Construction of C/ZnO/BiOI photocatalyst for enhanced degradation of carbaryl: Characterization, performance and mechanism

Pesticide residues lead to increasingly serious harmful ecological environment, which poses tremendous threats on human health. To overcome this problem, researchers are focusing on the development of highly efficient composites with excellent photocatalytic efficiency. In this work, a new C/ZnO/BiOI photocatalyst was successfully synthesized using hydrothermal, hydrolysis and ultrasonic technique for carbaryl degradation. The as-prepared photocatalyst was characterized by XRD, FT-IR, XPS, SEM, TEM, BET, UV–vis DRS and PL. The photocatalyst exhibited better carbaryl removal performances than that of ZnO, C/ZnO and ZnO/BiOI under simulated sunlight irradiation, which might be attributed to the efficient electron-hole separation and wider region of light response. The optimum C/ZnO/BiOI (20%) composite exhibited the highest degradation efficiency (62.9%) of carbaryl and excellent cycling stability. Reactive species scavenging and ESR experiments illustrated that .OH was the most important active species. Furthermore, the identification of intermediates revealed possible degradation pathways of carbaryl.