Preparation and water-splitting photocatalytic behavior of S-doped WO3

In the present work, sulfur (S)-doped tungsten oxide (WO3) was studied by photoelectrochemical and photocatalytic methods in order to evaluate the photoactivity and the possibility of its application in water splitting. S-doped WO3 powders were prepared by solid-state annealing method using thiourea as S precursor. The crystal structure, composition and morphology of pure and S-doped WO3 were compared using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The influence of doping concentration and annealing temperature on the properties of S-doped WO3 powders and their photocatalytic activities under both ultraviolet (UV) and visible light (VIS) irradiation compared with WO3 were investigated. The results indicate that sulfur can be doped successfully into WO3 and the S-doped WO3 powder annealed at 500 °C exhibited the highest photocatalytic activity under both UV and visible light irradiation. The highest average oxygen evolution rate of S-doped WO3 under UV (99.9 μmol L−1 g−1 h−1) and visible light (76.7 μmol L−1 g−1 h−1) irradiation is 1.25 and 1.57 times the value of that of undoped WO3, respectively.