Bare WO3 Research Articles

Construction of a sunflower-like S-scheme WO3/ZnIn2S4 heterojunction with spatial charge transfer for enhanced photocatalytic CO2 reduction

The construction of step-scheme (S-scheme) heterojunction has become an effective strategy for enhancing photocatalytic CO2 reduction. In this study, a sunflower-like S-scheme WO3/ZnIn2S4 heterostructure is fabricated through the in-situ growth of ZnIn2S4 nanosheets on WO3 hollow sphere, aimed at improving selective CO2 reduction. The constructed embedding configuration, featuring a WO3 hollow sphere core and an outer layer of ZnIn2S4 nanosheet, increases the contact interface and establishes a significant built-in electric field, thereby promoting the migration and separation of photogenerated carriers. The confined internal cavity of the three-dimensional (3D) sunflower-like architecture aids in limiting the free diffusion of CO2, and enriching CO2 molecules at the surface of the photocatalyst, consequently enhancing reaction kinetics.Moreover, S vacancies on ZnIn2S4 nanosheets promote the chemisorption and activation of CO2. As a result, the optimized evolution rates for CH4 and CO of 58.7μmol g–1h−1 and 51.3μmol g–1h−1, respectively, are achieved for WO3/ZnIn2S4 heterojunction. The corresponding electron selectivity for CH4 reaches 82.1 %, which is 13 and 1.5 times higher than those of bare WO3 and ZnIn2S4, respectively. This provides valuable insights into the design of muti-functionalized S-scheme heterojunction photocatalysts.

Unveiling Morphology-Structure Interplay on Hydrothermal WO3 Nanoplatelets for Photoelectrochemical Solar Water Splitting.

Photoelectrochemical (PEC) water splitting offers a sustainable route for hydrogen production, leveraging noncritical semiconductor materials. This study introduces a seed layer-free hydrothermal synthesis approach for semiconductor photoanodes based on tungsten trioxide (WO3) nanoplatelets. Aiming to boost the efficiency of photoelectrochemical water splitting through optimization of the synthesis parameters of bare WO3, focusing on temperature, time, and layer thickness, we systematically explored their effects on the morphological, structural, and optical characteristics of WO3 photoanodes. Combining a low-temperature regime (90 °C for 12 h) with a multilayer strategy (up to six-layers) resulted in significant improvements in photocurrent. Particularly, the five-layer sample exhibited a remarkable increase of over 70% compared to the single-layer photoanode. Morphological aspects, particularly the fractal dimension of nanoplatelets and the emergence of the (220) crystalline orientation, usually neglected, were found to play pivotal roles in modulating the PEC response. Rietveld refinement of X-ray diffraction patterns further underscored the importance of crystallographic facets, volume unit cell expansion, and microstrain in influencing photocurrent outcomes. Furthermore, we adapted the Mott-Schottky equation to incorporate the fractal dimension reflecting the nanostructures' nature, usually set to a planar interface. Our findings highlight the interchange between nanoplatelet morphology and structural parameters in determining the PEC efficiency of WO3 photoanodes.

Nickel-doped and surface fluorinated tungsten trioxide photoanode with enhanced photoelectrochemical water oxidation

To improve the slow charge transfer and high electron-hole recombination rate of tungsten trioxide (WO3), a nickel-doped and surface fluorinated WO3 photoanode is proposed. Compared with the unmodified and one-step modified WO3 photoanodes, the co-modified F/Ni-WO3 with two steps exhibits superior photoelectrochemical (PEC) performance with a significantly high photocurrent density of 1.03 mA/cm2 compared to 0.51 mA/cm2 of bare WO3 at 1.23 V vs. RHE. Ni doping can accelerate the kinetics of water oxidation and extend the light absorption range of the WO3 photoanode, while surface fluorination can enhance the surface electronegativity and hydrophilicity of the WO3 photoanode. The synergistic influence of the Ni doping and surface fluorination results in a lower carrier transport impedance, higher charge separation efficiency and larger electrochemically active surface of the WO3 photoanode which eventually contribute to the enhanced PEC performance for water oxidation.

