Enhanced reactivity of the CuO-FeO intimate heterojunction for the oxidation of quinoline yellow dye (E104).

This research work describes the degradation of quinoline yellow (QY) in aqueous solutions by the heterogeneous Fenton and photo-Fenton processes in the presence of CuO/FeO photocatalyst. CuO/FeO derived from LDH structure was synthesized by the co-precipitation method. The physiochemical characteristics of CuO/FeO were described by XRD, TEM/SEM, BET surface area, and FTIR techniques. The effects of pH, HO concentration, dye concentration, catalyst dose, reaction temperature, and reusability of catalyst on the QY decolorization efficiency were studied. The results indicated that a complete removal of QY was achieved within 150 min, when the HO and QY concentrations were 27.6 mM and 100 mg/L, respectively. The rate constants for QY removal by the heterogeneous Fenton system were calculated, and the experimental data were found to fit the pseudo-first order model. Under optimal conditions, the rate constants were, respectively, 0.02032 and 0.01715 min for the photo-Fenton and Fenton systems; this means that the addition of light has not a noticeable effect.