Hydroxyl Radical Scavenging-based Method for Evaluation of TiO2 Photocatalytic Activity

Abstract

A novel hydroxyl radical scavenging method was developed to establish the photocatalytic activity of TiO2 thin films. Transparent TiO2 thin films were prepared on soda-lime glass substrates using the sol-gel method and characterized using X-ray diffraction. During photoirradiation in aqueous buffered solutions, activity of the films was followed using the substituted nitrobenzene N,N’-(5-nitro-1,3 phenylene)bisglutaramide as a hydroxyl radical scavenger and its hydroxylated products were quantified using HPLC. The yield of hydroxyl radicals was evaluated at various pH of the reaction media, and reflected the dependence of the rate of the hydroxylation reaction on the experimental conditions and on the different qualities of the TiO2 thin films. The proposed method allows for direct assessment of hydroxyl radical production, it is straightforward and is proposed for routine use.