes in angled vortex fluidic flow. Nanoscale Adv. 2021, 3, 3064–3075. [Google Scholar] [CrossRef] [PubMed]
  93. Vimalanathan, K.; Suarez-Martinez, I.; Peiris, M.C.R.; Antonio, J.; de Tomas, C.; Zou, Y.; Zou, J.; Duan, X.; Lamb, R.N.; Harvey, D.P.; et al. Vortex fluidic mediated transformation of graphite into highly conducting graphene scrolls. Nanoscale Adv. 2019, 1, 2495–2501. [Google Scholar] [CrossRef]
  94. Al-Antaki, A.H.M.; Luo, X.; Alharbi, T.M.D.; Harvey, D.P.; Pye, S.; Zou, J.; Lawrance, W.; Raston, C.L. Inverted vortex fluidic exfoliation and scrolling of hexagonal-boron nitride. RSC Adv. 2019, 9, 22074–22079. [Google Scholar] [CrossRef]
  95. Huang, G.; Mei, Y. Thinning and shaping solid films into functional and integrative nanomembranes. Adv. Mater. 2012, 24, 2517–2546. [Google Scholar] [CrossRef] [PubMed]
  96. Hao, S.; Yang, B.; Gao, Y. Fracture-induced nanoscrolls from CVD-grown monolayer molybdenum disulfide. Phys. Status Solidi Rapid Res. Lett. 2016, 10, 549–553. [Google Scholar] [CrossRef]
  97. Qian, Q.; Zu, R.; Ji, Q.; Jung, G.S.; Zhang, K.; Zhang, Y.; Buehler, M.J.; Kong, J.; Gopalan, V.; Huang, S. Chirality-dependent second harmonic generation of MoS2 nanoscroll with enhanced efficiency. ACS Nano 2020, 14, 13333–13342. [Google Scholar] [CrossRef] [PubMed]
  98. Fan, X.; Su, L.; Zhang, F.; Huang, D.; Sang, D.K.; Chen, Y.; Li, Y.; Liu, F.; Li, J.; Zhang, H.; et al. Layer-dependent properties of ultrathin ges nanosheets and application in uv–vis photodetectors. ACS Appl. Mater. Interfaces 2019, 11, 47197–47206. [Google Scholar] [CrossRef]
  99. Morales-Guio, C.G.; Sterna, L.-A.; Hu, X. Nanostructured hydrotreating catalysts for electrochemical hydrogen evolution. Chem. Soc. Rev. 2014, 43, 6555–6569. [Google Scholar] [CrossRef]
  100. Zhou, X.; Lin, S.H.; Yang, X.; Li, H.; Hedhili, M.N.; Li, L.J.; Zhang, W.; Shi, Y. MoSx-coated NbS2 nanoflakes grown on glass carbon: An advanced electrocatalyst for the hydrogen evolution reaction. Nanoscale 2018, 10, 3444–3450. [Google Scholar] [CrossRef]
  101. Li, H.; Jia, X.; Zhang, Q.; Wang, X. Metallic transition-metal dichalcogenide nanocatalysts for energy conversion. Chem 2018, 4, 1510–1537. [Google Scholar] [CrossRef]
  102. Mattinen, M.; Leskelä, M.; Ritala, M. Atomic layer deposition of 2D metal dichalcogenides for electronics, catalysis, energy storage, and beyond. Adv. Mater. Interfaces 2021, 8, 2001677–2001724. [Google Scholar] [CrossRef]
  103. Wang, W.; Li, Y.; Li, M.; Shen, H.; Zhang, W.; Zhang, J.; Liu, T.; Kong, X.; Bi, H. Metallic phase WSe2 nanoscrolls for the hydrogen evolution reaction. New J. Chem. 2022, 46, 8381–8384. [Google Scholar] [CrossRef]
  104. Hinnemann, B.; Moses, P.G.; Bonde, J.; Jørgensen, K.P.; Nielsen, J.H.; Horch, S.; Chorkendorff, I.; Nørskov, J.K. Biomimetic hydrogen evolution: MoS2 nanoparticles as catalyst for hydrogen evolution. J. Am. Chem. Soc. 2005, 127, 5308–5309. [Google Scholar] [CrossRef] [PubMed]
  105. Wang, F.; Shifa, T.A.; Zhan, X.; Huang, Y.; Liu, K.; Cheng, Z.; Jiang, C.; He, J. Recent advances in transition-metal dichalcogenide based nanomaterials for water splitting. Nanoscale 2015, 7, 19764–19788. [Google Scholar] [CrossRef] [PubMed]
