Anchored CoP3 nanoparticles on layered Bi2O2S constructing heterojunction for boosted water pollutant degradation: Insights into multi-pathway cooperative mechanisms

Persulft-based advanced oxidation processes (PS-AOPs) are an efficient strategy to degrade refractory pollutants. Fabricating a highly efficient catalyst is the most pivotal factor in PS activation. This study designs a novel CoP 3 -anchored layered Bi 2 O 2 S through an interface engineering strategy, where the unique electronic structure and surface properties of Bi 2 O 2 S lead to dramatically reduced cobalt ion leaching compared with that of CoP 3 . It exhibited outstanding catalytic activity and achieved nearly complete removal (>99%) of 50 mg L −1 2,4-Dichlorophenol (2,4-DCP) within 30 min. Radical quenching experiments, EPR technique, electrochemical tests, and HPLC validated the coexistence of radical (•OH, SO 4 •− ) and non-radical ( 1 O 2 , electron transfer, high-valent metal species) pathways in the Light/Bi 2 O 2 S/CoP 3 /PMS system for 2,4-DCP degradation. Importantly, Bi 2 O 2 S/CoP 3 induced a pronounced photothermal effect that enhanced 2,4-DCP degradation efficiency. Furthermore, the attack sites of 2,4-DCP were precisely identified based on the Fukui index. Based on density functional theory calculation and high-performance liquid chromatography-mass spectrometry, the detailed degradation pathways were proposed. The toxicity of 2,4-DCP and its intermediate products were predicted by using the toxicity assessment software tool. Moreover, excellent reusability, real-water treatment efficacy (verified by 3D-EEM), high-efficiency removal of multiple pollutants, and wide pH adaptability (3−11) confirm practical potential for sewage treatment. This study provides insight into designing a highly efficient and green catalyst for simultaneous pollutant treatment.