Photocatalytic degradation of dodecyl-benzenesulfonate over TiO2–Cu2O under visible irradiation

A series of TiO2–Cu2O mixed oxides were prepared by the hydrolysis of titanium butoxide and reduction of copper acetate with hydrazine. These composite oxides were characterized by X-ray diffraction (XRD), inductively coupled plasma spectrometry (ICP), high-resolution transmission electron microscopy (HRTEM), N2 adsorption and UV–vis techniques. Photocatalytic degradation of dodecyl-benzenesulfonate (DBS) under visible irradiation was performed, and effects of composition of catalysts and reaction conditions were studied. It was observed that TiO2–Cu2O composite oxides exhibited better photocatalytic activity than Cu2O or TiO2 alone. Among these composite oxides, the 5%TiO2–Cu2O displayed the highest activity, and the degradation percentage of DBS and COD reached 97.3% and 65%, respectively. In addition, it was found that the decomposition of DBS followed the first-order kinetics and the adsorption of DBS followed the Langmuir model. Oxygen in solution played a vital role in the elimination of COD.