Enhanced plasmonic photocatalytic disinfection on noble-metal-free bismuth nanospheres/graphene nanocomposites

Bi nanospheres and Bi nanospheres/graphene (Bi@graphene) nanocomposites are fabricated by a facile method. Their UV-assisted plasmon-mediated antibacterial activity for Escherichia coli is reported for the first time. The Bi@graphene nanocomposites exhibit higher photocatalytic disinfection efficiency in comparison with pristine Bi nanospheres. The mechanism of the enhanced antibacterial activity of Bi@graphene is revealed by a combined experimental and theoretical method. The reactive oxygen species (ROS) with high oxidation capacity, generated from the surface plasmon resonance (SPR) of Bi metal, play a key role in killing the bacteria. The introduction of graphene could enhance the excitation and transfer of the SPR hot electrons, leading to the promoted generation of ROS. The present work provided a novel noble-metal-free plasmonic photocatalyst for promising application in disinfection, catalysis, and clinical and environment-related fields.