  106. Jaramillo, T.F.; Jørgensen, K.P.; Bonde, J.; Nielsen, J.H.; Horch, S.; Chorkendorff, I. Identification of active edge sites for electrochemical H2 evolution from MoS2 nanocatalysts. Science 2007, 317, 100–102. [Google Scholar] [CrossRef]
  107. Yan, Y.; Xia, B.; Xu, Z.; Wang, X. Recent development of molybdenum sulfides as advanced electrocatalysts for hydrogen evolution reaction. ACS Catal. 2014, 4, 1693–1705. [Google Scholar] [CrossRef]
  108. Henckel, D.A.; Lenz, O.M.; Krishnan, K.M.; Cossairt, B.M. Improved HER catalysis through facile, aqueous electrochemical activation of nanoscale WSe2. Nano Lett. 2018, 18, 2329–2335. [Google Scholar] [CrossRef]
  109. Voiry, D.; Yang, J.; Chhowalla, M. Recent strategies for improving the catalytic activity of 2D TMD nanosheets toward the hydrogen evolution reaction. Adv. Mater. 2016, 28, 6197–6206. [Google Scholar] [CrossRef] [PubMed]
  110. Lu, Q.; Yu, Y.; Ma, Q.; Chen, B.; Zhang, H. 2D transition-metal-dichalcogenide-nanosheet-based composites for photocatalytic and electrocatalytic hydrogen evolution reactions. Adv. Mater. 2016, 28, 1917–1933. [Google Scholar] [CrossRef] [PubMed]
  111. Yuan, J.; Wu, J.; Hardy, W.J.; Loya, P.; Lou, M.; Yang, Y.; Najmaei, S.; Jiang, M.; Qin, F.; Keyshar, K.; et al. Facile synthesis of single crystal vanadium disulfide nanosheets by chemical vapor deposition for efficient hydrogen evolution reaction. Adv. Mater. 2015, 27, 5605–5609. [Google Scholar] [CrossRef] [PubMed]
  112. Jiang, Z.; Zhou, W.; Hu, C.; Luo, X.; Zeng, W.; Gong, X.; Yang, Y.; Yu, T.; Lei, W.; Yuan, C. Interlayer-confined NiFe dual atoms withinMoS2 electrocatalyst for ultra-efficient acidic overall water splitting. Adv. Mater. 2023, 35, 2300505. [Google Scholar] [CrossRef] [PubMed]
  113. Kim, R.; Jang, J.-S.; Kim, D.-H.; Kang, J.-Y.; Cho, H.-J.; Jeong, Y.J.; Kim, I.-D. A general synthesis of crumpled metal oxide nanosheets as superior chemiresistive. Adv. Funct. Mater. 2019, 29, 1903128. [Google Scholar] [CrossRef]
  114. Bag, A.; Lee, N.-E. Gas sensing with heterostructures based on two-dimensional nanostructured materials a review. J. Mater. Chem. C 2019, 7, 13367–13383. [Google Scholar] [CrossRef]
  115. Kumar, R.; Goel, N.; Hojamberdiev, M.; Kumar, M. Transition metal dichalcogenides-based flexible gas sensors. Sens. Actuator A Phys. 2020, 303, 111875–111902. [Google Scholar] [CrossRef]
  116. Goswami, P.; Gupta, G. Recent progress of flexible NO2 and NH3 gas sensors based on transition metal dichalcogenides for room temperature sensing. Mater. Today Chem. 2022, 23, 100726–100739. [Google Scholar] [CrossRef]
  117. Liu, J.; Hu, Z.; Zhang, Y.; Li, H.Y.; Gao, N.; Tian, Z.; Zhou, L.; Zhang, B.; Tang, J.; Zhang, J.; et al. MoS2 nanosheets sensitized with quantum dots for room-temperature gas sensors. Nano-Micro Lett. 2020, 12, 59–72. [Google Scholar] [CrossRef]
  118. Bharathi, P.; Harish, S.; Shimomura, M.; Ponnusamy, S.; Mohan, M.K.; Archana, J.; Navaneethan, M. Conductometric NO2 gas sensor based on Co-incorporated MoS2 nanosheets for room temperature applications. Sens. Actuators B Chem. 2022, 360, 131600. [Google Scholar] [CrossRef]
