WO2017181826A1

WO2017181826A1 - Method for manufacturing three-dimensional hierarchical porous graphene powder

Info

Publication number: WO2017181826A1
Application number: PCT/CN2017/078523
Authority: WO
Inventors: 沈培康; 李运勇; 田植群; 朱金良; 尹诗斌
Original assignee: 广西大学
Priority date: 2016-04-19
Filing date: 2017-03-29
Publication date: 2017-10-26
Also published as: CN105923623A

Abstract

Provided is a method for manufacturing three-dimensional hierarchical porous graphene powder. The method comprises:(1) mixing a resin with 0.02-2 mol/L of a catalytic metal salt solution, stirring until homogeneous, then washing the mixture;(2) adding a pore forming agent solution to the mixture, stirring and mixing until homogeneous, then oven drying and pulverizing the mixture; (3) heating, under a protective environment, at a rate of 1-10°C/min to reach a temperature of 800-1200°C, then holding the temperature for 0.5-4 hours for thermal treatment; (4) acid washing for 2-12 hours, filtering, and then oven drying. A three-dimensional graphene manufactured using the method has a high specific surface area and high electrical conductivity. The method provides a simple manufacturing technique, greatly shortens processing steps, and has a low cost, and therefore can be easily scaled up and adapted to industrial production. The pore forming agent used can modify an external appearance and an internal pore structure of the three-dimensional graphene, thereby forming a hierarchical porous structure and increasing the specific surface area of the three-dimensional graphene.

Description

Method for preparing graphene powder with three-dimensional multi-stage pore structure

cross reference

The present invention claims the priority of Chinese Patent Application No. 201610246139.3, entitled "Preparation of a graphene powder of a three-dimensional multi-stage pore structure", which is filed by the Chinese Patent Office of the Chinese Patent Office, the entire contents of which is hereby incorporated by reference. The invention is incorporated by reference.

Technical field

The invention belongs to the technical field of graphene, and in particular relates to a method for preparing a graphene powder having a three-dimensional multi-stage pore structure.

Background technique

In recent years, with the rapid development of energy, separation technology and electrocatalytic technology, graphene is a single layer or a small layer of graphitized carbon material due to its large theoretical specific surface area, high conductivity, and strong electrochemical Characteristics such as stability and surface functionalization have been widely recognized in academia and industry. Theoretical studies have proved that graphene materials have special properties and can play a role in many fields, such as supercapacitors, hydrogen storage, secondary batteries, catalysis, environmental protection, etc., and will have great application prospects in other application fields in the future. [Adv. Mater. 2013, 25, 1296-1300; Adv. Mater. 2012, 24, 4419-4423; Mater. Today 2012, 15, 86-97]. At present, the two-dimensional graphene material produced in the market is mainly derived from the method of reducing graphene oxide, and the synthesis cost is high and the process is complicated. In addition, the graphene synthesized by the above method is generally affected by van der Waals force or π-π dangling bond, and is easy to accumulate or agglomerate when formed into a powder sample, so it needs to be dispersed in the stabilizer before use, and the concentration is very low, so it is disadvantageous Extensive use of graphene. In addition, commercial powder samples typically have a graphene specific surface area of less than 100 m ² /g, which is detrimental to practical industrial applications. Therefore, it is urgent to prepare a three-dimensional structure of graphene material, which has a self-supporting effect, can avoid graphene agglomeration, and maintain a high specific surface area. However, graphene which synthesizes three-dimensional structures is mainly used in self-assembly and vapor deposition (CVD). The three-dimensional graphene prepared by self-assembly method is mainly derived from graphene oxide or reductive graphene. Although it is re-reduced by chemical or physical methods, the resulting graphene structure still contains more Oxygen groups or distorted graphitized structures, thus affecting some of the intrinsic properties of graphene, such as electrical conductivity and electrochemical stability [Nanoscale 2012, 4, 5549 ~ 5563]. The three-dimensional graphene synthesized by CVD method has complete structure, good electrical conductivity and electrochemical stability, but usually requires special template and substrate, and the preparation conditions are strict, the process is complicated, and the cost is high [Chem. Soc. Rev. 2013, 42,794 ~ 830]. Further, the three-dimensional graphene prepared by the above method generally has a specific surface area of less than 500 m ² /g. Therefore, there are certain limitations in application to adsorbents, catalyst supports, electrode materials, and energy storage media. In addition, the method for preparing graphene with higher specific surface area in the prior art has higher strictness on the product, and requires pretreatment of the raw material, and the process time is longer and the operation is more complicated. Therefore, it is very important to develop a graphene powder with a high specific surface area and a three-dimensional multi-stage pore structure and a preparation method thereof, and at the same time, to simplify the process flow and shorten the process time.

