Temperature and Solvent Impact on Zinc Oxide Nanostructures Synthesized via Hydro-Solvo-Thermal Technique

This work presents temperature impact on ZnO nanostructures growth when synthesized via solvo-thermal technique. For a temperature range of 70, 100, 130 and 160 C, and precursors of Zinc acetate dihydrate and sodium hydroxide (both dissolved in methanol) we noticed an obvious temperature impact on the grain size and hence an obvious variation on the corresponding band gap energy. Having the fact that ZnO is a semiconductor, variation of ZnO nanostructures band gap energy means variation of quantum confinement effect, which is considered to be an essential parameter to tune semiconductors optical and electrical properties. This work also presents solvent impact on ZnO nanostructures growth when synthesized via hydro-solvo-thermal technique at temperatures of 70 C and 150 C, and precursors of Zinc acetate dihydrate and sodium hydroxide, both dissolved in H2OMethanole solution mixtures of 13, 22, 31 and 13. Again, we noticed an obvious solvent impact on ZnO nanostructures shapes and sizes. Morphology, crystalline structure and optical properties of ZnO nanostructures were determined using field emission scanning electron microscopy (FE-SEM), X-ray diffraction crystallography (XRD) and UV-Vis spectroscopy. SEM measurements showed particles sizes increment as temperatures increase. XRD measurements showed hexagonal crystalline-wurtzite phase structures in all temperatures. UV-vis measurements showed red shifts absorptions as a result of particles sizes increment, and hence, decrement for the corresponding band gap energy in comparison with the bulk one. Average sizes of ZnO nanostructures varied between 50 to 500nm. ZnO nanostructures, ZnO-XRD, ZnO-UV-vis, ZnO-SEM, ZnO-hydrothermal.