Visible light-responsive core-shell structured In2O3@CaIn2O4 photocatalyst with superior bactericidal properties and biocompatibility

Antibacterial activity of photocatalytic substrates is primarily induced by ultraviolet light irradiation. Visible light-responsive photocatalysts were recently discovered, offering greater opportunity to use photocatalysts as disinfectants in our living environment. The development of antibacterial photocatalysts, however, has mainly focused on titanium oxide (TiO2)-related materials with antibacterial properties not comparable with conventional chemical disinfectants. This study demonstrated that a core-shell structured In2O3@CaIn2O4 substrate has superior visible light-induced bactericidal properties, as compared with several commercially available and laboratory-prepared visible light-responsive photocatalysts. The high performance is enhanced by more easily photoexcited electron transfer between the interfaces of In2O3 and CaIn2O4 to minimize the electron-hole recombination during photocatalysis. Additionally, when compared with TiO2-based photocatalysts, In2O3@ CaIn2O4 treatments did not induce significant cell death and tissue damage, implying a superior biocompatibility. These findings suggest that In2O3@ CaIn2O4 may have potential application in the development of a safer and highly bactericidal photocatalyst.