CN102557018A - Preparation method of graphene based on green deoxidation technology - Google Patents

Abstract

The invention discloses a preparation method of graphene based on a green deoxidation technology, which comprises the following steps: preparing graphene oxide through the intercalated oxidation of graphite; and finishing the conversion from the graphene oxide to the graphene through a green deoxidizer. The preparation method has the beneficial effects that the graphene can be quickly prepared in batch through heating the adopted green deoxidizer, the deoxidizer can be recycled, and the reaction tail gas is single and is convenient to collect so as to achieve the green low-carbon production purpose. A deoxidizing section has the advantages of simplicity and convenience in operation, safety, low cost and zero emission.

Description

A kind of preparation method of graphene based on green deoxidation technology

【Technical field】

The invention relates to a method for preparing two-dimensional nanomaterials, in particular to a method for batch-preparing single-layer graphene based on green deoxidation technology.

【Background technique】

Graphene is a two-dimensional crystal composed of closely packed carbon atoms, and is the basic unit of carbon allotropes including fullerenes, carbon nanotubes, and graphite. Graphene has special optical, electrical, thermal, and mechanical properties. It has half-integer quantum Hall effect at room temperature, quantum tunneling effect, high-speed electron mobility of 20000m ² V ^-1 s ^-1 , and high thermal conductivity of 3000Wm ^{- 1} K ^-1 and excellent mechanical properties (high modulus 1060GPa, high strength 130GPa). With these characteristics, graphene can not only produce nanoelectronics and spintronics components with special properties, but also use its planar structure to design large-scale integrated nanoelectronic circuits using standard semiconductor photolithography processes. Functional composite materials, energy storage materials, catalyst supports, etc. have broad application prospects. But the industrial application of graphene is based on its mass production. Therefore, a large number of scientists at home and abroad focus their research on the industrial production of graphene. Graphene was first successfully produced by British physicists Andre Heim and Konstantin Novoselov through the method of micromechanical exfoliation. The biggest disadvantage of this method is low yield. So far, the preparation methods of graphene can be divided into four categories: micromechanical exfoliation method, chemical vapor deposition method, epitaxial growth method, and colloidal suspension preparation method. However, due to the hydrophobicity of graphene itself and the nature of agglomeration in solvents, its preparation is limited. From the perspective of short production cycle and high output in laboratory performance research, it is internationally believed that the wet chemical oxidation-reduction method in the preparation of colloidal suspension has the potential for large-scale production.

The wet chemical oxidation-reduction method refers to the method of firstly oxidizing the graphite raw material to obtain graphite oxide, and then obtaining graphene oxide by exfoliation, and then reducing it. There are only three commonly used oxidation methods: Brodie, Staudenmaier or Hummers. There are more researches on reduction methods. The commonly used reduction methods include chemical liquid phase reduction, plasma reduction, thermal reduction, hydrogen arc discharge stripping, light reduction, microwave reduction, etc. , commonly used chemical reduction, hydrazine hydrate, H ₂ , NaBH ₄ , vitamin C, ethylenediamine, Na/CH ₃ OH, etc. However, these methods will face problems such as high toxicity of the reducing agent, non-recyclable utilization, long reaction cycle, high energy consumption, and inability to deal with direct exhaust gas emissions, which hinder industrial production.

【Content of invention】

For the deficiencies of existing graphene preparation methods, the object of the invention is to provide a kind of preparation method of graphene based on green deoxidation technology that can solve the following technical problems:

1. Through the selection of deoxidizers, such as sodium carbonate, potassium carbonate, etc., the deoxidation process of deoxidizer cycle production, non-toxic, and zero-emission graphene oxide is realized;

2. Reduce the reaction time of the deoxidation process;

3. By introducing the weak alkalinity of carbonate, the stability of graphene in the water phase system is improved.

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

1. Intercalation oxidation of graphite;

2. The exfoliation of graphite oxide to obtain graphene oxide;

3. Convert graphene oxide to graphene through a deoxidizer;

4. The tail gas produced by the green deoxygenation process is pure carbon dioxide, which can be recycled directly to achieve zero carbon emissions.

