Effects of photo-irradiation on the rates of sonochemical reactions

摘要

Sono-photo chemical reactions of carboxylic acids, especially oxalic acid were performed in an Ar atmosphere. CO2, CO and H2 were evolved in gas phase. In liquid phase, any carbon products could not be detected. The yields of CO2 and CO were larger than the sum of yields of photolysis and sonolysis. Thus, synergetic effect was observed under both ultrasound and photo irradiations. In this synergetic effect, H2O2 formed from solvent (H2O) by sonolysis was thought to play an important role. To clear mechanism, examination was also performed in the absence or presence of H2O2 under only photo irradiation. Furthermore, effects of intensity of light and concentration of reactat on the rate of the reaction were examined.