Construction of S-scheme BiOCl/layered bimetallic oxide heterojunction for enhanced photocatalytic degradation of bisphenol A

Constructing heterogeneous photocatalysts to enhance the visible light absorption and photo-generated charge carrier separation for efficient degradation of organic pollutants in water samples remained a significant challenge. An S-scheme BiOCl/ZnCrZr-layered bimetallic oxide (LBMO) heterojunction was constructed by depositing BiOCl nanoparticles on ZnCrZr-LBMO. The characterization of material samples were by XRD, SEM, TEM, XPS, FTIR, UV-Vis-DRS, transient photocurrent response, and electrochemical impedance spectroscopy. The photocatalytic efficiency of BiOCl/ZnCrZr-LBMO heterojunction was obviously improved, about 3.95 and 1.68 folds higher than that of pristine BiOCl and ZnCrZr-LBMO, respectively. The fast separation and migration and the prolonged lifetime of photo-generated carriers in the BiOCl/ZnCrZr-LBMO heterojunction were validated by photoelectrochemical tests. The influence factors, versatility, and reusability of the heterojunction were also evaluated. Free radical scavenging test and ESR experiment revealed that & sdot;O2- and h+ active radicals were the dominant active radicals in the BPA degradation. Additionally, BPA degradation intermediates were detected by LC-MS, and the possible degradation pathway of BPA was deduced using density functional theory. This novel Sscheme model heterojunction was expected to provide new ideas for the study of the photocatalytic mechanism and the BPA removal.