Specific embodiments of the present invention are as follows:

1. Intercalation oxidation of graphite

(1) According to the proportion of graphite and pre-oxidant, put it into the flask; according to the proportion of graphite and intercalation oxidant, add the intercalation oxidant slowly, control the temperature to a suitable temperature, and stir it magnetically to make the reaction system uniform and stable to react.

(2), according to the proportioning of graphite and strong oxidizing agent, slowly add strong oxidizing agent in the reaction step (1) in stages; the temperature of the reaction system is quickly kept at a suitable temperature, magnetically stirred, and reacted to a suitable time.

(3), after the reaction step (2), add an appropriate amount of deionized water to terminate the reaction of the reaction system, adjust the reaction temperature to a suitable value under magnetic stirring, heat and keep warm, and magnetically stir.

(4) After the reaction system in the reaction step (3) is stable, add a strong oxidant according to the ratio of graphite and strong oxidant, and use a certain amount of deionized water to dilute the reaction system twice to obtain a suspension. Heat and keep warm ,Magnetic stirring.

(5) The suspension obtained in the reaction step (4) is filtered, separated, and impurity-removed to obtain an intercalation oxide of graphite.

2. The exfoliation of graphite intercalation oxide to obtain graphene oxide

Disperse the intercalation oxide of graphite obtained in the reaction step (5) into an appropriate amount of water, and carry out ultrasonic dispersion for a certain period of time through appropriate power to prepare a suspension of graphene oxide in water at a certain concentration.

3. Convert graphene oxide to graphene through deoxidizer

(1), in the suspension prepared in reaction step 2, according to the ratio of the aqueous solution of the green deoxidizer and the graphene oxide of a certain concentration, add the aqueous solution of the green deoxidizer, magnetically stir and mix evenly, at an appropriate temperature , heat preservation reaction, deoxygenation ends after a certain period of time, and a reaction liquid is obtained; the reaction system is closed, and the generated carbon dioxide is collected.

(2), the reaction liquid obtained in the reaction step (1), is filtered and separated to obtain graphene and filtrate.

4. Recycling of green deoxidizer

Put the filtrate obtained in the reaction step 3 in a round bottom flask, add zeolite to carry out vacuum distillation at an appropriate temperature, concentrate to the concentration required in the reaction step 3, and add the obtained concentrated solution to the reaction step 3 of the next group of experiments Recycling, because the reaction system will not pollute the green deoxidizer, so the green deoxidizer can be recycled for a long time.

The preparation method of graphene of the present invention, as graphite, optional natural graphite, artificial graphite, expanded graphite, the natural graphite and the expanded graphite that preferred lamellar structure is easy to the oxidation of intercalation or exfoliation; As intercalation oxidant, can Select concentrated sulfuric acid and phosphoric acid, preferably 98% concentrated sulfuric acid; as a pre-oxidant, sodium nitrate, potassium nitrate, preferably sodium nitrate; as a strong oxidant, potassium permanganate, potassium oxyacid, sodium nitrate, hydrogen peroxide, preferably high Potassium manganate or hydrogen peroxide; as a green deoxidizer, carbonates can be selected, preferably one or more of sodium carbonate, potassium carbonate and lithium carbonate.

The described graphite of above-mentioned scheme and pre-oxidizer, graphite and strong oxidant, graphite and intercalation oxidant, and the proportioning (in dry weight parts, below) of the aqueous solution of green deoxidizer and water, green deoxidizer and graphene oxide same) as:

The ratio of graphite to intercalation oxidant is 1:10 to 1:100, preferably 1:30 to 1:60; the ratio of graphite to preoxidant is 1:0 to 1:2, preferably 1:0.2 to 1:1; graphite The ratio of strong oxidant to 1:2~1:7, preferably 1:3~1:6; the ratio of green deoxidizer to water is 0.005:1~3.2:1, preferably 0.05:1~3.2:1; green deoxidizer The ratio of the aqueous solution of the agent to the graphene oxide is 1:200˜100:2, preferably 1:100˜100:1.

