Hydrothermal synthesis and photocatalytic properties of titanium acid H2Ti2O5·H2O nanosheets

doi:10.1016/j.molcata.2005.06.005

Journal of Molecular Catalysis A: Chemical

Volume 239, Issues 1–2, 14 September 2005, Pages 87-91

https://doi.org/10.1016/j.molcata.2005.06.005 Get rights and content

Abstract

Titanium acid H₂Ti₂O₅·H₂O with nanosheet morphology has been prepared by doping Zn²⁺ into Ti single bond O crystal structure through the hydrothermal method. The products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), transmission electron microscopy (TEM), and ultraviolet–visible (UV–vis) spectroscopy. It indicated that Zn²⁺ doping plays an important role in formation of layered H₂Ti₂O₅·H₂O. The photo-catalytic activity of the samples was characterized by the depigmentation of methyl orange solution by UV light irradiation. It demonstrated that H₂Ti₂O₅·H₂O possess good photocatalytic properties in water purification and may find potential application in related fields.

Graphical abstract

Titanium acid H₂Ti₂O₅·H₂O with nanosheet morphology has been prepared by doping Zn²⁺ into Ti single bond O crystal structure via a hydrothermal method. It demonstrated that H₂Ti₂O₅·H₂O show good photocatalytic properties in depigmentation of methyl orange solution by UV light irradiation.

Introduction

TiO₂ have attracted a great deal of attention because of its high photocatalytic activity which may find potential application in environmental purification [1], [2], [3], [4]. In the first instance, people devoted themselves to the synthesis of TiO₂ with nano-scale dimensions. This was motivated by a known concept that photocatalytic activity of TiO₂ will be enhanced due to quantum-size effect and specific surface effect. With the development of researches, it is found that the properties of some semiconductor nanomaterials are markedly affected by impurities, and consequently these constituents also affect applications and economic value [5], the researches of doping Zn²⁺ into TiO₂ have been widely unfolded [6] and gotten some initial results [7], [8], [9]. In spite of this, the research is farther away to complete and the synthesis conditions have not been investigated in detail.

In recent years, layered compounds have been extensively studied [10], [11], [12] in this domain due to its unique structure and chemical activity [13], [14]. Titanium acid, as one of the layered compounds, attracted wide attentions due to its compositional similarity to that of TiO₂. Some authors have obtained H₂Ti₃O₇ type through the alkali treatment of commercial TiO₂ [15], however, the uniformity of the products produced in this manner might be destroyed because its final transformation to H₂Ti₃O₇ was dynamically unfavorable although thermodynamically favorable [16]. Other authors got H₂Ti₂O₅·H₂O form by the ion-exchange reaction between H⁺ and prepared alkali titanates [17] which needed two steps to get the final product.

In this work, we have obtained layered titanium acid which proved to be H₂Ti₂O₅·H₂O form by doping Zn²⁺ into Ti single bond O structure through hydrothermal method. Some reaction parameters in the hydrothermal conditions were studied in detail. The products showed nanosheet morphology and possessed the potential to be a photocatalyst in water purification according to the photocatalytic experiments.

Section snippets

Experimental

All the reagents were of analytical grade and without further purification before utilization. Firstly, different molar ratio of titanium sulfate and zinc sulfate were mixed evenly as initial reactants. Afterwards, they were transferred to a 50 ml Teflon-lined autoclave, where corresponding quantity of alkali solution (n_NaOH = 4n_Ti + 2n_Zn) was added. Then the autoclave was sealed and heated under auto-generated pressure at 200 °C for different reaction times. The as-formed solid precipitate was

Results and discussion

Fig. 1 shows the XRD patterns of the products obtained from alkali treatment of titanium sulfate and zinc sulfate separately at 200 °C for 12 h. Seen from the pattern, pure TiO₂ and ZnO products can be obtained under this reaction conditions according to JCPDS 21-1272 and JCPDS 36-1451, respectively. However, when titanium sulfate and zinc sulfate were mixed with different molar ratio together, there happened some change. All of the XRD results showed the products are amorphous.

