Construction of a MAPbBr3/BiFeO3 Z-scheme heterojunction with enhanced piezo-photocatalytic performance

Abstract

Based on the large visible light absorption coefficient and tunable band gap of MAPbBr₃, weakening the strong photogenerated carrier recombination tendency to exploit the CO₂ reduction potential is a worthy research topic. The built-in polarized electric field induced by the piezoelectric effect can guide the directional movement of charged particles, which is considered to be an effective driving force for the separation of electron–hole pairs. In this work, a MAPbBr₃/BiFeO₃ Z-scheme heterojunction was prepared by a simple mechanical synthesis method, which showed an enhanced CO₂ reduction performance where the optimal sample (MB1) achieved yields of 8.4 μmol g⁻¹ (CH₄) and 3.7 μmol g⁻¹ (CO) under light alone as well as 4.1 μmol g⁻¹ (CH₄) and 1.7 μmol g⁻¹ (CO) under ultrasound alone, thanks to the improved separation rate of photogenerated carriers due to the construction of the MAPbBr₃/BiFeO₃ Z-scheme heterojunction. Moreover, MB1 had a CH₄ yield of 34.9 μmol g⁻¹ and a CO yield of 15.1 μmol g⁻¹ under the dual energy drive system of illumination and piezoelectricity, which are 6.7 and 5.6 times higher than the original MAPbBr₃, respectively.