Therefore, a kind of preparation method based on the graphene of green deoxidation technology of the present invention preferably adopts following embodiment:

1. Intercalation oxidation of graphite

(1), according to the ratio of natural graphite or expanded graphite: sodium nitrate 1: 0.2～1: 1, take natural graphite or expanded graphite and sodium nitrate, and feed into the flask, according to natural graphite or expanded graphite: 98% The ratio of concentrated sulfuric acid is 1:30 to 1:60, 98% concentrated sulfuric acid is slowly added, the reaction temperature is controlled at 0 to 5°C, and magnetic stirring is used to make the reaction system uniform and stable.

(2), after reaction step (1) is carried out 10min～2h, by natural graphite or expanded graphite: the proportioning of potassium permanganate 1: 3～1: 6, slowly add potassium permanganate in stages; Magnetic stirring, The reaction temperature is controlled at 25-45°C

(3) After the reaction step (2) is carried out for 2h-36h, 100-300mL of deionized water is added to terminate the reaction, and the reaction temperature is adjusted to 40-120° C. under magnetic stirring.

(4), the reaction step (3) is to be carried out for 10mim ~ 2h, after the reaction system is stable, add 10 ~ 50mL of hydrogen peroxide, remove the manganese dioxide produced, and use 120-280mL of deionized water to dilute the reaction system twice, Obtain a suspension; use a water bath to heat and insulate, and magnetically stir.

(5), with the suspension that reaction step (4) obtains, filter separation, impurity removal, obtain the intercalation oxide of graphite.

Exfoliation of graphite intercalation oxides to obtain graphene oxides

The graphite intercalation oxide obtained in the reaction step (5) and ionized water are placed at room temperature with a power of 50-500 W and ultrasonication for 2-30 minutes to prepare a suspension of graphene oxide in water.

3. Convert graphene oxide to graphene through deoxidizer

(1), in the suspension that reaction step 2 makes, by the volume ratio of graphene oxide aqueous solution and green deoxidizer aqueous solution (green deoxidizer and water proportioning 0.05: 1～3.2: 1) 1: 100～ 100:1, add one or more aqueous solutions of green deoxidizers sodium carbonate, potassium carbonate and lithium carbonate, heat to 50-120°C, stir magnetically, mix evenly, and the reaction time is 3min-5h to obtain a reaction liquid. The system is closed and the carbon dioxide produced is collected.

(2), the reaction liquid obtained in the reaction step (1), is filtered and separated to obtain graphene and filtrate.

4. Recycling of green deoxidizer

Put the filtrate obtained in the reaction step 3 in a round-bottomed flask, add zeolite to carry out vacuum distillation at 40-130°C, and concentrate to the concentration required in the reaction step 3; the obtained concentrated solution is added to the reaction step 3 of the next group of experiments For recycling, since the reaction system will not pollute the green deoxidizer, the green deoxidizer can be recycled for a long time.

[Technical key points of the present invention]

Key technical points of the present invention are:

Carbonate is used as a green deoxidizer, and carbonate and deionized water are made into a uniform and stable solution. Since the carbonate in the carbonate aqueous solution can release a certain amount of oxygen ions, it can attack the carbon connected to the oxygen-containing group on the graphene oxide to achieve the purpose of deoxidation. Oxygen ions attack to remove carbon dioxide, the reaction is fast and the conditions are mild, so that the reaction is easy to control and the reaction time is short; the product produced by the deoxygenation of the system is carbon dioxide, which is also the only by-product, which is easy to collect, so as to achieve zero-emission green and low-carbon Production method; graphene can be stably dispersed under alkaline conditions.

[Effects of the present invention]

The green deoxidizer used in the present invention can quickly prepare graphene by deoxidizing graphene oxide in batches by heating and stirring at a lower temperature under the condition of aqueous solution, and the green deoxidizer itself can be distilled under reduced pressure at a lower temperature Recycling and utilization, at the same time, the tail gas produced by the deoxidation process is single, composed of carbon dioxide, which is easy to collect, so as to achieve the purpose of green and low-carbon production; the deoxidation section of the present invention is easy to operate, safe, low in cost, zero emission, and the green deoxidizer can be recycled. The prepared graphene product has good dispersion in water phase, is not easy to agglomerate, retains more carbon-carbon double bonds, and has high conductivity potential.

