Solar-Driven One-Compartment Hydrogen Peroxide-Photofuel Cell Using Bismuth Vanadate Photoanode

One-compartment H2O2-photofuel cells using monoclinic scheelite BiVO4 film deposited on fluorine-doped tin oxide (ms-BiVO4/FTO) as the photoanode, Prussian blue film-coated FTO cathode, and deaerated aqueous electrolyte solution of 0.1 M NaClO4 and 0.1 M H2O2 were constructed. Mesoporous TiO2 photoanode cells with the same cathode and electrolyte solution were also prepared for comparison. The ms-BiVO4/FTO photoanode was prepared by a two-step route consisting of spin coating of a precursor solution on FTO and subsequent heating at 500 °C in the air. The thickness of the ms-BiVO4 film was controlled in the range from 50 to 500 nm by the number of the spin-coating times. There is an optimum thickness of the ms-BiVO4 film in the cell performances under illumination of simulated sunlight (AM 1.5, 100 mW cm–2, 1 sun). Under the optimum conditions, the ms-BiVO4/FTO photoanode cell provides a short-circuit current (Jsc) = 0.81 mA cm–2 and an open-circuit voltage (Voc) = 0.61 V, far surpassing the values of Jsc = 0.01 mA cm–2 and Voc = 0.31 V for the conventional mesoporous TiO2 photoanode cell. The striking cell performance is ascribable to the high visible-light activity of ms-BiVO4 for H2O2 oxidation and its low thermocatalytic activity for the decomposition.