Hydrothermal Synthesis Of ZnO Nanomaterials And Their Photocatalysis Properties

ZnO nanomaterials especially for one dimensional ZnO nanostructures haveattracted enormous concentrations for their extrodinary eletric and optoelectricproperties. Among all these, ZnO nanorods have been focused due to its enomousadvantages including lateral limit threshold effects, high electron transport efficiencyand large aspect ratios which promote both the fundamental researches and deviceapplications. Among all the existed growth methods, hydrothermal method isconsidered to be one of the most ideal ways for its largescale production.Hydrothermal method possesses advantages of low cost, eco-friendly and simpleness.There are many factors exist which both facile the growth of different ZnOnanostructures and complicate the corresponding growth mechanisms as well. Manyreasearchers have made their efforts on the study of synthesis methods andmechanisms of various ZnO nanomaterials, however, arguments still exist whichforbidden the furthur studies and applications. In this article, different ZnOnanostructures were synsised by changing factors including growth conditions of ZnOseed layers, concentrations and ratios of reactants, et al. Both the influences andgrowth processes were explored in details. The morphologies, crystal qualities andoptical properties were characteristiced by SEM, XRD and UV-Visible spectrumrespectively. It can be concluded that the hydrothermal growth processes of ZnO are inclose relationship with the crystal nucleation barriers and the degree ofsupersaturations which will influence the way of the crystal nucleations processes andgrowth rates of different facets. The relatively high supersaturations are benefit for thefabrications of rod-like ZnO nanostuffs. Or else, ZnO nanowires or even brick-likeZnO nanostrctures will be formed.Additionally, the photocatalytic properties of ZnO were also discussed. As ZnOnanoparticals have difficulties in recycle, the study of photocatalysis of ZnO nanorodsgrown on substrates is of great significance. In order to simulate the solar light, Xelamp was introduced. The corresponding efficiencies were judged by the lightabsorptances of methyl orange at465nm. As can be concluded that theirphotocatalytic properties are depended on the crystal quality and orientions of ZnOnanorod arrays.