[specific implementation plan]

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope of the present invention. The proportioning scope in the embodiment is the ratio of dry weight.

Embodiment one

The preparation method of graphene based on green deoxidation technology comprises the following reaction steps:

1. Intercalation oxidation of graphite

(1) Weigh 4g of natural graphite and 3g of sodium nitrate, put them into a flask, slowly add 120mL of 98% concentrated sulfuric acid, use a constant temperature water bath to control the temperature at 0°C, and stir magnetically to make the reaction system uniform and stable.

(2) After the reaction step (1) was carried out for 1 hour, 20 g of potassium permanganate was slowly added in portions, stirred by magnetic force, and the reaction temperature was controlled at 30° C.

(3) After the reaction step (2) was carried out for 24 hours, 100 mL of deionized water was added to terminate the reaction of the reaction system, and the reaction temperature was adjusted to 75° C. under magnetic stirring.

(4), the reaction step (3) is to be carried out for 20min, after the reaction system is stable, add 35mL of hydrogen peroxide, remove the manganese dioxide produced, and use 150mL of deionized water to dilute the reaction system twice to obtain a suspension; use Water bath heating and insulation, magnetic stirring.

(5), with the suspension that reaction step (4) obtains, filter and separate, remove impurity, obtain the intercalation oxide of graphite

Exfoliation of graphite intercalation oxides to obtain graphene oxides

The intercalated oxide of graphite obtained in the reaction step (5) and ionized water were placed at room temperature with a power of 200 W and ultrasonication for 10 min to prepare a suspension of graphene oxide in water with a concentration of 2 mg/mL.

3. Convert graphene oxide to graphene through deoxidizer

(1), add green deoxidizer potassium carbonate 100g and 100g water and mix uniformly in the suspension that reaction step 2 makes, graphene oxide aqueous solution and green deoxidizer aqueous solution mix by volume ratio 1: 1, heat 70 ℃, Magnetic stirring was used to mix evenly, and the reaction time was 5 minutes to obtain a reaction liquid, the reaction system was sealed, and the generated carbon dioxide was collected.

(2), to the reaction liquid that reaction step (1) obtains, filter and separate, obtain graphene 2.5g and filtrate.

4. Recycling of green deoxidizer

The filtrate obtained in the reaction step 3 was concentrated to the concentration required in the reaction step 3 by distillation under reduced pressure, and the distillation temperature was 60°C. The concentrated solution obtained is added to the reaction step 3 of the next set of experiments for recycling. Since it will not be polluted, the green deoxidizer can be recycled for a long time.

Embodiment two

The preparation method of graphene based on green deoxidation technology comprises the following reaction steps:

1. Intercalation oxidation of graphite

(1) Weigh 4g of expanded graphite and 2g of sodium nitrate, put them into a flask, slowly add 160mL of 98% concentrated sulfuric acid, use a constant temperature water bath to control the temperature at 3°C, and stir magnetically to make the reaction system proceed uniformly and stably.

(2) After the reaction step (1) was carried out for 30 minutes, 22 g of potassium permanganate was slowly added in portions, stirred by magnetic force, and the reaction temperature was controlled at 26° C.

(3) After the reaction step (2) was carried out for 5 hours, 200 mL of deionized water was added to terminate the reaction of the reaction system, and the reaction temperature was adjusted to 45° C. under magnetic stirring.

(4), the reaction step (3) is to be carried out for 1h, after the reaction system is stable, 15mL of hydrogen peroxide is added to remove the manganese dioxide produced, and the reaction system is diluted twice with 150mL of deionized water to obtain a suspension; Water bath heating and insulation, magnetic stirring.

(5) The suspension obtained in the reaction step (4) is filtered, separated, and impurity-removed to obtain an intercalation oxide of graphite.

