Photocatalysed Reactions of Benzyl Alcohol on Zinc Oxide

Department of Chemistry, Indian Institute of Technology, Madras 600 036

Manuscript received 24 April 1978, revised 30 September 1978, accepted 24 April 1979

The photocatalysed oxidation of benzyl alcohol on zinc oxide has been investigated. Benzaldehyde, toluene and hydrogen peroxide are formed as the products. Their reaction in the dark is negligible. The influence of different parameters like method of preparation of the catalyst, irradiation time, solvent effect etc was studied. Detailed investigations reveal that the products result from the reaction of radicals in the liquid phase as well as a direct surface reaction. Considering the various types of oxygen species on ZnO under these conditions it is possible that oxygen either in the form of the molecule itself or in the form of a molecular anion is the entity responsible for the reaction. Though the products remained the same in solvents of different polarity their quantities as well as their behaviour is different In different solvents. Thus, more than the nature of the organic substrate itself it is the conditions to which it is subjected that determines the nature as well as the distribution of products.