Superimposed surface plasma resonance effect enhanced the near-infrared photocatalytic activity of Au@Bi2WO6 coating for rapid bacterial killing

Bacterial infection has become a serious public health challenge because the misuse of antibiotics worldwide has induced bacterial resistance and superbug occurrences, that is, no suitable antibiotics are available. Herein, we design a new infrared photocatalytic system on titanium (Ti) substrates, and it consists of gold (Au) nanorod-decorated bismuth tungstate (Bi2WO6) nanosheets (Au@Bi2WO6). The surface plasmon resonance (SPR) effect induced by near infrared (NIR) facilitates partial photo-induced electron transfer between Au and Bi2WO6, resulting in accelerated charge transmission and consequently hindering electron-hole recombination, which imparts high photocatalytic property to the coating. In addition, the superimposed SPR from both Au and Bi2WO6 can improve the photothermal effect of Au@Bi2WO6. As a result, when irradiated with 808 nm NIR for 15 min, this hybrid coating exhibits a superior antibacterial efficiency of 99.96% and 99.62% against Escherichia coli and Staphylococcus aureus, respectively, due to the synergistic effects of high yield of radical oxygen species and hyperthermia; this efficiency cannot be achieved by either Au-Ti or Bi2WO6-Ti alone. This platform exhibits a great potential for noninvasive disinfection without using antibiotics.