小尺寸纳米铁颗粒的液相还原控制制备

Synthesis of Small Size Iron Nanoparticles by Controlling Liquid-phase Reduction Method

在液相还原法基础上,以醇水混溶为溶剂,聚乙烯吡咯烷酮（PVP）为稳定剂,通过控制醇和PVP用量合成出粒径在9~20nm的粒径均一、分散性好的纳米铁粒子.通过动态光散射（DLS）、透射电子显微镜（TEM）以及紫外-可见分光光度计等表征手段对醇和PVP在液相合成中的作用以及小尺寸纳米铁的活性进行考察.研究表明,醇的作用主要为抑制纳米铁生长以及使Fe2＋均匀分散到PVP中,而PVP则通过其空间位阻作用和静电排斥作用阻止纳米粒子的团聚;随醇中羟基数增加、碳链长度增长,纳米铁粒径逐渐减小;随醇浓度增加,纳米铁粒径减小;同时,随纳米铁尺寸减小,其活性显著增强.

A series of iron nanoparticles with uniform sizes and good dispersion ranging from 9 to 20 nm were produced on the basis of liquid-phase reduction method from water and alcohol as a solvent and polyvinylpyrrolidone（PVP）as a capping agent by controlling the dosage of alcohol and PVP.Dynamic Light Scattering（DLS）,transmission electron microscopy（TEM）and UV-vis spectroscopy（UV-vis）were used to investigate the role of alcohol and PVP in the liquid synthesis,as well as the activity of small size iron nanoparticles.In the liquid synthesis,the main role of alcohol is to inhibit the growth of nanoscale zero-valent iron（nZVI）and make Fe2＋evenly scattered in the PVP solution,while PVP through its vast steric hindrance and electrostatic repulsion to prevent agglomeration of nanoparticles.In the structure unit of alcohol,with the increase of alcoholic hydroxyl numbers and carbon chain lengths,the particle sizes of nZVI decrease.In solution,with the increase of alcohol concentrations,the nanoparticle sizes have the same varying trend.Meanwhile,with the decrease of nZVI sizes,the activity is significantly enhanced.