Mg2TiO4 spinel modified by nitrogen doping as a Visible-Light-Active photocatalyst for antibacterial activity

Nitrogen doped Mg 2 TiO 4 spinel, i.e. Mg 2 TiO 4−x N y , has been synthesized and investigated as a photocatalyst for antibacterial activity. Mg 2 TiO 4−x N y demonstrates superior photocatalytic activity for E. coli disinfection under visible light illumination (λ ≥ 400 nm). Complete disinfection of E. coli at a bacterial cell density of 1.0 × 10 7  CFU mL −1 can be achieved within merely 60 min. Mg 2 TiO 4−x N y is capable of generating superoxide radicals ( O 2 − ) under visible light illumination which are the reactive oxygen species (ROSs) for bacteria disinfection. DFT calculations have verified the importance of nitrogen dopants in improving the visible light sensitivity of Mg 2 TiO 4−x N y . The facile synthesis, low cost, good biocompatibility and high disinfection activity of Mg 2 TiO 4−x N y warrant promising applications in the field of water purification and antibacterial products.