黑茶还原制备绿色纳米铁及其对六价铬的去除性能  

Green synthesis of iron nanoparticles using brick tea for removal of hexavalent chromium

作　　者：刘清[1] 张美[1] 招国栋[1] 张艳霞[1] 陈春宁[1] 

机构地区：[1]南华大学污染控制与资源化技术湖南省重点实验室,湖南衡阳421001

出　　处：《功能材料》2016年第3期97-102,共6页Journal of Functional Materials

基　　金：国家自然科学基金青年基金资助项目(51304122);湖南省研究生科研创新资助项目(CX2013B390);湖南省高校创新平台开放基金资助项目(14K082);南华大学"青年英才"人才支持计划资助项目(南华政发[2014]49号);南华大学大学生研究性学习和创新性实验计划资助项目(南华教[2014]11号)

摘　　要：植物还原制备绿色纳米金属材料因环境友好、反应条件温和、可持续发展、可控等优势成为纳米材料合成领域的研究热点.利用黑茶还原制备绿色纳米铁颗粒（BT-FeNPs）,采用UV-Vis、XRD、SEM、TEM、EDX、FT-IR等方法对BT-FeNPs进行表征,结果表明,制备的BT-FeNPs为无定形的球形颗粒,粒径20~30nm 左右,纳米颗粒中的铁主要以铁氧化物、氢氧化物及Fe0 形式存在,颗粒表面包裹-OH、-NH2、C=O、-CH2、-CH3、C=N、C-O-C等有机基团.并探讨BT-FeNPs对Cr（Ⅵ）的去除性能,在25℃,pH值=4.0,Cr（Ⅵ）初始浓度20mg/L,反应时间90min条件下,Cr（Ⅵ）去除率达到96.3%.BT-FeNPs对Cr（Ⅵ）的去除效果及抗氧化性均优于化学法制备的NaBH4-FeNPs.BT-FeNPs对Cr（Ⅵ）的去除主要发生在颗粒表面,去除机理为还原、吸附、络合共同作用,且其表面的有机基团能促进Cr（Ⅵ）的去除及增强BT-FeNPs的抗氧化性.Green synthesis of metallic nanoparticles has become a promising field of research in recent years.It has been proved that the simple and cost-effective green synthesis process is environmentally friendly,stable and can be used for large-scale production.In this study,iron nanoparticles were synthesized using aqueous brick tea extracts as both the reducing and capping agent.The prepared BT-FeNPs are amorphous spherical particle with particle size ranging between 20 and 30nm,and contain Fe0,iron oxide and iron hydroxides.In addition,BT-FeNPs are encapsulated by the organic groups of —OH,—NH2,C O,—CH2,—CH3,C N and C—O—C.This was confirmed by UV-Vis,XRD,SEM,TEM,FT-IR and EDX techniques.The removal of Cr(Ⅵ)from aqueous solution by BT-FeNPs was also investigated.The optimum removal conditions were found to be as follows:an initial Cr(Ⅵ)concentration of 20mg/L,a temperature of 25℃,a reaction time of 90 min,pH of 4.At this condition,the removal rates of Cr(Ⅵ)reached 96.3% by BT-FeNPs.The removal of Cr(Ⅵ)and the oxidation resistance property of BT-FeNPs are better than that of NaBH4-FeNPs prepared by chemical method because the surface of BT-FeNPs is coated by the organic groups in brick tea extract.Finally,the plausible mechanism for the removal Cr(Ⅵ)using BT-FeNPs has been suggested to be the combined action of reduction,adsorption and complexation.Further more,the remoel of Cr(Ⅵ)and the resistance to oxidation of BT-FeNPs are improved by the organic groups.

关 键 词：绿色合成 黑茶 BTGFeNPs Cr(Ⅵ) 去除 

分 类 号：X523[环境科学与工程—环境工程]