连二亚硫酸钠还原制备纳米银粉

通过向银的乙二胺四乙酸络合溶液中滴加还原剂连二亚硫酸钠溶液制备了纳米尺寸的银粉。考察了硝酸银浓度、络合剂用量、还原剂浓度、pH值、反应温度、搅拌速度、还原剂溶液滴加速度对所制得银粉粒径的影响, 用X射线衍射和场发射扫描电镜对所制银粉的晶体结构和形貌进行了表征。试验结果表明, 在Ag-EDTA络合溶液浓度为0.005 mol/L, EDTA过量10%, pH值为11.5, 还原剂浓度为0.0075 mol/L, 搅拌转速为400 r/min, 反应温度为50 ℃, 还原剂滴加速度为0.06 mL/s的条件下, 所得银粉的平均粒径为58 nm。

Preparation of Silver Nanoparticles Using Sodium Dithionite as Reducing Agent

Nano-sized silver powder was prepared by dropwise adding sodium dithionite solution to the solution of silver ethylene diamine tetraacetic acid(EDTA) complex.The effects of silver nitrate concentration,dosage of complexing agent,concentration of reducing agent,pH,reaction temperature,stirring speed,and adding speed of reducing agent solution on silver particle size have been investigated.The crystal structure and morphology of silver particles prepared were characterized using X-ray diffraction(XRD) and field emission scanning electron microscope(FESEM).The experimental results showed that silver particles with an average size of 58 nm were prepared under the conditions such as Ag-EDTA complex solution concentration of 0.005 mol/L,excessive amount of EDTA of 10%,pH of 11.5,reductant concentration of 0.0075 mol/L,stirring speed of 400 r/min,reaction temperature of 50 ℃ and reductant adding speed of 0.06 mL/s.