Fabrication of WO3/Co3O4 nanorods as a p-n heterojunction photoanode for efficient photoelectrochemical oxygen evolution

Developing efficient photoelectrocatalysts is seen as a promising method for generating hydrogen through photoelectrochemical (PEC) water splitting. In this study, the WO3/Co3O4 heterojunction was fabricated on FTO substrates, serving as an effective photoanode for PEC water splitting. The p-type Co3O4 nanoparticles were loaded onto n-type WO₃ nanorods to create a p-n heterojunction, thereby reducing charge recombination due to the internal electric field at the heterointerface. Under LED illumination (∼80 mW/cm2), the photocurrent density of the WO3/Co3O4 photoanode reached 161.1 μA/cm2 at 1.23 V vs. RHE, which is 2.3 times higher than that of bare WO3 photoanode. The results show that loading Co3O4 onto WO3 nanorods significantly increased the absorption of visible light, boosted charge carrier density, and enhanced surface reaction kinetics. This work indicates the construction of p-n heterojunction photoanodes for achieving effective photoelectrochemical performance.

Visible light-induced photocatalytic degradation of tetrabromobisphenol A on platinized tungsten oxide

In this study, we investigated the degradation of the flame retardant tetrabromobisphenol A (TBBPA) using platinized tungsten oxide (Pt/WO3), synthesized via a simple photodeposition method, under visible light. The results of degradation experiments show a significant enhancement in TBBPA degradation upon surface platinization of WO3, with the degradation rate increasing by 13.4 times compared to bare WO3. The presence of Pt on the WO3 surface stores conduction band electrons, which facilitates the two-electron reduction of oxygen and enhances the production of valence band holes (hVB+) and hydroxyl radicals (●OH). Both hVB+ and ●OH are significantly involved in the degradation of TBBPA in the visible light-irradiated Pt/WO3 system. This was verified through fluorescence spectroscopy employing coumarin as a chemical probe and oxidizing species-quenching experiments. The analysis of degradation products and their toxicity assessment demonstrate that the toxicity of TBBPA-contaminated water is significantly reduced after Pt/WO3 photocatalysis. The degradation rate of TBBPA increased with increasing Pt/WO3 dosage, reached an optimum at a Pt content of 0.5 wt%, but decreased with increasing TBBPA concentration. The decrease in degradation efficiency of Pt/WO3 was minor, both in the presence of various anions and after repeated use. This study proposes that Pt/WO3 is a viable photocatalyst for the degradation of TBBPA in water under visible light.

Efficient WO3 Nanoplate Arrays Photoanode Modified by ZnO Nanosheets for Enhanced Charge Separation and Transfer to Promote Photoelectrochemical Performances

AbstractA key factor in the photoelectrochemical (PEC) performance of photoelectrodes is the efficient separation and transfer of photogenerated charges. Herein, a novel photoanode comprising three‐dimensional (3D) WO3 nanoplate@ZnO nanosheet hierarchical type‐II heterojunction arrays (3D WO3@ZnO HHAs) is designed and constructed via modification of the WO3 nanoplate arrays with ZnO nanosheets. The synthesized materials are characterized viaX‐ray diffraction (XRD), ultraviolet and visible spectrophotometry (UV–vis), scanning electon microscopy (SEM), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS) analyses. Photoelectrochemical (PEC) test results reveal that the synthesized 3D WO3@ZnO HHAs photoanode exhibits reduced charge transfer resistance, improved electron‐hole pair life, and enhanced photocurrent density (≈4.5 times increase in comparison to that of the bare WO3). The increased light capture and high surface area in contact with the electrolyte as well as the enhanced charge transfer through the synergy between morphology and band structures may be responsible for the improved PEC characteristics.

