WO3 Nanoplates Research Articles

Bipyridine-Co2+ molecular catalyst modified WO3 nanoplate arrays photoanode with enhanced photoelectrochemical activity

Here we report for the first time that bpy-Co2+ complex (bpy = 4,4′-bipyridine) can be used as an efficient molecular co-catalyst to significantly enhance photoelectrochemical (PEC) activity of WO3 nanoplate arrays photoanode. As a result, bpy-Co2+ complex modified WO3 nanoplate arrays photoanode achieved a considerable photocurrent density (2.88 mA cm−2) at 1.5 V versus a reversible hydrogen electrode (RHE), which is 1.7 and 1.4-times larger than that obtained by WO3 photoanode without any modification (1.61 mA cm−2) and cobalt phosphate (Co-Pi) modified WO3 photoanode (2.01 mA cm−2) in Na2SO4 electrolyte, respectively. The present work provides a new strategy for designing highly efficient PEC water splitting device.

Facile fabrication and photocatalytic performance of WO3 nanoplates in situ decorated with Ag/β-Ag2WO4 nanoparticles

In this work, we first successfully designed and fabricated the ternary plasmonic Ag/β-Ag2WO4/WO3 photocatalysts with different contents of Ag/β-Ag2WO4 particles in situ decorated on the surface of WO3 nanoplates by a simple precipitation method at room temperature condition. The photocatalytic activity of as-prepared samples was investigated by degradation of rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) under visible-light irradiation. It was found that the prepared 40 wt% Ag/β-Ag2WO4/WO3 photocatalyst showed the highest photocatalytic RhB efficiency with 83.21 and 86.83 times higher than those of pure WO3 and Ag/β-Ag2WO4 samples, respectively. The highly enhanced photocatalytic performance was attributed to the Z-scheme mechanism in this ternary composites, in which Ag particles play a crucial role by the surface plasmon resonance (SPR) effect; meanwhile, Ag particles also can work as the charge transmission-bridge, giving rise to effectively restraining recombination of the photogenerated charge carriers. This novel ternary Ag/β-Ag2WO4/WO3 nanostructures may provide an appropriate insight in the consideration as an ideal candidate in environmental remediation.

Pronounced effects of the nominal concentrations of WO3 and Ag: WO3 nano-plates (obtained by a co-precipitation method) on their structural, morphological and optical properties

Tungsten oxide and different concentration of silver (Ag)-doped tungsten oxide nano material were synthesized by co-precipitation technique. The functional vibrations, structure, and morphology of as-prepared nano material were studied by Fourier transmission infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM) and High-resolution transmission electron microscopy (HR-TEM) techniques. The SEM and HR-TEM analysis revealed the formation of nano-plate/nano rods with an average diameter of 40–80 nm diameter and 1–1.5 mm length. Fluorescence (PL) and UV–visible absorption techniques have been used to study the optical properties of the prepared nanoparticles. The observed red shift in the visible absorption spectra confirmed the promoted electron–phonon interaction in WO3 and Ag: WO3 nanoparticles compared to bulk structures. The photoluminescence of nanocrystalline Ag2+ doped WO3 exhibited a strong violet–blue, blue–green emission. Concentration dependence of the emission intensity of Ag2+ in WO3 was studied, and the significant concentration was found to be 0.5% of Ag: WO3. The effluent dye degradation executed for the 0.5% of Ag: WO3 sample under the visible light which reveals the highest degradation efficiency in appropriate time.

Ni doped WO3 nanoplates: An excellent photocatalyst and novel nanomaterial for enhanced anticancer activities

We report on the effects of Ni doping on the structural, optical, photocatalytic and anticancer activities of WO3. Ni doped WO3 nanoplates were obtained via soft chemical co-precipitation method. The structural, morphological and vibrational modes of Ni doped WO3 were confirmed through XRD, SEM, EDX, FTIR and Raman spectroscopy. The substitution of Ni2+ ions on the sites of W6+ ions was confirmed through X-ray photoelectron spectroscopy (XPS) analysis. The diffusion reflectance spectroscopy revealed the narrow optical band gap in the visible region for undoped sample, this further reduced upon Ni doping. The defects and oxygen deficiencies were analyzed by photoluminescence spectroscopy. Most importantly, the mineralization degree of organic dye using Ni doped WO3 photocatalyst was determined by total organic carbon analysis (TOC), reaching percentages of mineralization up to 96% of methyl red in just 2 h under illumination of visible light. Interestingly, it was also found that the percent cells viability of human breast (MCF-7) and liver (Hep-2) cancers cells were reduced remarkably up to 30% and 35% respectively with 5% Ni ions doping.

