Photocatalytic degradation of dimethomorph on nanometer titanium dioxide by silver depositing in aqueous suspension

摘要

A series of catalysts of nanometer TiO2 were prepared by silver depositing. The photocatalytic degradation of dimethomorph in an aqueous suspensions by silver depositing with nanometer titanium dioxide as catalyst was investigated by radiation of UV-light and sunlight. A pseudo-first-order kinetic model was used to describe the results. The effects of the dosage of catalyst, oxidant, pH and radiation source on degradation were examined. The experimental results show that the decomposed rate of DMM is 94% when the dosage of catalyst is 1.25g/L and the concentration of DMM is 100mg/L under the conditions of solution pH of 7, the air flow of 1.5L/min and shining for 5h by UV-light. When it is shined by sun-light under the same condition, the decomposed rate of DMM is 48%. The mechanism of decomposition was discussed based on the data by analysis of LC-MS.