Photocatalytic degradation of E. coli bacteria using TiO2/SiO2 nanoparticles with photodeposited platinum

In this work, TiO2 /SiO2 (pure anatase), and TiO2 /SiO2 (anatase/rutile) nano-photocatalysts are prepared by using sol-gel method and control of acidity. The particles size is calculated using Scheerer, s equation and is estimated to be around 7-15 nm. In order to improve the photocatalytic activity of TiO2 /SiO2 ,1% (wt) platinum particles are loaded on both catalysts using photoreductive method. SEM images show that doping of Pt particles is not homogenous. FT-IR, BET and UV-Vis Reflectance are used to characterize the structures and properties of photocatalysts. The photocatalytic activities of these catalysts are investigated by their bactericidal activities on E. coli bacteria. 100% destruction of E. coli bacteria has occurred under UV light illumination after 5, 15, 20 and 60 min using Pt-TiO2 /SiO2 (pure anatase), TiO2 /SiO2 (pure anatase), Pt-TiO2 /SiO2 (anatase/rutile) and TiO2 /SiO2 (anatase/rutile) photocatalyst, respectively. The effect of doping Pt is remarkable and rate of destruction using Pt doped catalysts (both catalysts) is three times faster than that of TiO2 /SiO2 catalysts.