Fabrication of hand-like CuO nanostructured films by free oxidation of Cu2O nanoporous films in alkaline solution

Abstract

In this work, hand-like CuO nanostructured films were successfully fabricated by free oxidation of sputtered Cu2O nanoporous films in alkaline solution. Scanning electron microscopy, powder x-ray diffraction and ultraviolet–visible spectrum testing were carried out for a detailed characterization. As-fabricated CuO films were composed of a lot of intriguing hand-like CuO which was inclined randomly to the substrate and thus exhibited a highly nanostructured film surface. The corrosion processes were further studied and the possible formation mechanism was consequently revealed. Optical testing results demonstrated that the band gap of the as-fabricated hand-like CuO nanostructured films was estimated to be 2.15 eV, which demonstrates a large blue shift relative to that of bulk CuO.