Hydrothermal Synthesis And Characterization Of CdS Nanomaterials

Semiconductor nanomaterials have attracted considerable research activities due to many excellent properties. CdS is one of the semiconductor materials which have been prepared. CdS nanoparticles have aroused people's great attention. It has application potential and broad development prospects in the optical, electriical, magnetic, catalytic. CdS nanopowders and nanorods were prepared with hydrother- mal method at different reaction time and temperature respectively.Firstly, CdS nanoparticles were prepared successfully by hydrothermal meth- od. The crystal structure, morphology, and particle size of CdS nanoparticles was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experimental results showed that the crystal shape of CdS nanocrystals can be changed under proper processing parameters. In a certain temperature, CdS is available from cubic phase to hexagonal phase. Changing the reaction time, the result is same. Of course, samples are in favour of crystallization as the longer reaction time.Secondly, CdS nanorods were synthesized by hydrothermal method as a coor- dinating experimental conditions. The structure and morphology of the prepared samples were characterized by X ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM). The results indicated that the wurtzite CdS nanorods, with a typical diameter of 48~74nm, had a preferential [001] growth direction and displayed a quantum confinement effect. Process of photocatalytic decomposition of methylene blue on cadmium sulphide was studied using cadmium sulphide nanorods as photocatalyst and tungsten as simulated visible light. The impact of illumination time, amount of photocatalyst and initial concentration of pollutants on the photocatalytic activity was investigated. We also proposed a possible formation mechanism for the CdS nanocrystals based on the experimental results.All the same time, Optical properties of the prepared samples were charact- erized by UV-Vis and PL. The result is that nanoscale CdS of absorption peaks, whether particles or sticks, all happened blueshift other than block materials, but with the reaction temperature elevatory, absorb summit produce must happened redshift. Photoluminescence peaks all greatly occurred redshift due to the impact of surface defects.In addition, Copper nanoparticles were prepared successfully by anodic arc discharging plasma. The crystal structure,morphology, specific surface area and particle size of copper nanoparticles was characterized by X-ray diffraction (XRD), BET N2 adsorption, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction(SAED). In addition, the lattice parameters for different faces of the sample were computed.The experimental results showed that the crystal structure of the copper nanoparticles is fcc structure, and the lattice contraction was found.