Bifunctional Bi0.98Sm0.02FeO3/g-C3N4 Piezocatalyst for Simultaneous H2 and H2O2 Production

Piezocatalysis portrays a promising alternative for producing hydrogen (H₂) and hydrogen peroxide (H₂O₂) in a clean and safe way, but the simultaneous enhancement of both properties remains challenging. In this study, a BiFeO₃-based bifunctional piezocatalytic strategy via Sm doping and g-C₃N₄ compositing (Bi_0.98Sm_0.02FeO₃/g-C₃N₄) was proposed for efficient simultaneous H₂ and H₂O₂ production. Benefiting from the synergistic effect between the optimized energy band structure and piezo-generated charges, the performances of hydrogen evolution reaction (HER) and water oxidation reaction (WOR) are both enhanced remarkably. As a result, the evolution rates of BSFO/g-C₃N₄ for pure water splitting into H₂ and H₂O₂ simultaneously reach 988 and 214 μmol g^–1 h^–1 without any sacrificial agent, which is 4.6 and 7.6 times higher than those of pure BiFeO₃. Theoretical calculations reveal the critical role of this optimization in reducing the adsorption energy barriers of HER and WOR intermediates by factors of 10.83 and 12.38, respectively. This study broadens new insight into the design of efficient piezocatalysts for water splitting.