Facile construction of Z-scheme AgBr/BiO(HCOO)0.75I0.25 photocatalyst for visible-light-driven BPA degradation: Catalytic kinetics, selectivity and mechanism

Abstract

Herein, a novel AgBr/BiO(HCOO)0.75I0.25 Z-scheme photocatalyst was constructed through a facile hydrothermal and post-precipitation method for visible-light (VL) driven wastewater remediation. The 10 wt% AgBr/BiO(HCOO)0.75I0.25 composite (10%ABB) could completely decompose bisphenol A (BPA) within 25 min, and multiple coexisting inorganic anions and natural organic matters only slightly affected the BPA removal efficiency. The wonderful photocatalytic performance could attribute to the construction of Z-scheme heterojunction, which modulated the energy band, accelerated the electron transfer and also raised the redox ability of the system. Since the superoxide radicals (O2−) and non-radical pathway (1O2 and h+) were proved to be the dominating reactive species, 10%ABB/VL system exhibited a highly selective oxidation on aromatics with electron donating groups, whereas a relatively low value for organics with electron with drawing groups. By investigating the ionization potential (IP) of five representative organics, a negative correlation between IP value and reaction kinetics was reported. Moreover, the possible photocatalytic mechanism and elimination pathway were proposed via a series of photoelectrochemical analysis and LC-MS/MS. This work provides a strategy for engineering novel Bi-based photocatalyst and establishing selective oxidation system for organic contamination removal.