Highly improved photoelectrocatalytic efficiency and stability of WO3 photoanodes by the facile in situ growth of TiO2 branch overlayers.

The development of highly efficient and stable visible-light-responsive photoanode materials is essential for practical photoelectrocatalytic (PEC) applications. In this work, a novel method was proposed to enhance the PEC efficiency and stability of WO3 photoanodes by the facile in situ growth of TiO2 branch overlayers on WO3 nanoplates (TWNP) based on the lattice match between monoclinic WO3 and anatase TiO2. The WO3 nanoplates (WNP) with a fluted body and a thickness of 160 nm were first prepared on tungsten foil by a hydrothermal method. Then, numerous 001-oriented anatase TiO2 branches were directly grown in situ on the WNP with an average thickness of 50 nm and a length of 35 ± 5 nm. TWNP exhibited a photocurrent of ∼2.37 mA cm-2, which is 157% of that of WNP, and showed no obvious decay over 100 h continuous testing, compared to only 11.8% that remained for WNP. During the PEC degradation of phenol, the rate constant was 0.322 h-1 for TWNP while it was only 0.131 h-1 for WNP, and the activity of TWNP remained at 97.2% after 10 repeat tests compared to only 67.4% for WNP. According to the transient photovoltage and transient photocurrent measurements, these improvements can be attributed to the TiO2 branches which enhanced the charge separation efficiency and surface reaction kinetics, and hindered the inactivation of TWNP by providing an atomic-level protective cover. Overall, the in situ wet chemical growth of the TiO2 branches is a meaningful way to overcome WO3's drawbacks, i.e., sluggish surface reaction kinetics, rapid charge recombination and gradual loss of photoactivity, to improve the PEC activity and stability of WO3 photoanodes.

Simultaneous photocatalytic degradation of p-cresol and Cr (VI) by metal oxides supported reduced graphene oxide

The visible light active photocatalysts WO3 (C1), Fe2O3 (C2), WO3/rGO (C3), Fe2O3/rGO (C4) were synthesized under in-situ hydrothermal method. The physico-chemical characteristics were studied and characterized by XRD, Raman, UV–vis-DRS, TEM, SEM, BET, EDX and XPS. The formation of WO3 and Fe2O3 was confirmed by XRD and the average crystallite size of the prepared samples was less than 50nm. The Raman spectroscopy confirms the decreasing ID/IG ratio of WO3/rGO composite than the pure rGO. The band gap calculated by UV–vis diffuse reflectance spectroscopy was found to be lower for the composites C3 and C4 than C1 and C2. The TEM results confirmed that the WO3 nanoplates are uniformly distributed on rGO sheets and no significant lattice distortion was observed on growing WO3 nanoplates on rGO. The chemical composition and oxidation states of synthesized nanocomposites (C3 and C4) can be characterized by X-ray Photoelectron Spectroscopy. The surface area of photocatalyst C3 was found to be 16m2/g. The visible light activity of prepared photocatalysts was tested for the degradation of p-cresol and the reduction of Cr (VI). Typical results highlighted that WO3/r-GO (C3) is the best active catalyst and the simultaneous degradation of the pollutants is beneficial over the removal of individual pollutants. The mineralization of the organic pollutant was confirmed by the TOC analyzer and the percentage of mineralization for the best active photocatalyst was ∼80%.

Highly Active Tungsten Oxide Nanoplate Electrocatalysts for the Hydrogen Evolution Reaction in Acidic and Near Neutral Electrolytes.

An efficient, cost-effective, and earth-abundant catalyst that could drive the production of hydrogen from water without or with little external energy is the ultimate goal toward hydrogen economy. Herein, nanoplates of tungsten oxide and its hydrates (WO3·H2O) as promising electrocatalysts for the hydrogen evolution reaction (HER) are reported. The square-shaped and stacked WO3·H2O nanoplates are synthesized at room temperature under air in ethanol only, making it as a promising green synthesis strategy. The repeated electrochemical cyclic voltammetry cycles modified the surface of WO3·H2O nanoplates to WO3 as confirmed by X-ray photoelectron and Auger spectroscopy, which leads to an improved HER activity. Hydrogen evolution is further achieved from distilled water (pH 5.67) producing 1 mA cm–2 at an overpotential of 15 mV versus the reversible hydrogen electrode. Moreover, WO3·H2O and WO3 nanoplates demonstrate excellent durability in acidic and neutral media, which is highly desirable for practical application. Improved hydrogen evolution by WO3(200) when compared to that by Pt(111) is further substantiated by the density functional theory calculations.

