Photosynthesis-Inspired Porous ZnIn ₂ S ₄ /AgVO ₃ @PVDF Photocatalytic Membranes with High Catalytic Performance and Broad-Spectrum Antibacterial Activity

To overcome ZnIn₂S₄'s limitations (narrow-visible-light absorption, rapid charge-carrier recombination, and low efficiency), this study designed photosynthesis-inspired ZnIn₂S₄/AgVO₃ heterojunctions guided by density functional theory (DFT) calculations. Combined DFT and experimental analysis confirmed a chloroplast-like Z-scheme charge-transfer mechanism within the heterojunction. Photocatalytic technology was then integrated with membrane separation via electrospinning to fabricate porous ZnIn₂S₄/AgVO₃@PVDF membranes, solving recovery and secondary pollution issues. Experimental results showed that the ZnIn₂S₄/AgVO₃@PVDF photocatalytic membrane containing 30 wt % AgVO₃─referred to as P-ZA30─degraded 93.97% of sulfamethazine (SMT) within 80 min, demonstrating excellent photocatalytic performance. Meanwhile, DFT calculations elucidated the SMT degradation pathway. In addition, the membrane exhibited broad-spectrum antibacterial properties against both Gram-positive bacteria (e.g., <i>Staphylococcus aureus</i>) and Gram-negative bacteria (e.g., <i>Escherichia coli</i>). These findings provide valuable guidance for the design of heterojunction materials, offer considerable experimental and theoretical support for understanding the catalytic mechanism of Z-scheme heterojunctions, and help in the develop of strategies for the treatment of antibiotic-contaminated wastewater.