Photoresponsive MXene/HKUST-1@CuS Antimicrobial Nanosheets towards Efficient Solar-Driven Water Evaporation and Biofilm Eradication

Bacterial adhesion and proliferation on the surface of solar energy evaporator lead to contamination of the evaporation water and reduce the efficiency of photothermal evaporation. In this work, the metal-organic framework (MOF), HKUST-1 was in situ synthesized onto the surface of MXene, and CuS was sulfurized onto the Cu 2+ sites to form MX/HK@CuS nanosheets. The morphology, microstructure, and crystallinity of MX/HK@CuS were characterized using SEM, EDS, FTIR, XRD, and XPS. Results shows that MX/HK@CuS exhibited fair photothermal water evaporation capabilities, with a photothermal evaporation efficiency exceeding 30% in aqueous solution under irradiation. The photothermal water evaporation efficiency of MX/HK@CuS-3 thin sheets was 86%, demonstrating significant photothermal water evaporation performance. The antibacterial properties of the MX/HK@CuS series were attributed to Cu 2+ release, photothermal and photodynamic conditions via sulfurization times. Interestingly, MX/HK@CuS-3 shows over 99.9% of inactivation to E. coli and S. aureus within 20   min of exposure under NIR and simulated sunlight illumination. Meanwhile, MX/HK@CuS-3 demonstrated improved efficacy in biofilm eradication, with weak bacterial adhesion. The MX/HK@CuS series showed impressive blood compatibility, indicating its biocompatibility and environmental safety. In conclusion, this study provides a novel multifunctional platform for solar-energy evaporator materials, combining triple functional antibacterial properties with high photothermal conversion efficiency.