Titanium dioxide is used to kill viruses and bacteria and to decompose organics via photocatalysis.

Andrew Barron and colleagues, Rice University, USA, have shown that addition of silicone to TiO₂ dramatically increases its ability to degrade aerosol- and water-borne viruses. Treatment of TiO₂(P25) in glass flasks sealed with silicone grease resulted in a significant improvement in the catalytic activity of titania as did the purposeful reaction of TiO₂(P25) with 2.5 wt % silica. The rate constant for the irradiation of viruses was three times higher with addition of silica.

The increased activity and low cost of the reagents makes this a very promising alternative for use as a disinfectant for water systems. Initial testing using the Yangtze River, considered the most polluted river in the world, as a baseline, showed complete destruction of viruses in minutes.

• Simple Route to Enhanced Photocatalytic Activity of P25 Titanium Dioxide Nanoparticles by Silica Addition
  H. R. Jafry, M. V. Liga, Q. Li, A. R. Barron,
  Environ. Sci. Technol. 2011.
  DOI: 10.1021/es102749e