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Bottom up methods
|
| Epitaxial treatment |
Possibility of epitaxial growth of graphene on silica carbide, thermally used for silicon fabrication technologies, electrochemical detection of heavy metal salts in sea water, reduced cost, allowing seamless integration/bulk production of SiC substrates, reflects limitations in terms of costs, sizes, and difficulty in conduct. |
139 and 140
|
| Thermal treatment |
Production of thermally reduced graphene from graphene oxide, remarkable source for polymer electrolyte membrane for fuel cells applications, reduction causes significant weight loss and volume expansion of the materials. Reduction of GO is mainly concerned with the elimination of hydroxyl and epoxy groups; other groups like carbonyl, carboxylic and ester groups exhibit no significant role in conductivity. |
141 and 142
|
| Plasma treatment |
Used in cleaning the surface material, etching, deposition and modification of the surface properties of the material, potential hinge in hydrophilicity, adhesion, conductivity, functionalization, reduction, and doping of GO, necessary for the correct selection of promising parameters in order to reduce the negative impacts. |
143 and 144
|
| Pyrolysis treatment |
Used for the formation of thermally induced chemical decomposition of organic materials in the absence of oxygen, resulting in the production of carbon materials, however, presence of oxygen within the paralyzing precursor leads to partial combustion of the material. |
145
|
| Chemical vapor deposition |
Involves the process of depositing material as a thin film onto the substrates from vapour species through chemical reactions, the method is suitable for the growth of graphene for the solid, liquid and gaseous carbon sources, helps monitoring various factors affecting the quality of graphene film, however, the growth process is a tedious process due to the required maintanance of system total pressure, partial pressure of hydrogen, presence of hydrocarbon species, growth temperature and source of power respectively. |
146
|
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Topdown method
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| Liquid-phase exfoliation |
Method helped in obtaining a stable dispersion of monolayer or few-layer defect-free graphene, direct exfoliation prevented the agglomeration of the nano sheets, however, the method only involves the exfoliation of natural graphite via high-shear mixing or sonication, suffers from high energy extensive consumption and low efficiency. |
147 and 148
|
| Modified unzipping of carbon nanosheets |
Method is used in the production of graphene nano-ribbons, reflects the reduction of the oxygen-functional groups at the ends of graphene basal planes, reduction in electrical conductivity, adjustment achieved in the reduction step is observed, reduced consumption of chemicals make the overall process more economic and eco-friendly, however, harmful effect of the oxygen-functional groups take place at the edges of the graphene sheets and on the properties of the prepared material. |
149
|
| Arc discharge method |
Anode and cathode are submerged in a gas or liquid medium of a reaction chamber, use of asphalt a carbon rich source is used, makes the method cost effective due to vacuum usage. |
150
|
| Oxidation reduction |
Method is usally used in the synthesis of graphene from graphite, oxidation of graphene increases the interlayer spacing of graphite layer due to incorporation of intercalation compounds, graphene is found devoid of any functional groups and thus is found insoluble in water and organic solvents. |
150
|
