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

Abstract

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 V2CTx nanosheets. Briefly, the exfoliated V2CTx 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@V2CTx 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.