To quest for the

Conclusion

In summary, layered titanium acid H₂Ti₂O₅·H₂O nanosheet has been synthesized via doping Zn²⁺ into the Ti single bond O crystal structure in hydrothermal process. The as-synthesized products were characterized by XRD, XPS, TEM, and UV–vis spectroscopy. In this route, Zn²⁺ played important role in the formation of final product. Layered titanium acid H₂Ti₂O₅·H₂O synthesized by this method has showed superior photocatalytic property in water purification and may find much wider applications due to its unique

Acknowledgement

The authors are grateful to the Project of New Star of Science and Technology of Beijing for financial support.

References (24)

T. Sekiguchi et al.
J. Cryst. Growth
(2000)
D.C. look et al.
Solid State Commun.
(1998)
C.K. Chan et al.
J. Am. Ceram. Soc.
(1999)
Z.R. Tian et al.
Science
(1997)
Maria das Gracas A. Korn et al.
Microchem. J.
(2002)
N.N. Lysova et al.
J. Appl. Chem. USSR
(1993)
H.H. Deng et al.
Science
(1998)
Y.Q. Wang et al.
Thin Solid Films
(1999)
Vlasta Brezová et al.
J. Mol. Catal. A: Chem.
(1995)
Masato Ueda et al.
Sci. Technol. Adv. Mater.
(2004)

Dong Won Hwang et al.

Catal. Today

(2004)

H.Y. Zhu et al.

Appl. Clay Sci.

(2005)

Cited by (29)

