Titanium(IV) oxide photocatalyst of ultra-high activity: a new preparationprocess allowing compatibility of high adsorptivity and low electron-hole recombination probability

Microcrystalline anatase titanium(IV) oxide (TiO2) particles were synthesiz ed by hydrothermal crystallization in organic media (HyCOM) followed by cal cination, and used in a photocatalytic reaction system of silver metal depo sition. Upon elevating the post-calcination temperature, the photocatalytic activity was enhanced in spite of the simultaneous decrease in amount of s urface-adsorbed Ag+. Comparison with the effect of calcination temperature on the other reaction systems revealed that the annealing effect became mor e significant with increasing number of electrons (or holes) required to co mplete the photocatalytic reaction process.