Dual built-in spontaneous electric fields in an S-scheme heterojunction for enhanced photocatalytic H2O2 production

Abstract

Hydrogen peroxide production using solar energy is of great significance because it can ameliorate the energy crisis and environmental pollution. Bismuth vanadate (BiVO₄) is a promising photocatalyst, but the sluggish oxygen reduction reaction (ORR) limits its H₂O₂ production. In this study, a step-scheme (S-scheme) heterojunction with tightly coupled interfaces consisting of BiVO₄ and Cu₂O was prepared by a photodeposition method, and a MnOOH cocatalyst was modified on the BiVO₄ surface. The MnOOH/BiVO₄/Cu₂O photocatalyst exhibited an outstanding H₂O₂-generation performance of 112 μmol L⁻¹ h⁻¹ in pure water. The increased H₂O₂-evolution activity was ascribed to the formation of dual built-in spontaneous electric fields in the S-scheme heterojunction, which significantly promoted the dual directed charge transfer in the bulk phase of single-crystal BiVO₄ and the interface of the S-scheme heterojunction. This study offers valuable insights for constructing promising S-scheme photocatalysts for H₂O₂ generation.