2. The exfoliation of graphite intercalation oxide to obtain graphene oxide

The intercalated oxide of graphite obtained in the reaction step (5) and ionized water were placed at room temperature, and a power of 60W was applied to ultrasonication for 30 minutes to prepare a suspension of graphene oxide in water with a concentration of 2 mg/mL.

3. Convert graphene oxide to graphene through deoxidizer

(1), add green deoxidizer sodium carbonate 150g and 100g water and mix uniformly in the suspension that reaction step 2 makes, graphene oxide aqueous solution and green deoxidizer aqueous solution are mixed by volume ratio 10: 1, heat 55 ℃, Magnetic stirring was used to mix evenly, and the reaction time was 5 hours to obtain a reaction liquid, the reaction system was closed, and the generated carbon dioxide was collected.

(2), to the reaction liquid that reaction step (1) obtains, filter and separate, obtain graphene 2.7g and filtrate.

4. Recycling of green deoxidizer

The filtrate obtained in the reaction step 3 was concentrated to the concentration required in the reaction step 3 by distillation under reduced pressure, and the distillation temperature was 70°C. The concentrated solution obtained is added to the reaction step 3 of the next set of experiments for recycling. Since it will not be polluted, the green deoxidizer can be recycled for a long time.

Embodiment Three

The preparation method of graphene based on green deoxidation technology comprises the following reaction steps:

1. Intercalation oxidation of graphite

(1) Weigh 4g of expanded graphite and 1g of sodium nitrate, put them into a flask, slowly add 200mL of 98% concentrated sulfuric acid, use a constant temperature water bath to control the temperature at 5°C, and stir magnetically to make the reaction system proceed uniformly and stably.

(2) After the reaction step (1) was carried out for 2 hours, 17 g of potassium permanganate was slowly added in portions, stirred by magnetic force, and the reaction temperature was controlled at 35°C.

(3) After the reaction step (2) was carried out for 7 hours, 300 mL of deionized water was added to terminate the reaction of the reaction system, and the reaction temperature was adjusted to 90° C. under magnetic stirring.

(4), the reaction step (3) is to be carried out for 2h, after the reaction system is stable, add 35mL of hydrogen peroxide to remove the manganese dioxide produced, and use 220mL of deionized water to dilute the reaction system twice to obtain a suspension; use Water bath heating and insulation, magnetic stirring.

(5) The suspension obtained in the reaction step (4) is filtered, separated, and impurity-removed to obtain an intercalation oxide of graphite.

2. The exfoliation of graphite intercalation oxide to obtain graphene oxide

The intercalated oxide of graphite obtained in the reaction step (5) and ionized water were placed at room temperature through a power of 500W and ultrasonication for 20min to prepare a suspension of graphene oxide in water with a concentration of 2mg/mL.

3. Convert graphene oxide to graphene through deoxidizer

(1), in the suspension that reaction step 2 makes, add green deoxidizer lithium carbonate 200g and 100g water and mix evenly, graphene oxide aqueous solution and green deoxidizer aqueous solution mix by volume ratio 1: 70, heat 100 ℃, Magnetic stirring was used to mix evenly, and the reaction time was 3 hours to obtain a reaction liquid, the reaction system was sealed, and the generated carbon dioxide was collected.

(2), to the reaction liquid that reaction step (1) obtains, filter and separate, obtain graphene 2.6g and filtrate.

4. Recycling of green deoxidizer

The filtrate obtained in the reaction step 3 was concentrated to the concentration required in the reaction step 3 by distillation under reduced pressure, and the distillation temperature was 70°C. The concentrated solution obtained is added to the reaction step 3 of the next set of experiments for recycling. Since it will not be polluted, the green deoxidizer can be recycled for a long time.

Embodiment four

The preparation method of graphene based on green deoxidation technology comprises the following reaction steps:

1. Intercalation oxidation of graphite

(1) Weigh 4g of natural graphite and 1g of sodium nitrate, put them into a flask, slowly add 220mL of 98% concentrated sulfuric acid, use a constant temperature water bath to control the temperature at 2°C, and stir magnetically to make the reaction system proceed uniformly and stably.

(2) After the reaction step (1) was carried out for 10 minutes, 13 g of potassium permanganate was slowly added in portions, stirred by magnetic force, and the reaction temperature was controlled at 40° C.