Minimizing CO2 emissions by photocatalytic CO2 reduction to CH3OH over Li2MnO3/WO3 heterostructures under visible illumination

Photocatalytic CO2 reduction to valuable fuels has proved to be a favourable process to produce renewable energy and reduce CO2 emissions, which mostly depends on designing effective photocatalysts with the rapid separation rate of charge carriers. In this contribution, mesoporous n-n heterojunction Li2MnO3/WO3 nanocomposites were designed via a simplistic sol-gel process for CO2 reduction utilizing visible illumination (λ > 420 nm). XRD and TEM measurements confirmed the synthesized Li2MnO3/WO3 nanocomposite is a monoclinic structure, and its particle size is 25 ± 5 nm. The obtained Li2MnO3/WO3 exhibited narrower bandgap energy (1.74 eV), larger surface area (212 m2g−1), exceedingly visible absorbing, and lower recombination of electron and hole. The yield of CH3OH was determined about 198, 871, 1140, 1550 and 1570 mmolg−1 for bare WO3 and 5%, 10%, 15% and 20% Li2MnO3/WO3 nanocomposites, respectively. These results evidenced that the 15% Li2MnO3/WO3 photocatalyst exhibited the best reduction ability compared to other nanocomposites. The CO2 reduction over 15% Li2MnO3/WO3 photocatalyst achieved a maximal CO2 conversion with the substantially boosted CH3OH, i.e., 1550 mmolg−1 after 9 h, which was enhanced 7.8 folds great than of WO3 NPs. Mesoporous Li2MnO3/WO3 nanocomposites, in comparison with bare WO3 NPs, created more active sites for facilitating CO2 and had a specific electric field to more effectively separate charge carriers. The Li2MnO3/WO3 photocatalyst has superior photostability during the continuous reduction of CO2 for 45 h with no remarkable decrease. The possible direct S-scheme mechanism for electron transfer over Li2MnO3/WO3 photocatalyst with the enhanced CO2 reduction ability was discussed. The present work demonstrates an avenue for building highly effective heterostructure photocatalysts in solar-energy-induced potential applications.

Ultrasonic processing of WO3 nanosheets integrated Ti3C2 MXene 2D-2D based heterojunctions with synergistic effects for enhanced water splitting and environmental remediation

This article describes a straightforward chemical procedure that involves hydrothermal and ultrasonic treatments to create a new 2D/2D ultrathin WO3/Ti3C2 heterojunctions. The features of the fabricated heterojunctions were characterized and examined by field emission electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), optical absorption spectroscopy (UV–Vis). By photodegrading an organic dye under the influence of visible light, the photocatalytic degradation capabilities of the heterojunctions were also investigated. The performance of WO3/Ti3C2 was superior to that of bare WO3, with a removal rate of 94% and a kinetic rate constant (k) that was approximately 3 times that of WO3. The creation of 2D/2D heterojunction was observed to encourage the spatial charge separation and increase the surface reactive sites, to result with the increased photocatalytic activity in WO3/Ti3C2 heterojunction. The photocurrent values discovered through photoelectrochemical studies further indicated Ti3C2′s active function in enhancing water-splitting performance. The impedance analysis examined by an electrochemical method revealed that heterojunctions might be helpful in accelerating the migration of charges quickly to get the outcomes seen.

Interface Oxygen Vacancy‐Enhanced Co3O4/WO3 Nanorod Heterojunction for Sub‐ppm Level Detection of NOx

Herein, a cobalt oxide/tungsten oxide (Co3O4/WO3) p–n heterojunction for NOx detection is developed and optimized. Field‐emission scanning electron microscopy shows that the WO3 nanorods are embellished with Co3O4 nanostructure. X‐ray photoelectron spectroscopy reveals the presence of oxygen vacancy on the Co3O4 coupled with WO3 heterojunction. Compared to bare WO3 and pure Co3O4, the Co3O4/WO3 heterojunction sensor shows significant sensitivity to NOx at 200 °C. The sensor exhibits higher linearity from 0.4 to 10 ppm of NOx, with a sensing response of 4.4–93%. The NOx sensitivity of the Co3O4/WO3 heterojunction sensor is ninefold higher than that of the pure WO3 sensor. Even in a high humidity (84%) environment, the Co3O4/WO3 heterojunction sensor demonstrates high NOx sensitivity. The sensor maintains remarkable stability measured for up to 4 weeks. The possible NOx sensing mechanism of the Co3O4/WO3 heterojunction is additionally discussed.

