KINETIC AND MECHANISTIC OVERVIEW OF TIO2-PHOTOCATALYZED OXIDATION REACTIONS IN AQUEOUS-SOLUTION

Destruction of trace organic compounds in water by photocatalytic oxidation over titanium dioxide is the subject of worldwide interest. In this paper we review chemical mechanisms that have been put forward to account for the observed reactions and identify some band gap and thermodynamic limitations that must be considered in developing a solar-driven process. Recent work will be discussed which tests predictions made by the mechanism concerning dependence of rates of destruction on light flux and on the presence of hydrogencarbonate ion, a known hydroxyl radical scavenger.