The information disclosed in this Background section is only intended to provide an understanding of the general background of the invention, and should not be construed as an admission

Summary of the invention

The invention aims to overcome the deficiencies of the prior art for preparing three-dimensional graphene, in particular for preparing three-dimensional graphene having high specific surface area, and the obtained three-dimensional graphene has low specific surface area, poor electrical conductivity, high cost, complicated process and process flow. The method of preparing a graphene powder having a high specific surface area and a controllable three-dimensional multi-stage pore structure by using a resin as a precursor to provide a long-term, difficult-to-scale and industrialized problem.

To achieve the above object, the technical solution provided by the present invention is as follows:

A method for preparing a graphene powder of a three-dimensional multi-stage pore structure comprises the following steps:

(1) mixing the resin with a catalyst metal ion salt solution having a molar concentration of 0.6 to 1.0 mol/L, stirring uniformly, and washing;

(2) adding a pore former solution to the resin obtained after washing in the step (1), stirring and mixing uniformly, drying and pulverizing;

(3) The material obtained after the pulverization in the step (2) is heated at a rate of 1 to 10 ° C / min under a protective atmosphere, and the temperature is 800 to 1200 ° C, and the heat treatment is performed after the temperature is maintained at 0.5 to 4 hours after the specified temperature is reached;

(4) The material obtained by the heat treatment in the step (3) is pickled for 2 to 12 hours, filtered, and dried.

A method for preparing a graphene powder of a three-dimensional multi-stage pore structure, the more detailed steps of which are:

(2) adding the pore-forming agent solution to the resin obtained after washing in the step (1), stirring and mixing uniformly, and drying at a temperature of ≤100 ° C until the water content is ≤10%, and pulverizing;

(4) The material obtained by the heat treatment in the step (3) is pickled with one or more of hydrochloric acid, sulfuric acid or nitric acid for 2 to 12 hours, filtered, and kept at a temperature of 50 to 200 ° C to be dried. The amount of water is ≤ 20%.

Preferably, the resin described in the step (1) is one or a mixture of one or more of an ion exchange resin, a phenol resin or a phenol resin.

Preferably, the metal ion salt solution described in the step (1) is a metal ion salt solution having a concentration of 0.02 to 2 mol/L by dissolving the metal ion salt in deionized water.

Preferably, the ratio of the catalyst metal ion salt to the resin in the step (1) is from 0.002 to 0.4 mol of the metal ion salt: 1 g of the resin.

Preferably, the ratio of the catalyst metal ion salt to the resin in the step (1) is 0.02 to 0.2 mol of the metal ion salt: 1 g of the resin.

Preferably, the metal ion salt is one or more of an iron salt, a cobalt salt or a nickel salt; wherein the iron salt is ferric chloride, ferrous chloride, iron sulfate, sulfuric acid One or more mixtures of ferrous iron, iron nitrate, ferrous nitrate, iron acetate, ferrous acetate, potassium ferrocyanide, potassium ferricyanide, sodium ferrocyanide or sodium ferricyanide; The cobalt salts are cobalt chloride, cobalt chloride, cobalt sulfate, cobaltous cobalt sulfate, cobalt nitrate, cobaltous cobalt nitrate, cobalt acetate, cobaltous cobalt acetate, sodium hexanitrocobaltate or potassium hexanitrocobaltate. One or more mixtures; the nickel salt being one or more mixtures of nickel chloride, nickel sulfate, nickel nitrate or nickel acetate.