Construction of cobalt ferrite nanoparticles anchored on mesoporous WO3 for accelerated photoreduction of Cr(VI)

In this contribution, the synthesis of mesoporous WO3 nanoparticles (NPs) by the utilization of cationic surfactant by a facile hydrothermal approach was performed. A series of heterojunction CoFe2O4/WO3 photocatalysts were synthesized by impregnation and calcination for Cr(VI) photoreduction during visible light exposure. The TEM images of 12%CoFe2O4/WO3 nanocomposite revealed a beans-like structure with highly crystalline particles with a length of 200 nm and a diameter of 30 nm. The obtained CoFe2O4/WO3 nanocomposites indicated the occurrence of mesostructures with a high surface area. With an optimized 12% CoFe2O4/WO3 nanocomposite, 100% of Cr(VI) photoreduction was achieved after 45 min illumination, which was enhanced 2.85 folds greater than bare WO3 NPs. The reaction rate constant of 12% CoFe2O4/WO3 nanocomposite amounted to about 0.0947 min-1, which was fostered 6.1 times larger than that of bare WO3 (0.0155 min-1). The enhanced Cr(VI) removal efficiency can be ascribed to the design of heterostructures CoFe2O4/WO3, which functionally promoted the mobility and separation of photoinduced charge carriers. The increased surface area and the extended visible light region of CoFe2O4/WO3 nanocomposites contributed to the enhancement of the Cr(VI) reduction efficiency. Accordingly, a possible mechanism for Cr(VI) photoreduction over heterojunction CoFe2O4/WO3 photocatalyst was illustrated. The 12% CoFe2O4/WO3 nanocomposite exhibited 94% Cr(VI) reduction ability after five cycles with high stability. The results showed that the obtained p-n heterojunctions CoFe2O4/WO3 nanocomposites have considerable potential in Cr(VI) removal from wastewater.

BiVO4 nanoparticle-modified WO3 nanosheet arrays via a stepwise spin-coating process for improved photoelectrochemical performance

A photoelectrode of WO3 nanosheet@BiVO4 nanoparticle heterostructured arrays (WO3@BiVO4 HAs) on a transparent F-doped SnO2 glass substrate was designed and manufactured using a hydrothermal and subsequent stepwise spin-coating process. The size and the distribution of BiVO4 nanoparticles on the surface of WO3 NSs can be regulated by the number of the stepwise spin-coating cycles. SEM, UV–vis, TEM, and XPS were used to characterize the obtained samples. The PEC performance can be optimized by controlling the number of the stepwise spin-coating cycles. The results of the photoelectrochemical (PEC) measurements display that the WO3@BiVO4 HA photoelectrodes obtained at 8 cycles showed a higher photocurrent density (about 3.5 times higher than that of the bare WO3 nanosheet array (NSA) photoelectrodes), lower charge transfer resistance (from 4019 to 904 Ω cm2), improved electron-hole pair life (from 1 to 50.36 ms), and higher monochromatic photon-to-electron conversion efficiency (from 9 to 38.8%). The remarkable enhancement of the PEC performance may be due to the enhanced light capture, the large contact area with the electrolyte, and the improvement of charge transfer and separation by synergizing the band structure, morphology of photoelectrode, and the reasonable modification of BiVO4 nanoparticles using a stepwise spin-coating process.

