Heterogeneous catalytic degradation of phenol by CuFe2O4/Bi12O15Cl6 photocatalyst activated peroxymonosulfate

Abstract

In this study, Bi12O15Cl6 and CuFe2O4 were synthesized by solvothermal and sol-gel methods, respectively, and the binary composite CuFe2O4/Bi12O15Cl6 was successfully synthesized by heat treatment. The structure and morphology were characterized by a series of tests such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). And the effects of catalysts of different composite proportions, peroxymonosulfate (PMS) dosage, anionic environment and initial pH on the photocatalytic degradation of phenol were investigated. The experimental results showed that BCF-30 had the highest photocatalytic activity with 97.8% removal of phenol at 30 min and a pseudo primary kinetic constant k = 0.13539 min−1. The stability and reusability of the CuFe2O4/Bi12O15Cl6 composites were demonstrated by cycling experiments. The results of free radical analysis indicated that SO4•−, •O2−, h+ and •OH were the main active species, and on this basis, the mechanism of PMS activation and phenol degradation by CuFe2O4/Bi12O15Cl6 under visible light conditions was proposed. In addition, the intermediate products degraded by phenol were detected by liquid chromatography and mass spectrometry (LC-MS). Density functional theory (DFT) calculations were used to expound the phenol degradation and conversion pathways.