Studies On The Synthesis And Characterization Of Monodispersed Nano-oxides Suspension

The nano-oxides have been widely used because they have special function in catalysis, optics and electricity . However, the nano-sized particles acquired by the conventional methods have a strong tendency to agglomerate and easily become biggish conglomerations, which are difficult to disperse again. Agglomeration has become a bottleneck of the application of the nanopowders and restrains namomaterials from producing industrially and applying sweepingly.Ever since, the nanoparticles acquired by conventional methods usually need further dispersion. But few studies on the dispersion in process of synthesis are reported. Here, the dispersion during the crystallization of nano-oxides is attempted to discuss in this paper. During the process of formation of nanoparticles, the surface of particles is separated through controlling the reaction conditions and the particles cannot agglomerate. Thus the monodispersed nano-oxides have been prepared directly and they need not further modification and disposal. In-situ reaction is usable to the synthesis of metal colloids in previous reports. Now ZnO and ATO have been synthesized through this route.Aqueous solution of monodispersed ZnO nanorods was prepared with ZnCl₂ as raw material and PVP as surfactant by a simple chemical reduction. The ZnO nanorods were characterized by means of transmission electron microscopy(TEM), X-ray diffraction(XRD) and their properties of ultraviolet and visible light absorbing were also studied. The influence of experimental conditions, such as reaction time, quantity of PVP and concentration of Zn²⁺ etc on the quality of the nanorods were discussed. Through altering Zn²⁺/ PVP wt ratio, the size of ZnO could be controlled. The present method is simple and the product only contains ZnO and PVP, which are unharmful to the people. Therefore, if the present technique is properly extended, it will be widely used for practice.ATO nanoparticles obtained with the conventional methods have a strong tendency to agglomerate because a better doping needs higher temperature. So it is difficult to obtain the monodispersed nanoparticles together with a preferable Sb doped level by conventional methods. In this paper, we report a method for one step synthesis ofmonodispersed ATO nanoparticles employing mild hydrothermal route by controlling the heating temperature with stage elevation. The samples are analyzed by XRD, TEM and SEM-EDS. These ATO nanoparticles show a good dispersability. The present method is simple but realizes one-step synthesis of monodispersed antimony-doped tin oxide suspension under low temperature in a short time, which highly enhance the application of the ATO particles. Therefore, the present technique can be properly extended to other doped oxides;it will be worthy of further research.