Preferably, the pore former solution in the step (2) is prepared by dissolving the pore former in a solvent. a saturated pore-forming agent solution; wherein the pore-forming agent is a hydroxide or an oxide, the hydroxide is potassium hydroxide or sodium hydroxide, and the oxide is potassium oxide or sodium oxide; Wherein the solvent is one of water, acetone, methanol or ethanol.

Preferably, the mass ratio of the resin to the pore former obtained after the step (1) is added in the step (2) is from 20:1 to 100.

Preferably, the mass ratio of the resin to the pore former obtained after the step (1) is added in the step (2) is 20:2 to 60.

Preferably, the heat treatment described in the step (3) is to raise the temperature to a temperature of 4 to 5 ° C / min to 100 ° C in a protective atmosphere, and then to 2 to 3 ° C / min to 450 ° C, and then The temperature is raised to 800 to 1000 ° C at 5 to 10 ° C, and the temperature is maintained for 0.5 to 3 hours.

Compared with the prior art, the present invention has the following beneficial effects:

The obtained three-dimensional graphene prepared by the method of the invention has high specific surface area, high conductivity, low cost, simple preparation process, greatly shortened flow, easy scale and industrial production; and the invention adopts one-step catalytic activation combined method to synthesize specific surface area adjustable The graphene powder of the three-dimensional multi-stage pore structure adopts the raw material resin to adsorb or exchange metal ions in the catalyst effectively and uniformly, so that the metal ions are uniformly distributed in the resin; further, the method of the invention does not need to be harsh The material pretreatment, the resin used, the source is wide, the cost is low, the metal ions can be uniformly adsorbed or exchanged, so that the metal ions are uniformly distributed in the resin; the further high temperature cracking process forms uniform metal nanoparticles, and the localized catalytic graphite The formation of a graphene layer; the pore former used in the present invention can regulate the appearance structure and internal pore structure of the three-dimensional graphene, resulting in a multi-stage pore structure and increasing the specific surface area of the three-dimensional graphene.

DRAWINGS

1 is a graph showing the graphene powders of a three-dimensional multi-stage pore structure prepared according to Example 1 of the present invention, wherein A is a scanning electron microscope image, B is a transmission electron micrograph, and C is a pore distribution map.

2 is a graph showing the thickness of a graphene wall of a graphene powder having a three-dimensional multi-stage pore structure prepared according to Example 1 of the present invention, wherein the graph A shows that the graphene wall thickness is 3 nm, and the B graph shows that the graphene wall thickness has <1 nm.

3 is an X-ray diffraction chart of a graphene powder having a three-dimensional multi-stage pore structure prepared according to Example 1 of the present invention.

4 is a scanning electron micrograph A of a graphene powder having a three-dimensional multi-stage pore structure prepared according to Embodiment 2 of the present invention, a transmission electron micrograph B, and a high-resolution graphene pore wall structure C.

Figure 5 is a nitrogen gas absorption and desorption curve A of a graphene powder having a three-dimensional multi-stage pore structure prepared according to Embodiment 2 of the present invention, and a pore distribution diagram B.

detailed description

The detailed description of the present invention is not limited by the specific embodiments, but it should be understood that the scope of the present invention is not limited by the specific embodiments.

Example 1

(1) Dissolving 0.2 mol of nickel acetate in deionized water to form a nickel metal ion salt solution having a concentration of 1.0 mol/L, adding 10 g of ion exchange resin, magnetically stirring uniformly, so that the ion exchange resin adsorbs metal nickel, and then used Ion water cleaning ion exchange resin after adsorbing metallic nickel;