  119. Bai, H.; Guo, H.; Feng, C.; Wang, J.; Liu, B.; Xie, Z.; Guo, F.; Chen, D.; Zhang, R.; Zheng, Y. Light-activated ultrasensitive NO2 gas sensor based on heterojunctions of CuO nanospheres/MoS2 nanosheets at room temperature. Sens. Actuators B Chem. 2022, 368, 132131–132146. [Google Scholar] [CrossRef]
  120. Zhang, L.; Hao, Q.; Liu, J.; Zhou, J.; Zhang, W.; Li, Y. Rolling up of 2D nanosheets into 1D Nanoscrolls: Visible-light-activated chemiresistors based on surface modified indium selenide with enhanced sensitivity and stability. Chem. Eng. J. 2022, 446, 136937. [Google Scholar] [CrossRef]
  121. Park, H.; Park, J.; Kang, S.-W.; Jeong, S.-H. 3D-nanostructured MoS2 nanoscroll with highly active sites for improving NO2 gas detection. Mater. Lett. 2023, 349, 134733–134737. [Google Scholar] [CrossRef]
Nanomaterials 13 02433 g002
Figure 2. Volatile organic solvent-assisted fabrication of MoS2 nanoscroll [23]. (a,b) CVD growth of monolayer MoS2 nanosheets. (c) A drop of ethanol is deposited on MoS2 nanosheets. (d) The edges of MoS2 nanosheets are rolled up during the evaporation of ethanol. (e) MoS2 nanoscrolls were formed.
Figure 2. Volatile organic solvent-assisted fabrication of MoS2 nanoscroll [23]. (a,b) CVD growth of monolayer MoS2 nanosheets. (c) A drop of ethanol is deposited on MoS2 nanosheets. (d) The edges of MoS2 nanosheets are rolled up during the evaporation of ethanol. (e) MoS2 nanoscrolls were formed.
Nanomaterials 13 02433 g002
Nanomaterials 13 02433 g003
Figure 3. The mixture of ethanol and water-assisted fabrication of MoS2 nanoscroll [24]. (a) CVD growth of MoS2 nanosheet. (b) Strain-balanced MoS2 on substrate. (c) After ethanol intercalation, the strain-adhesion balance between MoS2 and substrate is broken. (d) Rolling up the edge of the MoS2 nanosheet. (e) The as-prepared MoS2 nanoscroll.
Figure 3. The mixture of ethanol and water-assisted fabrication of MoS2 nanoscroll [24]. (a) CVD growth of MoS2 nanosheet. (b) Strain-balanced MoS2 on substrate. (c) After ethanol intercalation, the strain-adhesion balance between MoS2 and substrate is broken. (d) Rolling up the edge of the MoS2 nanosheet. (e) The as-prepared MoS2 nanoscroll.
Nanomaterials 13 02433 g003
Nanomaterials 13 02433 g004
Figure 4. Alkaline droplet-assisted fabrication of nanoscrolls [19]. (a) CVD-grown MoS2/WS2 heterostructures nanosheet on SiO2/Si substrate. (b) Etching the SiO2 layer beneath the nanosheet by dropping an alkaline solution. (c) The edge of the WS2/MoS2 nanosheet is rolled up due to the elimination of strong adhesion from the substrate. (d) The as-formed WS2/MoS2 heterojunction nanoscroll. (e,f) Show the comparison before and after dropping the alkali solution on the MoS2/WS2 nanosheets.
Figure 4. Alkaline droplet-assisted fabrication of nanoscrolls [19]. (a) CVD-grown MoS2/WS2 heterostructures nanosheet on SiO2/Si substrate. (b) Etching the SiO2 layer beneath the nanosheet by dropping an alkaline solution. (c) The edge of the WS2/MoS2 nanosheet is rolled up due to the elimination of strong adhesion from the substrate. (d) The as-formed WS2/MoS2 heterojunction nanoscroll. (e,f) Show the comparison before and after dropping the alkali solution on the MoS2/WS2 nanosheets.
