Improvement Possibilities of Heterogeneous Photocatalysis with the Aim of In-Field Use

Abstract

Heterogeneous photocatalysis can be successfully applied for the degradation of organic pollutants, although the efficiency of this method is insufficient. It can be increased by modification of the catalyst with precious metals (e.g. silver) or heterogeneous catalysis can be combined with other oxidative procedures such as ozonation. Another obstacle to the in-field use of the method is that separating the catalyst from the liquid phase is difficult. This problem can be eliminated by the immobilization of the catalyst. The poly(vinyl alcohol)-TiO2 immobilized catalyst has been prepared for this purpose. During TiO2-based photocatalysis, active oxygen species such as the hydroxyl radical, superoxide radical and hydrogen peroxide are produced. The formation rate of the oxidative •OH radicals was also determined in the case of the previously mentioned techniques. As a scavenger of this radical, coumarin was added.