Study On The Preparation Of Metal Oxide Nanoparticles By Laser Heating Gas-Evaporation Method

Co/CoO , Cu/CuO, Zn/ZnO nanopartiles were prepared by Laser heating gas- evaporation method with Co(AC)2 ?4H2O, Cu(AC)2 ?4H2O or Zn as the targets respectively, and a laser of 150W CW CO2 as the light source. Complexo-metrictitration of EDTA, Transmission electron microscopy (TEM), electron diffraction patterns (ED), X-ray-diffraction (XRD) and vibrating-sample magnetometer (VSM) were used to describe the characteristics of these samples. The effects of process parameters on the nanoparticles have been pilot studied.The results of preparation of Co/CoO nanoparticles 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, in the oxygen or in the hydrogen, the products are Co and CoO. In addition, the particles have been found have magnetic properties: o s=51.96emu/g,Hc= 614 Oe.The results of preparation of Cu/CuO nanoparticles show that the process parameters such as Laser power density, reaction pressure, the sorts and rate of airflow et al, effect the sizes and crystal system of nanoparticles. In inert gases, the products are Cu and CU2O, the diameter of nanoparticles is between 10 and 30 nm; In the oxygen, the products are Cu , Cu2O and CuO, the diameter of nanoparticles is between 10 and 50 nm .The results of preparation of Zn/ZnO nanoparticles show that the process parameters such as reaction pressure, the sorts and rate of airflow etal, effect the sizes and crystal system of nanoparticles. In the different reaction atmosphere, the products are different. It is also discovered that in inert gases, in the oxygen or in the hydrogen, the products are Zn and ZnO; In the oxygen, the products are pure ZnO nanoparticles, in the hydrogen, the products are Zn nanoparticles only.In short, The preparation of the oxide nanopartiles by the method of the heating gas-evaporation is controlled easily. The products have some quality such as good dispersing and small diameter. The process has simple technology, highly yield and low cost. And it is expected to have the possibility of wide applications in industry in the future.Moreover, on the basis of classical theory of nucleation, the effects of process parameters on the nanopaticles have been pilot studied by application thermodynamics and dynamics theory in the forming process in this paper, and some primary conclusion has been achieved.