维生素E绿色还原法制备银纳米粒子的研究

Study of Preparation of Ag Nanoparticles with Vitamin E through Green Chemical Reduction

采用一种绿色还原法制备银纳米粒子，以维生素E为还原剂，淀粉为稳定剂，在液相中还原硫酸银，通过改变溶液的pH值和反应时间，得到不同粒径的黄色银纳米粒子，并分别采用透射电镜、红外光谱、紫外-可见吸收光谱、扫描电镜和电化学方法对银纳米粒子进行表征。结果表明：维生素E在溶液中被氧化生成苯醌，反应得到的银纳米粒子为球形，粒径为8~25 nm；在较强碱性条件下，得到的银纳米粒子尺寸较小，分布较均匀，其平均粒径约为10 nm；不同条件下生成的银溶胶分别在417、411、409、408 nm处出现紫外吸收峰，这些吸收峰均为银纳米粒子的表面共振吸收；生成的银纳米粒子具有很好的电化学性质，并对L 半胱氨酸的电化学反应显示了良好的催化活性。

In this paper,the silver nanoparticles were prepared through green chemical reduction of silver sulfate in the liquid phase using vitamin E（VE） as a reducing agent,and starch as a stabilizer.Yellow silver nanoparticles with different sizes were obtained by changing pH value of solution and reaction time.The silver nanoparticles were characterized by transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FT-IR）,ultraviolet-visible spectroscopy（UV-vis）,scanning electron microscopy（SEM） and electrochemical method.The results indicated that VE molecules in the solution were oxidized to benzoquinone,and the synthesized silver nanoparticles were spherical with a diameter range of 8-25 nm.And in strong alkaline condition,the silver nanoparticles were smaller,distributing more uniformly with an average diameter of about 10 nm.The strong absorption bands at 417,411,409,408 nm appeared in the UV-vis spectra for different silver particle solutions,which could attribute to the excitation of surface plasmons in the nanoparticles.The silver nanoparticles also exhibited excellent electrochemical property and good electrocatalytic activity for the electrochemical behavior of L-cysteine.