Single-crystal ZnO nanowires long up to several microns were fabricated by one-step electrochemical deposition. A template-based process employing track-etched polycarbonate (TE-PC) membranes was used for this purpose. The morphology and the structure characteristics of the ZnO nanowires were analyzed by means of Scanning Electron Microscopy (SEM), Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM), and Selected Area Electron Diffraction (SAED). The growth process conditions turned out to have a marked influence on the crystal nature and morphology of the nanowires. Deposition rates ranging from 0.4 nm s −1 and up to 0.6 nm s −1 were recorded for the growth of ZnO nanowires. The obtained results showed that by using carefully controlled deposition conditions single crystalline nanowires and fine-grained structures can be routinely obtained. ZnO has extrusive physical properties such as a direct bandgap in the ultraviolet range (3.37 eV) or a large exciton binding energy (60 meV) which have made it a great application prospect.1, 2 ZnO nano-objects have been widely investigated in the recent years owing to promising applications in nanodevices. They showed high sensitivity to different chemicals, have piezo-and pyro-electric properties, etc. 3,4 As it has been shown that band edge, exciton energies, and UV luminescence of ZnO nanostructures are affected by crystallite size and crystal morphology, 5,6 it is desirable to tailor their electronic properties in order to exploit the broad range of applications.Nowadays, many efforts still focus on synthesizing oriented onedimensional ZnO nanostructures. Up to now, techniques using sophisticated and expensive equipments but also low temperature and cost-effective methods such as electrodeposition (ED) and hydrothermal deposition were employed for the synthesis of nanostructures. 7-9The major advantage of the electrochemical synthesis is given by its application for large area and high throughput productions, therefore suitable for an industrial use. [10][11][12][13] The ED of ZnO nanowires has been focused mostly on the preparation of nanorod/nanowire arrays by the template method and on flat substrates. 14, 15The ZnO electrodeposition is based on the reduction of an oxygen precursor such as dissolved molecular oxygen, nitrate ions or hydrogen peroxide. For example, Cembrero et al. 16 reported on the cathodic electrodeposition of ZnO nanocolumns and nanowires from zinc chloride solutions saturated in molecular oxygen. The general scheme for ED of ZnO employing different oxygen precursors is supposed as follows.The reaction at the cathode surface employing different oxygen precursors: The process evolves itself drifting the pH of the electrolyte to a constant increase and to a local supersaturation of the bath in the vicinity of the electrode, thus provoking the precipitation on the electrode surface of ZnO;18 therefore, if a specific crystal order is desired, the pH of the electrolytic solution has to be precisely controlled and adjusted to a proper value.As...

The electrodeposition of cuprous oxide (Cu2O) onto FTO-coated glass substrate was studied by using a statistical approach in order to control the Cu2O morphology and optical properties. The factorial design considered four electrodeposition conditions at two representative levels as input variables (electrolyte temperature and pH, deposition potential and duration) and the deposition charge and morphology of obtained Cu2O as the output variables. The morphology analysis showed the highest influence on crystal shape was exhibited by electrolyte temperature and pH, reaching significance levels of 95 and 98%, respectively. Temperature as low as 35°C and pH 12.2 results in cubic morphology, while other parameters result in octahedron shape. The highest absorbance was exhibited by the Cu2O with cubic morphology.