CN105502359A - Preparation method of low-cost porous graphene - Google Patents

Abstract

The invention belongs to the field of high-performance carbon materials, and in particular relates to a preparation method of low-cost porous graphene. Porous graphene is prepared by using low-cost carbon precursors and additives as raw materials, through raw material mixing, low-temperature carbonization, and pickling processes. The invention has the advantages of simple process, low cost and easy industrial promotion; the prepared porous graphene has high purity, few structural defects and uniform pore size distribution.

Description

A kind of preparation method of low-cost porous graphene

technical field

The invention belongs to the field of carbon materials, and in particular relates to a preparation method of low-cost porous graphene.

Background technique

Porous graphene is a graphene material with a three-dimensional network structure. As a new type of carbon material, porous graphene has good application prospects in various electrochemical device electrode materials, catalyst supports, gas separation and storage, etc. due to its unique three-dimensional structure and excellent physical and chemical properties. On the one hand, porous graphene has the advantages of graphene's unique electrochemical properties, ultra-high thermal conductivity and large specific surface area; on the other hand, on this basis, its unique three-dimensional structure can effectively avoid the graphene material itself. The agglomeration and stacking of graphene, making full use of its large specific surface area, good electron transfer rate, and the excellent performance of graphene, further expand the application of this material in the fields of energy and electronics.

At present, the template method and chemical etching method are mainly used to prepare porous graphene. The template method to prepare porous graphene mainly adopts CVD technology, and magnesium oxide is used as a template to prepare porous graphene with controllable pore size. Chemical etching methods include KOH activation method, nitric acid oxidation method, catalyst oxidation method and other methods. The raw material is mainly graphene sheets, and the graphene sheets are etched through chemical reactions to greatly avoid the agglomeration of graphene. However, the above methods more or less have the problems of complex process, high cost, environmental pollution, many product defects and difficulty in batch production, which limits the application and promotion of porous graphene.

Contents of the invention

The purpose of the present invention is to provide a low-cost porous graphene preparation method for the deficiencies of the prior art. The preparation process is simple, the cost is low, and the industrialization is easy. The prepared porous graphene has a good three-dimensional porous structure, few structural defects, and high product purity.

In order to realize the above-mentioned purpose of the invention, the present invention adopts following technical scheme:

A preparation method of low-cost porous graphene, comprising the following steps:

1) Mixing of raw materials: Weigh the carbon precursor and aluminum-containing compound according to the mass ratio of 100:1~100:100, add solvent, stir at 25°C~150°C for 1~5h, evaporate the solvent, and place the solid residue in Dry in an oven at 40℃～100℃ for 1~12h;

2) Low-temperature carbonization: Put the dried material in step 1) into the atmosphere furnace, then raise the temperature to 1100-2000°C at a rate of 1°C/min-50°C/min, keep it for 0.1h-10h, and cool to room temperature take out;

3) Pickling: The carbonized product obtained in step 2) is placed in an acid solution and stirred for 1-5 hours, fully washed with deionized water until neutral, and then dried in a vacuum oven to prepare porous graphene.

In step 1), the mass ratio of the total mass of the carbon precursor and the aluminum-containing compound to the solvent is: 1:1~1:10.

The aluminum-containing compound described in step 1) is aluminum chloride, aluminum sulfate, aluminum carbonate, aluminum acetate, aluminum nitrate, aluminum hydroxide, sodium metaaluminate, aluminum nitride, aluminum phosphate, aluminum silicate, aluminum carbide, Aluminum ammonium sulfate dihydrate, aluminum metasilicate, aluminum trifluoromethanesulfonate, trialkylaluminum, dialkylaluminum chloride, monoalkylaluminum dichloride, trialkylaluminum dichloride, isopropanol Aluminum, aluminum butyl, aluminum acetate, aluminum formate, aluminum oxalate, aluminum propionate, polyaluminum chloride, aluminum silicate, aluminum fluoride, aluminum sec-butoxide, aluminum triacetylacetonate, aluminum triisobutyl, 8- Aluminum quinoline, aluminum perchlorate, aluminum monostearate, aluminum distearate, aluminum diacetate, ethylaluminum dichloride, aluminum ethylphosphonate, aluminum acetylacetonate, aluminum dihydrogen phosphate, aluminum oleate, bromine One of aluminum chloride, aluminum iodide, aluminum ethoxide, aluminum lactate, aluminum isooctanoate, and aluminum trioctyl.

