Facile growth of 1-D nanowire-based WO3 thin films with enhanced photoelectrochemical performance

A flame reactor embedded with a constant tungsten wire feeding system to prepare one-dimensional (1-D) nanostructured tungsten oxide thin film for photoelectrochemical (PEC) water splitting was developed. Photoactive vertically-aligned nanowire-based WO3 thin films could be obtained with a controlled thickness via a flame vapor deposition process followed by air-annealing. The PEC performances of WO3 photoelectrodes for different thin film thicknesses were examined. The optimum thickness of WO3 thin film was found to be about 7.2 μm for PEC water splitting based on incident photon-to-current efficiency plots and I–V curves. The WO3 prepared with optimum thickness showed better PEC performance than those of recently reported nanostructured WO3 photoanodes. © 2015 American Institute of Chemical Engineers AIChE J, 62: 421–428, 2016