| In this paper, ZnO and SnO2 nanoparticles were prepared by Laser heating gas-evaporation method, sol-gel, homogeneous precipitation method. Transmission electron microscopy (TEM), electron diffraction patterns (ED), X-ray-diffraction (XRD) and heat analyzer(TG-DTA) were used to describe the characteristics of these samples. The effects of process parameters on the nanoparticles have been studied. The results of preparation of ZnO nanoparticle show that the more powerful laser power, the higher reaction temperature; the size of the particles is small as the pressure is low and the rate of carrier gas is high; and different content of the nanoparticles is the result of the different reaction gas. It is also discovered that in inert gases, the products are Zn and ZnO; in the oxygen, the products are ZnO. Dispersed nanometer-size SnO2 particles were prepared by sol-gel method, with alkali and Tin tetra-chlorine as the starting materials. The results indicate that the calcination temperature, alkali and the tolerance of reagent greatly influence SnO2 nanoparticles size. The results show that the mean grain size of the SnO2 nanoparticles is about 20～100nm in the experiment conditions. Nano-SnO2 particles were also prepared by homogeneous precipitation method with urea and Tin tetra-chlorine as raw materials. The results show that well-crystallized nanometer-size SnO2 particles were prepared at annealing temperature of 600℃.The particles with average size of 15nm, fine dispersion and narrow-size distribution were obtained by controlling reaction conditions. In addition, the reaction mechanism of nano-SnO2 is also discussed.
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