Selective and Efficient Gd-Doped BiVO4 Photoanode for Two-Electron Water Oxidation to H2O2

Photoelectrochemical oxidation of water presents a pathway for sustainable production of hydrogen peroxide (H 2 O 2 ). Two-electron water oxidation toward H 2 O 2, however, competes with the popular four-electron process to form oxygen and one-electron water oxidation to form OH radical. To date, bismuth vanadate (BiVO 4 ) has been shown to exhibit promising selectivity toward H 2 O 2, especially under illumination, but it suffers from high overpotential and notoriously poor stability. Herein, using density functional theory calculations, we predict that doping BiVO 4 with optimal concentrations of gadolinium (Gd) not only enhances its activity for H 2 O 2 production but also improves its stability. Experimentally, we demonstrate that intermediate amounts of Gd doping (6–12%) reduce the onset potential of BiVO 4 for H 2 O 2 production by ∼110 mV while achieving a Faradaic efficiency of ∼…