Electrochemical Deposition of ZnO Nanowires on CVD-Graphene/Copper Substrates.

ZnO nanostructures were electrochemically synthesized on Cu and on chemical vapor deposited (CVD)-graphene/Cu electrodes. The deposition was performed at different electrode potentials ranging from -0.8 to -1.2 V, employing a zinc nitrate bath, and using voltametric and chronoamperometric techniques. The effects of the electrode nature and of the working electrode potential on the structural, morphological, and optical properties of the ZnO structures were investigated. It was found that all the samples crystallize in hexagonal wurtzite structure with a preferential orientation along the c-axis. Scanning electron microscopy (SEM) images confirm that the presence of a graphene covered electrode led to the formation of ZnO nanowires with a smaller diameter compared with the deposition directly on copper surface. The photoluminescence (PL) measurements revealed that the ZnO nanowires grown on graphene/Cu exhibit stronger emission compared to the nanowires grown on Cu. The obtained results add another possibility of tailoring the properties of such nanostructured films according to the specific functionality required.