氢还原硝酸银气溶胶制备纳米银粉

摘要

采用高频超声波发生器生成硝酸银气雾滴,然后用氢气还原硝酸银制备纳米银粉.研究前驱体浓度和反应温度对产物粒径、形貌和晶粒尺寸的影响.在200℃的氢气气氛中,以硝酸银为原料制得的纳米银粉中含有氧化物.当反应温度超过200℃时可以制得纯银粉:X射线衍射分析表明,所制得样品的晶粒尺寸为29～47 nm.研究表明反应温度对产物的粒径有明显影响.随着前驱体浓度的增加,所得纳米粉末的晶粒尺寸增加.SEM观察表明,产物银粉呈球形,粒径为210～525 nm.反应温度和前驱体浓度对产物粒径有明显影响.%Nanocrystalline silver particles were produced by hydrogen reduction of silver nitrate aerosol droplets formed by high frequency ultrasonic generator.The dependences of the particle size,morphology and crystallite size on the precursor concentration and the reaction temperature were investigated.Ultrasonic spray pyrolysis process was combined with hydrogen reduction to research the effects on the silver particle production.Nanocrystalline silver particles including slight oxide structure were prepared at temperature as low as 200 ℃ from silver nitrate under hydrogen atmosphere.X-ray diffraction (XRD) studies showed that pure silver particles were obtained above 200 ℃ reaction temperature.The crystallite sizes of the samples ranged from 29 to 47 nm.The results indicate that the crystallite sizes hardly ever depended on the reaction temperature.Crystallites slightly enlarged by increasing precursor concentration.SEM observations showed that particles were obtained in spherical morphology with particle sizes between 210 and 525 nm.Reaction temperature and precursor concentration strongly influenced the particle size.