Nanomaterials 13 02433 g004
Nanomaterials 13 02433 g005
Figure 5. Fabrication of TMDCs nanoscrolls by dragging water droplets at 100 °C [52]. (a) Monolayer MoS2 nanosheet was grown by CVD at 680 °C. (b) Heat the substrate and MoS2 nanosheets for 10 min. (c) A drop of H2O on the MoS2 film. (d) The H2O droplet was dragged across the MoS2 nanosheet on the SiO2/Si substrate by a coverslip at 3 mm/s−1; (e) MoS2 nanoscroll was formed after removing the H2O droplet; (f) Schematic diagram of the formation of the MoS2-NS.
Figure 5. Fabrication of TMDCs nanoscrolls by dragging water droplets at 100 °C [52]. (a) Monolayer MoS2 nanosheet was grown by CVD at 680 °C. (b) Heat the substrate and MoS2 nanosheets for 10 min. (c) A drop of H2O on the MoS2 film. (d) The H2O droplet was dragged across the MoS2 nanosheet on the SiO2/Si substrate by a coverslip at 3 mm/s−1; (e) MoS2 nanoscroll was formed after removing the H2O droplet; (f) Schematic diagram of the formation of the MoS2-NS.
Nanomaterials 13 02433 g005
Nanomaterials 13 02433 g006
Figure 6. Amine-functional amphiphilic molecule assisted fabrication of TMDCs nanoscrolls. (a) Scheme of Amine-functional amphiphilic molecule assisted fabrication of 1T@2H MoS2 nanoscrolls [49]. (b,c) Scheme of Amine-functional amphiphilic molecule assisted fabrication of MoS2-Ag and MoS2-Au nanoscrolls [83].
Figure 6. Amine-functional amphiphilic molecule assisted fabrication of TMDCs nanoscrolls. (a) Scheme of Amine-functional amphiphilic molecule assisted fabrication of 1T@2H MoS2 nanoscrolls [49]. (b,c) Scheme of Amine-functional amphiphilic molecule assisted fabrication of MoS2-Ag and MoS2-Au nanoscrolls [83].
Nanomaterials 13 02433 g006
Nanomaterials 13 02433 g007
Figure 7. Supercritical fluid processing-assisted fabrication of TMDCs nanoscrolls. FE-SEM images of (a) bulk MoS2 flake and (b,c) supercritical fluid-prepared MoS2 nanoscrolls [88]. FE-SEM images of (d) bulk WS2 flake and (e,f) supercritical fluid prepared WS2 nanoscrolls; (g) Schematic diagram of supercritical fluid processing-assisted preparation of TMDCs nanoscrolls [68].
Figure 7. Supercritical fluid processing-assisted fabrication of TMDCs nanoscrolls. FE-SEM images of (a) bulk MoS2 flake and (b,c) supercritical fluid-prepared MoS2 nanoscrolls [88]. FE-SEM images of (d) bulk WS2 flake and (e,f) supercritical fluid prepared WS2 nanoscrolls; (g) Schematic diagram of supercritical fluid processing-assisted preparation of TMDCs nanoscrolls [68].
Nanomaterials 13 02433 g007
Nanomaterials 13 02433 g008
Figure 8. Shear force-assisted fabrication of nanoscrolls [50]. (a–c) Schematic illustration of the fabrication of MoS2 scrolls in VFD. SEM images of the (d) MoS2 bulk material and (e) as-prepared MoS2 scrolls in VFD.
Figure 8. Shear force-assisted fabrication of nanoscrolls [50]. (a–c) Schematic illustration of the fabrication of MoS2 scrolls in VFD. SEM images of the (d) MoS2 bulk material and (e) as-prepared MoS2 scrolls in VFD.
Nanomaterials 13 02433 g008
Nanomaterials 13 02433 g009
Figure 9. Ar plasma-assisted fabrication of MoS2 nanoscrolls [18]. Schematic structures of (a) monolayer, (b) edge distortion, and (c) scrolled edge of MoS2 nanosheet under Ar plasma treatment. AFM images of (d) monolayer MoS2 nanosheet and (e) as-obtained MoS2 nanoscrolls.
