Controlled Growth and Supercapacitive Behaviors of CVD Carbon Nanotube Arrays

2011 ◽  
Vol 688 ◽  
pp. 11-18 ◽  
Author(s):  
Dan Dan Zhao ◽  
Zhi Yang ◽  
Hao Wei ◽  
Ya Fei Zhang
Keyword(s):  
Carbon Nanotube ◽  
Particle Density ◽  
Chemical Vapor ◽  
Growth Time ◽  
Controlled Growth ◽  
Si Substrate ◽  
Graphene Layers ◽  
Wide Range ◽  
Cnt Arrays ◽  
Vertically Aligned

Low-pressure chemical vapor deposition (LP-CVD) technique has been utilized for controlled growth of carbon nanotube (CNT) arrays on silicon wafers. The tube-diameters of CNTs and the number of graphene layers are controlled by varying the thickness of catalyst films. The catalyst particle density and the growth conditions such as the ambient gas and the local environment are all crucial for the formation of vertically aligned CNT arrays. The length of CNT arrays can be controlled by altering the growth time. In addition, the supercapacitive properties of CNT arrays with various morphologies growing on different current collectors have been investigated using a less corrosive 0.5 M Na2SO4aqueous solution as the electrolyte. Vertically aligned CNT arrays on Ti-Si substrate produce a higher capacitance compared to randomly oriented CNTs on the same current collector. Furthermore, Ni foam enables better utilization of active materials than Ti-Si substrate. CNT arrays electrodes fabricated by this simple, low cost approach demonstrate stable and consistent capacitor behaviors for a wide range of scan rates. Moreover, CNT arrays electrodes provide better platform for further integration with transitional metal oxide, via simple sputtering or electrodeposition technique, to enhance the supercapacitive performance.

scholarly journals Ultrafast Oatterning Vertically Aligned Carbon Nanotube Forest on Al Foil and Si Substrate Using Chemical Vapor Deposition (CVD)

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1332 ◽  
Author(s):  
Yan-Rui Li ◽  
Chin-Ping Huang ◽  
Chih-Chung Su ◽  
Shuo-Hung Chang
Keyword(s):  
Carbon Nanotube ◽  
Chemical Vapor ◽  
Test Sample ◽  
Weight Percent ◽  
Si Substrate ◽  
Percent Concentration ◽  
Vertically Aligned ◽  
Styrene Maleic Anhydride ◽  
The Relationship ◽  
Hard Substrates

This study introduces a method of patterning carbon nanotube (CNTs) forests that is both fast and simple. We found that, as commercially available oil-based markers undergo nanotube synthesis, a thin film forms that prevents the catalyst, ferrocene, from coming into contact with the surface of the test sample. This, thus, blocks CNT growth. Through further deduction, we used styrene maleic anhydride (SMA) to conduct CNT patterning, in addition to analyzing the relationship between the weight percent concentration of the SMA and the extent to which it blocked CNT growth. We developed two separate methods for applying ink to soft and hard substrates: one method involved ink printing and the other laser stripping. In the CNT pattern we produced, a minimum line width of around 10 µm was attained.

Synthesis of Nano Structured Membrane from Carbon Nanotube for Waste Water Treatment

2013 ◽  
Vol 829 ◽  
pp. 386-390 ◽  
Author(s):  
Mehri Imani ◽  
Alimorad Rashidi ◽  
Mojtaba Shariaty-Niassar ◽  
Elahe Sarlak ◽  
Amir Zarghan
Keyword(s):  
Waste Water ◽  
Carbon Nanotube ◽  
Metal Ion ◽  
Low Cost ◽  
Waste Water Treatment ◽  
Chemical Vapor ◽  
Morphological Properties ◽  
Carbon Membranes ◽  
Vertically Aligned ◽  
Simple Technology

Carbon membranes have high adsorption capacitiy with respect to its incredible properties such as unique structural, electronic, optoelectronic, semiconductor, mechanical, chemical and physical. Carbon nanotube (CNT) membranes because of its high permeance have been recently developed.Great attention has been currently paid to the field of fabrication methods capable of producing uniform, well-aligned and monodispersed CNT array. Current research concerns with fabrication of vertically aligned CNT membrane in order to remove heavy metal ion presents in waste water. For this purpose, CNTs are vertically grown up through the holes of anodic aluminium oxide (AAO); as a template, by chemical vapor deposition (CVD) of acetylene gas.In this work a few heavy metals such as Pb (II), Cu (II) and Cd (II) has been examined for checking the perfomance of membrane in aqueous solution. The morphological properties of the aligned CNT membrane were investigated with scanning electron microscopy (SEM). The method has simple technology, low cost, and easy reproduction.

