scholarly journals Graphene Synthesis Using a CVD Reactor and a Discontinuous Feed of Gas Precursor at Atmospheric Pressure

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
A. Moreno-Bárcenas ◽  
J. F. Perez-Robles ◽  
Y. V. Vorobiev ◽  
N. Ornelas-Soto ◽  
A. Mexicano ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Flow System ◽  
Chemical Vapor ◽  
Industrial Applications ◽  
Production Costs ◽  
Growth Time ◽  
Graphene Layers ◽  
Graphene Synthesis ◽  
Graphene Films ◽  
Gas Precursor

The present work shows a new method in order to cost-effectively achieve the synthesis of graphene by Chemical Vapor Deposition (CVD). Unlike most usual processes, where precursors such as argon, H2, CH4, and high purity copper foil are used, the proposed method has replaced the previous ones by N2, N2 (90%) : H2 (10%), C2H2, and electrolytic copper (technical grade) since the use of industrialized precursors helps reduce production costs. On the other hand, the process was modified from a continuous flow system with vacuum to a discontinuous one at atmospheric pressure, eliminating the use of vacuum pump. In addition, this modification optimized the consumption of gases, which reduced the waste and the emission of pollutant gases into the atmosphere. Graphene films were grown under different gas flowrates and temperatures. Then, the obtained material was characterized by TEM, Raman spectroscopy, and AFM, confirming the presence of few graphene layers. In brief, the growth time was reduced to six minutes with acetylene as a carbon precursor at 1000°C and at atmospheric pressure, with a flow rate of 30 sccm. Finally, the reported conditions can be used for the synthesis of good quality graphene films in industrial applications.

scholarly journals Chemical vapor deposition of partially oxidized graphene

RSC Advances ◽  
2017 ◽  
Vol 7 (51) ◽  
pp. 32209-32215 ◽  
Author(s):  
Zafer Mutlu ◽  
Isaac Ruiz ◽  
Ryan J. Wu ◽  
Robert Ionescu ◽  
Sina Shahrezaei ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Copper Foils ◽  
Graphene Films

Mutlu et al. reported on chemical vapor deposition (CVD) of partially oxidized graphene films on copper foils under near-atmospheric pressure.

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 Influence of Different Copper Treatment on the Formation of Single-Layer Graphene by CVD Method

2020 ◽  
Vol 4 (1) ◽  
pp. 14
Author(s):  
Ivan Kondrashov ◽  
Maxim Komlenok ◽  
Pavel Pivovarov ◽  
Sergei Savin ◽  
Elena Obraztsova ◽  
...  
Keyword(s):  
Copper Foil ◽  
Single Layer ◽  
Chemical Vapor ◽  
Copper Surface ◽  
Single Layer Graphene ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Graphene Synthesis ◽  
Number Of Layers ◽  
Optimized Conditions

Chemical vapor deposition synthesis of graphene on copper foil from methane is the most promising technology for industrial production. However, an important problem of the formation of the second and subsequent graphene layers during synthesis arises due to the strong roughness of the initial copper foil. Here we demonstrate the various approaches to prepare a smooth copper surface before graphene synthesis to reduce the formation of multi-layer graphene islands. Six methods of surface processing of copper foils are studied, and the decrease of the roughness from 250 to as low as 80 nm is achieved. The correlation between roughness and the formation of multi-layer graphene is demonstrated. Under optimized conditions of surface treatment, the content of the multi-layer graphene islands drops from 9% to 2.1%. The quality and the number of layers of synthesized graphene are analyzed by Raman spectroscopy, scanning electron microscopy, and measurements of charge mobility.

Synthesis of Large-Area and Monolayer of Graphene: Role of Transition Metal Support and Growth Time by CVD Method

2011 ◽  
Vol 306-307 ◽  
pp. 331-335
Author(s):  
Hui Gao ◽  
Yun Fei Wang ◽  
Yan Xia Liu ◽  
Er Qing Xie ◽  
Pulickel M. Ajayan
Keyword(s):  
Graphene Sheet ◽  
Chemical Vapor ◽  
Liquid Hydrocarbon ◽  
Growth Time ◽  
Monolayer Graphene ◽  
Large Area ◽  
Cvd Method ◽  
Graphene Synthesis ◽  
Transmission Electron ◽  
Metal Support

Continuous monolayer graphene sheet with large area has been synthesized via chemical vapor deposition (CVD) method using liquid hydrocarbon as precursor. Synthesis parameters including growth substrate and growth time have been investigated to assess their influence on monolayer graphene synthesis. Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) reveal that the number of layers and quality of graphene sheet depend greatly on the varied synthesis parameter. The study could be used to improve understanding the growth of graphene by CVD method in order to meet the needs of graphene in various electronic applications.

scholarly journals Preparation of Copper Surface for the Synthesis of Single-Layer Graphene

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1071
Author(s):  
Ivan Kondrashov ◽  
Maxim Komlenok ◽  
Pavel Pivovarov ◽  
Sergey Savin ◽  
Elena Obraztsova ◽  
...  
Keyword(s):  
Copper Foil ◽  
Single Layer ◽  
Chemical Vapor ◽  
Copper Surface ◽  
Single Layer Graphene ◽  
Graphene Layers ◽  
Layer Graphene ◽  
Additional Layer ◽  
Graphene Synthesis ◽  
Few Layer Graphene

Chemical vapor deposition synthesis of graphene on copper foil from methane is the most promising technology for industrial production. However, an important problem of the formation of the additional graphene layers during synthesis arises due to the strong roughness of the initial copper foil. In this paper, various approaches are demonstrated to form a smooth copper surface before graphene synthesis to reduce the amount of few layer graphene islands. Six methods of surface processing of copper foils are studied and the decrease of the roughness from 250 to as low as 80 nm is achieved. The correlation between foil roughness and the formation of the additional layer is demonstrated. Under optimized conditions of surface treatment, the content of the additional graphene layer drops from 9 to 2.1%. The quality and the number of layers of synthesized graphene are analyzed by Raman spectroscopy, scanning electron microscopy and measurements of charge mobility.