The carbon precursor described in step 1) is pitch, sucrose, lignin and its derivatives, hemicellulose, cellulose, starch, tannin, rosin, chitin, polyvinyl alcohol, polyethylene glycol, polyethylene, Melamine and its derivatives, urea, polyvinyl acetal, polyvinyl butyral, polystyrene, polyurethane, polyimide, phenolic resin, furfural resin, furfuryl alcohol resin, furan resin, epoxy resin, bis One of maleimide resin and cyanate resin.

The solvent in step 1) is water, ethanol, dichloromethane, acetone, chloroform, methanol, tetrahydrofuran, carbon tetrachloride, cyclohexane, isopropanol, 1,2-trichloroethane, triethylamine, Toluene, pyridine, ethylenediamine, butanol, acetic acid, chlorobenzene, p-xylene, xylene, N,N-dimethylformamide, cyclohexanone, cyclohexanol, N,N-dimethylacetamide , N-methylformamide, phenol, dimethylsulfoxide, ethylene glycol, N-methylpyrrolidone, formamide, sulfolane, glycerin.

Step 2) N ₂ or argon in the atmosphere furnace; gas flow: 25mL/min～300mL/min.

The acid solution in step 3) is one of hydrochloric acid, oxalic acid and sulfuric acid, the concentration of the acid solution is 0.05mol/L-6mol/L, and the stirring speed is 25-200r/min.

Step 3) The vacuum degree of the vacuum drying oven is 1.0×10 ⁻¹ ~1.0×10 ⁵ Pa, and the drying temperature is 40~100° C.

The beneficial effects of the present invention are:

1) The specific surface area of the porous graphene prepared by the present invention is 100-1500m ² /g, the number of layers is 1-15, and the pore diameter is 2nm-50nm;

2) The raw materials used in the preparation method of the present invention are rich in raw materials and low in price; the process equipment is simple and easy for large-scale production; the prepared porous graphene has a high specific surface area, few structural defects, and uniform pore size distribution.

Description of drawings

Fig. 1 is the scanning electron microscope picture of the porous graphene that adopts embodiment 1 technique to prepare;

Fig. 2 is the scanning electron microscope picture of the porous graphene that adopts embodiment 2 technique to prepare;

Fig. 3 is the scanning electron microscope picture of the porous graphene that adopts embodiment 3 technique to prepare;

Fig. 4 is the scanning electron microscope picture of the porous graphene that adopts embodiment 4 process to prepare;

5 is a scanning electron microscope picture of porous graphene prepared by the process of Example 5.

specific embodiment

The following are several specific embodiments of the present invention to further illustrate the present invention, but the present invention is not limited thereto.

Example 1

1) Raw material mixing: Weigh the water-based mesophase pitch and aluminum acetate according to the mass ratio of 100:100, use deionized water as the solvent, and the mass ratio of the raw material to the solvent is 1:10; mix the two evenly by mechanical stirring, and stir The temperature is 25°C, and the stirring time is 0.5h; after stirring evenly, the solvent is distilled off under reduced pressure, placed in a vacuum oven (1.0×10 ^-1 Pa) at 60°C for 4 hours, and cooled to room temperature;

2) Carbonization: place the dried sample in an atmosphere furnace, pass in argon gas (the flow rate of argon gas is 100mL/min), raise the temperature to 1800°C at 10°C/min, keep it warm for 2 hours, cool to room temperature and take it out;

3) Pickling: Place the carbonized product in a hydrochloric acid solution (the molar concentration of the acid solution is 1mol/L), stir for 4 hours at a stirring speed of 120r/min, filter and separate, wash with deionized water until neutral; place in a vacuum drying oven (1.0×10 ^-1 Pa) drying at 60°C for 8 hours to obtain porous graphene;

The properties of the prepared porous graphene are as follows: the number of layers is 2-10 layers, the pore size is 2nm-25nm, and the specific surface area is 1500m ² /g.

Example 2

1) Mixing of raw materials: Weigh sucrose and aluminum sulfate according to the mass ratio of 100:50, use acetone as the solvent, and the mass ratio of raw materials to solvent is 1:3; mix the two evenly by mechanical stirring, and the stirring temperature is 30°C. The stirring time is 1 hour; after stirring evenly, the solvent is distilled off under reduced pressure, placed in a 35°C vacuum oven (1.0×10 ^-1 Pa) to dry for 2 hours, and cooled to room temperature;

2) Carbonization: place the dried sample in an atmosphere furnace, pass in nitrogen gas (nitrogen flow rate is 50mL/min), raise the temperature to 1400°C at 5°C/min, keep it warm for 1h, cool to room temperature and take it out;

3) Pickling: Place the carbonized product in a sulfuric acid solution (the molar concentration of the acid solution is 0.5mol/L), stir for 2 hours at a stirring speed of 60r/min, filter and separate, wash with deionized water to neutrality; place in vacuum drying Dry in oven (1.0×10 ^-1 Pa) at 80°C for 4 hours to obtain porous graphene;

The properties of the prepared porous graphene are as follows: the number of layers is 5-15, the pore size is 10nm-50nm, and the specific surface area is 400m ² /g.