scholarly journals Feedstock Diffusion and Decomposition in Aligned Carbon Nanotube Arrays

2009 ◽  
Author(s):  
Rong Xiang ◽  
Erik Einarsson ◽  
Junichiro Shiomi ◽  
Shigeo Maruyama
Keyword(s):  
Carbon Nanotube ◽  
Carbon Source ◽  
Flow Rate ◽  
Chemical Vapor ◽  
Mean Free Path ◽  
Diffusion Limit ◽  
Diffusion Resistance ◽  
Diffusion Controlled ◽  
Cnt Arrays ◽  
Growth Deceleration

Feedstock diffusion and decomposition in the root growth of aligned carbon nanotube (CNT) arrays is discussed. A non-dimensional modulus is proposed to differentiate catalyst-poisoning controlled growth deceleration from one which is diffusion controlled. It is found that, at current stage, aligned multi-walled carbon nanotube (MWNT) arrays are usually free of feedstock diffusion resistance. However, for single-walled carbon nanotube (SWNT) arrays, since the inter-tube distance is much smaller than the mean free path of carbon source (ethanol here), high diffusion resistance is significantly limiting the growth rate. The method presented here is also able to predict the critical lengths in different chemical vapor deposition (CVD) processes from which CNT arrays begin to meet this diffusion limit, as well as the possible solutions to this diffusion caused growth deceleration. The diffusion of carbon source inside of an array becomes more important when we found ethanol undergoes severe thermal decomposition at the reaction temperature. This means, in a typical alochol CVD, hydrocarbons and radicals decomposed from ethanol may collide and react with the outer walls of SWNTs before reaching catalyst particles. We found when flow rate is low and ethanol is thoroughly decomposed, the produced SWNTs contain more soot structures than the SWNTs obtained at higher ethanol flow rate. Understanding the mass transport and reaction inside a SWNT array is helpful to synthesize longer and cleaner SWNTs.

Optoelectronic characterization of morphology-controlled zinc oxide nanowires

2011 ◽  
Vol 1315 ◽  
Author(s):  
Shou-Yi Kuo ◽  
Fang-I Lai ◽  
Chun-Chieh Wang ◽  
Woei-Tyng Lin
Keyword(s):  
Field Emission ◽  
Visible Region ◽  
Chemical Vapor ◽  
Growth Time ◽  
Emission Measurement ◽  
Oxide Nanowires ◽  
Average Reflectance ◽  
Vertically Aligned ◽  
Metal Catalyzed

ABSTRACTIn this paper, we report the characterization of vertically aligned ZnO nanowire (NW) arrays synthesized by metal-catalyzed chemical vapor deposition. The growth mechanism of ZnO NWs may be related to vapor-solid-nucleation. Morphological, structural, optical and field emission characteristics can be modified by varying the growth time. For growth time reaches 120 min, the length and the diameter of ZnO NWs are 1.5 μm and 350 nm, and they also show preferential growth orientation along the c-axis. Moreover, strong alignment and uniform distribution of ZnO NWs can effectively enhance the antireflection to reach the average reflectance of 5.7% in the visible region as well. Field emission measurement indicated that the growth time play an important role in density- and morphology-controlled ZnO NWs, and thus ZnO NWs are expected to be used in versatile optoelectronic devices.

Carbon nanotube cathodes covered on the cylindrical surface of a fiber

RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 17049-17053 ◽  
Author(s):  
Xianqi Wei ◽  
Youzhang Zhu ◽  
Xianjun Xia ◽  
Xiaoli Wang ◽  
Weihuan Liu ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Carbon Nanotube ◽  
Field Emission ◽  
Vapor Deposition ◽  
Cylindrical Surface ◽  
Chemical Vapor ◽  
Quartz Optical Fiber ◽  
Cnt Arrays ◽  
Field Emission Cathodes ◽  
Waveguide Surface

Carbon nanotube (CNT) arrays were synthesized on the cylindrical waveguide surface of a quartz optical fiber by chemical vapor deposition (CVD) to serve as field emission cathodes.

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