Ce and Er Co-doped TiO(2) for rapid bacteria- killing using visible light

Bacterial infection and related diseases are threatening the health of human beings. Photocatalytic disinfection as a simple and low-cost disinfection strategy is attracting more and more attention. In this work, TiO(2) nanoparticles (NPs) were modified by co-doping of Ce and Er using the sol–gel method, which endowed TiO(2) NPs with enhanced visible light photocatalytic performance but not pure ultraviolet photocatalytic properties compared the untreated TiO(2). Our results disclosed that as the doping content of Er increased, the photocatalytic activity of modified TiO(2) NPs initially increased and subsequently decreased. The same trend occurred for Ce doping. When the doping dose of Er and Ce is 0.5 mol% and 0.2 mol%, the 0.5Ce0.2Ti–O calcined at 800 °C presented the best antibacterial properties, with the antibacterial efficiency of 91.23% and 92.8% for Staphylococcus aureus and Escherichia coli, respectively. The existence of Er ions is thought to successfully turn the near-infrared radiation into visible region, which is easier to be absorbed by TiO(2) NPs. Meanwhile, the addition of Ce ions can effectively extend spectral response range and inhibit the recombination of electrons and holes, enhancing the photocatalytic disinfection activity of co-doped TiO(2).