Polarization synergizes defective interface heterojunctions boosting piezocatalytic hydrogen production and simultaneous pollutant degradation

Abstract

Piezocatalysis has been demonstrated as a safe, eco-friendly and energy-efficient approach to trigger redox reactions. However, the mechanical energy conversion efficiency is limited and the piezoelectric interface mechanism remains ambiguous. Herein, a highly efficient dual functional BiOIO₃-VO/NH₂-MIL-125 (BIOVO/NM) S-scheme heterojunction was developed via synchronous polarization regulation and interface engineering. The introduction of oxygen vacancies (VOs) induced a stronger polarization of BiOIO₃ along the b-axis, which propels the electrons to migrate onto the (010) surface of BIOVO. Then, the electrons recombine with the holes from the closely coupled (111) face of NM driven by the interfacial electric field provided by the S-scheme heterojunction, achieving spatial charge separation. In addition, BIOVO/NM possesses high proton adsorption and activation capabilities and lower reaction energy barriers, further promoting the H₂ evolution reaction. In a methylene blue (MB) solution without sacrificial agents, the optimal BIOVO/NM catalyst achieves an exceptional H₂ evolution rate (330.15 μmol g⁻¹ h⁻¹) and a simultaneous MB degradation rate (98.67%). It also exhibits a sustainable dual functional activity for as long as 8 h. This work presents an innovative approach to design efficient and sustainable catalysts for mechanical force driven renewable energy preparation and environmental purification.