A kind of method that heat reduction prepares graphene

A graphene and vacuum heating technology, applied in chemical instruments and methods, inorganic chemistry, non-metallic elements, etc., can solve the problems of graphite electrochemical performance limitations, inconvenient industrial production, and many oxygen-containing functional groups, and achieve good flame retardation Features, convenient operation, fast response and efficient effect

Inactive Publication Date: 2014-10-15
CENT SOUTH UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this thermal reduction process needs to be carried out under a protective atmosphere, the conditions are very harsh, the reaction operation is complicated, and it is not convenient for industrial production; there are also reports on the reduction of graphite by flame ignition and high-temperature metal ignition, but the graphene prepared by these methods has graphite. There are many oxygen-containing functional groups on the surface of alkene and a large degree of agglomeration, which greatly limits the electrochemical performance of graphite.

Method used

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  • A kind of method that heat reduction prepares graphene
  • A kind of method that heat reduction prepares graphene
  • A kind of method that heat reduction prepares graphene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Graphene oxide was prepared by the classic Hummers method: Weigh 1 g of flake graphite and stir it for 10 min in a three-necked bottle filled with 23 mL of concentrated sulfuric acid, and then move the device into an ice bath environment below 4 °C. Slowly add 0.5g of sodium nitrate, 3g of potassium permanganate, and stir in an ice bath for 2h. After the low-temperature oxidation is completed, remove the ice bath, raise the temperature to 35-40°C for medium-temperature oxidation, and keep it for 30 minutes. Add 46~50mL deionized water after the middle temperature oxidation, and carry out high temperature oxidation at 95~98°C for 30min. Subsequently, 140 mL of deionized water and 5 mL of 30% hydrogen peroxide were added to terminate the reaction, and filtered and washed. The graphene oxide product was obtained by repeated washing with deionized water and ethanol for 1 to 3 times, and vacuum drying at 50°C.

[0030] Weigh 100 mg of graphene oxide and ultrasonically disp...

Embodiment 2

[0034] Graphene oxide was prepared by the classic Hummers method, and the method for the alkali metal content in graphene oxide being 0.4% was the same as that described in Example 1.

[0035] A bulk graphene oxide sheet with a potassium metal content of 0.4% was ignited by a high-temperature copper rod, and the copper rod was heated to 400 °C and 800 °C by a muffle furnace, respectively. The ignited graphene oxide will undergo a combustion heat reduction process, and finally generate black flake and powder solid graphene. The surface structure of the graphene is loose and porous, and the edge of the graphene in contact with the high-temperature copper rod will burn red, and the inside of the graphene is stable, and no combustion reaction will occur after ignition, which shows that the reduced graphene prepared by the combustion heat reduction method Material has good flame retarding properties. Graphene obtained by igniting copper rods at 800°C has greater loss than graphene...

Embodiment 3

[0038] Graphene oxide was prepared by the classic Hummers method, and the method for the alkali metal content in graphene oxide being 0.4% was the same as that described in Example 1.

[0039] The bulk graphene oxide sheet with a potassium content of 0.4% was ignited on the outer flame of an alcohol lamp, and a spontaneous combustion reaction occurred. After the reaction is completed, the brown graphene oxide sheet will turn into black powdered graphene, which can still maintain a sheet-like structure, which is soft, fluffy and porous, and the surface structure expands due to the reduction process of combustion heat, reducing the The degree of agglomeration of graphene. At the same time, the combustion heat reduction reaction can greatly reduce the oxygen-containing functional groups on the surface of graphene oxide, which improves the electric double layer capacitance characteristics of graphene.

[0040] The steps and test methods for making electrodes from the graphene mat...

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Abstract

The invention discloses a method for preparing graphene through thermal reduction. The method comprises the following steps in sequence: processing dispersed graphene oxide colloid through a solution containing alkali metal ion or alkaline earth metal ion, wherein the dispersed graphene oxide colloid is prepared by a Hummers method; drying in vacuum to obtain the graphene oxide containing the alkali metal ion or alkaline earth metal ion; heating and igniting the obtained graphene oxide in order to realize the reduction reaction; washing and filtering the reaction product; and drying to obtain the graphene. The graphene prepared by the method is thin in lamella, dilated and loosen in structure, and few in oxygen-containing functional groups on the surface; and a super capacitor electrode adopting the graphene can generate ideal electrical double-layer resistance in a water electrolyte and reaches the specific capacity of 78F / g; and the graphene has a certain retardant characteristic respect to the combustion flam, so that the graphene can be used as the material of the fire retardant; and the method is simple in process, low in cost, short in production period, and easy for massive production.

Description

technical field [0001] The invention relates to a method for preparing graphene by a combustion heat reduction method, and belongs to the technical field of graphene material preparation. Background technique [0002] Since graphene was discovered by Manchester University scientists in 2004 [Science, 306 (2004): 666], because of its large theoretical specific surface area (2675m 2 / g), high electrical conductivity (64mS / cm), excellent chemical stability and thermodynamic stability, as well as physical and mechanical properties, have been widely studied and applied in sensor devices, optoelectronics, and energy materials. Graphene is a single layer of carbon atoms through sp 2 The two-dimensional honeycomb lattice carbon-based new material that is hybridized and closely packed has a thickness of only 0.335nm. Its unique two-dimensional structural properties make it an energy material that can be used in supercapacitors and batteries. [0003] At present, the preparation met...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B31/04C01B32/192
Inventor 纪效波宋维鑫邓文韬鲁放周洲陈启元李叙
Owner CENT SOUTH UNIV
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