Example 3

1) Mixing of raw materials: Weigh polystyrene and aluminum isopropoxide according to the mass ratio of 100:70, use N,N-dimethylformamide as the solvent, and the mass ratio of raw materials to solvent is 1:5; through mechanical stirring Mix the two evenly, the stirring temperature is 120°C, and the stirring time is 1.5h. After stirring evenly, the solvent was distilled off under reduced pressure, placed in a vacuum oven (1.0×10 ^-1 Pa) at 80°C for 10 hours, and cooled to room temperature;

2) Carbonization: place the dried sample in an atmosphere furnace, pass in argon gas (the flow rate of argon gas is 120mL/min), raise the temperature to 2000°C at 15°C/min, keep it warm for 0.5h, cool to room temperature and take it out;

3) Pickling: Place the carbonized product in an oxalic acid solution (the molar concentration of the acid solution is 2mol/L), stir for 3 hours at a stirring speed of 80 rpm, filter and separate, wash with deionized water until neutral; place in vacuum drying Dry in oven (1.0×10 ^-1 Pa) at 70°C for 8 hours to obtain porous graphene;

The properties of the prepared porous graphene sheet are as follows: the number of layers is 5-10, the pore size is 20nm-35nm, and the specific surface area is 350m ² /g.

Example 4

1) Mixing of raw materials: Weigh lignin and anhydrous aluminum chloride according to the mass ratio of 100:80, use toluene as solvent, and the mass ratio of raw material to solvent is 1:9; mix the two evenly by mechanical stirring, and the stirring temperature The temperature is 80°C, and the stirring time is 4 hours; after stirring evenly, the solvent is distilled off under reduced pressure, placed in a vacuum oven (1.0×10 ^-1 Pa) at 60°C for 3 hours, and cooled to room temperature;

2) Carbonization: place the dried sample in an atmosphere furnace, pass in nitrogen gas (nitrogen flow rate is 80mL/min), raise the temperature to 1100°C at 2°C/min, keep it warm for 5h, cool to room temperature and take it out;

3) Pickling: Place the carbonized product in a hydrochloric acid solution (the molar concentration of the acid solution is 0.05mol/L), stir for 5 hours at a stirring speed of 40 rpm, filter and separate, wash with deionized water until neutral; place in a vacuum Dry in a drying oven (1.0×10 ⁵ Pa) at 100°C for 2 hours to obtain porous graphene;

The properties of the prepared porous graphene are as follows: the number of layers is 2-12 layers, the pore size is 30nm-40nm, and the specific surface area is 500m ² /g.

Example 5

1) Mixing of raw materials: Weigh the thermoplastic phenolic resin and aluminum nitrate according to the mass ratio of 100:30, use N-methylformamide as the solvent, and the mass ratio of the raw material to the solvent is 1:4; mix the two evenly by mechanical stirring , the stirring temperature was 100°C, and the stirring time was 3.5h. After stirring evenly, the solvent was distilled off under reduced pressure, placed in a vacuum oven (1.0×10 ² Pa) at 70°C for 5 hours, and cooled to room temperature;

2) Carbonization: place the dried sample in an atmosphere furnace, pass in argon gas (the flow rate of argon gas is 200mL/min), raise the temperature to 1700°C at 20°C/min, keep it warm for 6h, cool to room temperature and take it out;

3) Pickling: Place the carbonized product in a hydrochloric acid solution (the molar concentration of the acid solution is 4mol/L), stir for 5 hours at a stirring speed of 90 rpm, filter and separate, and wash with deionized water until neutral. Place in a vacuum drying oven (1.0×10 ^-1 Pa) and dry at 60°C for 10 hours to obtain porous graphene. The properties of the prepared porous graphene are as follows: the number of layers is 3-9 layers, the pore size is 5nm-25nm, and the specific surface area is 800m ² /g.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (8)

1. a preparation method for low cost porous graphene, is characterized in that: comprise the following steps:

