In this study, the mechanism of zinc oxide (ZnO) electrodeposition from aqueous zinc nitrate solution at 70 degrees C was investigated on vitreous carbon and bulk zinc electrodes using cyclic voltammetry experiments. The first widely accepted route corresponds to ZnO precipitation from Zn2+ and OH- produced by NO3- reduction; the second route, which is discussed in this article, is due to Zn2+ reduction into metallic Zn followed by its oxidation by nitrate ions. For this case, we demonstrate why Zn formation cannot be observed while Zn2+ reduction was detected. Structure and morphology of bulk deposits were investigated using X-ray diffraction and scanning electron microscopy. Thin films of well-oriented ZnO nanorods were grown on vitreous carbon from Zn(NO3)(2) solution at low cathodic potential corresponding to that of zinc metal deposition. X-ray diffraction (XRD) measurements showed that the nanorods are crystalline and preferably grow along the (002) direction. (C) 2013 Elsevier Ltd. All rights reserved.