共查询到19条相似文献,搜索用时 62 毫秒
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采用非芳香烃类环己烷作为碳源,通过浮游法实现了超长垂直碳纳米管(Carbon nanotube,CNT)阵列的生长。研究表明:浮游催化过程中反应温度、催化剂前体补给速度、进料速度、生长气氛等因素对CNT阵列的生长影响显著。在直径为25mm的石英反应器中,反应温度、催化剂前体二茂铁的补给速度、碳源环己烷的补给速度、反应气氛分别控制在820℃、0.24mg/min、0.12mL/min、640mL/min(H2/Ar=1∶15)的生长窗口内,实现了CNT阵列的快速协同生长。在单因素考察的基础上,通过对宏观参数的调变,可以制备出长度达5.0mm的CNT阵列。所获得的CNT取向一致,长径比大于105,纯度达到96.7%。 相似文献
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本文介绍了一种微图形化碳纳米管场发射阵列冷阴极,每个图形的直径仅为1μm,构成一个发射单元。制作工艺如下:首先在硅(100)基片上沉积氮化钛缓冲层,然后采用曝光工艺获得直径为1μm的胶孔阵列,沉积催化剂铁,最后采用直流等离子体增强化学气相沉积(DC-PECVD)生长直立的碳纳米管。并对17500个发射单元的阵列阴极进行了表面形貌表征及场发射特性测试。结果表明,碳纳米管阵列阴极的一致性较好;最低开启电场为1 V/μm;电场为17 V/μm时,测得的电流密度已达到90 mA/cm^2;发射电流为550μA时,在2.5 h内的波动小于5.6%。 相似文献
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定向碳纳米管阵列在石英玻璃基底上的模板化生长研究 总被引:5,自引:0,他引:5
分别以带有刻痕的石英玻璃和溅射过Au膜的石英玻璃为生长基底,通过催化裂解二茂铁和二甲苯混合物的方法,在基底上制备出了模板化的定向碳纳米管(CNT)阵列,扫描电镜(SEM)和透射电镜(TEM)观察表明:在这两种基底上生长的定向碳纳米管阵列的模板化程度都很高,其中的碳纳米管多为直径在20~50nm的多壁管(MWNT),且具有很好的定向性。本文还分析、对比了基底材料对定向碳纳米管生长的影响,初步探讨了定向碳纳米管模板化生长的形成机制。 相似文献
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通过普通的紫外(UV)光刻工艺,结合"变倾角缩口"新技术,研制了不同发射单元尺寸的碳纳米管(CNTs)阵列阴极。扫瞄电镜分析表明,随着缩口尺寸的依次减小(从0.6μm到0.4μm,最后到0.2μm),发射单元内CNTs的根数也不断减少。当孔径缩至0.2μm时,发射单元仅由1根~3根CNTs组成,并且大部分单元顶端均有单根CNT伸出,使得整个发射体近似于单根CNT。场发射特性测试结果表明,0.2μm发射单元尺寸的阵列阴极,开启电场约2V.μm-1;当场强为20V.μm-1时,该阵列的电流密度达到0.35A.cm-2,比1μm尺寸的阵列阴极提高了近4倍,比连续生长的薄膜CNTs阴极则高1~2个数量级。 相似文献
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H2O2原位净化定向碳纳米管阵列的研究 总被引:2,自引:2,他引:0
采用无模板的化学气相沉积法(CVD),在石英衬底上制备了大面积、高定向性、自支撑的定向碳纳米管阵列。对此阵列采用原位H2O2氧化,可以有效地达到净化定向碳纳米管阵列的目的。扫描电镜(SEM)检测表明净化碳纳米管的过程并不会破坏其定向性。此种方法可以获得不同厚度的、多数碳管端帽打开、非晶碳、缺陷碳管和杂质较少的定向碳纳米管阵列,此种阵列在场发射等方面具有应用价值。Raman光谱和热失重分析(TGA)表明经过净化的碳纳米管的晶化程度和热稳定性都有所提高。 相似文献
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The field emission (FE) properties of carbon nanotubes (CNTs) films with different morphologies were simulated and examined. Based on the FE mechanism of aligned CNTs’ emitter the theoretical analysis exhibited the following relations: the FE enhancement factor with the distance between the emitters, the electric field with work function, and the work function with FE enhancement factor. Using the structure-induced CNTs growing method and theoretical results the direction of aligned CNTs could be controlled and the special morphology with different aligned CNTs’ film could be fabricated. Comparing to the experimental results (the medium density and patterned CNTs’ emitters) with the theoretically calculating results the I-V curves had the same trend with only 0.05 mA deviation. Based on the better experimental methods and means the accurate of formula could be further improved by modified the FE properties (Φ, β). 相似文献
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Metallic nanoparticles containing single and binary components have been known for their catalytic properties to grow carbon nanotube (CNT) arrays. In this paper, an intermetallic catalyst consisting of iron and zirconium was used to grow millimeter long, well aligned arrays. The Fe-Zr catalysts enabled the growth of 1.7 mm-long carbon nanotube arrays in 45 min. A comparison with pure iron catalyst indicated that adding Zr to iron can stabilize the Fe catalyst at the CNT growth temperature and moderate its reactivity. SEM images showed the different growth behaviors for Fe-Zr and Fe catalysts. The long, uniform CNT arrays grown here have potential applications in many advanced composites. 相似文献
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Yang Z Chen T He R Guan G Li H Qiu L Peng H 《Advanced materials (Deerfield Beach, Fla.)》2011,23(45):5436-5439
Aligned carbon nanotube sheets are developed as a new family of electrodes to fabricate dye-sensitized solar cells. The energy conversion efficiency of the resulting cell is higher than the randomly dispersed carbon nanotube film and comparable with the platinum. Novel and flexible solar cells can be easily made from such carbon nanotube sheets with high potentials. 相似文献