Electrodeposition of Cu-ZnO nanocomposites: Effect of growth conditions on morphologies and surface properties

Nanostructured Cu-ZnO films were synthesized on zinc foil using an electrochemical deposition method. The effects of the deposition time and stirring of the electrolyte on the growth process were investigated. The properties of the synthesized films were characterized using different techniques. The X-ray diffractometry results indicated a set of diffraction peaks, which were indexed to the ZnO, Zn(OH)2, and Cu phases. In the case of stirring, more characteristic diffraction peaks were found, such as for the CuCl phase and other Zn(OH)2 planes. Scanning electron microscopy observations revealed agglomerated particles with irregular shapes when stirring the electrolyte, and leaf-like, flower-like, and hexagonally funnel tube structures for the unstirred condition. Energy-dispersive X-ray spectrometry studies only indicated the presence of Cu, Zn, Cl, and, O atoms for the stirred condition, whereas the same results with different percentages and an absence of Cl atoms were found in the unstirred condition. Transmission electron microscopy results showed that the synthesized nanostructures consisted of Cu nanoparticles, along with a ZnO dendrite shape with several branches. A possible growth mechanism, based on the growth conditions, was proposed. The UV-visible diffuse reflectance spectra and photoluminescence studies confirmed the effect of the growth conditions on the optical properties. Finally, the water contact angle technique was used for wettability measurements. The wettability results showed a great superhydrophobicity for the film. © 2014 Elsevier Ltd.