(2) Weigh 16g of the ion exchange resin obtained in the above step (1), add it to an aqueous solution containing 40g of pore-forming agent potassium hydroxide, stir and dry, and keep the temperature to ≤100 °C to dry to ≤10 After smashing;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, from a room temperature to a temperature of 5 ° C / min at a heating rate of 5 ° C / min to 100 ° C under a shielding gas flow rate of 60 mL / min. , then rise to 450 ° C at 2 ° C / min, then rise to 850 ° C at 5 ° C / min, and incubated at 850 ° C temperature for 2h;

(4) The material obtained by the step (3) is treated with 3 mol/L hydrochloric acid for 6 h, filtered, and the filter residue is washed with deionized water until the pH of the washing liquid is neutral, and then dried at 80 ° C, and dried. Graphene powder with three-dimensional multi-stage pore structure (Fig. 1) with a water content of ≤ 20%, a specific surface area of about 1800 m ² /g, and a higher degree of graphitization (Fig. 2 and Fig. 3), the obtained graphite The layer is very thin and less than <3nm (Figure 2).

Example 2

(1) Dissolving 2.0 mol of nickel acetate in deionized water to form nickel gold at a concentration of 1.0 mol/L. Is an ion salt solution, adding 10g ion exchange resin, magnetically stirred evenly, so that the ion exchange resin adsorbs metal nickel, and then the ion exchange resin after adsorbing the metal nickel is washed with deionized water;

(2) Weigh 16g of the ion exchange resin obtained in the above step (1), and add it to an ethanol solution containing 20g of pore-forming agent potassium hydroxide, stir and dry, and keep the temperature at ≤100 °C until the water content ≤ After 10%, it is pulverized;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, at a temperature increase rate of 4 ° C/min, from a room temperature to 100 ° C under a shielding gas having a nitrogen flow rate of 60 mL/min. , then rise to 450 ° C at 3 ° C / min, then rise to 800 ° C at 5 ° C / min, and incubated at 800 ° C temperature for 3h;

(4) The material obtained by the step (3) is treated with 3 mol/L hydrochloric acid for 6 h, filtered, and the filter residue is washed with deionized water until the pH of the washing liquid is neutral, and then dried at 80 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 1500 m ² /g (Fig. 4 and Fig. 5).

Example 3

(1) Dissolving 1.0 mol of nickel acetate in deionized water to form a nickel metal ion salt solution having a concentration of 0.02 mol/L, adding 10 g of ion exchange resin, magnetically stirring uniformly, so that the ion exchange resin adsorbs metal nickel, and then used Ion water cleaning ion exchange resin after adsorbing metallic nickel;

(2) Weigh 16g of the ion exchange resin obtained after the above step (1), add it to an ethanol solution containing 70g of pore-forming agent potassium hydroxide, stir and dry, and keep the temperature at ≤100 °C until the water content ≤ After 10%, it is pulverized;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, from a room temperature to a temperature of 5 ° C / min at a heating rate of 5 ° C / min to 100 ° C under a shielding gas flow rate of 60 mL / min. , then rise to 450 ° C at 2 ° C / min, then rise to 1000 ° C at 10 ° C / min, and incubated at 1000 ° C for 0.5 h;

(4) The material obtained by the step (3) is treated with 3 mol/L hydrochloric acid for 4 hours, filtered, and the filter residue is washed with deionized water until the pH of the cleaning solution is neutral, and then dried at 50 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 2700 m ² /g.

Example 4

(1) Dissolving 0.02 mol of sodium hexanitrocobaltate in deionized water to form a cobalt metal ion salt solution having a concentration of 0.02 mol/L, adding 10 g of ion exchange resin, magnetically stirring uniformly, and causing the ion exchange resin to adsorb metal Cobalt, and then the ion exchange resin after adsorbing the metal cobalt is washed with deionized water;

(2) Weigh 16g of the ion exchange resin obtained in the above step (1), add it to an ethanol solution containing 1.6g of pore-forming agent potassium hydroxide, stir and dry, and keep the temperature to ≤100 °C to dry to moisture content After ≤10%, the pulverization is carried out;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, at a heating rate of 4 ° C/min, from a room temperature to 100 ° C under a shielding gas having a nitrogen flow rate of 50 mL/min. , then rise to 450 ° C at 3 ° C / min, then rise to 850 ° C at 7 ° C / min, and incubated at 850 ° C temperature for 2h;

(4) The material obtained after the heat treatment in step (3) is washed with 3 mol/L nitric acid for 10 h, filtered, and the filter residue is washed with deionized water until the pH of the washing liquid is neutral, and then dried at 100 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 1900 m ² /g.

