Thickness control in electrophoretic deposition of WO3 nanofiber thin films for solar water splitting

•A novel method combining electrospinning and electrophoretic deposition was established for the creation of nanostructured semiconductor thin films.•The created thin films displayed a high chemical stability with a controllable thickness.•The PEC water splitting performance of the thin films was optimized by fine-tuning the thickness of the films.•A maximum photoconversion efficiency was achieved by 18μm nanofibrous thin films. Electrophoretic deposition (EPD) of ground electrospun WO3 nanofibers was applied to create photoanodes with controlled morphology for the application of photoelectrochemical (PEC) water splitting. The correlations between deposition parameters and film thicknesses were investigated with theoretical models to precisely control the morphology of the nanostructured porous thin film. The photoconversion efficiency was further optimized as a function of film thickness. A maximum photoconversion efficiency of 0.924% from electrospun WO3 nanofibers that EPD deposited on a substrate was achieved at a film thickness of 18μm.