Effects of sintering of TiO2 particles on the mechanisms of photocatalytic degradation of organic molecules in water

Partial degradations of 4-methoxyresorcinol and p-anisyl-1-neopentyl alcohol were carried out with the PC series of photocatalysts from Millenium Chemicals and with Degussa P25. The PC series of anatase catalysts varies only in the degree of sintering, and thus particle size and type of crystal defects. The initial product distributions were not substantially sensitive to catalyst, implying that none of the major products depended on particular binding sites that could be annealed away. Rate constants varied from catalyst to catalyst, but not dramatically, on a weight-to-volume basis. Thus there was also not a direct connection between available surface area and the rate of degradation. The product distribution as a function of suspension pH is also discussed.