A photoassisted hydrogen peroxide fuel cell using dual photoelectrodes under tandem illumination for electricity generation

Photoassisted hydrogen peroxide fuel cells are promising for converting chemical energy into electricity due to the high energy density and safe storage of H2O2. Despite this, the power density produced by H2O2 photocatalytic fuel cells is still low. Here, we demonstrate a membrane-free hydrogen peroxide photocatalytic cell using a W-BiVO4/V2O5 photoanode and a Cu2O/CuO photocathode under tandem lighting, which operates in an air-saturated NaHCO3/H2O2 aqueous solution (pH 8). H2O2 plays a dual role as an electron donor and acceptor, thus eliminating the need to use a membrane to separate the photoanode from the photocathode. Under simulated sunlight, the cell produces a short-circuit photocurrent density of 8.05 mA cm−2, an open-circuit potential of 0.41 V, and a power density of 0.84 mW cm−2. The power density of dual-photoelectrode cells is significantly higher than the single-photoelectrode cells due to the higher efficiency of charge separation and light absorption provided by the tandem cell. Finally, this simple cell design should be attractive for constructing efficient, green, and sustainable H2O2 photocatalytic fuel cells.