Preparation of WO3 thin films by dip film-drawing for photoelectrochemical performance

Here we report the WO3 thin films on F-doped SnO2 conducting glass (FTO) substrates which were prepared by using dip film-drawing method. Dip film-drawing was a simple, convenient, economical method and in large-scale to prepare photoanodes for future applications. The FTO substrates were dipped in tungstic acid solution then film-drawn included 3, 6, 9, 12 and 15 times for prepared different thicknesses of WO3 thin film photoanodes. Then the photoanodes were employed as the electrodes in photoelectrochemical property measurements, which include scan linear sweep, repeated on/off illumination cycles, electrochemical impedance spectroscopy and incident photon to current conversion efficiency, respectively. The results showed that the WO3 thin films dipped 9 times with 175 nm thicknesses had the best photoelectrochemical performance of 0.067 mA·cm−2 at 1.23 V versus RHE.