A sunlight sensitive metal–organic framework film for the environment-friendly self-sterilization application

Frequent outbreaks of respiratory diseases caused by the spread of pathogenic microorganisms poses a great threat to human health. Disposable surgical masks (SM) can limit the transmission to some extent but the inability to self-sterilize leads to a potential source of cross-contamination as well as causing hazardous impacts on the soil and aquatic ecosystems. Herein, a sunlight-triggered photoactive self-sterilization metal–organic framework (MOF) film modified SM is reported. The MOF film can be prepared easily and quickly by the co-assembly of UiO-66 nanoparticles and metal-phenolic networks (MPNs, the complexation of tannic acid and iron ions). Unlike the traditional MPN only assisted assembly, this MOF film exhibited a dramatic synergetic photodynamic and photothermal self-sterilization ability for protective equipment surfaces under simulated-solar irradiation without any extra photosensitizers or photothermal agents. A study of the mechanism revealed that the light absorption region of UiO-66 can be expanded by the MPNs, demonstrating a unique photocatalytic sensitization, and thus the MOF film can utilize the sunlight extensively to achieve a photodynamic property. Moreover, such an MOF film demonstrated excellent cytocompatibility, haemocompatibility and breathability, indicating the security of the skin-touched application. This dual-modal photocatalytic MOF film are promising for the long-term usage of disposable protective equipment and for mitigating the heavy burden on the environment.