A Facile Approach for the Preparation of Nano-size Zinc Oxide in Water/Glycerol with Extremely Concentrated Zinc Sources

A facile process to prepare zinc oxide (ZnO) nanoparticles from an aqueous zinc chloride (ZnCl 2 ) solution and an aqueous hydroxide solution under a glycerol stabilizer at room temperature was developed. ZnCl 2 aqueous solutions as concentrated as 65–80 wt% were used as the concentrated zinc source. The concentration of ZnCl 2 solutions and the molar ratio of glycerol to Zn 2+ had obvious effects on the sizes and shapes of the ZnO nanoparticles. The shape of ZnO nanoparticles changed from rods approximately 50–120 nm long and 30–70 nm in diameter to globular with diameters of approximately 20 nm with the increasing of the concentration of the ZnCl 2 solution and the mole ratio of glycerol to Zn 2+ . Glycerol, as a stabilizer, played an important role in the formation of ZnO nanostructures at room temperature, even for a highly concentrated zinc source.