Preparation And Characterization Of Ultrafine Ag, Ni And NiO Powders

Ultrafine (nano) metal and its oxide powders have broaden applicationprospect in fields of catalysis, photoelectric, electromagnetic materials for theirunique and excellent properties. The performances of the superfine powdersdepend on particle size, particle size distribution and morphology, thereforepreparation of high purity and ultrafine powders with small particle size andnarrow particle size distribution has always been the hot area of research. In thispaper, ultrafine (nano) Ag, Ni and NiO powders were successfully prepared byliquid phase reduction method and glycine-nitrate route (GNP) respectively. Theinfluences of preparation methods on the properties, morphology and particlesize of powders were systematically studied; this paper also explored the way ofpreparation high purity and superfine powders preliminarily.1. By using silver nitrate, hydrazine hydrate, glycine as raw materials, Agpowders were prepared by liquid phase reduction method and glycine-nitrateprocess respectively. Under the action of composite protective agent, Agpowders with the average particle size of16nm, narrow particle sizedistribution range and spherical nanometer were obtained. The Ag powderscollected by GNP route own the particle size of91nm, nearly sphericalmorphology. GNP route owns higher productive rate and collecting rate.2. By using nickel nitrate hexahydrate, hydrazine hydrate, glycine as rawmaterials, preparation of Ag powders was performed by liquid phase reductionmethod and glycine-nitrate process respectively. The average particle size is100nm, narrow size distribution range and spherical nanosized nickel powders wereprepared by using composite protective agent. When the mole ratio of glycineand Ni2+was1.4:1, pure nickel powders were prepared by GNP route with theparticle size of10nm and spherical morphology.3. By using nickel nitrate hexahydrate, glycine as raw materials, pure phaseNiO powders were synthesized when the mole ratio of glycine and Ni2+was0.3:1with particle size of65nm, nearly spherical morphology, what’s more,the degradation rate of methyl orange reach up to93.4%after2h ultravioletlight irradiation.4. Nitrate-doped nanosized NiO powders were prepared by calcining different quality of NiO powders and urea, and samples with the mass ratio of1:2demonstrate a degradation rate of methyl orange up to82.1%after2h sunlightlamp irradiation.