Example 5

(1) Dissolving 4.0 mol of ferrous nitrate in deionized water to form a 2 mol/L iron metal ion salt solution, adding 10 g of ion exchange resin, magnetically stirring uniformly, so that the ion exchange resin adsorbs metallic iron, and then used Ion water cleaning ion exchange resin after adsorbing metal iron;

(2) Weigh 16g of the ion exchange resin obtained after the above step (1), add it to a methanol solution containing 0.8g of pore-forming agent potassium hydroxide, stir and dry, and keep the temperature to ≤100 °C to dry to moisture content After ≤10%, the pulverization is carried out;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, from a room temperature to a temperature of 5 ° C / min at a heating rate of 5 ° C / min to 100 ° C under a shielding gas flow rate of 60 mL / min. , then rise to 450 ° C at 2 ° C / min, then rise to 850 ° C at 5 ° C / min, and at 850 ° C temperature Insulation for 2h;

(4) The material obtained by the step (3) is treated with 3 mol/L hydrochloric acid for 2 h, filtered, and the filter residue is washed with deionized water until the pH of the washing liquid is neutral, and then dried at 200 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure (Fig. 1) having a water content of ≤ 20% has a specific surface area of about 1700 m ² /g.

Example 6

(1) Dissolving 0.8 mol of ferrous sulfate in deionized water to form an iron metal ion salt solution with a concentration of 0.6 mol/L, adding 10 g of phenol resin, magnetically stirring uniformly, allowing the phenol resin to adsorb metallic iron, and then using deionized Washing the phenol resin after adsorbing metallic iron;

(2) Weigh 16g of the phenol resin obtained after the above step (1), add it to an aqueous solution containing 48g of pore-forming agent sodium hydroxide, stir and dry, and keep the temperature at ≤100 °C until the water content is ≤10%. After smashing;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, at a temperature increase rate of 4 ° C/min, from a room temperature to 100 ° C under a shielding gas having a nitrogen flow rate of 60 mL/min. , then rise to 450 ° C at 3 ° C / min, then rise to 900 ° C at 5 ° C / min, and incubated at 900 ° C temperature for 2.5h;

(4) The material obtained by the step (3) is treated with 3 mol/L hydrochloric acid for 5 hours, filtered, and the filter residue is washed with deionized water until the pH of the cleaning solution is neutral, then dried at 90 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 1850 m ² /g.

Example 7

(1) Dissolving 0.1 mol of cobalt chloride in deionized water to form a cobalt metal ion salt solution having a concentration of 0.8 mol/L, adding 10 g of phenolic resin, uniformly stirring magnetically, and adsorbing metal cobalt by the phenolic resin, and then using deionized Washing the phenolic resin after adsorbing metallic cobalt;

(2) Weigh 16g of the phenolic resin obtained after the cleaning in the above step (1), add it to an ethanol solution containing 80g of pore-forming agent sodium oxide, stir and dry, and keep the temperature to ≤100% at a temperature of ≤100 °C. After smashing;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, at a temperature increase rate of 4 ° C/min, from a room temperature to 100 ° C under a shielding gas having a nitrogen flow rate of 60 mL/min. , then rise to 450 ° C at 3 ° C / min, then rise to 870 ° C at 5 ° C / min, and incubated at 870 ° C temperature for 2h;

(4) The material obtained by the step (3) is treated with 3 mol/L of sulfuric acid for 9 hours, filtered, and the filter residue is washed with deionized water until the pH of the cleaning solution is neutral, and then dried at 60 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 1800 m ² /g.