1) mixing of raw material: 100:1 ~ 100:100 takes carbon precursor and aluminum contained compound in mass ratio, adds solvent, after stirring 1 ~ 5h at 25 DEG C ~ 150 DEG C, solvent evaporated, is placed in the dry 1 ~ 12h of 40 DEG C ~ 100 DEG C baking ovens by solid residue;

2) low-temperature carbonization: material dried for step 1) is put into atmosphere furnace, keeps 0.1h ~ 10h after being then warming up to 1100 DEG C ~ 2000 DEG C with the temperature rise rate of 1 DEG C/min ~ 50 DEG C/min, is cooled to room temperature and takes out;

3) pickling: by step 2) gained carbonizing production is placed in acid solution and stirs 1 ~ 5h, and deionized water fully washs to neutrality, then puts into after vacuum drying oven carries out drying, obtained porous graphene.

2. the preparation method of low cost porous graphene according to claim 1, is characterized in that: in step 1), the total mass of carbon precursor and aluminum contained compound and the mass values of solvent are: 1:1 ~ 1:10.

3. the preparation method of low cost porous graphene according to claim 1, it is characterized in that: the aluminum contained compound described in step 1) is aluminum chloride, Tai-Ace S 150, aluminium carbonate, Burow Solution, aluminum nitrate, aluminium hydroxide, sodium metaaluminate, aluminium nitride, aluminum phosphate, pure aluminium silicate, aluminium carbide, ten sulfate dihydrate aluminium ammonia, metasilicic acid aluminium, trifluoromethanesulfonic acid aluminium, trialkylaluminium, dialkylaluminum chloride, one alkyl al dichloride, trialkyl tri-chlorination two aluminium, aluminum isopropylate, butyl aluminium, aluminum acetate, al formate, oxalic acid aluminium, propionic acid aluminium, poly aluminium chloride, pure aluminium silicate, fluoric acid aluminium, aluminium secondary butylate, praseodynium aluminium, triisobutyl aluminium, oxine aluminium, aluminum perchlorate, aluminum monostearate, aluminium distearate, oxalic acid aluminium, ethyl aluminum dichloride, second squama aluminium, aluminium acetylacetonate, aluminium dihydrogen phosphate, aluminium oleate, aluminum bromide, aluminum iodide, aluminum ethylate, Aluctyl, isocaprylic acid aluminium, one in trioctylaluminum.

4. the preparation method of low cost porous graphene according to claim 1, it is characterized in that: the carbon precursor described in step 1) is pitch, sucrose, xylogen and derivative thereof, hemicellulose, Mierocrystalline cellulose, starch, tannin, rosin, chitin, polyvinyl alcohol, polyoxyethylene glycol, polyethylene, trimeric cyanamide and derivative thereof, urea, polyvinylacetal, polyvinyl butyral acetal, polystyrene, urethane, polyimide, resol, furfuryl resin, furfuryl alcohol resin, furane resin, epoxy resin, bimaleimide resin, one in cyanate ester resin.

5. the preparation method of low cost porous graphene according to claim 1, it is characterized in that: the solvent described in step 1) is water, ethanol, methylene dichloride, acetone, chloroform, methyl alcohol, tetrahydrofuran (THF), tetracol phenixin, hexanaphthene, Virahol, 1, 2-trichloroethane, triethylamine, toluene, pyridine, quadrol, butanols, acetic acid, chlorobenzene, p-Xylol, dimethylbenzene, N, dinethylformamide, pimelinketone, hexalin, N, N-N,N-DIMETHYLACETAMIDE, N-METHYLFORMAMIDE, phenol, methyl-sulphoxide, ethylene glycol, N-Methyl pyrrolidone, methane amide, tetramethylene sulfone, one in glycerine.

6. the preparation method of low cost porous graphene according to claim 1, is characterized in that: step 2) be N in atmosphere furnace ₂or argon gas; Gas flow: 25mL/min ~ 300mL/min.

7. the preparation method of low cost porous graphene according to claim 1, is characterized in that: the acid solution described in step 3) is the one in hydrochloric acid, oxalic acid, sulfuric acid, and the concentration of acid solution is 0.05mol/L ~ 6mol/L, and stirring velocity is 25 ~ 200r/min.

8. the preparation method of low cost porous graphene according to claim 1, is characterized in that: in step 3), the vacuum tightness of vacuum drying oven is 1.0 × 10 ^-1~ 1.0 × 10 ⁵pa, drying temperature is 40 ~ 100 DEG C.