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

Recent advances in vacuum- and laser-based fabrication processes for solar water-splitting cells

“…This involved depositing a WO 3 thin film via DC sputtering and forming wellseparated Ag 2 S nanorods using MS-GLAD. 57 The WO 3 /Ag 2 S heterojunction showed superior light absorption and a higher photocurrent density of 2.40 mA cm À2 (at 1.0 V Ag/AgCl) than the bare WO 3 thin film (0.34 mA cm À2 ). The vertically tilted Ag 2 S nanorods enhanced light trapping, and electrochemical impedance spectroscopy indicated low charge-transfer resistance at the semiconductor-electrolyte interface, reflecting a high flat band potential.…”

Gradient oxygen doping triggered a microscale built-in electric field in CdIn2S4 for photoelectrochemical water splitting

“…Photoelectrochemical (PEC) water splitting is regarded as a promising strategy for addressing the energy crisis and environmental challenges 1–5 Rational design of photoanodes with high photoelectric activity is of great importance to achieve the ideal conversional efficient. 6,7 Most of the reported photoanodes in PEC cells are based on metal oxides, including WO 3 , 8 ZnO, 9 In 2 O 3 , 10 Fe 2 O 3 11,12 and BiVO 4 , 13 etc . However, the valence band (VB) is occupied by the O-2p orbital, resulting in an expanded bandgap and limiting its response to only UV light.…”

High-performance photocatalytic reduction of Cr(VI) using a retrievable Fe-doped WO3/SiO2 heterostructure

“…Various types of controlled WO 3 morphologies incorporating single transition metal dopants or two metals as co-dopants can be obtained via different synthetic techniques—these semiconductors (offering different band gap energies) can be combined with supporting materials, such as mesoporous SiO 2 nanoparticles (NPs), to form heterostructures that raised the light-harvesting ability of the photocatalyst [ 10 ]. In the past decade, several researchers have reported on the superior performance of metal-ion-doped WO 3 photocatalysts and (material-supported) W-/metal oxide-based heterostructures in the photocatalytic degradation of wastewater pollutants, including various organic dyes [ 11 – 14 ] and toxic Cr 6+ contaminants, [ 15 – 18 ], hydrogen production [ 19 , 20 ], and enhanced gas-sensing performance [ 21 ]. Considering the above-mentioned literature sources and the advantages and drawbacks of photocatalysts based on WO 3 , metal doped WO 3 , and heterojunctions with SiO 2 , this work aimed to improve upon the WO 3 photocatalyst, implementing heterojunction modifications of the WO 3 semiconductor by blending with SiO 2 NPs and further doping with Fe 3+ ions to improve the photocatalytic reduction efficiency of Cr 6+ .…”