空气氧化对球磨后纳米碳管场发射特性的影响  

Effect of oxidation in air on field emission properties of ball-milled carbon nanotubes

作　　者：张哲娟[1] 孙卓[1] 林丽锋[1] 冯涛[1] 高阳[1] 陈奕卫[1] 杨介信 

机构地区：[1]华东师范大学纳光电集成与先进装备教育部工程研究中心,上海200062 [2]上海纳晶科技有限公司,上海200062

出　　处：《材料热处理学报》2008年第4期16-20,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(50672026);上海市纳米专项(No.0752nm011);上海市科委科技攻关项目(No.06DZ11404);上海市经委高新技术产业科技开发项目

摘　　要：以乙炔为原料气,采用铬-镍复合催化剂,在550℃下,由化学气相沉积法（CVD）制得了直径为20～300nm的多壁碳纳米管（MWNT）。经过45min的高能球磨处理后,通过空气氧化法对所获碳纳米管进行提纯,去除了碳纳米管中的无定形碳、碳纳米颗粒等非晶碳成分,提高了碳纳米管的纯度;并研究了提纯温度和场发射特性的关系。用扫描电镜、Raman光谱对其形貌和结构进行了表征。结果表明：碳纳米管在空气中,400～450℃加热10min后,非晶碳成分基本去除,纯度得到提高可以得到优化的场发射特性,如低的阈值电场和高场发射电流等。Multiwall carbon nanotubes（CNTs） were prepared by catalytic decomposition of acetylene at 550℃ with Cr-Ni as catalysts and then the CNTs were treated by ball-milling for 45min. The CNTs were purified by removing most of amorphous carbon using air oxidation from 300℃ to 500 ℃ in ambient air. Field emission properties of the CNTs were investigated. The results indicate that morphology and field emission properties of the CNTs are mainly dependent on oxidation temperatures. Field emission current density increases to the maxium value at 400℃ and then decreases dramatically with increase of oxidizing temperature. When the oxidizing temperature is 400 ～ 450℃, the most of amorphous carbon is removed and purity of the CNTs is improved greatly, and the purified CNTs shows excellent field emission properties, such as high emission current density and low turn-on field. The emission properties are degraded if the oxidizing temperature is high （ 〉 450℃ ） due to the increasing of amorphous phase and graphitization of CNTs.

关 键 词：碳纳米管 高能球磨 空气氧化 场发射性能 

分 类 号：TB383[一般工业技术—材料科学与工程] TN104.3[电子电信—物理电子学]