Structural, photoluminescence, electrical, anti cancer and visible light driven photocatalytic characteristics of Co doped WO3 nanoplates

In this study, soft chemical route has been adopted for the synthesis of Co doped WO3 nanoplates. The prepared samples are crystallized into monoclinic phase of WO3 and composed of two dimensional (2-D) nanoplates. The substitution of Co2+ ions on the sites of W6+ ions has been confirmed through X-ray photoelectron spectroscopy (XPS) analysis. The presence of functional groups and chemical bonding has been verified through FTIR and Raman spectra. Narrowing of the optical gap with Co doping has been observed which is linked with formation defects levels in the band of WO3. The Co doping has been found to be very effective in enhancing the visible light driven photodegradation activity of WO3 nanoplates up to 90% which is attributed to trapping photo-generated electrons by defects. Furthermore, Co doped WO3 nanoplates have also shown good anticancer activities against human breast (MSF-7) and lever (Hep-2) cancer cells.

Enhanced nitrogen oxide sensing performance based on tin-doped tungsten oxide nanoplates by a hydrothermal method

The great demand for gas sensors in practical applications has stimulated tremendous attention in this area due to its important significance in real life. A facile synthesis of WO3 nanoplates and their subsequent Sn doping strategy by using a hydrothermal method was investigated to enhance gas sensing performance for NO2 gas, one of the gases toxic to human beings and the environment. Various techniques were used to characterize all the products. The morphology characterizations demonstrated that all the samples exhibited a similar nanoplate structure with or without Sn doping. The gas sensing properties of the sensors based on different doping concentrations (0, 1, 2 and 5wt%) have been systematically investigated. The sensor based on the 2wt% Sn-doped WO3 nanoplates showed the maximum response to NO2 (55–100ppb NO2). Furthermore, the introduction of Sn ions into the sensing materials of WO3 resulted in shorter response and recovery times. This finding could be attributed to the increased number of oxygen vacancies on the surface of the sensing material and the resistance of the gas sensors. The results provide a new doping strategy to fabricate high performance NO2 gas sensors.

Improving Visible-light Responses and Electric Conductivities by Incorporating Sb2S3 and Reduced Graphene Oxide in a WO3 Nanoplate Array for Photoelectrochemical Water Oxidation

The WO3, reduced graphene oxide (rGO), and Sb2S3 nanocomposite is firstly synthesized on a transparent conducting oxide glass by using a chemical bath deposition method coupled with a post-thermal treatment for catalysing the artificial photosynthesis under the framework of Z–scheme water splitting. Sb2S3 acts as the light absorber to mitigate poor visible light absorption and rGO serves as a electrically conductive layer to enhance the low quantum efficiency of WO3. An improved photocurrent density of 1.20mA/cm2 (at 1.23V vs. RHE) is obtained for the WO3/rGO/Sb2S3 electrode under AM 1.5G illumination, comparing to those for the WO3/Sb2S3 (0.27mA/cm2) and WO3 (0.05mA/cm2) electrodes. The negatively shifted onset potential of 0.35V vs. RHE is obtained when Sb2S3 and rGO are participated in the WO3 electrode, as compared with those of 0.42 and 0.45V vs. RHE for the WO3/Sb2S3 and WO3 electrodes, respectively. The improvements on the photoelectrochemical performances for the WO3/rGO/Sb2S3 electrode is primarily due to the broader light absorption and the enhanced electric conductivity. The results suggest that an efficient photocatalyst for water oxidation can be fabricated by carefully designing the composition of the nanocomposite with complementary optical and electrical preperties.