Hydrothermally synthesized titanate nanomaterials for the removal of heavy metals and radionuclides from water: A review
2021, Chemosphere
Citation Excerpt :
These hydrothermally synthesized TNMs are connected by TiO6 octahedral blocks to form a two-dimensional layer, with hydrogen ions and sodions inserted into the interlayer space and abundant hydroxyl groups (−OH) on the surface. Depending on different crystal structures, TNMs can be constructed from monoclinic trititanate H2Ti3O7/Na2Ti3O7/NaxH2−xTi3O7 (El-Deen et al., 2016; Liu et al., 2015a, 2019; Weng et al., 2006), or tetratitanate H2Ti4O9·H2O (Dong et al., 2017; Gu et al., 2019; Nakahira et al., 2004; Nosheen et al., 2009), and orthorhombic lepidocrocite HxTi2−x/4□x/4O4 (x~0.7, □: vacancy) (Gao et al., 2009; Ma et al., 2003), or bititanate H2Ti2O4(OH)2/Na2Ti2O4(OH)2 (Fig. 1a and b) (Song et al., 2005; Zhang et al., 2004, 2019b). Meanwhile, according to their microscopic morphologies, TNMs could be divided into titanate nanotubes (Cheng et al., 2019b; Dang et al., 2020; Kim et al., 2014; Qiu and Li, 2014), nanofibers (Abureden et al., 2016; Chacko et al., 2013; Kang et al., 2020; Saleh et al., 2019; Xu et al., 2014), nanoflowers (Chang et al., 2016; Feng et al., 2013; Huang et al., 2008, 2012), nanowires (Barrocas et al., 2019, 2020; Hsieh et al., 2019; Osawa et al., 2020), nanorods (Chang et al., 2018; Stengl et al., 2006; Wang et al., 2015a), nanoribbons (Gu et al., 2019; Kiatkittipong et al., 2010), etc.
Hazardous heavy metals and radionuclides in water and wastewater are of drastic concern owing to their detrimental impacts on the organisms as well as the circumambient ecosystem. To remove them as much as we can, both technique and materials were studied in the past years. The adsorption technique as superior water remediation method with the simplicity of design, environmental friendliness and high efficiency was well established. Consequently, it is practically important to explore advanced and economically feasible absorbents for removing these poisonous pollutants from aqueous solutions. So far, large numbers of experiments proved hydrothermally synthesized titanate nanomaterials (TNMs) could be a prospectively excellent adsorbent extracting heavy metals and radionuclides from water due to the high specific surface area, tunable pore size, abundant surface active sites, favorable hydrophilic properties. The objective of this work is to give an overview of hydrothermal synthesis, adsorption performance of TNMs for heavy metals and radionuclides, as well as the various influencing factors for water purification. It comprehensively reviews the structural changes and regenerability of TNMs after adsorption, and different modification methods adopted for improving removal capacity. Additionally, it uniquely highlights the efficient decontamination of the pollutants through a synergistic effect of adsorption and photocatalysis by TNMs. This review provides detailed information for the development, application, and research challenges faced by hydrothermally synthesized TNMs for the removal of heavy metals and radionuclides from aqueous solutions, which will serve as a reference guide for scientists in related fields.
Hierarchical surface morphology on Ti6Al4V via patterning and hydrothermal treatment towards improving cellular response
2019, Applied Surface Science
Titanium implants are widely used in load bearing applications. Failure analysis for several decades revealed poor interfacial bonding at implant-tissue interface is the major cause. Diverse morphological and chemical modifications are carried out to overcome to this issue. In this study, we developed a simple, user friendly combinatorial approach of embossing followed by hydrothermal treatment for generating nano/micro/macro hierarchical architecture on Ti6Al4V surface with deposition of calcium phosphate minerals for improving osseointegration property. The hydrothermally treated groove/pillar patterned sample had uniformly distributed nanorods with 65 ± 3 nm diameter, surface roughness ~118 nm and ~532 nm height, respectively. Presence of phosphate and calcium were confirmed through EDS and XRD with Ca/P ratio ~1.66 which is similar to apatite like deposition. Calcium phosphate apatite formation was also confirmed on the surface by XPS. The hydrothermal treated samples demonstrated improved hMSC cell adhesion, migration, proliferation and differentiation as compared to untreated ones. Therefore, this method has potential to minimize interfacial failure through morphological fixation via tissue ingrowth as well as ongrowth.
Hydrothermal synthesis of size-controllable Yttrium Orthovanadate (YVO <inf>4</inf>) nanoparticles and its application in photocatalytic degradation of direct blue dye
2012, Journal of Alloys and Compounds
Citation Excerpt :
Photocatalysis using semiconductors is of great importance in solving energy and environment issues [1–3]. In the past decade, a great deal of efforts have been devoted to developing novel oxide semiconductor photocatalysts that are applicable to environmental purification and water splitting to generate clean energy hydrogen by light energy conversion [4–6]. Among them, the vanadate such as InVO4, BiVO4, M3V2O8 (M = Mg, Ni, Zn), etc., catches scientists’ attention, due to V 3d orbital electron that can be activated by light [7–14].