Figure 9. Ar plasma-assisted fabrication of MoS2 nanoscrolls [18]. Schematic structures of (a) monolayer, (b) edge distortion, and (c) scrolled edge of MoS2 nanosheet under Ar plasma treatment. AFM images of (d) monolayer MoS2 nanosheet and (e) as-obtained MoS2 nanoscrolls.
Nanomaterials 13 02433 g009
Nanomaterials 13 02433 g010
Figure 10. Schematic diagram of nanoscroll formed by thermal strain [96]. (a) Monolayer MoS2 nanosheets were prepared on SiO2/Si substrate by CVD. (b) S vacancy acts as crack nuclei due to the thermal strain upon quenching. (c) Self-curling at the fractures of the MoS2 layer because of the temperature difference between the MoS2 and SiO2 layer. (d) The MoS2 nanoscroll is formed by thermal strain.
Figure 10. Schematic diagram of nanoscroll formed by thermal strain [96]. (a) Monolayer MoS2 nanosheets were prepared on SiO2/Si substrate by CVD. (b) S vacancy acts as crack nuclei due to the thermal strain upon quenching. (c) Self-curling at the fractures of the MoS2 layer because of the temperature difference between the MoS2 and SiO2 layer. (d) The MoS2 nanoscroll is formed by thermal strain.
Nanomaterials 13 02433 g010
Nanomaterials 13 02433 g011
Figure 11. Photodetection performance of TMDCs-NS based device. (a) Top panel: Scheme of photodetector based on MoS2 nanoscroll. Bottom panel: PDR plot of photodetectors based on MoS2 nanosheet and nanoscroll under 405 nm laser [23]. (b) The scheme of nanoscrolls is made by dropping ethanol and water droplets, respectively. PDR plot of corresponding photodetectors under 405 nm laser [52].
Figure 11. Photodetection performance of TMDCs-NS based device. (a) Top panel: Scheme of photodetector based on MoS2 nanoscroll. Bottom panel: PDR plot of photodetectors based on MoS2 nanosheet and nanoscroll under 405 nm laser [23]. (b) The scheme of nanoscrolls is made by dropping ethanol and water droplets, respectively. PDR plot of corresponding photodetectors under 405 nm laser [52].
Nanomaterials 13 02433 g011
Nanomaterials 13 02433 g012
Figure 12. Photodetector based on TMDCs-NS composite. (a) Plots of the PDRs of photodetectors based on WS2/MoS2 nanosheet and nanoscroll under blue laser [19]. (b) PDRs plots of photodetectors based on MoS2 nanoscrolls and PbI2/MoS2 nanoscrolls under 405 nm lasers [51]. (c) Plots of the PDRs of the MoS2 nanosheet, MoS2 nanoscroll, MoS2-Ag nanosheet, and MoS2-Ag NS under a 633 nm laser [35]. (d) Photocurrent variations in hybridized WS2 nanoscroll photodetectors under different power densities of a 532 nm laser [79].
Figure 12. Photodetector based on TMDCs-NS composite. (a) Plots of the PDRs of photodetectors based on WS2/MoS2 nanosheet and nanoscroll under blue laser [19]. (b) PDRs plots of photodetectors based on MoS2 nanoscrolls and PbI2/MoS2 nanoscrolls under 405 nm lasers [51]. (c) Plots of the PDRs of the MoS2 nanosheet, MoS2 nanoscroll, MoS2-Ag nanosheet, and MoS2-Ag NS under a 633 nm laser [35]. (d) Photocurrent variations in hybridized WS2 nanoscroll photodetectors under different power densities of a 532 nm laser [79].
Nanomaterials 13 02433 g012
Nanomaterials 13 02433 g013
Figure 13. Hydrogen evolution reaction (HER) based on TMDCs-NS. (a) HER polarization curves for M-WSe2 nanoscrolls, 2H-WSe2 nanoscrolls, and the commercial Pt/C [103]. (b) Polarization curves for Pt electrode, MoS2 sheet, MoS2 nanoscroll, MoS2 nanoscrolls@Pt, MoS2@Pt sheet, and MoS2@Pt nanoscroll [48].
