Photocatalytic Oxidation of Cyanide on Platinized TiO2

Article abstract of DOI:10.1021/j100450a008

The photocatalytic oxidation of cyanide on platinized TiO2 was studied mainly from the standpoint of semiconductor electrochemistry to elucidate the role of platinum deposited on TiO2 photocatalysts.It was found that platinization enhances the rate of the oxygen reduction which constitutes a partial process of the photocatalytic reaction, but suppresses the rate of photosensitized oxidation as the counter partial process in which cyanide is oxidized competitively with water.The activities of single crystal and powder TiO2 catalysts for photocatalytic reaction were compared for cases with and without 50 monolayers of Pt.They were found comparable in spite of a large surface area of the latter, suggesting that the number of photons striking the catalyst surface entirely controls the rate of photocatalytic reaction.Effects of platinization on the electrochemical properties of TiO2, evaluation of the rate of photocatalytic reaction by electrochemical analyses, and effects of illumination on the photocatalytic process are discussed.