One-step growth of reduced graphene oxide on arbitrary substrates
Graphical abstract
Introduction
Reduced graphene oxide (rGO) has attracted a great deal of attention from researchers thanks to its anticipated applications in transparent and flexible electronics [1,2], supercapacitors [3], batteries [4], sensors [5], photodetectors [6], electromagnetic shielding [7], etc. It possesses higher in-plane electrical conductivity than graphene oxide (GO) and contains more active sites (e.g., hydroxyl groups and defects) for chemical functionalization and catalysis than pristine graphene [[8], [9], [10], [11]]. Currently, modified Hummers’ methods are the most popular way to prepare GO and its derivatives, such as rGO [[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]]. Briefly, graphite is oxidized and intercalated using a mixture of potassium permanganate (KMnO4), NaNO3, and concentrated H2SO4. The product is purified to obtain GO. Then, an aqueous dispersion of the obtained GO is treated with reducing agents, such as a solution of hydrazine and ammonia, to partially restore the graphitic sp [2] carbon. Finally, these rGO dispersions has to be transferred onto target substrates via spray or filtration for thin-film applications. Due to the strong oxidizers and various reducing agents involved in these processes, it is difficult to control the size, roughness, and thickness of the end rGO product. In this work, we report a facile way of growing ultrathin rGO films on arbitrary substrates and free-standing rGO powders, where the solid precursor (cellulose acetate) is transformed by thermal annealing. Regarding the selection of solid precursors, small organic molecules such as glucose need to go through polymerization process under certain conditions to form oxygen-containing polymers first before transformed into rGOs, otherwise they will sublime away completely under vacuum at high temperature. Therefore, in our procedure of one-step growth of rGO, polymers such as cellulose acetate are our first choice considering the cost, simplicity and practicability. Here, we refer to rGO derived from cellulose acetate as CA-rGO. Cellulose acetate is an ester of cellulose, which is abundant in natural resources such as cotton, wood, and hemp. It can be readily dissolved in a wide range of solvents, such as acetone, dioxane, and methal acetate [13,14], and spin-coated onto arbitrary substrates, which has facilitated its use in both academic and industrial applications [[14], [15], [16]].
Section snippets
Cellulose acetate spin-coating parameters and CA-rGO growth conditions
Generally, the target substrates (quartz, SiO2/Si, Cu, Si, glass etc.) were spin-coated with a 10 mg/mL cellulose acetate (Sigma Aldrich, average Mn ∼ 30,000 by GPC) solution in acetone at 5000 rpm for 60 s. The spin-coated device was loaded into a quartz tube inside a self-assembled Chemical Vapor Deposition (CVD) system. Then, pressure in the tube chamber was pumped down to high vacuum (1 mtorr). At room temperature, 50 sccm H2 and 250 sccm Ar were introduced into the tube chamber to maintain
One-step growth process of CA-rGO
Here, we synthesized the cellulose acetate derived rGO (CA-rGO) by direct thermal annealing of the cellulose acetate polymer under a continuous flow of H2/Ar. In a typical experiment, we spin-coated the target substrate (quartz, SiO2/Si, Cu, etc.) with an acetone dispersion of cellulose acetate (Fig. 1a and b) and then transferred to a CVD furnace to grow CA-rGO at a high temperature (Fig. 1c and d). The solution of cellulose acetate exhibits Tyndall effect under a beam of red laser (635 nm),
Conclusions
We demonstrated a one-step growth of CA-rGO from cellulose acetate on arbitrary substrates, which is far simpler than the traditional processes for preparing rGO. The size of the CA-rGO nanoplatelets and their extent of graphitization can be mediated by controlling the reaction temperature and the percentage of H2 in the reductive gas mixture. The graphene-like in-plane crystalline structure of our CA-rGO thin film, along with its abundant chemically active sites (hydroxyl groups and defects)
Data availability
The data related to this study are available from the corresponding authors upon request.
Competing financial interests
The authors declare no competing financial interests. We are applying a patent for this study.
Acknowledgements
The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST), under award number: URF/1/2634 (CRG4) and URF/1/2996 (CRG5).
References (49)
- et al.
Melamine based, n-doped carbon/reduced graphene oxide composite foam for Li-ion hybrid supercapacitors
Carbon
(2018) - et al.
Visualization of defect densities in reduced graphene oxide
Carbon
(2012) - et al.
Thin-film particles of graphite oxide 1:: high-yield synthesis and flexibility of the particles
Carbon
(2004) - et al.
Electrospun cellulose acetate nanofibers: the present status and gamut of biotechnological applications
Biotechnol. Adv.
(2013) - et al.
Preparation and performance of cellulose acetate–polyurethane blend membranes and their applications–II
J. Membr. Sci.
(2000) - et al.
