BiSnSbO6-TiO2 composites enhance LED light-driven photocatalytic antibacterial activity

A new type of BiSnSbO6-TiO2 composite photocatalytic antibacterial material with heterojunction structure was synthesized by solid phase sintering and characterized by XRD, SEM, TEM, FT-IR and UV-vis diffuse reflectance spectroscopy methods. The photocatalytic antibacterial experiments were carried out under LED light irradiation, and the experimental results showed that BiSnSbO6-TiO2 composite had significantly stronger photocatalytic antibacterial performance against bacteria and fungi than BiSnSbO6 and TiO2 alone. The antibacterial efficiency of 500 mg/L BiSnSbO6-TiO2 composite against E. coli, S. aureus, Bacillus subtilis and P. aeruginosa could reach 71.33%, 100%, 100% and 100%, respectively. The antibacterial efficiency of 125 mg/L BiSnSbO6-TiO2 composite against Candida albicans reached 61.16% under light conditions. The feasibility of removing pathogenic microorganisms from livestock and poultry effluent by composite material under LED light was investigated. In addition, SEM was used to observe the structural changes of the bacteria, and the bacterial morphology was wrinkled and broken, leading to the death of the bacteria. Meanwhile, the antibacterial mechanism was explored through free radical scavenging experiments, and it was found that center dot OH, H+, e(-) played a major role in the photocatalytic antibacterial process. Finally, BiSnSbO6-TiO2 composite was confirmed to have no cytotoxicity by cytotoxicity test. This experiment provides a new type of environment-friendly photocatalytic composite material which can be excited by LED light and has broad application prospect in practical antibacterial field.