Porous graphene and preparation method therefor

Abstract

The present invention discloses porous graphene and a preparation method therefor. The preparation method comprises the following steps: adding a graphite raw material into an acetic acid solution of chitosan; and by taking chitosan as a peeling agent, carrying out ultrasonic treatment and centrifugal purification to prepare the porous graphene material. The graphene material not only has a porous structure, but also is relatively few in number of layers, and the transverse size of the flaky layer is relatively large. Compared to the prior art, as only ultrasonic treatment is carried out, the preparation method is simple and easy to implement; as the graphite is taken as the raw material, the prepared porous graphene material is high in degree of graphitization. The porous graphene material has a huge application value in the fields of absorption, catalysis, gas separation, super capacitors and the like.

Description

Technical field

[0001] The invention belongs to the technical field of graphene materials, and specifically relates to a porous graphene and a preparation method thereof. Background technique

[0002] Graphene material is a nano-scale graphite material composed of a single layer of graphite. Porous graphene is a physical or chemical method to create some nano-sized pores in the graphene sheet. The porous structure makes graphene useful in energy, catalysis or There are great advantages in adsorption materials.

[0003] At present, the preparation of graphene materials with porous structure mainly includes the following methods: (1) The multi-layer graphene and surfactant are hydrothermally reacted in a strong alkali aqueous solution, but this method is due to the addition of surfactants. Many functional groups are introduced into the graphene sheet; (2) The carbon materials such as graphene and transition metals are heated at the same time to obtain porous graphene, but this metho...

Examples

Embodiment 1

[0023] Prepare an acetic acid aqueous solution with a volume concentration of 0.5%, and set the weight average molecular weight to 5.0×10 3 , Chitosan with a degree of deacetylation of 40% is dissolved in an aqueous acetic acid solution to prepare a chitosan solution with a mass concentration of 0.1 mg / mL, and stir evenly;

[0024] Add graphite to the above chitosan solution, and control the mass ratio of chitosan to graphite to 1:10;

[0025] The above-mentioned mixed liquid was put into an ultrasonic cleaner for ultrasonic treatment, the temperature was 75° C., the time was 0.5 hours, and the ultrasonic power was 600 W.

[0026] After centrifuging the above-mentioned ultrasonic solution at 1000 rpm for 10 minutes, the above-mentioned acetic acid aqueous solution was used for centrifugal cleaning at 15000 rpm, and the centrifugation time was 0.5 hours.

Embodiment 2

[0028] Prepare an aqueous acetic acid solution with a volume concentration of 2%, and set the weight average molecular weight to 2.0×10 4 , Chitosan with a degree of deacetylation of 53% is dissolved in an aqueous acetic acid solution to prepare a chitosan solution with a mass concentration of 0.2mg / mL, and stir evenly;

[0029] Add graphite to the above chitosan solution, and control the mass ratio of chitosan to graphite to 1:5;

[0030] The above-mentioned mixed liquid was put into an ultrasonic cleaner for ultrasonic treatment, the temperature was 60°C, the time was 2 hours, and the ultrasonic power was 540W.

[0031] After centrifuging the above-mentioned ultrasonic solution at 2000 rpm for 10 minutes, the above-mentioned aqueous acetic acid solution was used for centrifugal cleaning at 20000 rpm, and the centrifugation time was 1 hour.

Embodiment 3

[0033] Prepare an aqueous solution of acetic acid with a volume concentration of 4%, and set the weight average molecular weight to 1.5×10 5 , Chitosan with a degree of deacetylation of 60% is dissolved in an aqueous acetic acid solution to prepare a chitosan solution with a mass concentration of 0.5 mg / mL, and stir evenly;

[0034] Add graphite to the above chitosan solution, and control the mass ratio of chitosan to graphite to 1:1;

[0035] The above-mentioned mixed liquid was put into an ultrasonic cleaner for ultrasonic treatment, the temperature was 30°C, the time was 8 hours, and the ultrasonic power was 480W.

[0036] After centrifuging the above-mentioned ultrasonic solution at 2000 rpm for 5 minutes, the above-mentioned aqueous acetic acid solution was used for centrifugal cleaning at 16000 rpm, and the centrifugation time was 1.5 hours.

Technical field

[0001] The invention belongs to the technical field of graphene materials, and specifically relates to a porous graphene and a preparation method thereof. Background technique

[0002] Graphene material is a nano-scale graphite material composed of a single layer of graphite. Porous graphene is a physical or chemical method to create some nano-sized pores in the graphene sheet. The porous structure makes graphene useful in energy, catalysis or There are great advantages in adsorption materials.

[0003] At present, the preparation of graphene materials with porous structure mainly includes the following methods: (1) The multi-layer graphene and surfactant are hydrothermally reacted in a strong alkali aqueous solution, but this method is due to the addition of surfactants. Many functional groups are introduced into the graphene sheet; (2) The carbon materials such as graphene and transition metals are heated at the same time to obtain porous graphene, but this metho...

Examples

Embodiment 1

[0023] Prepare an acetic acid aqueous solution with a volume concentration of 0.5%, and set the weight average molecular weight to 5.0×10 3 , Chitosan with a degree of deacetylation of 40% is dissolved in an aqueous acetic acid solution to prepare a chitosan solution with a mass concentration of 0.1 mg / mL, and stir evenly;

[0024] Add graphite to the above chitosan solution, and control the mass ratio of chitosan to graphite to 1:10;

[0025] The above-mentioned mixed liquid was put into an ultrasonic cleaner for ultrasonic treatment, the temperature was 75° C., the time was 0.5 hours, and the ultrasonic power was 600 W.

[0026] After centrifuging the above-mentioned ultrasonic solution at 1000 rpm for 10 minutes, the above-mentioned acetic acid aqueous solution was used for centrifugal cleaning at 15000 rpm, and the centrifugation time was 0.5 hours.

Embodiment 2

[0028] Prepare an aqueous acetic acid solution with a volume concentration of 2%, and set the weight average molecular weight to 2.0×10 4 , Chitosan with a degree of deacetylation of 53% is dissolved in an aqueous acetic acid solution to prepare a chitosan solution with a mass concentration of 0.2mg / mL, and stir evenly;

[0029] Add graphite to the above chitosan solution, and control the mass ratio of chitosan to graphite to 1:5;

[0030] The above-mentioned mixed liquid was put into an ultrasonic cleaner for ultrasonic treatment, the temperature was 60°C, the time was 2 hours, and the ultrasonic power was 540W.

[0031] After centrifuging the above-mentioned ultrasonic solution at 2000 rpm for 10 minutes, the above-mentioned aqueous acetic acid solution was used for centrifugal cleaning at 20000 rpm, and the centrifugation time was 1 hour.

Embodiment 3

[0033] Prepare an aqueous solution of acetic acid with a volume concentration of 4%, and set the weight average molecular weight to 1.5×10 5 , Chitosan with a degree of deacetylation of 60% is dissolved in an aqueous acetic acid solution to prepare a chitosan solution with a mass concentration of 0.5 mg / mL, and stir evenly;

[0034] Add graphite to the above chitosan solution, and control the mass ratio of chitosan to graphite to 1:1;

[0035] The above-mentioned mixed liquid was put into an ultrasonic cleaner for ultrasonic treatment, the temperature was 30°C, the time was 8 hours, and the ultrasonic power was 480W.

[0036] After centrifuging the above-mentioned ultrasonic solution at 2000 rpm for 5 minutes, the above-mentioned aqueous acetic acid solution was used for centrifugal cleaning at 16000 rpm, and the centrifugation time was 1.5 hours.

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