Multifunctional dual Z-scheme heterostructured Sm2O3-WO3-La2O3 nanocomposite: Enhanced electrochemical, photocatalytic, and antibacterial properties

In this study, heterostructured dual Z-scheme Sm2O3-WO3-La2O3 nanocomposite (NC) and bare Sm2O3, WO3, and La2O3 nanostructured (NSs) were prepared using a co-precipitation approach. The comparative electrochemical, photocatalytic, and antimicrobial properties of NC and NSs were studied. The XRD spectrum exhibits the formation of bare NSs and NC having cubic-Sm2O3, monoclinic-WO3, and hexagonal-La2O3 phases. FESEM results showed mesoporous morphology of NC. The higher electrical conductivity 261.33 mho-cm−1 and lower optical energy bandgap 2.55 eV were obtained for NC. The photodegradation tests exhibited that NC photocatalyst has degraded 99% (methylene blue), 96% (Methyl orange), 99% (safranin-O), 48% (p-nitroaniline), and 98% (methyl red) dyes pollutants in 40 min sunlight radiation and showed strong inhibition activity against E. coli, K. pneumoniae, S. aureus, P. Vulgaris, and P. aeruginosa bacterial strains with zones of inhibition (ZOI) 31 mm, 30 mm, 30 mm, 28 mm, and 31 mm, respectively. Electrochemical studies revealed the excellent capacitive characteristics of NC with a specific capacitance 532F/g at a scan rate 5 mV/s, energy density 48.0278 W h Kg−1, and power density 0.3782 KW Kg−1 at 0.006 A/cm2 current density. Furthermore, the present study revealed a novel composition for environmental remediation and energy storage applications.

Visible photocatalytic hydrogen production from CH3OH over CuO/WO3: The effect of electron transfer behavior of the adsorbed CH3OH

Tungsten oxide (WO3) and copper oxide (CuO)/WO3 samples were prepared, and their photocatalytic performance towards the reforming of CH3OH to hydrogen was compared under visible light irradiation at ambient temperature. CuO/WO3 had an approximately 64 times higher hydrogen production activity than bare WO3. CH3OH accepted electrons from WO3 but provided electrons to CuO/WO3 thin films, indicating that the hydrogen production from CH3OH was related to electron transfer during CH3OH adsorption. The characterization results showed that Cu exists in a mixed-valence state in CuO/WO3, which activated the lattice oxygen of WO3 to form the corresponding interfacial oxygen vacancies (VOs). The oxygen atom of CH3OH was fixed at VOs sites, which facilitated the cleavage of the OH bond. Cu2+ sites favored the cleavage of the CH bond in CH3OH because VOs fixed the oxygen atom. Then, the production of hydrogen via these two processes was accompanied by the transfer of electrons from CH3OH to Cu2+ sites at the interface. This was followed by hydrogen production after accepting photogenerated electrons from WO3. The reason for the low catalytic activity of the WO3 support was that it contained no VOs nor Cu2+ sites to oxidize CH3OH to produce more protons. This study provides an approach to improve catalysts used for the photocatalytic reformation of methanol.

Au/WO3 nanocomposite based photocatalyst for enhanced solar photocatalytic activity

Gold nanoparticles (AuNPs) were loaded on tungsten trioxide (WO3) platelet-like support by a simple impregnation deposition technique at room temperature. Textural, structural and electrical properties were characterized for the as prepared material. The SEM/TEM investigations revealed that formed AuNPs possess a mean diameter of 7 nm and a preferential deposition on the (0 2 0) planes of the orthorhombic WO3 structure. The photodegradation efficiency was evaluated under solar light irradiation using dye pollutant solutions such as rhodamine B (RhB), methylene blue (MB) and methyl orange (MO). According to the affinity between the organic pollutant and the catalyst support, the adsorption/photocatalysis yield and the degradation pathway differ. It was observed that MB created strong electrostatic bonds with the catalyst support while RhB and MO did not adsorb on Au/WO3 hybrid sample. Photocatalytic tests revealed a high performance of Au/WO3 photocatalyst with a complete degradation in 90 min for a cationic dye mainly due to the oxidation by the hydroxyl reactive oxidant species. LC-MS analyses confirmed a higher decomposition with gold compared to bare WO3 on the MB pollutant and results permit to propose a degradation pathway.

