Bifunctional Ti3C2Tx MXene/ZnIn2S4 Schottky heterojunction for photocatalytic water treatment: Efficient pollutant degradation and antibacterial performance.

Bacterial infections and antibiotic residue contamination pose a severe and growing threat to public health, highlighting the urgent need for efficient environmental remediation strategies. This study employed a facile one-step solvothermal method to in-situ grow ZnIn2S4 nanosheets on two-dimensional Ti3C2Tx MXene, forming a Ti3C2Tx MXene/ZnIn2S4 (TC/ZIS) Schottky heterojunction. This composite material achieves both the efficient degradation of tetracycline hydrochloride (TCH) and effective bacterial inactivation in aqueous environments. The constructed Schottky heterojunction facilitates the separation and migration of photogenerated carriers through an interfacial built-in electric field and broadens the visible-light absorption range, thereby greatly improving the photocatalytic activity. Under visible light irradiation, 2%-TC/ZIS generated abundant reactive oxygen species (ROS), including ·OH, h+, ·O2-, and 1O2. Through a series of redox reactions, it achieved a 95.4% degradation efficiency for TCH within 120 min. Furthermore, it disrupted the cell membrane integrity of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) within 30 min, leading to cell death and achieving high antibacterial rates of 99.38% and 98.77%, respectively. The electron transfer mechanism during the photocatalytic reaction was revealed through density functional theory (DFT) calculations. This work provides a novel strategy for developing a photocatalytic platform capable of degrading environmental antibiotic pollutants while simultaneously inactivating S. aureus and E. coli, demonstrating broad application prospects in environmental remediation.