摘要
采用液相还原法,通过调控氧化剂硝酸银与还原剂抗坏血酸的摩尔比例制备出具有多级结构的花状及枝状银微-纳米晶,考察了反应介质对形貌及尺寸的影响。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、表面增强拉曼光谱(SERS)、紫外-可见(UV-Vis)漫反射光谱等方法,对样品的形貌、微晶结构、光学及催化性能进行了研究。结果表明:花状及枝状多级结构银微-纳米晶均具有面心立方晶体结构,且(111)晶面为主要曝露晶面;表面增强拉曼光谱表明花状及枝状银微-纳米晶为基底时均表现出优异的表面增强拉曼效应;微结构上的差异使枝状银在紫外-可见漫反射光谱上352 nm处有较强的吸收峰;在银催化硼氢化钠还原4-硝基苯酚的实验中,多级结构枝状银表现出最优良的催化活性。
The flower-like and dendritic silver micro-nanocrystals with multi-stage structure were prepared by liquid phase reduction method by adjusting the molar ratio of oxidant silver nitrate to reducing agent ascorbic acid.The effects of reaction media on the size and morphology of silver crystallite was investigated.The morphology,crystal structure,optical and catalytic properties of the products were studied by scanning electron microscopy(SEM),Xray diffraction(XRD),surface enhanced Raman scattering spectroscopy(SERS)and UV-Vis reflectance spectroscopy(UV-Vis).The XRD results show that both the flower-like and dendritic silver micro-nanocrystals have face-centered cubic crystal structure,and(111)plane is the dominant crystal plane exposed on the surface of Ag crystals.The SERS surveys show that the hierarchical structure Ag micro-nanocrystals are excellent substrates for SERS.The UV-Vis diffuse reflectance spectra shows that the dendritic silver has a strong absorption peak at 352 nm because of the finer microstructure.The catalytic reduction experiment of 4-nitrophenol by sodium borohydride on the silver crystals reveals that the dendritic silver shows excellent catalytic activity.
作者
聂士东
李江涛
张志颖
刘云
刘春艳
NIE Shidong;LI Jiangtao;ZHANG Zhiying;LIU Yun;LIU Chunyan(Key Laboratory of Photochemical Conversion and Optoelectonic Materials,Technical Institute of Physics and Chemistry(TIPC),Chinese Academy of Sciences,Beijing 100190,China;Key Laboratory of Functional Crystals and Laser Technology,Technical Institute of Physics and Chemistry(TIPC),Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2018年第9期4090-4096,共7页
CIESC Journal
基金
国家自然科学基金项目(21273256)~~
关键词
制备
多级结构
银
形貌
表面增强拉曼
催化
preparation
hierarchical structures
silver
morphology
SERS
catalysis
作者简介
第一作者:聂士东(1980—),男,博士,助理研究员。;联系人:刘春艳。
