The sorption properties of rutile and its catalytic activity in the destruction of dyes

The photocatalytic destruction of cationic and anionic dyes on dispersed spectrally pure rutile in the presence of oxygen was studied. The rate constant for these reactions does not correlate with the rate constant for the photobleaching of these dyes in homogeneous solutions in the absence of a catalyst, the rate constants for adsorption, and the rate of establishment of sorption equilibrium in rutile-dye systems, but increases as the sorption value grows. The photocatalytic process substantially disturbs sorption equilibrium in most of the systems studied. The conclusion is drawn that both weakly and strongly sorbed substrate molecules can participate in the photocatalytic process.