Correlation between some physical properties of titanium dioxide particles and their photocatalytic activity for some probe reactions in aqueous systems

Nanocrystalline anatase titanium(IV) oxide (TiO2) particles were synthesized by hydrothermal crystallization in organic media (HyCOM) followed by calcination at various temperatures up to 1273 K, and they were characterized by analysis of surface adsorption of the substrates, as well as by X-ray diffraction (XRD) and Brunauer−Emmet−Teller (BET) surface area measurements. These HyCOM TiO2 samples were used for three kinds of photocatalytic reactions:  mineralization of acetic acid (AcOH) in aerated aqueous suspensions, dehydrogenation of 2-propanol (2-PrOH) by in situ platinized powders, and silver-metal deposition from silver ions (Ag+) in deaerated aqueous suspensions of bare TiO2 samples. Dependence of the photocatalytic activities on calcination temperature (Tc) and on the amount of adsorbed substrates in each reaction and correlations with the physical properties of HyCOM TiO2 were examined. In the case of mineralization of AcOH, the activitiy of each sample was almost proportional to the amount of su...