Visible light photocatalysts-N-doped TiO2 by sol-gel, enhanced with surface bound silver nanoparticle islands

Antimicrobial thin film photocatalysts consisting of N-doped titania have been prepared by sol-gel methods and further enhanced using silver nanoparticles formed in situ on the surface of the films. The films have been characterised using XRD, SEM, XPS, UV-Visible spectroscopy and functionally tested using measurements for the photoinduced superhydrophilicity, stearic acid destruction and antimicrobial measurements using both E. coli and an epidemic strain of MRSA, EMRSA-16. The N-doped TiO2 films were seen to have interstitially doped nitrogen with the N 1s peak appearing at 400.0 eV in the XPS and as such showed good photocatalytic activity under white light. The photoactivity was then further enhanced by silver nanoparticle formations on the surface. The highly active photocatalytic films were seen to be effective agents against both bacteria and stearic acid using a white light source that is commonly found in UK hospitals.