Pd nanocubes supported on the porous V2CTx nanosheets with enhanced nanozyme activity and photothermal property for antibacterial application

Rational design and controllable construction of supported nanostructures with excellent antibacterial property remain a great challenge. Recently, transition metal carbides/nitrides/carbonitrides (MXenes) have attracted much interest in many fields due to their large specific surface areas and good photothermal property. Herein, a simple yet effective surface engineering strategy based on the tuning of MXene surface chemistry is presented, which allows in-situ controlled growth of the Pd nanocubes on the V 2 CT x nanosheets. Briefly, the exfoliated V 2 CT x nanosheets by HF are annealed, which changes the composition of surface terminations while creating the mesoporous structures. The annealing largely affects the exposure and oxidation states of the adjacent V atoms and allows the controllable growth of Pd nanocubes. Interestingly, the obtained Pd@V 2 CT x nanocomposites show enhanced peroxidase-/oxidase-like activities and intrinsic photothermal effect in the near infra-red (NIR) region due to the strong metal-support interaction. Furthermore, the combined nanocatalytic-photothermal treatment by their versatilities remarkably improves the antibacterial efficacy, giving a high killing rate (above 98 % for both Escherichia coli and Staphylococcus aureus ). This work provides a new avenue to develop the supported metal nanostructures based on MXenes for antibacterial application.