Enhanced visible-light-induced photocatalytic disinfection of E-coli by carbon-sensitized nitrogen-doped titanium oxide

Nitrogen-doped titanium oxide (TiON) nanoparticle photocatalysts were synthesized by a sol-gel process, for disinfection using E coli as target bacteria. Our work shows that the calcination atmosphere has strong effects on the composition, structure, optical, and antimicrobial properties of TiON nanoparticles. Powders calcinated in a flow of N-2 atmosphere (C-TiON) contain free carbon residue and demonstrate different structures and properties compared to the TiON powders calcinated in air. Disinfection experiments on Escherichia coli indicate that C-TiON composite photocatalyst has a much better photocatalytic activity than pure TiON photocatalyst under visible light illumination. The enhanced photocatalytic activity is related to stronger visible light absorption of the carbon-sensitized TiON.