Preparation And Properties Of BN, GaN, ZnS Nanomaterials

In recent years, semiconductor materials and other novel function materials have attracted scientific researchers' considerable attention due to their unique performances, which enable them to find applications in electronic industry, high temperature resistant structural ceramics and photocatalytic activity aspects etc.. Researches on their synthesis, properties and application are becoming more and more important.In this thesis, the BN, GaN nanomaterials have been synthesized via thermal routes, ZnS nanomaterials has been synthesized through simple solvothermal route. The phase structures, morphologies and properties of the products were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric (TGA) and photocatalysis etc. measurements. The main results are as follows:(1) In this experiment, we use NH4HB4O7·3H2O,NaBH4,H3BO3 as boron source and NH4Cl,N2H4·2HCl as nitrogen source, metallic Mg powders as reductant to synthesize nanocrystalline hexagonal boron nitride. Nanocrystalline GaN has been synthesized in an autoclave, which we use Ga2O3 as gallium source, NH4Cl as nitrogen source and metallic magnesium powders as reductant. About 500℃-650℃, raw materials can be synthesized target product. And in this route, the influences of different ratio of raw materials, reaction temperature and time on the phase structure and morphology of the products were all investigated. The results show that the optimal condition was at 650℃for 8h, the products have the nanocrystalline h-BN and h-GaN structure. Compared with other methods, the synthesis temperature is 400℃lower. And the as-prepared h-GaN exhibits good photocatalytic oxidation decomposition activity in degradation of Rhodamine-B (RhB) under 300 W mercury lamp light irradiation.(2) In this experiment, ZnS microns ball have been synthesized through simple solvothermal route by the reaction of ZnCl2 and CH3CSNH2. From the SEM images:ZnS microns ball is assembled into the 3D multilevel structure by ZnS nanoparticles.The influence of different solvents, reaction temperature and time on the phase structure and morphology of the products were all investigated. The results show that c-ZnS nanoparticle can be synthesized when the reaction condition was 200℃,5h, distilled water as solvent. On the base, we study photocatalysis activities of ZnS doping Mn²⁺,Cu²⁺,Cd²⁺, respectively. Among them, doping Cd²⁺ promote the photocatalysis activity of the ZnS microns ball,which it can degrade 100ml Rhodamine-B (RhB) (10^-5 mol/L) in two hours under 300 W mercury lamp light irradiation.