Preparation of size-controlled TiO2 nanoparticles and derivation of optically transparent photocatalytic films

Abstract

TiO2 nanoparticles were prepared by hydrothermal reaction of titanium alkoxide stabilized in acidic ethanol/water solution. The sizes of particles have been controlled to the range of 7-25 nm by adjusting the concentration of Ti precursor and the composition of the solvent system. The TiO2 samples synthesized under this acidic ethanol/water environment were mainly primary particles in anatase phase without secondary structure. The suspension of as-prepared 7-nm-sized TiO2 nanoparticles demonstrates long-term stability, and has been applied successfully for the fabrication of ultra-transparent particulate TiO2 films. The photocatalytic efficiency of TiO2 films prepared from the 7-nm-sized nanoparticles was 1.6 times of that of films derived from Degussa P25 in decomposing gaseous 2-propanol.