An aqueous solution of 0.1 M NH4OH was mixed with 0.1 M of Zn(NO3)2•6H2O for 1 hr to obtained Zn(OH)2 precipitate. The Zn(OH)2 precipitate was dispersed as sol in 100 mL of ethylene glycol and then heated at 75 °C for 24 hrs in close glass vessel. After that, 100 mL of 0.2 M NH4OH was added into the treated sol to obtain the ZnO nanoparticles. The ZnO nanoparticles were separated by centrifugation at 3000 rpm for 5 min and dried at 75 °C in an oven for overnight. The ZnO nanoparticles were characterization by X-ray diffractometer (XRD; Bruker AG, D8 Advance) and scanning electron microscope (SEM; JEOL, JSM-5410LV).