Photoassisted degradation of endocrine disruptors over CuOx-FeOOH with H2O2 at neutral pH

CuOx-doped alpha-FeOOH (CuOx-FeOOH) nanorods were synthesized by controlling the reaction between ferrous sulfate, cupric sulfate and sodium borohydride at ambient atmosphere. The resulting materials were characterized by transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. CuOx-FeOOH was mainly composed of alpha-FeOOH and CuOx (CuO and Cu2O). The catalyst was found to be highly effective for the degradation of endocrine disruptors, including dimethyl phthalate, 2,4-dichlorophenoxyacetic acid, and 2,4-dichlorophenol in the presence of H2O2 and UVA at neutral pH. By the total organic carbon and GC-MS analysis, the degradation process of DMP was shown to proceed with the cleavage of C-O bond in ester linkages and the phenyl ring opening into organic acids and CO2. The studies of (OH)-O-center dot formation and cyclic voltammetry revealed that the H2O2 was decomposed into (OH)-O-center dot or O-2 by the promotion of metal oxide. The obtained results showed that the synergistic effect between CuOx and alpha-FeOOH markedly enhanced the H2O2 decomposition into (OH)-O-center dot in CuOx-FeOOH suspension, causing the higher catalytic reactivity. A possible reaction mechanism was proposed. (C) 2008 Published by Elsevier B.V.