Ultrashort-term dual ultraviolet-irradiated nickel-doped titanium dioxide nanoparticle mesh for photocatalytic disinfection with minimum exposure risk to human health

The photocatalytic antibacterial activity of a nickel-doped titanium dioxide nanoparticle mesh (Ni–TiO2 mesh) against E. coli was investigated in chlorinated water under ultrashort-term dual ultraviolet (UV) irradiation. Ni–TiO2 nanoparticles (NPs) were prepared via Ni doping to TiO2 NPs and uniformly distributed on the mesh via electrospraying and hot-pressing, of which the morphology and particle size distribution were maintained after immobilization. In the Ni–TiO2 mesh, the elements, Ti, O, Ni, iron, chromium and silicon were included suggesting multi- and mixed metal oxides. Irradiation distance and lamp cleaning were analyzed as controllable factors to maintain the dual UV intensity. The Ni–TiO2 mesh showed a significant antibacterial activity even at the smallest mesh size of 0.25 cm2 under 5-sec irradiation after the UV intensity adjustment. The results suggest that the improved NP characteristics on a steel mesh substrate, including multi- and mixed metal oxides, can display photocatalytic antibacterial activity against E. coli along with minimization of NP exposure due to NP immobilization. This can be directly extended to other environmental, industrial, and clinical applications as a safe and sustainable photocatalytic antibiotic agent for photocatalytic disinfection.