Synergistic Photocatalytic-Photothermal Contribution to Antibacterial Activity in BiOI-Graphene Oxide Nanocomposites

The threat of environmental microbial contamination to the health of human beings has drawn particular attention. In order to explore the synergistic effect of photocatalytic and photothermal process to the antibacterial property, a stably combined BiOI-graphene oxide (GO) nanocomposite was constructed and prepared through a facile solvothermal method. BiOI crystals were uniformly distributed on the GO nanosheets by the formation of the Bi-C bond. On the basis of various characterizations, the great surface area, the high light harvesting with extension into NIR region, and the efficient transfer of photoinduced electrons by the conductivity of GO were demonstrated, all of which are beneficial for the photocatalytic antibacterial activity. More importantly, the photothermal effect of GO increased the temperature of the BiOI-GO composite with high photothermal conversion efficiency and induced the photogenerated electrons from BiOI crystals to obtain more energy and higher carrier mobility. Conversely, the temperature elevation of BiOI-GO composite improved its capability for light absorption and separation of photoinduced charges. As a result, the BiOI-GO composite enabled the synergistic photocatalytic-photothermal effect for the improvement of the antibacterial property for Acinetobacter baumannii with higher efficiency of TOC removal and leakage of K+ ions, in comparison with the individual photocatalytic process. Thus, the synergistic photocatalytic-photothermal contribution of BiOI-GO composite will provide significance for the potential application of environmental disinfection in the future.