Raman spectroscopy in graphene
Phys. Rep.
(2009) - et al.
Large-scale cellulose-assisted transfer of graphene toward industrial applications
Carbon
(2016) - et al.
Evolution of the band-gap and optical properties of graphene oxide with controllable reduction level
Carbon
(2013) - et al.
Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide
Carbon
(2007) - et al.
Optical and electronic properties of thin films and solutions of functionalized forms of graphene and related carbon materials
Carbon
(2014)
Large scale synthesis of N-doped multi-layered graphene sheets by simple arc-discharge method
Carbon
Organometallic chemistry of graphene: photochemical complexation of graphene with group 6 transition metals
Carbon
Two-beam-laser interference mediated reduction, patterning and nanostructuring of graphene oxide for the production of a flexible humidity sensing device
Carbon
Humidity-sensing properties of chemically reduced graphene oxide/polymer nanocomposite film sensor based on layer-by-layer nano self-assembly
Sensor. Actuator. B Chem.
Effect of constructive rehybridization on transverse conductivity of aligned single-walled carbon nanotube films
Mater. Today
Evaluation of solution-processed reduced graphene oxide films as transparent conductors
ACS Nano
Large-area ultrathin films of reduced graphene oxide as a transparent and flexible electronic
Material. Nat. Nanotechnol.
Reduced graphene oxide/tin–antimony nanocomposites as anode materials for advanced sodium-ion batteries
ACS Appl. Mater. Interfaces
Room-temperature hydrogen sensing with heteronanostructures based on reduced graphene oxide and tin oxide
Angew. Chem. Int. Ed.
Self-powered, visible-light photodetector based on thermally reduced graphene oxide–ZnO (rGO–ZnO) hybrid nanostructure
J. Mater. Chem.
Two-dimensional materials: emerging toolkit for construction of ultrathin high-efficiency microwave shield and absorber
Front Phys. Beijing
Reduced graphene oxide films with ultrahigh conductivity as Li-ion battery current collectors
Nano Lett.
Origin of reduced graphene oxide enhancements in electrochemical energy storage
ACS Catal.
Reduced graphene oxide by chemical graphitization
Nat. Commun.
Cited by (12)
Ammonia-assisted hydrothermal carbon material with schiff base structures synthesized from factory waste hemicelluloses for Cr(VI) adsorption
2021, Journal of Environmental Chemical EngineeringCitation Excerpt :Noteworthily, carbon materials have become a promising adsorbent candidate due to the high pore volume, rich functional groups, strong mechanical properties, and good thermal stability [20,21]. There have been many researchers using low-cost resources (e.g. agricultural and industrial waste) to synthesize carbon-based adsorbents such as activated carbon materials and graphene materials [22–24]. As the popular of dissolving pulp from wood pulp, every factory with annual capacity of 50,000 tons could produce several hundred thousand tons of hemicellulose concentrate, which is usually incinerated as waste [25].
Evolution of cellulose acetate to monolayer graphene
2021, CarbonCitation Excerpt :It has long been known that polymers can undergo carbonization and graphitization processes under thermal treatment [26–28]. In our previous work, it was demonstrated that cellulose acetate could transform into reduced graphene oxide (rGO) after thermal treatment under proper conditions [29–31]. However, it is extremely difficult to convert cellulose acetate to graphene directly, as the intermediate rGO is thermally very stable.
Synergic effect of Cu<inf>2</inf>O/MoS<inf>2</inf>/rGO for the sonophotocatalytic degradation of tetracycline and ciprofloxacin antibiotics
2021, Ceramics InternationalCitation Excerpt :In the past decade, graphene, graphene oxide (GO) and rGO have been used for the synthesis of metal oxide based composites, due to their outstanding properties such as sp2-hybridized carbon with high mechanical, thermal, optical transparency and charge carriers. The rGO can be synthesized using several techniques, possesses tunable properties and offers numerous applications [19–22]. For the synthesis of composites materials, several methods have been adopted, such as wet chemical, hydrothermal, solvothermal and sonochemical.
An extensive case study on the dispersion parameters of HI-assisted reduced graphene oxide and its graphene oxide precursor
2020, Journal of Colloid and Interface ScienceHighly antibacterial rGO/Cu<inf>2</inf>O nanocomposite from a biomass precursor: Synthesis, performance, and mechanism
2020, Nano Materials ScienceCitation Excerpt :As soon as the reaction ended, the air blower was used to quickly cool down the quartz chamber to room temperature. Pristine rGO powders were grown under the same conditions without adding CuCl2 into cellulose acetate dispersions as a reference. [17]. The rGO/Cu2O powders were ground between two 300 nm SiO2/Si wafers, then placed under a Nicolet Almega XR Dispersive Raman microscope to obtain the measurements.