Structural, Raman and photoluminescence properties of Fe doped WO3 nanoplates with anti cancer and visible light driven photocatalytic activities

Doping is an effective way to tailor the properties of metal oxides for various applications. Herein, a series of Fe doped WO3 nanoplates have been synthesized using a facile co-precipitation method. The successful inclusion of Fe ions doping in the monoclinic structure of WO3 has been confirmed by XRD, EDX, FTIR, XPS and Raman spectroscopy. The optical band gap of WO3 has been facilely tuned with Fe doping which is attributed to positive shift in valance band. The photoluminescence (PL) spectroscopy studies revealed the presence of large number of defects in the crystal structure of WO3. Interestingly, it has been observed that photocatalytic activity of WO3 nanoplates could be significantly enhanced with Fe doping. This enhancement has been linked to the narrowing of optical band gap and lower electron-hole pair recombination rate due to the trapping of electrons by the crystal defects. This study provides a facile and effective method to prepared Fe doped WO3 nanoplates with enhanced visible light driven photocatalytic degradation of methyl red. Furthermore, the Fe doped WO3 nanoplates have also shown highly efficient anticancer activities against human liver (Hep-2) and breast (MCF-7) cancer cells. The percent cell viability of both cancer cells lines is significantly decreased (up to 50%) with Fe doping.

Highly selective transformation of ammonia nitrogen to N2 based on a novel solar-driven photoelectrocatalytic-chlorine radical reactions system

A highly selective method for transforming ammonia nitrogen to N2 was proposed, based on a novel solar-driven photoelectrocatalytic-chlorine radical reactions (PEC-chlorine) system. The PEC-chlorine system was facilitated by a visible light response WO3 nanoplate array (NPA) electrode in an ammonia solution containing chloride ions (Cl−). Under illumination, photoholes from WO3 promote the oxidation of Cl− to chlorine radical (Cl). This radical can selectively transform ammonia nitrogen to N2 (79.9%) and NO3− (19.2%), similar to the breakpoint chlorination reaction. The ammonia nitrogen removal efficiency increased from 10.6% (PEC without Cl−) to 99.9% with the PEC-chlorine system within 90 min operation, which can be attributed to the cyclic reactions between Cl−/Cl and the reaction intermediates (NH2, NHCl, etc.) that expand the degradation reactions from the surface of the electrodes to the whole solution system. Moreover, Cl is the main radical species contributing to the transformation of ammonia nitrogen to N2, which is confirmed by the tBuOH capture experiment. Compared to conventional breakpoint chlorination, the PEC-chlorine system is a more economical and efficient means for ammonia nitrogen degradation because of the fast removal rate, no additional chlorine cost, and its use of clean energy (since it is solar-driven).

Facilitated photoinduced electron storage and two-electron reduction of oxygen by reduced graphene oxide in rGO/TiO2/WO3 composites

A triple-component composite (GTW) comprising of reduced graphene oxide (rGO), TiO2 and WO3 was studied for the photoinduced electron storage and release. The composite was assembled through a one-step hydrothermal method using graphene oxide (GO), TiO2 and peroxotungstic acid as the precursors. The crystal structure and morphology of the composites were characterized by X-ray diffraction (XRD) and high resolution-transmission electron microscopy (HRTEM), respectively. Monolithic WO3 nanoplates and mixture phase TiO2 nanoparticles were dispersed over the surface of rGO nanosheets. The photocharge and discharge tests and the reduction of Cr(VI) and H2O2 by the stored electrons were carried out. Compared to the composite in the absence of rGO, the composite GTW displayed a ten times higher electron storage capacity (∼115C/g) and a much faster charging rate (8min less charging time to reach balanced EOC); and electrons stored in GTW achieved 17% more Cr(VI) reduction efficiency and 65% higher H2O2 reduction rate. Two electron reduction of oxygen by the stored photoinduced electrons was indicated by the generation of H2O2. The highest H2O2 concentration reached 39.6μM during the oxygen reduction for the composite with rGO, while no H2O2 was detected for the samples in the absence of rGO. Accompanied with the enhanced electrochemical oxygen reduction reaction and chemically adsorbed O2 on the composite, the critical roles of rGO as an electron mediator to facilitate interfacial charge transfer, as the electron container to improve electron storage capacity, and as a promoter for two-electron reduction of O2 were established.