Example 8

(1) Dissolving 2 mol of ferrous nitrate in deionized water to form an iron metal ion salt solution having a concentration of 1.0 mol/L, adding 10 g of phenol resin, magnetically stirring uniformly, and phenol resin adsorbing metallic iron, and then using deionized water. Cleaning the phenol resin after adsorbing the metallic iron;

(2) Weigh 16g of the phenol resin obtained after the above step (1), add it to an acetone solution containing 25g of pore-forming agent potassium oxide, stir and dry, and keep the temperature to ≤100% at a temperature of ≤100 °C. After smashing;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, at a temperature increase rate of 4 ° C/min, from a room temperature to 100 ° C under a shielding gas having a nitrogen flow rate of 60 mL/min. , then rise to 450 ° C at 3 ° C / min, then rise to 850 ° C at 5 ° C / min, and incubated at 850 ° C temperature for 2h;

(4) The material obtained after the heat treatment in step (3) is washed with 3 mol/L nitric acid for 6 h, filtered, and the filter residue is washed with deionized water until the pH of the washing liquid is neutral, and then dried at 80 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 1900 m ² /g.

Example 9

(1) Dissolving 0.8 mol of nickel nitrate in deionized water to form a nickel metal ion salt solution having a concentration of 0.6 mol/L, adding 10 g of phenolic resin, and uniformly stirring magnetically, so that the phenolic resin adsorbs metallic nickel. Then, the phenolic resin after adsorbing the metallic nickel is washed with deionized water;

(2) weighing 16 g of the phenolic resin obtained after the above step (1), adding it to an aqueous solution containing 80 g of a pore-forming agent sodium hydroxide, stirring and drying, and drying at a temperature of ≤100 ° C until the water content is ≤10%. After smashing;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, at a temperature increase rate of 4 ° C/min, from a room temperature to 100 ° C under a shielding gas having a nitrogen flow rate of 60 mL/min. , then rise to 450 ° C at 3 ° C / min, then rise to 860 ° C at 8 ° C / min, and incubated at 860 ° C temperature for 2h;

(4) The material obtained by the step (3) is treated with 3 mol/L hydrochloric acid for 5 h, filtered, and the filter residue is washed with deionized water until the pH of the washing liquid is neutral, and then dried at 80 ° C, and dried. A graphene powder having a three-dimensional multi-stage pore structure with a water content of ≤ 20% has a specific surface area of about 1870 m ² /g.

Example 10

(1) Dissolving 2 mol of nickel acetate in deionized water to form a nickel metal ion salt solution having a concentration of 0.8 mol/L, adding 10 g of phenol resin, uniformly stirring magnetically, and absorbing the metal nickel by the phenol resin, and then washing with deionized water. a phenol resin after adsorbing metallic nickel;

(2) Weigh 16g of the phenol resin obtained after washing in the above step (1), add it to an aqueous solution containing 40g of pore-forming agent potassium hydroxide, stir and dry, and keep the temperature at ≤100 °C until the water content is ≤10%. After smashing;

(3) The material obtained by the pulverization in the step (2) is placed in a tube furnace for heat treatment, that is, from a room temperature to a temperature of 5 ° C / min at a heating rate of 5 ° C / min to 100 ° C under a shielding gas flow rate of 60 mL / min. , then raise to 450 ° C at 3 ° C / min, then rise to 850 ° C at 5 ° C / min, and incubated at 850 ° C for 2 h; (4) the step (3) after heating the resulting material with 3 mol / L The nitric acid is pickled for 4 hours, filtered, and the filter residue is washed with deionized water until the pH of the cleaning solution is neutral, then dried at 100 ° C, and dried to a water content of ≤ 20% to obtain a graphene powder having a three-dimensional multi-stage pore structure. The specific surface area is about 1900 m ² /g.

