S-scheme g-C3N4/BiOBr heterojunction for efficient photocatalytic H2O2 production

Abstract

The establishment of S-scheme heterojunctions has arisen as a promising strategy for the advancement of efficient photocatalytic systems with superior charge separation and redox ability, specifically for H₂O₂ production. In this investigation, an innovative 2D/2D g-C₃N₄/BiOBr S-scheme heterojunction was meticulously engineered through an in situ growth methodology. The synthetic composites exhibit boosted H₂O₂ production activity, achieving a peak generation rate of 392 μmol L^–1 h^–1, approximately 8.7-fold and 2.1-fold increase over the pristine BiOBr and g-C₃N₄, respectively. Such a superior activity should be attributed to the highly efficient charge separation and migration mechanisms, along with the sustained robust redox capability of S-scheme heterostructure, which are verified by time-resolved photoluminescence spectroscopy, photocurrent test and electron paramagnetic resonance measurements. Furthermore, the interfacial electric field induced S-scheme charge transfer mechanism between g-C₃N₄ and BiOBr is systematically certificated by in situ irradiated X-ray photoelectron spectroscopy and density functional theory calculation. This research offers a comprehensive protocol for the systematic development and construction of highly efficient S-scheme heterojunction photocatalysts, specifically tailored for enhanced H₂O₂ production.