Facile synthesis of Ni-doped WO3 nanoplate arrays for effective photoelectrochemical water splitting

A two-step hydrothermal process for preparing Ni-doped WO3 nanoplate arrays (NPAs) is developed, and the obtained samples were used as a photoanode to produce a highly active and stable electrocatalyst for photoelectrochemical (PEC) water splitting under visible light. The NPAs are formed as a single-phase solid solution with high purity. X-ray photoelectron spectroscopy measurement verifies the binding energy of W element is negatively shifted due to the substitution of W6+ by Ni2+ in the monoclinic lattice and thereby the formation of Ni-O-W bonds. Notably, the two-step 3 at% Ni-doped WO3 NPAs exhibits the highest PEC performance, compared with pure and one-step Ni-doped WO3 NPAs. At 1.0 V (vs Ag/AgCl), the current density of two-step 3 at% Ni-doped WO3 is 0.80 mA/cm2, which is about 1.74- and 2.35-fold of that of WO3 (0.46 mA/cm2) and one-step 3 at% Ni-doped WO3 (0.34 mA/cm2), respectively. The PEC performance of WO3 NPAs can be modified by Ni doping in a two-step hydrothermal process; both the changes of band gap and electrochemically active surface area (ECSA) are playing important roles on improving the activity of the WO3 NPAs photoanode.

2-D WO3 decorated with Pd for rapid gasochromic and electrical hydrogen sensing

The ultrathin two-dimensional (2D) nanomaterials display unique properties owing to their ultrahigh specific surface area and strong quantum confinement of electrons in two dimensions. In this work, we fabricated a rapid gasochromic and electrical hydrogen sensing system containing 2D WO3 and Pd nanoparticles. 2D WO3 nano-plates (NP) are synthesized using sol–gel method and Pd nanoparticles are coated on WO3 by green photochemical deposition method. The sensor is fabricated by dispersing the 2D WO3/Pd composite on filter paper. In presence of hydrogen gas, 2D WO3/Pd composite produces visible change in color from brown to dark blue. With the fabricated sensor, as low as 0.1% H2 gas in air at room temperature can be easily detected using electrical sensing scheme whereas for higher concentration from 1 to 100%, eye readable gasochromic scheme can be utilized. The use of 2D WO3 decreased the response time in great deal compared to WO3 nanoparticles indicating the advantage of 2D structure in fabricating rapid response H2 sensors. The proposed method is simple and can be easily employed to large scale fabrication system for commercial applications.

Synthesis of WO3/BiVO4 photoanode using a reaction of bismuth nitrate with peroxovanadate on WO3 film for efficient photoelectrocatalytic water splitting and organic pollutant degradation

In this work, we developed a novel, facile, cost-effective method based on a reaction of bismuth nitrate with peroxovanadate on WO3 nanoplate films to synthesize nanostructured WO3/BiVO4 photoanodes, which prevented the introduction of structural defects in the WO3 substrates that occurs in conventional deposition-annealing (DA) methods, for highly efficient photoelectrocatalytic (PEC) water splitting and degradation of organic pollutants. The method is also versatile, allowing dopants such as Mo to be easily incorporated into BiVO4 structures to improve the charge-transfer properties. Both the amount of BiVO4 and doping level can be tailored by modifying the preparation conditions. The PEC performance of the optimized WO3/BiVO4 photoanode was markedly improved with a photocurrent density of 2.83mAcm−2, which was 9.43 times that of a BiVO4 photoanode and 2.19 times that of a WO3 photoanode. A Mo-doped WO3/BiVO4 (WO3/Mo-BiVO4) photoanode exhibited a further enhanced photocurrent density of 3.78mAcm−2. Specifically, a cobalt–phosphate (Co–Pi) co-catalyst decorated WO3/Mo-BiVO4 photoanode showed the highest photocurrent density of 5.38mAcm−2, which is comparable to the values of reported WO3/BiVO4 photoanodes, with stoichiometric H2 (94.7μmolcm−2h−1) and O2 (46.5μmolcm−2h−1) evolution. Furthermore, the WO3/Mo-BiVO4 photoanode exhibited efficient performance for PEC degradation of organic pollutants with rate constants of 0.683, 0.385, and 1.05h−1 for tetracycline hydrochloride, phenol, and Congo red, respectively. Intensity-modulated photocurrent spectroscopy measurements indicated the WO3/BiVO4 photoanode should contain fewer nanostructural defects than the WO3/BiVO4 photoanode prepared using DA methods, possibly because the moderate preparation process avoids the harmful repeated heating-cooling process used in DA.

