NiO/CuO/TiO2 ternary composites : development, physicochemical characterization and photocatalytic degradation study over Reactive Orange 30 solutions under solar light irradiation

The photocatalytic degradation and mineralization of Reactive Orange 30 on NiO/CuO/TiO2 ternary composites have been studied using solar light irradiation. The NiO/CuO/TiO2 ternary composites were prepared by producing ethanolic dispersions containing varied amounts of NiO and CuO/TiO2 (3wt% to 15wt.%), followed by annealing at 300 ̊ C. SEM, UV- Vis DRS, PL, XRD and FTIR analysis have been used to characterize the unary (parent photocatalysts), binary and ternary composites. Under solar light irradiation, NiO/CuO/TiO2 ternary composites exhibited an excellent photocatalytic activity in degradation of reactive orange 30 in aqueous solution, whereas the NiO/TiO2, CuO/TiO2 and bare photocatalyst such as NiO, CuO, TiO2 showed lower activities. It was deduced that the remarkable visible-light absorption phenomenon and band gap reduction of the NiO/CuO/TiO2 ternary composites taking place. It paves way for the photogenerated electron transfer between CB of the NiO, CuO, TiO2 semiconductors and also holes shifting between VB of above mentioned materials. The NiO/CuO/TiO2 ternary composite shows good photostability and the photocatalyst retains 94% of its initial activity in the seventh cycle, respectively.