Efficient piezophotocatalysis of ZnO@PVDF coaxial nanofibers modified with BiVO4 and Ag for the simultaneous generation of H2O2 and removal of pefloxacin and Cr(VI) in water

Abstract

Reactive oxygen species (ROSs) are important oxidants widely used in biological and environmental fields. Piezophotocatalysis opens a new route for generating ROSs and overcoming rapid charge recombination. Here, ROSs (H2O2, •O2–, •OH) were generated on ZnO@PVDF coaxial nanofibers modified with BiVO4 and Ag (Ag/BiVO4: 2 % ZnO@PVDF Coaxial Nanofibers Membrane named as ABZCNM) by piezophotocatalysis. The H2O2 production of ABZCNM was approximately 147.7 μM within 90 min. In addition, the effects of H2O2 on pefloxacin and Cr(VI) during the degradation process were investigated. A Janus heterojunction constructed with coaxial nanofibers (i.e., a confined structure) facilitates the separation of charge carriers, thus boosting piezophotocatalytic efficiency. The coaxial nanofiber exhibits excellent mechanical properties and cyclability. The piezophotocatalytic performance enhanced by the Janus heterojunction was demonstrated by COMSOL simulation and density functional theory (DFT) calculation, which reveals the relationship between structure and efficiency. This work provides novel insights into the piezophotocatalytic mechanism and H2O2 generation for pollutant removal.