Photothermal/photodynamic synergistic antibacterial Nanocellulose film modified with antioxidant MXene-PANI Nanosheets

TEMPO-CNF film modified by two-dimension transition metal MXene has certain antibacterial properties. However, the problem of long-lasting stability greatly restricts the feasibility of long-term use of the composite film. Here, we introduced polyaniline (PANI) as a modifying molecule, which was electrostatically adsorbed on the surface of the MXene nanosheets to prevent its self-stacking and delay its oxidation. The modified MXene could still maintain >85 % stability after 30 days of room temperature storage. The MXene-PANI nanocellulose (MXP/CNF) film was further prepared by combining electrostatic attraction and hydrogen bonding interactions. Thanks to the synergistic effects of the photothermal conversion and photodynamic of MXene and PANI themselves, as well as the high light-trapping properties of the heterostructures, the photothermal and photodynamic efficiencies of the MXP/CNF film were greatly improved. Under the irradiation of 808 nm near-infrared light at 1.5 W/cm 2 , the MXP/CNF film reached a temperature of 132.9 °C within 20 s. Meanwhile, reactive oxygen species are generated to degrade 55 % of crystalline violet by modified MXene composite film under light irradiation. Compared to 15 % bacterial survival on cellulose film not modified with PANI, S. aureus and E. coli were completely killed on MXP/CNF film under light conditions. The prepared thin film materials exhibit low cytotoxicity, highlighting their potential applications in biomedicine and desalination.