Enhanced visible photocatalytic activity of tree-like ZnO/CuO nanostructure on Cu foam

Novel tree-like ZnO/CuO composite, composed of CuO nanowire trunks and ZnO nanorod branches, have been successfully synthesized on Cu foam substrate. Single-crystalline CuO nanowires and ZnO nanorods are obtained by thermal oxidation and hydrothermal processes, respectively. The morphological, crystal and optical properties of the as-prepared samples have been studied by field-emission scanning microscopy, X-ray diffractometer, transmission electron microscopy, and UV-vis spectrophotometer. The resultant tree-like ZnO/CuO composites on Cu foam show excellent photocatalytic activity with a rate constant of about 0.0073 min(-1) in the photo-degradation of Rhodamine B (RhB) under visible light (lambda > 420 nm). The Cu foam not only provides extra-large surface area for the growth of tree-like CuO/ZnO composites, but also acts as an effective frame to support the catalysts. Furthermore, tree-like ZnO/CuO composite catalysts show high recovery yield for the recycling during the degradation of organic pollutants. This work provides an insight view into the design and synthesis of composite photocatalyst effectively supported by a substrate.