CN-115579250-B - Preparation method of capacitive graphene

Abstract

The invention relates to the technical field of preparation of capacitive graphene, and particularly discloses a preparation method of capacitive graphene. The preparation method of the capacitive graphene comprises the steps of (1) crushing litchi trunks, performing high-temperature carbonization reaction to obtain carbonized litchi trunk powder, (2) performing pore-forming reaction to obtain mesoporous carbon on the carbonized litchi trunk powder, (3) performing acidification treatment to the mesoporous carbon to obtain acidified mesoporous carbon, and (4) performing ultrasonic stripping on the acidified mesoporous carbon to obtain the capacitive graphene. The research shows that the capacitive graphene prepared by taking the litchi trunk as the raw material has higher mass specific capacitance and cycle stability when being used as the electrode material of the supercapacitor, and in addition, the method disclosed by the invention is safe and environment-friendly, is simple and convenient to operate, is low in preparation cost and is easy for industrial production.

Inventors

• LI JIANHUI
• YANG YAOJUN
• TANG SHUAI

Assignees

• 深圳材启新材料有限公司

Dates

Publication Date

20260512

Application Date

20221109

Claims (7)

1. 1. The preparation method of the capacitive graphene is characterized by comprising the following steps of: (1) Crushing the litchi trunks, and performing high-temperature carbonization reaction to obtain carbonized litchi trunk powder; (2) Performing pore-forming reaction on carbonized litchi trunk powder to obtain mesoporous carbon; (3) Acidizing the mesoporous carbon to obtain acidized mesoporous carbon; (4) Ultrasonic stripping is carried out on the acidified mesoporous carbon to obtain the capacitive graphene; The high-temperature carbonization reaction in the step (1) is specifically carried out for 2-6 hours in nitrogen atmosphere at 400-600 ℃; The pore-forming reaction in the step (2) is specifically that a pore-forming agent is added into carbonized litchi trunk powder, and high-temperature pore-forming reaction is carried out for 2-8 hours in nitrogen atmosphere at 600-1000 ℃; the pore-forming agent consists of potassium hydroxide and calcium hydroxide.
2. 2. The preparation method of the capacitive graphene according to claim 1, wherein the mass ratio of potassium hydroxide to calcium hydroxide is 1:1-1:0.1.
3. 3. The preparation method of the capacitive graphene according to claim 1, wherein the dosage ratio of the pore-forming agent to carbonized litchi trunk powder is 30-60 g/10-15 g.
4. 4. The method for preparing capacitive graphene according to claim 1, wherein the acidification treatment in the step (3) is specifically: And acidizing mesoporous carbon by using sulfuric acid with the mass concentration of 98% at 60-90 ℃, wherein the dosage ratio of the sulfuric acid to carbonized litchi trunk powder is 20-60 mL:10-15 g.
5. 5. The preparation method of the capacitive graphene according to claim 1 is characterized in that the specific method of ultrasonic stripping in the step (4) comprises the steps of dispersing acidified mesoporous carbon in ultrasonic liquid and then carrying out ultrasonic treatment for 1-12 h.
6. 6. The method for preparing capacitive graphene according to claim 5, wherein the ultrasonic liquid is selected from one or more of water, N-methylpyrrolidone, N-dimethylformamide and ethanol.
7. 7. The preparation method of the capacitive graphene according to claim 5, wherein the dosage ratio of the ultrasonic liquid to carbonized litchi trunk powder is 50-60 mL/10-15 g.

Description

Preparation method of capacitive graphene Technical Field The invention relates to the technical field of preparation of capacitive graphene, in particular to a preparation method of capacitive graphene. Background In 2004, graphene was found, and in 2010, the creator of graphene obtained the nobel prize, and has received much attention due to its extremely excellent electrical properties. For example, its carrier transport behavior is similar to that of the neutrino in relativity, and quantum hall effect, bipolar field effect, etc. can be observed at room temperature. And the unique physical and mechanical properties of the graphene widen the application space of the graphene, namely the graphene has larger theoretical specific surface area (2630 m 2g-1), high carrier mobility (2×10 5cm2 v-1s-1), high Young modulus (1.0 TPa), high heat conductivity (5000 Wm -1 K-1), high light transmittance (97.7%) and high electrical conductivity (6×10 6 S/m). In the near future, graphene may be used to make new generation electronic components or transistors that are thinner and have faster conduction speeds. And due to good light transmittance and conductivity of graphene, the graphene is also suitable for replacing ITO to manufacture transparent touch screens, optical plates and even solar cells. Good mechanical properties of graphene have been applied to heat shrink materials or film materials to improve stretch resistance. Since graphene is considered to be the hardest substance found so far, some researchers have been developing body armor made of graphene, which is lighter and thinner, and will greatly reduce the load on soldiers. The graphene has extremely high theoretical surface area, so that the graphene is used as a carrier material of a catalyst in the field of catalysis, and not only can the extremely high conductivity of the graphene promote the transfer of photoelectrons, the exciton service life is prolonged, the photocatalysis efficiency is improved well, and the graphene is applied to the field of photocatalysis. The demand for graphene will also increase with the expansion of its application field, so that a means for synthesizing graphene at low cost and on a large scale is necessary. The graphene materials can be divided into powder graphene and film graphene, and are applied to different application fields, wherein the powder graphene is widely applied to the fields of energy sources, corrosion resistance, reinforcement, heat dissipation and the like, so that the preparation method is most widely studied and is various. The preparation method of the graphene mainly comprises a mechanical stripping method, a chemical vapor deposition method, a SiC epitaxial growth method, an oxidation-reduction method and a liquid phase stripping method. The chemical vapor deposition method, the SiC epitaxial growth method and the mechanical stripping method are complex in operation, low in yield and high in preparation cost, and cannot realize large-scale production of graphene. The redox method can prepare graphene in a large scale, but generates a lot of harmful gases and causes a lot of corrosive waste liquid in the process of producing graphene, which is easy to cause environmental pollution, and the synthesized graphene contains a lot of structural defects, which severely limits the wide application of the graphene. Graphene prepared by the liquid phase exfoliation method has fewer structural defects and lower oxygen content, but the liquid phase exfoliation method is often affected by poor exfoliation efficiency and low graphene concentration (typically <0.1 mg/mL). The litchi trunk has rich sources and low raw material cost, but no report on the preparation of the capacitive graphene by taking the litchi trunk as a raw material exists at present, and particularly, the preparation of the high-performance capacitive graphene is reported. Therefore, developing a method for preparing the capacitive graphene by taking the litchi trunk as a raw material, and particularly preparing the high-performance capacitive graphene has important application value. Disclosure of Invention In order to overcome at least one technical problem in the prior art, the invention provides a preparation method of capacitive graphene. The technical problems to be solved by the invention are realized by the following technical scheme: A preparation method of capacitive graphene comprises the following steps: (1) Crushing the litchi trunks, and performing high-temperature carbonization reaction to obtain carbonized litchi trunk powder; (2) Performing pore-forming reaction on carbonized litchi trunk powder to obtain mesoporous carbon; (3) Acidizing the mesoporous carbon to obtain acidized mesoporous carbon; (4) And carrying out ultrasonic stripping on the acidified mesoporous carbon to obtain the capacitive graphene. The invention provides a method for preparing capacitive graphene by taking litchi trunks as raw materials for the first time