Efficient oxidative hydrogen peroxide production and accumulation in photoelectrochemical water splitting using a tungsten trioxide/bismuth vanadate photoanode

Abstract

An aqueous solution of hydrogen carbonate (HCO₃⁻) facilitated oxidative hydrogen peroxide (H₂O₂) production from water on a WO₃/BiVO₄ photoanode with the simultaneous production of hydrogen (H₂) on a Pt cathode even at an applied voltage far lower than the theoretical electrolysis voltage (+1.77 V vs. RHE) under simulated solar light. The unprecedentedly efficient simultaneous production and accumulation of H₂O₂ and H₂ was achieved in 2.0 M KHCO₃ at low temperature, and the maximum selectivity, accumulated concentration and turnover number (TON) of H₂O₂ generated reached ca. 54%, more than 2 mM and 108, respectively.