摘要:
MCPA was irradiated in various conditions: in aqueous solution at different wavelengths, on silica in the absence of water, in the presence of TiO2, in aqueous suspension. In solution a wavelength effect was observed: the formation of 4-hydroxy-2-methylphenoxyacetic acid is the main pathway at wavelengths shorter than 300 nm, whereas 4-chloro-2-methylphenol is the main product resulting from sunlight irradiation. Direct photolysis on silica and photocatalytic transformation mainly lead to the formation of 4-chloro-2-methylphenol.