Heterostructured metal oxides-ZnO nanorods films prepared by SPPS route for photodegradation applications

This work presents the first preparation using the Solution Precursor Plasma Spray process of heterostructured films associating ZnO nanorods (NRs) and various metal oxides (CuO, Fe2O3 and Co3O4) by Solution Precursor Plasma Spray process. These CuO/ZnO, Fe2O3/ZnO and Co3O4/ZnO films exhibit hierarchically chocolate sticks-like, dandelion-like or chrysanthemum-like surface morphologies. These heterostructures were confirmed by SEM, XRD, EDS and Raman analyses. The bandgaps of heterostructured films are narrower than that of pure ZnO. The CuO/ZnO film exhibits the highest photocatalytic activity both under UV and visible light irradiation for the degradation of the Orange II dye due to the homogenous distribution of CuO at the surface of ZnO. The high photocatalytic performances originate from the increased visible light absorption and from the effective separation of charge carriers in CuO/ZnO films compared to ZnO NRs.