Sized-controlled YVO₄ nanoparticles have been synthesized by a simple hydrothermal method by changing hydrothermal time from 4 to 24 h. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), specific surface area (Brunauer–Emmett–Teller (BET)), and ultraviolet–visible spectroscopy (UV–vis) measurements. The results showed that the size of as-synthesized YVO₄ nanoparticles was in the range of 11–40 nm and was extremely dependent on the hydrothermal time. Photocatalytic measurement showed that the YVO₄ nanoparticles with particle size of about 11 nm (prepared by 4 h hydrothermal time) possess superior photocatalytic properties in the decolorization of direct blue dye. Due to simple preparation, high photocatalytic oxidation of direct blue dye and low cost, the YVO₄ photocatalyst is a potential candidate for pollutants removal and will find wide application in the coming future in photocatalytic oxidation processes. The overall kinetics of photodegradation of direct blue dye using YVO₄ nanopowders photocatalyst was found to be of first order. The photocatalyst could be easily removed from the reaction mixture and its recyclability with no loss of activity was possible for six times. The catalytic performance was found to decrease by 5% after run number six.
Investigation of the hydrogen evolution on Ni deposited titanium oxide nano tubes
2012, International Journal of Hydrogen Energy
Citation Excerpt :
This decrease was slightly lower for the Ni–Co–V. It is reported that titanium oxide tube which have large surface area, the ease of preparation, eco-friendliness, good chemical inertness and the strong oxidizing power of the photogenerated holes [10–13]. This material is demonstrated a number of important applications including gas sensors [14], solar cells [15], photo-catalysts [16] and electro-catalyst [17].
Titanium oxide nano tubes (TiOx) were prepared by the electrochemical anodizing method from at different process time and different potential in 0.1 M HF solution. Their morphologies were determined with surface photographs and scanning electron microscopy (SEM) images. Ni nano particles were deposited in conductive TiOx nano tubes arrays via pulsed electrodeposition method. Their catalytic activity towards the hydrogen evolution reaction (HER) was assessed by recording cyclic voltammetry technique, cathodic current–potential curves, hydrogen gas volumes and electrochemical impedance spectroscopy techniques. The highest HER activity thought the studied is observed on the TiOx₍₃₀₎-Ni.
Silver decorated titanate/titania nanostructures for efficient solar driven photocatalysis
2012, Journal of Solid State Chemistry
Photocatalysis has attracted significant interest to solve both the energy crisis and effectively combat environmental contamination. However, as the most widely used photocatalyst, titania (TiO₂) suffers from inefficient utilization of solar energy due to its wide band gap. In the present paper, we describe a method to extend the absorption edge of photocatalyst to visible region by the surface plasmon effect of silver. Silver ions are photo-reduced onto the surface of titanate nanotubes, which are synthesized by a conventional hydrothermal method. The as-synthesized Ag/titanate composite is transformed into Ag/titania nanoparticles by annealing at different temperatures. It is found that the interaction of Ag nanoparticles with the supports (titanate/titania) plays a key role for the visible light activity. The samples annealed at low temperature (<350 °C) do not show significant activity under our conditions, while the one annealed at 450 °C shows fast-degradation of methyl orange (MO) under visible light irradiation. The detailed mechanisms are also discussed.
Exfoliation and thermal transformations of Nb-substituted layered titanates
2011, Journal of Solid State Chemistry
Citation Excerpt :
Layered titanates with lepidocrocite (γ-FeOOH)-type structure attracts attention due to prominent photocatalytic activity [1,2] and interlayer chemistry [3,4].
Single-layer Nb-substituted titanate nanosheets of ca. 1 nm thickness were obtained by exfoliating tetrabutylammonium (TBA)-intercalated Nb-substituted titanates in water. AFM images and turbidity measurements reveal that the exfoliated nanosheets crack and corrugate when sonicated. Upon heating, the thermal transformation into anatase and further to rutile is retarded. This suppression of the phase transition upon higher valent substitution may promote technological applications of anatase thin films, hereunder development of films with TCO properties. Depending on the oxygen partial pressure during the transformation, the Nb-substitution into TiO₂ provokes different defect situations and also electronic properties. At reducing conditions, Nb is incorporated as Nb^V and an equivalent amount of Ti^IV is transformed to Ti^III as evidenced by XPS. Magnetic susceptibility data show accordingly paramagnetic behavior. For samples heated in air Ti^IV and Nb^V cations prevail, the latter is compensated by cation vacancies. ⁹³Nb MAS NMR data prove that Nb is finely dispersed into the transformed (Ti,Nb)O₂ oxide matrices without sign of Nb₂O₅ (nano)precipitates. The Nb–O–Ti bonds and defects at cation sites are considered key factors for increasing the transformation temperatures for conversion of the nanosheets to anatase and finally into rutile. It is further tempting to link the delay in crystallization to morphology limitations originating from the nanosheets. The present work shows that layered Nb-titanates are appropriate precursors for formation of highly oriented Nb-substituted anatase thin films via delamination, reconstruction and subsequent heat treatment.

View all citing articles on Scopus

View full text

Hydrothermal synthesis and photocatalytic properties of titanium acid H2Ti2O5·H2O nanosheets

Abstract

Graphical abstract

Introduction

Section snippets

Experimental

Results and discussion

Conclusion

Acknowledgement

J. Cryst. Growth

Solid State Commun.

J. Am. Ceram. Soc.

Science

Microchem. J.

J. Appl. Chem. USSR

Science

Thin Solid Films

J. Mol. Catal. A: Chem.

Sci. Technol. Adv. Mater.

Catal. Today

Appl. Clay Sci.

Hydrothermal synthesis and photocatalytic properties of titanium acid H₂Ti₂O₅·H₂O nanosheets