Effect of supporting electrolytes on the growth and optical properties of electrochemically deposited ZnO nanorods

•ZnO nanorods have been synthesized by electrodeposition at relatively low temperature.•Supporting electrolyte influence the growth and crystalline quality of ZnO nanorods.•KNO3 supporting electrolyte incorporates a new defect in ZnO nanorods and which is attributed to zinc vacancy.•Optical properties of ZnO nanorods can be tuned by supporting electrolytes.

The effect of supporting electrolytes on the electrochemical deposition of ZnO nanorods have been investigated by introducing KCl, K2SO4 and KNO3, respectively, into zinc nitrate electrolyte. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL) showed that the ZnO nanorods tend to grow in all three supporting electrolytes. However, the density and aspects ratio of nanorods strongly depend on the nature of supporting electrolytes. The nanorods exhibit good crystalline quality with wurtzite crystal structure. The nanorods have strong UV emission peak centered at 380 nm and a broad defect band around 590 nm. The intensity of defect-related emission peak strongly depends on the nature of supporting electrolytes.