Plasmonic molybdenum oxide nanosheets supported silver nanocubes for enhanced near-infrared antibacterial activity: Synergism of photothermal effect, silver release and photocatalytic reactions

Plasmonic MoO3-x nanosheets supported Ag nanocubes were designed as high-efficient Near-infrared (NIR) light driven antibacterial agent. The as-designed MoO3-x-Ag not only significantly reduces the cost and toxicity of Ag, but also greatly enhances the antibacterial activity towards E. coil and S. aureus in comparison with bare MoO3-x and Ag upon NIR laser irradiation. Three effects are believed to contribute to this enhancement: (1) the plasmonic MoO3-x-Ag exhibits excellent NIR light absorption and photothermal conversion abilities, which help to kill bacteria; (2) NIR light induced heat in MoO3-x also diffuses to Ag nanocubes and triggers the release of more Ag+, leading to bacterial cell death; (3) under NIR light irradiation, hot electrons and holes are generated and separated through MoO3-x-Ag interface, which produces reactive species for the oxidation of out membrane of bacteria. The synergism of NIR light driven photothermal effect, silver release and photocatalytic reaction makes the designed plasmonic MoO3-x-Ag a promising antibacterial agent for cleaning the microbial contaminated water environment.