Enhanced photoelectrochemical activities for water oxidation and phenol degradation on WO3 nanoplates by transferring electrons and trapping holes

It is highly desired to improve the photoelectrochemical (PEC) performance of nanosized WO3 by artificially modulating the photogenerated electrons and holes simultaneously. Herein, WO3 nanoplates have been successfully prepared by a simple one-pot two-phase separated hydrolysis-solvothermal method, and then co-modified with RGO and phosphate acid successively by wet chemical processes. Subsequently, the as-prepared WO3-based nanoplates were immobilized on the conductive glasses to explore the PEC activities for both water oxidation to evolve O2 and phenol degradation. It is clearly demonstrated that the co-modified WO3 nanoplates exhibit significantly improved PEC activities compared with pristine WO3, especially for that with the amount-optimized modifiers by ca. 6-time enhancement. Mainly based on the evaluated hydroxyl radical amounts produced and the electrochemical impedance spectra, it is suggested that the improved PEC activities are attributed to the greatly enhanced photogenerated charge separation after chemically modification with RGO and phosphate groups to WO3, respectively by transferring electrons as the collectors and trapping holes via the formed negative field after phosphate disassociation. This work provides a feasible synthetic strategy to improve the photoactivities of nanosized WO3 for energy production and environmental remediation.

Crystal Phase and Size-Controlled Synthesis of Tungsten Trioxide Hydrate Nanoplates at Room Temperature: Enhanced Cr(VI) Photoreduction and Methylene Blue Adsorption Properties

Controlling the crystal phase of a material using solution-based method is a challenging task and has significant consequence to the material’s properties. Herein we report the phase and size-controlled synthesis of tungsten oxide hydrates at room temperature via a simple precipitation method. In the absence and presence of oxalic acid, orthorhombic WO3·H2O and monoclinic WO3·2H2O nanoplates of size in the range of 200–600 (thickness <50 nm) and 40–200 nm (thickness <20 nm) were respectively synthesized. Oxalic acid is found to play the central role in the phase transition due to its chelating nature that facilitates bonding of oxalate ions to tungsten cations leading to formation of WO3·2H2O. Upon annealing at 400 °C for 2 h under air, both WO3·H2O and WO3·2H2O nanoplates were converted to monoclinic WO3 nanoplates. These nanoplates were demonstrated to be highly efficient for the photocatalytic detoxification of toxic Cr(VI) in the acidic pH under the visible light irradiation. The best Cr(VI) reduction...

Controllable Synthesis of Hexagonal WO3 Nanoplates for Efficient Visible-Light-Driven Photocatalytic Oxygen Production.

Facilitating charge-carrier separation and transfer is fundamentally important to improve the photocatalytic performance of semiconductor materials. Herein, two-dimensional hexagonal WO3 nanoplates were synthesized by a two-step route: rapid evaporation and solid-phase sintering. The as-prepared WO3 exhibits an enhanced activity of photocatalytic water oxidation compared to bulk monoclinic WO3 . The electron dynamics analysis reveals that a more efficient charge-carrier separation in the former can be obtained, the origin of which can be attributed to an increased number of surface defects in hexagonal WO3 nanoplates. This work not only presents a novel and simple method to produce two-dimensional hexagonal WO3 nanoplates, but also demonstrates that surface defects and two-dimensional geometric structures can promote the charge separation, which may be extended to the design of other efficient photocatalysts.

Facile morphology control of WO3 nanostructure arrays with enhanced photoelectrochemical performance

A moderate hydrothermal approach has been developed to synthesize the perpendicular oriented WO3 nanostructure films. The morphology of the WO3 films could be easily controlled by adjusting the applied amount of HCl in the synthesis procedure. The effects of acidic conditions on morphological control were investigated in details, and the formation process of WO3 nanostructures varying from nanoplates to nanorods has been proposed. Both typical platelike and rodlike nanostructure arrays demonstrate better photoelectrochemical performance than other WO3 nanostructures. The WO3 nanoplate arrays showed a superior photocurrent density of about 1.0mA/cm2 at 1.6V vs. RHE, compared to 0.8mA/cm2 of the WO3 nanorod arrays. The increased photocurrent can be mainly attributed to the larger active surface area and more effective charge transfer. Approximately 55% improvement in photoelectrochemical catalytic efficiency was obtained by the WO3 nanoplates photoanode in comparison to the nanorods photoanode in a methyl orange degradation experiment. Such results demonstrate the importance of morphology optimization for improving the photoelectrochemical performance. And the method provides a facile and reasonable way for nanostructure design and morphology control of the photoelectrodes in photoelectrochemical devices.