WO3/Ag2S type-II hierarchical heterojunction for improved charge carrier separation and photoelectrochemical water splitting performance

In the present work, WO3/Ag2S heterojunction was fabricated to achieve an improved photoelectrochemical (PEC) water splitting performance. To prepare the working electrodes, a two-step method was adopted which includes, a thin film of WO3 deposited using DC sputtering and well-separated Ag2S nanorods fabricated by glancing angle deposition. The PEC response was studied for bare WO3, Ag2S, and WO3/Ag2S heterojunction. The as-prepared WO3/Ag2S heterojunction samples revealed higher absorption as well as a higher photocurrent density of 2.40 mA/cm2 (at 1 V Ag/AgCl) as compared to bare WO3 thin film (0.34 mA/cm2). The enhancement in the photocurrent density of WO3/Ag2S electrodes could be ascribed to the formation of the type-II heterojunction between WO3 and Ag2S which effectively separates and transfers the charge carriers at the interface. In addition, increased trapping of light due to vertically tilted Ag2S nanorods structures results in effective absorption of light. Furthermore, electrochemical impedance spectra measurements showed that WO3/Ag2S samples have lower charge transfer resistance at the semiconductor electrolyte interface with high flat band potential. This work provides a deeper insight into the role of the interface formed between WO3 and Ag2S for the photoelectrochemical water splitting response.

Novel visible light driven crystalline carbon nitride-tungsten oxide composites for photodegradation of phenol

A series of new tungsten oxide modified heptazine-based crystalline carbon nitride (CCN-(x)WO3) composite materials with different W loading amount (x = 0.1–1.0 wt%) were successfully synthesized via modified ionothermal and wet impregnation methods. The XRD and FTIR analyses results of confirmed the presence of highly ordered heptazine unit and CN terminal of CCN framework in the synthesized CCN-WO3 composites. The introduction of more WO3 has shifted the optical property of the CCN-WO3 composites to higher wavelength. The TEM and FESEM analyses on CCN-WO3 revealed the presence of WO3 in needle like shape decorated on the surface of CCN. Among, material CCN-(0.25)WO3 has exhibited the highest photocatalytic degradation of phenol which was 1.5 and 15 times higher than bare CCN and WO3 within 6 h exposure of visible light, respectively. The synergistic effect by co-existence of CCN and WO3 has induced the formation of highly ordered hepatize subunit of CCN, broadening light absorption in visible region, high surface area, low electron-hole recombination and high electron-transfer rate constant, which in turn enhanced the photocatalytic performance of CCN-WO3. The radical scavenger studies confirmed that the synthesized CCN-WO3 composite was an excellent visible light driven photocatalyst for phenol degradation.

Study on the role of rGO in enhancing the electrochromic performance of WO3 film

In the present work, an improved electrochromic thin film has been developed with faster color switching time on incorporation of rGO in WO3 film. Here, pristine WO3 and rGO-WO3 (rGO concentration varying from 1–7wt%) based nanocomposite electrochromic films were fabricated on ITO coated glass substrate, by utilizing a facile sol-gel dip-coating technique. Detailed structural and morphological analyses of the films were carried out using XRD, FESEM, TEM and Raman Spectroscopy. Assimilating the electrochromic properties of all the films showed that, 5wt% rGO incorporated WO3 film gave a maximized electrochemical performance with minimum degradation in optical transmittance. The film also exhibited an optical modulation of ∼ 50% and a better switching response having coloration time (tc) ~ 5.3 s and bleaching time (tb) ~ 6.2 s as compared to the pristine film (tc~ 9.6 s, tb ~ 10.4 s). Incorporation of rGO also resulted in an enhancement of coloration efficiency from ∼ 81 to ∼ 386 cm2/C. The Electrochemical Impedance Spectroscopy (EIS) analysis of pristine and rGO loaded film clearly revealed better charge transfer on incorporation of rGO. The cyclic stability study exhibited ∼ 25% deterioration in optical transparency of the bare WO3 film which was < 10% for the rGO impregnated film. An ex-situ XRD analysis demonstrated that a crystal dislocation occurring in pristine WO3 sample was responsible for the same.