Figure 13. Hydrogen evolution reaction (HER) based on TMDCs-NS. (a) HER polarization curves for M-WSe2 nanoscrolls, 2H-WSe2 nanoscrolls, and the commercial Pt/C [103]. (b) Polarization curves for Pt electrode, MoS2 sheet, MoS2 nanoscroll, MoS2 nanoscrolls@Pt, MoS2@Pt sheet, and MoS2@Pt nanoscroll [48].
Nanomaterials 13 02433 g013
Nanomaterials 13 02433 g014
Figure 14. Gas sensor based on C-InSe nanoscrolls [120]. (a,b) Schematic illustration of C-InSe nanoscroll-based gas sensor and test platform. (c) Response curves of C-InSe nanoscrolls sensor towards 1 ppm NO2 under blue light irradiation with different light intensities. (d) Relationship between the response of C-InSe nanosheets and nanoscrolls based sensors and NO2 concentration.
Figure 14. Gas sensor based on C-InSe nanoscrolls [120]. (a,b) Schematic illustration of C-InSe nanoscroll-based gas sensor and test platform. (c) Response curves of C-InSe nanoscrolls sensor towards 1 ppm NO2 under blue light irradiation with different light intensities. (d) Relationship between the response of C-InSe nanosheets and nanoscrolls based sensors and NO2 concentration.
Nanomaterials 13 02433 g014
Nanomaterials 13 02433 g015
Figure 15. Summary of preparation and applications of TMDCs nanoscrolls.
Figure 15. Summary of preparation and applications of TMDCs nanoscrolls.
Nanomaterials 13 02433 g015
Table 1. The advantages and disadvantages of preparation methods for TMDCs nanoscrolls.
Table 1. The advantages and disadvantages of preparation methods for TMDCs nanoscrolls.
MethodsAdvantagesChallengesReferences
In liquidSolvent evaporation to make nanoscrollLarge area, large size, high productivity, short time consuming, easy to operateSolvent residue, loose nanoscrolls[22,23,24,25,33,53,56,67,70,79,97]
Alkaline droplet-assisted fabrication of nanoscrollHigh yield, high productivity for thick nanosheetSubstrate etching, solvent residue[19,21,26,27,35,51]
Fabrication of TMDCs nanoscroll by dragging water dropletHigh yield, solvent-free residue, tightly packed nanoscrollNot suitable for water and oxygen-sensitive material[52]
Amine-functional amphiphilic molecule assisted fabrication of TMDCs nanoscrollHigh yield, easy to operateSmall dimension, solvent residue[48,49,82]
Supercritical fluid-assisted fabrication of nanoscrollSimple, fastSmall dimension, solvent residue[88]
Shear force-assisted fabrication of nanoscrollHigh productivity, easy to operateLow proportion of monolayer nanosheet[50]
In airPlasma-assisted fabrication of TMDCs nanoscrollSimple process, high yieldSmall dimension, structural damage[18,20]
Strain-assisted fabrication of TMDCs nanoscrollSimple and repeatableComplex process, low productivity, incomplete nanoscroll[17]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Yu, S.; Wang, P.; Ye, H.; Tang, H.; Wang, S.; Wu, Z.; Pei, C.; Lu, J.; Li, H. Transition Metal Dichalcogenides Nanoscrolls: Preparation and Applications. Nanomaterials 2023, 13, 2433. https://doi.org/10.3390/nano13172433

AMA Style

Yu S, Wang P, Ye H, Tang H, Wang S, Wu Z, Pei C, Lu J, Li H. Transition Metal Dichalcogenides Nanoscrolls: Preparation and Applications. Nanomaterials. 2023; 13(17):2433. https://doi.org/10.3390/nano13172433

Chicago/Turabian Style

Yu, Shilong, Pinyi Wang, Huihui Ye, Hailun Tang, Siyuan Wang, Zhikang Wu, Chengjie Pei, Junhui Lu, and Hai Li. 2023. "Transition Metal Dichalcogenides Nanoscrolls: Preparation and Applications" Nanomaterials 13, no. 17: 2433. https://doi.org/10.3390/nano13172433

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop