Boost piezocatalytic H2O2 production in BiFeO3 by defect engineering enabled dual-channel reaction

Piezocatalytic H2O2 production is a promising alternative to the traditional anthraquinone method and direct synthesis, for obtaining desired products in a clean and safe way. In this work, we studied the piezocatalytic behavior of narrow band gap material BiFeO3 and achieved a superior H2O2 generation performance by defect engineering enabled dual-channel reaction. The concentration of oxygen vacancies (OVs) is adjusted by the hydrothermal process parameters, so that the valence band shifts to a more positive position with more OVs. As the water oxidation reaction is selectively enhanced as its energy barrier is lowered, while the oxygen reduction reaction is basically maintained, i.e. a dual-channel for H2O2 production. Meanwhile, OVs act as the electron capture center to facilitate charge separation, which further improves the reaction activity. Accordingly, the H2O2 yield of BiFeO3 catalyst with suitable OVs concentration reaches 110.07 μmol/g/h in pure water and 342.36 μmol/g/h under sacrificial agent system. This work provides a promising strategy for the development of narrow band gap catalysts for H2O2 production.