The effects of NaCl electrolyte concentrations in the range 6-48mM on the galvanic deposition of ZnO in Zn(Ac)(2) electrolyte is presented. Effects of thermal annealing on their structural and optical properties have been investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) microanalysis and photoluminescence (PL). The results show that the increase of NaCl electrolyte concentration not only results in the increase of the diameter of ZnO nanorods, but also promotes the blue-shift of UV emission of ZnO. After air annealing at 200 degrees C, 300 degrees C and 400 degrees C, the UV emission is first enhanced then quenched sharply, while the visible emission tends to be enhanced tremendously. It can be ascribed to the new defect states introduced in ZnO after annealing at high temperature. (C) 2011 Elsevier B. V. All rights reserved.