FORMATION OF ENERGY RICH COMPOUNDS AT LIGHT ACTIVATED SENSITIZER SURFACES

Study of photosensitized oxidation of isopropyl alcohol to acetone at ZnO surfaces irradiated by light at 3650 A indicates that an excited O anion, probably O2(-), is the photo-activated center formed at the catalyst surface. The alcohol is quantitatively converted to acetone. Formation of high molecular weight polymers on irradiation of methyl methacrylate in dilute solutions at ZnO surfaces confirms the role of O2(-). Both formation and decomposition of H2O2 at irradiated ZnO surfaces are inhibited by cyanides and amides. Extensive IR studies of ZnO catalysts pretreated with solutions of cyanides and amides show strongly adsorbed N containing fragments. Knowledge of the effects of O and formamide at irradiated ZnO surfaces was utilized to construct photoelectric cells with electrodes made by coating ZnO on Pt mesh. Discovery of a unique and efficient photosensi tizedformation of carotene in the presence of pheophytine irradiated by red light is reported.