Polarization synergizes defective interface heterojunction boosting piezocatalytic hydrogen production simultaneous pollutant degradation

Abstract

Piezocatalysis has been demonstrated as a safe, eco-friendly and energy-efficient approach to trigger redox reaction. 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 S-scheme heterojunction, achieving spatial charge separation. In addition, BIOVO/NM possesses high proton adsorption and activation capabilities as well as lower reaction energy barriers, further promoting 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 umol·g-1·h-1) and simultaneous MB degradation rate (98.67%). It also exhibits a sustainable dual functional activity 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.