Regulating interface charge separation to unlock photocatalytic non-radical pathways: Construction of BiOCl/COF S-scheme heterojunction for efficient antibiotic remediation

BOC/COF S-scheme heterojunction significantly boosted charge separation efficiency. • The non-radical pathway predominated, facilitating efficient photocatalytic degradation. • Elevated 1 O 2 quantum yield was achieved via optimized charge transfer. • The reduction in toxicity was confirmed via the plant models and DFT calculations. • The non-radical-dominated and radical-assisted synergy achieved efficient TC degradation. The inefficiency of charge separation and the unselective nature of radical-based pathways severely limit the practical application of photocatalysis for water purification. Herein, a BiOCl/COF (BOC/COF) S-scheme heterojunction was successfully constructed via ultrasonic assistance. Remarkably, the optimized S-scheme heterojunction significantly enhanced photo-generated carrier separation efficiency, which effectively promoted ROS generation and improved the removal rate of tetracycline hydrochloride (TC) (degradation rate: 91.6%). The research has found that non-radical pathways collectively accounted for 89.11% of the degradation activity, endowing the system with high selectivity. It is worth noting that the BC-20 membrane can efficiently eliminate TC in a continuous-flow wastewater treatment system. Furthermore, BC-20 can degrade TC in an enlarged reactor under natural sunlight irradiation. The three possible degradation pathways were analyzed through Fukui function and LC-MS. The toxicity of the TC solution after being treated with the BOC/COF S-scheme was evaluated using mung beans as a crop model. Through (in-situ) characterization and density functional theory (DFT) calculations, the S-scheme charge transfer mechanism and interfacial electric field (IEF) driving efficient 1 O 2 production were systematically elucidated. These findings not only deciphered the interface engineering-mediated non-radical generation mechanism in BOC/COF S-scheme photocatalysis but also advanced its practical application in aquatic environmental remediation. Download: Download high-res image (519KB) Download: Download full-size image