Construction of BiVO4/CoPc S-scheme heterojunctions with enhanced photothermal-assisted photocatalytic activity

Photothermal-assisted photocatalytic degradation of antibiotics is a promising way to alleviate pollutant issues in the environment. Herein, a BiVO4 (BVO)-cobalt phthalocyanine (CoPc) S-scheme heterojunction was constructed by coupling the solvothermal method with sonication, which can facilitate photothermal-assisted photocatalytic tetracycline (TC) removal. The BVO-1% CoPc sample exhibited optimal TC removal efficiency, reaching 76% within 10 min; its apparent rate constant was 1.8 times that of pure BVO. Additionally, BVO-1% CoPc exhibited excellent reusability and stability in cycling experiments. Photoluminescence measurements demonstrated that the S-scheme heterojunction structure improved the charge separation efficiency. Infrared thermography images showed that the increased temperatures of the reaction system can be attributed to the photothermal effect of CoPc. The degradation intermediates and possible degradation pathways of TC were analyzed. Based on active species trapping experiments, in situ X-ray photoelectron spectrometry, and band structures, a possible S-scheme photocatalytic charge transfer mechanism for BVO-CoPc was reasonably proposed. This study provides a feasible strategy to construct an S-scheme heterojunction system with photothermal assistance for the practical removal of organic pollutants.