Interfacial engineering of BiS/TiCT MXene based on work function for rapid photo-excited bacteria-killing.

In view of increasing drug resistance, ecofriendly photoelectrical materials are promising alternatives to antibiotics. Here we design an interfacial Schottky junction of BiS/TiCT resulting from the contact potential difference between TiCT and BiS. The different work functions induce the formation of a local electrophilic/nucleophilic region. The self-driven charge transfer across the interface increases the local electron density on TiCT. The formed Schottky barrier inhibits the backflow of electrons and boosts the charge transfer and separation. The photocatalytic activity of BiS/TiCT intensively improved the amount of reactive oxygen species under 808 nm near-infrared radiation. They kill 99.86% of Staphylococcus aureus and 99.92% of Escherichia coli with the assistance of hyperthermia within 10 min. We propose the theory of interfacial engineering based on work function and accordingly design the ecofriendly photoresponsive Schottky junction using two kinds of components with different work functions to effectively eradicate bacterial infection.