Z-Scheme Charge Transfer in BiOCl/CoWO4 Heterostructures for Enhanced Photocatalytic Removal of Ciprofloxacin and Microplastics
摘要
To develop highly efficient photocatalysts for environmental pollution control, constructing Z-scheme heterojunctions with excellent redox capabilities is one of the effective approaches. In this study, a Z-scheme BiOCl (BOC)/CoWO₄ (CWO) heterostructure was fabricated via a solvothermal method. When exposed to visible light, this composite showed substantially higher efficiency in degrading ciprofloxacin (CIP) via photocatalysis. The best-performing sample, BCW-2, attained a 91.2% degradation efficiency over 40 min. Its degradation rate constant (k) was 37.59 times and 3.44 times higher than that of pure CoWO₄ and pristine BiOCl, respectively. Notably, BCW-2 showed a moderate degradation effect on polyethylene (PE) microplastics, resulting in an 8.3% decrease in weight within 24 h. Characterization tests revealed that the enhanced charge separation and transfer capabilities, as well as the suppression of carrier recombination in the heterojunction, contributed to the improved photocatalytic performance. Furthermore, quenching experiments combined with ESR spectroscopy revealed a Z-scheme charge transfer pathway, offering a theoretical foundation for the exceptional photocatalytic degradation efficiency observed.
Graphical Abstract