Solvothermal synthesis of SrTiO sub(3) nanoparticles precisely controlled in surface crystal planes and their photocatalytic activity

Strontium titanate (SrTiO sub(3)) nanoparticles of cubes, spheres, and flake-type morphology were obtained by a solvothermal synthesis in H sub(2)O/polyols mixed solution. Size of cubic particles bounded by {100} faces was controlled in the range from 24 to 43 nm by the adjustment of initial volume ratio in H sub(2)O/diethylene glycol. Cubic particles exhibited high decomposition activity of organic compounds under ultraviolet irradiation. On the other hand, flake-type particles bounded mainly by {110} faces were obtained in H sub(2)O/ethylene glycol solution system, highly active for H sub(2) evolution in photocatalytic reaction. These results indicate that the {100} surface shows high oxidative activity and that the {110} surface shows high reductive activity.