Photocatalytic selective oxidation of aromatic alcohols coupled with hydrogen evolution over CdS/WO3 composites

Simultaneously utilizing photogenerated electrons and holes to convert renewable biomass and its derivatives into corresponding value-added products and hydrogen (H2) is a promising strategy to deal with the energy and environmental crisis. Herein, we report a facile hydrothermal method to construct a direct Z-scheme CdS/WO3 binary composite for photocatalytic coupling redox reaction, simultaneously producing H2 and selectively converting aromatic alcohols into aromatic aldehydes in one pot. Compared with bare CdS and WO3, the CdS/WO3 binary composite exhibits significantly enhanced performance for this photocatalytic coupled redox reaction, which is ascribed to the extended light harvesting range, efficient charge carrier separation rate and optimized redox capability of CdS/WO3 composite. Furthermore, the feasibility of converting various aromatic alcohols to corresponding aldehydes coupled with H2 evolution on the CdS/WO3 photocatalyst is proved and a reasonable reaction mechanism is proposed. It is hoped that this work can provide a new insight into the construction of direct Z-scheme photocatalysts to effectively utilize the photogenerated electrons and holes for photocatalytic coupled redox reaction.

Highly efficient and stable WO3/MoS2-MoOX photoanode for photoelectrochemical hydrogen production; a collaborative approach of facet engineering and P-N junction

In this paper, we demonstrate a facet-controlled WO3 nanoplate heterojunction with MoS2-MoOX nanosheets that produces extremely efficient and stable photoelectrochemical H2 production. Furthermore, the effect of the hydrothermal process time (t = 1, 2, and 3 h) for the WO3 photoanode and drop-casting process of the MoS2 nanosheets (4, 8, and 12 times) to obtain the optimum amount of the material (MoS2 and MoOX) for the PEC performance of the WO3/#n-MoS2 and WO3/#n-MoS2-MoOX (n = 4, 8, and 12) photoanodes were investigated. The photocurrent density of the WO3/MoS2-MoOX photoanode was approximately 2.15 mA.cm−2 at 1.23 V vs. RHE, which was 8.6 and 1.2 times higher compare to pure WO3 and WO3/MoS2 photoelectrodes, respectively. The incident photon current efficiency of the WO3/MoS2-MoOX photoanode is approximately 27.5%, which is a significant improvement over that of bare WO3. The WO3/MoS2-MoOX photoanode produced 54.5 μmolcm−2 of H2 and 25.8 μmolcm−2 of O2 after 2 h, at 1.23 V vs. RHE and 100 mWcm−2. The electrochemical kinetics clearly showed that water oxidation reaction was accelerated. The WO3/MoS2-MoOX photoanode, which was developed through simple and facial drop casting of MoS2 nanosheets onto WO3 photoanode, resulted in effective photogenerated carrier separation and enhanced oxygen evolution reactions on the anode surface.

Excellent photocatalytic degradation and antibiosis of WO3/Fe2O3 heterojunction

The extensive light absorption, enhanced separation of photoinduced carriers and convenience of recycling are crucial for the practical application of WO3 photocatalyst in the dye degradation and the antibiosis activity. Hence, in this work, we synthesize WO3/Fe2O3 composite film on FTO conductive substrate through hydrothermal method. The higher degradation rate for methylene blue (MB) is achieved by WO3/Fe2O3 composite film, and the value of C/C0 is 0.28 which is lower than that of 0.58 for bare WO3 with the irradiation for 4 h. Moreover, the sterilization rate of 28.99% is achieved for WO3-based film with the deposition of Fe2O3 for 3 h. The deeper measurements indicate that the enhanced photocatalytic performances are attributed to the expand light absorption, improved transfer kinetics and separation efficiency of photoinduced carriers with the formation of heterojunction. This work establishes the effective template for WO3-based film with the enhanced photocatalytic prosperities for dye degradation and antibiosis.