2D/1D BiOBr/TiO2 flexible nanofibrous film heterojunction photocatalyst for tetracycline degradation

Abstract

Semiconductor photocatalysis is an ideal and sustainable solution to effectively remove Tetracycline (TC). Herein, a hierarchical flexible nanofibrous film (NF) heterojunction photocatalyst of BiOBr/TiO2 was fabricated via a combination of electrospinning and solvothermal method, obtaining the two-dimensional (2D) BiOBr nanosheets uniformly anchored on the surface of one-dimensional (1D) TiO2 nanofiber, and the amount of BiOBr significantly influences the physicochemical properties of the heterojunction photocatalyst, the optimal sample of BT-2 manifests large pore size and high surface area, prominent visible light response ability and narrow band gap as well as outstanding charge separation efficiency, thus achieves significantly enhanced photocatalysis activity for TC degradation, which is about twice higher than that of the pristine TiO2 NF. More importantly, the BT-2 sample also displays high reusability and stability over a 10-cycle period and can be easy to recover. Meanwhile, the radical scavenging experiments and electron spin resonance characterization reveal that ·O2– and h+ occupy an irreplaceable role in degrading TC. Moreover, regarding the analysis of intermediates and density functional theory calculations, the TC photodegradation mechanism and pathways are proposed. Our finding offers a prospective solution for designing BiOBr/TiO2 heterojunction recyclable photocatalysts for efficient TC photodegradation.