PVP surfactant-modified flower-like BiOBr with tunable bandgap structure for efficient photocatalytic decontamination of pollutants

Abstract

Designing semiconductor catalysts with superior charge carrier transfer and adequately exposed reactive sites is crucial for acquiring remarkable photocatalytic activity. Herein, a series of BiOBr catalysts with PVP as “organic armor” were synthesized via a facile precipitation strategy. As expected, the BiOBr-PVP hybrids exhibited superior catalytic oxidation toward the removal of organic dyes and tetracycline, but also catalytic reduction of Cr (VI). By virtue of tunable bandgap structure, sufficient abundance of reactive sites and decreased work function, the BiOBr-PVP composites could effectively expedite the charge carrier separation and transfer via enhanced transport pathways. Simultaneously, the reduced particle size and enlarged specific surface area achieved by loading PVP on the BiOBr catalyst could provide greater contact area and channels for intimate interaction between reactive sites and pollutants. Moreover, a photodegradation pathway for tetracycline was proposed based on LC-MS measurement and the intrinsic mechanism between BiOBr and PVP was discussed by first-principles calculation. The constructed BiOBr-PVP composites extend the scope and comprehension of photocatalysts via surface structural engineering and sufficient interfacial coupling for use in several environmental purification applications.