It can be seen from the A diagram in FIG. 1 and the B diagram in FIG. 1 that the graphene powder prepared in Example 1 exhibits a three-dimensional porous structure, and macropores and mesopores are clearly visible; FIG. 1 C shows that the graphene powder is known. Body Micropores, mesopores, and macropores. The A diagram in FIG. 2 and the B diagram in FIG. 2 indicate that the graphene powder material consists essentially of 3 to 8 layers of graphene. Figure 3 shows that the graphene powder material has good crystallization. 4 and FIG. 5 are the three-dimensional graphene powder materials prepared in Example 2. The material still maintains a three-dimensional structure, and the proportion of micropores is reduced, and the pore structure is successfully controlled.

The foregoing description of the specific exemplary embodiments of the present invention has The description is not intended to limit the invention to the precise forms disclosed. The embodiments were chosen and described in order to explain the particular embodiments of the invention Choose and change. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

A method for preparing a graphene powder having a three-dimensional multi-stage pore structure, comprising the following steps:

(1) mixing the resin with a catalyst metal ion salt solution having a molar concentration of 0.6 to 1.0 mol/L, stirring, and washing;

(2) adding a pore former solution to the resin obtained after washing in the step (1), stirring and mixing, drying and pulverizing;

(3) The material obtained after the pulverization in the step (2) is heated at a rate of 1 to 10 ° C / min under a protective atmosphere, and the temperature is 800 to 1200 ° C, and the heat treatment is performed after the temperature is maintained at 0.5 to 4 hours after the specified temperature is reached;

(4) The material obtained by the heat treatment in the step (3) is pickled for 2 to 12 hours, filtered, and dried.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 1, wherein the resin in the step (1) is one or a kind of an ion exchange resin, a phenol resin or a phenol resin. The above mixture.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 1, wherein the metal ion salt solution in the step (1) is prepared by dissolving a metal ion salt in deionized water to prepare a concentration. It is a metal ion salt solution of 0.02 to 2 mol/L.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 3, wherein the ratio of the catalyst metal ion salt to the resin in the step (1) is 0.002 to 0.4 mol of the metal ion salt: 1 g of the resin.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 3, wherein the ratio of the catalyst metal ion salt to the resin in the step (1) is 0.02 to 0.2 mol of the metal ion salt: 1 g of the resin.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 3, wherein the metal ion salt is one or one of an iron salt, a cobalt salt or a nickel salt. In the above mixture, the iron salt is ferric chloride, ferrous chloride, iron sulfate, ferrous sulfate, iron nitrate, ferrous nitrate, iron acetate, ferrous acetate, potassium ferrocyanide, potassium ferricyanide, One or more mixtures of sodium ferrocyanide or sodium ferricyanide; the cobalt salts are cobalt chloride, cobalt chloride, cobalt sulfate, cobaltous cobalt sulfate, cobalt nitrate, cobaltous nitrate, acetic acid One or more mixtures of cobalt, cobalt acetate, sodium hexanitrocobaltate or potassium hexanitrocobaltate; the nickel salt is nickel chloride, nickel sulfate, nickel nitrate or nickel acetate One or more mixtures.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 1, wherein the pore-forming agent solution in the step (2) is formed by dissolving a pore-forming agent in a solvent to form a saturated state. a pore solution; wherein the pore former is a hydroxide or an oxide, the hydroxide is potassium hydroxide or sodium hydroxide, and the oxide is potassium oxide or sodium oxide; wherein The solvent is one of water, acetone, methanol or ethanol.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 7, wherein the mass ratio of the resin to the pore-forming agent after the step (1) is added to the step (2) is 20:1. 100.
The method for preparing a graphene powder having a three-dimensional multi-stage pore structure according to claim 7, wherein the mass ratio of the resin to the pore-forming agent after the step (1) is added to the step (2) is 20:2. 60.
The method for preparing a graphene powder of a three-dimensional multi-stage pore structure according to claim 1, wherein the heating treatment in the step (3) is performed under a protective atmosphere, and the heating rate is 4 to 5 ° C/ The temperature is raised to 100 ° C, and then raised to 450 ° C at 2 ~ 3 ° C / min, and then heated to 800 ~ 1000 ° C at 5 ~ 10 ° C, and kept for 0.5 ~ 3 h.