O–O Bond Homolysis Inhibition Strategy on B-g-C3N4 Boosts Selectivity for the Photosynthesis of H2O2

Abstract

Photocatalytic oxygen reduction offers a green and sustainable route for hydrogen peroxide production. Among various photocatalysts, graphitic carbon nitride (g-C₃N₄) stands out owing to its low cost and tunable electronic structure. However, the competing four-electron O₂ reduction reaction (ORR) to H₂O significantly compromises the selectivity, posing a major challenge for practical applications. In this study, we propose a boron atom decoration strategy on carbon nitride tubes (BCN) to enhance H₂O₂ production. Combined experimental and theoretical analyses reveal that the incorporation of B atoms facilitates O₂ adsorption and inhibits O–O bond homolysis, improving the selectivity of the two-electron ORR pathway to H₂O₂. Moreover, B atoms, acting as Lewis acid sites, stabilize the ^•O₂^– intermediate through acid–base interactions. As a result, the optimized BCN catalyst (BCN₄₀₀) achieves a remarkable H₂O₂ yield of 30 μmol·h^–1, representing a 4-fold increase in H₂O₂ production. This study provides a novel strategy for the design of photocatalysts with optimized active sites, offering significant potential for a wide range of applications in sustainable chemical production.