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.