(3) After the reaction step (2) was carried out for 10 h, 220 mL of deionized water was added to terminate the reaction of the reaction system, and the reaction temperature was adjusted to 110° C. under magnetic stirring.

(4), proceed to the reaction step (3) for 1.5h, after the reaction system is stable, add 20mL of hydrogen peroxide to remove the manganese dioxide produced, and use 260mL of deionized water to dilute the reaction system twice to obtain a suspension; Use a water bath to heat and keep warm, and stir magnetically.

(5) The suspension obtained in the reaction step (4) is filtered, separated, and impurity-removed to obtain an intercalation oxide of graphite.

2. The exfoliation of graphite intercalation oxide to obtain graphene oxide

The intercalated oxide of graphite obtained in the reaction step (5) and ionized water were placed at room temperature through a power of 400 W and ultrasonication for 15 min to prepare a suspension of graphene oxide in water with a concentration of 3 mg/mL.

3. Convert graphene oxide to graphene through deoxidizer

(1), in the suspension that reaction step 2 makes, add green deoxidizer sodium carbonate and potassium carbonate respectively 50g mix uniformly and dissolve in 100g deionized water, graphene oxide aqueous solution and green deoxidizer aqueous solution are by volume 60: 1 Mixed, heated to 110°C, magnetically stirred and mixed evenly, and reacted for 30 minutes to obtain a reaction liquid, the reaction system was sealed, and the generated carbon dioxide was collected.

(2), to the reaction liquid that reaction step (1) obtains, filter and separate, obtain graphene 2.2g and filtrate.

4. Recycling of green deoxidizer

The filtrate obtained in the reaction step 3 was concentrated by vacuum distillation to the concentration required in the reaction step 3, and the distillation temperature was 80°C. The concentrated solution obtained is added to the reaction step 3 of the next set of experiments for recycling. Since it will not be polluted, the green deoxidizer can be recycled for a long time.

Embodiment five

The preparation method of graphene based on green deoxidation technology comprises the following reaction steps:

1. Intercalation oxidation of graphite

(1) Weigh 4g of natural graphite and 2g of sodium nitrate, put them into a flask, slowly add 230mL of 98% concentrated sulfuric acid, use a constant temperature water bath to control the temperature at 0°C, and stir magnetically to make the reaction system uniform and stable.

(2) After the reaction step (1) was carried out for 1.5 hours, 24 g of potassium permanganate was slowly added in portions, stirred by magnetic force, and the reaction temperature was controlled at 42°C.

(3) After the reaction step (2) was carried out for 15 hours, 130 mL of deionized water was added to terminate the reaction of the reaction system, and the reaction temperature was adjusted to 100° C. under magnetic stirring.

(4), the reaction step (3) is to be carried out for 45min. After the reaction system is stable, add 40mL of hydrogen peroxide to remove the manganese dioxide produced, and use 125mL of deionized water to dilute the reaction system twice to obtain a suspension; use Water bath heating and insulation, magnetic stirring.

(5) The suspension obtained in the reaction step (4) is filtered, separated, and impurity-removed to obtain an intercalation oxide of graphite.

2. The exfoliation of graphite intercalation oxide to obtain graphene oxide

The intercalated oxide of graphite obtained in the reaction step (5) and ionized water were placed at room temperature through a power of 300 W and ultrasonication for 13 minutes to prepare a suspension of graphene oxide in water with a concentration of 2 mg/mL.

3. Convert graphene oxide to graphene through deoxidizer

(1), in the suspension that reaction step 2 makes, add green deoxidizer sodium carbonate, potassium carbonate and Lithium Retard respectively 30g mix and be dissolved in 90g deionized water, graphene oxide aqueous solution and green deoxidizer aqueous solution by volume Mix at 3:1, heat at 90° C., magnetically stir and mix evenly, and react for 2 hours to obtain a reaction liquid. The reaction system is sealed and the generated carbon dioxide is collected.

(2), to the reaction liquid that reaction step (1) obtains, filter and separate, obtain graphene 2.4g and filtrate.