Synthesis of High Quality Graphene Films by Atmospheric Pressure CVD and their Application in Laser Q-Switching

2013 ◽  
Vol 747 ◽  
pp. 514-517 ◽  
Author(s):  
Mei Qi ◽  
Yu Ping Zhang ◽  
Wei Long Li ◽  
Man Jiang ◽  
Xin Liang Zheng ◽  
...  
Keyword(s):  
Saturable Absorber ◽  
Atmospheric Pressure ◽  
Graphene Film ◽  
Chemical Vapor ◽  
Single Pulse ◽  
High Quality ◽  
Synthesis Conditions ◽  
Graphene Films ◽  
Q Switching ◽  
Cu Foil

Synthesis of high quality graphene films on Cu foil by atmospheric pressure chemical vapor deposition (APCVD) was studied systematically. Acetylene and Cu foil were chosen as the carbon source and the catalyst (or the support) for the synthesis of graphene, respectively. The effect of several synthesized parameters on the structure of graphene films were investigated in detail. The controlled synthesis of graphene and the optimal synthesis conditions were derived. The prepared graphene film was transferred to a coated mirror as a Q-switching saturable absorber used in a Nd:YAG laser. The obtained shortest laser pulse width with single-pulse energy of 8.18 μJ was 242.8 ns. The results indicate that graphene film synthesized by APCVD can be excellently used as saturable absorber material in ultrashort pulse laser.

scholarly journals Atmospheric Pressure Catalytic Vapor Deposition of Graphene on Liquid In and Cu-In Alloy Substrates

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1318
Author(s):  
Maryam A. Saeed ◽  
Ian A. Kinloch ◽  
Brian Derby
Keyword(s):  
Atmospheric Pressure ◽  
Defect Density ◽  
Growth Parameters ◽  
Chemical Vapour ◽  
Growth Conditions ◽  
Growth Time ◽  
Graphene Growth ◽  
Graphene Films ◽  
Reactive Gases

Liquid substrates are great candidates for the growth of high-quality graphene using chemical vapour deposition (CVD) due to their atomically flat and defect free surfaces. A detailed study of graphene growth using atmospheric pressure CVD (APCVD) on liquid indium (In) was conducted. It was found that the effect of the growth parameters on the quality of the graphene produced is highly dependent on the properties of the substrate used. A short residence time of 6.8 sec for the reactive gases led to a high graphene quality, indicating the good catalytic behaviour of In. The role of hydrogen partial pressure was found to be crucial, with monolayer and bilayer graphene films with a low defect density obtained at low PH2 (38.6 mbar), whilst more defective, thicker graphene films with a partial coverage being obtained at high PH2 (74.3 mbar). The graphene deposition was insensitive to growth time as the graphene growth on liquid In was found to self-limit to bilayer. For further investigation, five compositions of Cu-In alloys were made by arc-melting. Graphene was then grown using the optimum conditions for In and the quality of the graphene was found to degrade with increasing Cu wt.%. This work will aid the future optimisation of the growth conditions based upon the substrate’s properties.

Three-Dimensional Printing of Carbon Nanostructures

2019 ◽  
Author(s):  
Alex Resnick ◽  
Jungkyu Park ◽  
Biya Haile ◽  
Eduardo B. Farfán
Keyword(s):  
Thermal Properties ◽  
Flexible Electronics ◽  
Carbon Nanostructures ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Industrial Applications ◽  
Species Structure ◽  
Carbon Nanostructure ◽  
Graphene Layers ◽  
Laser Lithography

Abstract Multi-layered carbon nanostructures are the next leap for many advanced consumer and industrial applications that require both high strength and uniquely high electrical and thermal properties. Applications of three-dimensional (3D) carbon nanostructures have already been theorized to include wearable technology, processor chip heat transfer material, and flexible electronics. 3D carbon nanostructures appear in the form of carbon nanotubes (CNTs) and layered graphene tiers, however, many structures previously examined have been limited to one or two graphene layers or non-repeatable structured patterns. Many of the electrical and thermal properties of CNTs are still being investigated, but the initial studies demonstrate promising results such as the thermal conductivity ranging in the thousands W/m-K. Developing new ways to fabricate these structures at a reasonable cost has become a primary focus for graphene-based research. In this study, 3D carbon nanostructure samples are 3D printed using laser lithography, then a series of high temperature furnace burns and Nickel Chemical Vapor Deposition (CVD) is utilized to leave a previously multi-species structure as a solely carbon-species structure with mostly carbon sp-2 bonds. CVD has proven to be a leading method for forming graphene due to the ability to control graphene nucleation across larger surfaces and structures. Nanoscale 3D printing of carbon structures also allows for a great degree of freedom towards the creation of repeatable patterns or structures that are currently trying to be achieved in other studies. This study employs the use of controlled cleanroom environments with cutting edge technology and machines to fabricate the 3D carbon nanostructures.

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