WO3–TiO2 nanotubes modified with tin oxide as efficient and stable photocatalysts for photoelectrochemical water splitting

Abstract

One-step anodization combined with chemical bath deposition was used to prepare ternary hybrid SnO2@WO3–TiO2 photoelectrodes. Various analytical techniques such as X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectrometry and ultraviolet visible spectroscopy were applied to characterize the synthetic hybrids. Photoelectrochemical water splitting performance of new hybrid photoelectrodes significantly enhanced compared with bare WO3–TiO2 photoelectrodes, as shown by the investigation of the photoelectrochemical properties of electrodes. In comparison with bare WO3–TiO2 sample, WO3–TiO2 immersed in tin chloride for 60 min exhibited a maximum photocurrent density and better photoresponse under light illumination (about 6.5 times improvement in water splitting performance) according to the experimental results. Optimal contents of SnO2 in WO3–TiO2 sample act as mediators for trapping photoinduced electrons, minimize the recombination losses and enhance the transportation of photoinduced electrons in this ternary hybrid photoelectrodes. SnO2@WO3–TiO2 hybrid photoelectrodes were found to be highly stable and recyclable according to reusability experiments. The present work reports efficient, stable and highly active hybrid photocatalysts for hydrogen evolution without the application of precious metal co-catalysts.