4. Recycling of green deoxidizer

The filtrate obtained in the reaction step 3 was concentrated by vacuum distillation to the concentration required in the reaction step 3, and the distillation temperature was 75°C. The concentrated solution obtained can be added to the reaction step 3 of the next set of experiments for recycling. Since it will not be polluted, the green deoxidizer can be recycled for a long time.

Embodiment six

Repeat example one, the green deoxidizer that will obtain after the concentration is recycled when repeating example one for the second time, always circulates 11 times.

Claims (3)

1. a preparation method based on the graphene of green deoxidation technology, is characterized in that comprising following reaction steps: (1) Intercalation oxidation of graphite ①. According to the proportion of graphite and pre-oxidant, put it into the flask, according to the proportion of graphite and intercalation oxidant, add the intercalation oxidant slowly, control the temperature to a suitable temperature, and stir it magnetically to make the reaction system uniform and stable; ②. According to the proportion of graphite and strong oxidant, slowly add the strong oxidant to the reaction step ① step by step, the temperature of the reaction system is quickly kept at an appropriate temperature, stirred by magnetic force, and reacted for an appropriate time; ③. After the reaction step ② is finished, add an appropriate amount of deionized water to terminate the reaction of the reaction system, adjust the reaction temperature to a suitable value under magnetic stirring, heat and keep warm, and magnetically stir; ④. After the reaction step ③ is stable, add a strong oxidant according to the ratio of graphite and strong oxidant, and use a certain amount of deionized water to dilute the reaction system twice. Get a suspension, heat and keep it warm, and magnetically stir; 5. The suspension obtained in the reaction step 4. is filtered and separated to remove impurities to obtain the intercalation oxide of graphite; (2), exfoliation of graphite intercalation oxide to obtain graphene oxide Mix the intercalation oxide of graphite obtained in the reaction step 5 with ionized water at room temperature, and carry out ultrasonic dispersion for a certain period of time by appropriate power to obtain a suspension of graphene oxide in water at a certain concentration; (3) Convert graphene oxide to graphene through green deoxidizer 1. In the suspension obtained in the reaction step (2), add the aqueous solution of the green deoxidizer according to the ratio of the aqueous solution of the green deoxidizer and the graphene oxide at a certain concentration, and magnetically stir and mix evenly. , heat preservation reaction, after a certain period of time, the deoxygenation is completed, and the reaction liquid is obtained; the reaction system is closed, and the generated carbon dioxide is collected; 2. The reaction liquid obtained in the reaction step 1. is filtered and separated to obtain graphene and filtrate; (4), recycling of green deoxidizer The filtrate that reaction step (3) obtains is placed in the round bottom flask, adds zeolite and carries out underpressure distillation at an appropriate temperature, concentrates to the required concentration of reaction step (3); Reaction step (3) is recycled, because the reaction system will not pollute the green deoxidizer, so the green deoxidizer can be recycled for a long time. 2. a kind of preparation method based on the Graphene of green deoxidation technology according to claim 1, it is characterized in that described graphite is natural graphite and expanded graphite that lamellar structure is easy to the oxidation of intercalation or stripping off; The intercalation oxidant is 98% concentrated sulfuric acid; the pre-oxidant is sodium nitrate; the strong oxidant is potassium permanganate or hydrogen peroxide; the green deoxidizer is sodium carbonate or potassium carbonate or lithium carbonate one or more. 3. the preparation method of a kind of graphene based on green deoxidation technology according to claim 1 is characterized in that described graphite and preoxidant, graphite and strong oxidant, graphite and intercalation oxidant, green deoxidizer and water Proportioning, the aqueous solution of green deoxidizer and the proportioning of graphene oxide, in dry weight parts, are as follows: The ratio of graphite to preoxidant is 1:0.2~1:1; the ratio of graphite to strong oxidant is 1:3~1:6; the ratio of graphite to intercalation oxidant is 1:30~1:60; the ratio of green deoxidizer to The ratio of water is 0.05:1-3.2:1; the ratio of green deoxidizer aqueous solution to graphene oxide is 1:100-100:1.