CN103553034B - Preparation method three-dimensional porous graphene skeleton - Google Patents

Abstract

The invention discloses a preparation method of a three-dimensional porous graphene skeleton, relating to a preparation method of the graphene skeleton. The present invention aims to solve the technical problem that it is difficult to prepare high-performance and high-stability three-dimensional porous structure graphene at present. The method of the present invention is as follows: seal graphite oxide in a quartz tube under the condition of vacuum or filling with gas, transfer the quartz tube to a muffle furnace, heat it and keep it warm, then take out the quartz tube and quickly immerse it in ice water for several times Repeat the above heating-quenching process to collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton. The method of the present invention is simple and environmentally friendly, and the obtained three-dimensional graphene framework with a special structure can effectively increase the available load area of graphene, and the prepared three-dimensional porous graphene framework can be widely used in lithium ion batteries, fuel cells, solar energy Batteries, photocatalysis, catalytic oxidation, gas sensors, drug delivery and other fields.

Description

A kind of preparation method of three-dimensional porous graphene skeleton

technical field

The invention relates to a preparation method of a graphene skeleton.

Background technique

Graphene material is a single atomic layer material with a two-dimensional honeycomb structure, which is the basic structural unit of fullerene, carbon nanotube and graphite. Since the preparation of single-layer graphene by Andre K. Geim of the University of Manchester in 2004, it has received extensive attention from the scientific and industrial circles. Graphene has excellent electrical, thermal and mechanical properties. For example, the carrier mobility of graphene is 10 times that of commercial silicon chips, reaching 15000cm ² V ^-1 S ^-1 (Zhang, et al. Nature., 2005, 438, 201-204.); The strength of graphene can reach 130GPa, which is more than 100 times that of steel of the same weight (AKGein, Science., 2009, 324, 1530-4.); the thermal conductivity of graphene reaches 5000W/m K, which is higher than that of diamond at room temperature. 3 times (AA Balandin, Nano lett, 2008, 8, 902.). With the further development of graphene research, graphene with special structure, such as graphene with three-dimensional porous structure, has attracted more and more attention (Cao, et al. small., 2011, 7, 3163; Hu, et al. al. Adv. Mater., 2013, 25, 2219).

In addition to the physical and chemical properties of graphene itself, three-dimensional porous graphene has many other excellent properties, such as 1. Its unique three-dimensional porous structure can support and relieve internal stress, and can be used in lithium-ion batteries and other fields. Effectively alleviate the volume expansion of metal oxide anode materials in the process of lithium storage; 2. The internal pores are highly connected, which is conducive to heat conduction and electrical conduction, and can be used in thermal conductivity materials and solar cells; 3. The pores have capillary adsorption and can be used for adsorption materials etc.

At present, the preparation methods of three-dimensional porous graphene mainly contain the following several kinds: 1, gel sol method (Cong, et al.ACSNano., 2012,6,2693; Tang, et al.J.Am.Chem.Soc. , 2011, 133, 9262), this method generally starts from graphene oxide and needs to add organic substances such as crosslinking agents in the preparation process, which reduces the electrical and thermal properties of graphene and limits its further practical application; 2. Chemical vapor phase Deposition method (CVD method) (Cheng, et al.Nat.Mater.,2011,10,424; Cao.et al.Small.,2013,9,1703.), this three-dimensional network material has a unique shape of three-dimensional network Features and unique physical and chemical properties of graphene, high porosity and large specific surface area, but the templates used are metal templates such as copper and nickel, and the pores of the obtained graphene are too large, and the template is removed by etching solution. The process often destroys its three-dimensional pore-like structure, which limits its application. Therefore, it is currently difficult to prepare graphene with three-dimensional porous structure with high performance and high stability.

Contents of the invention

The present invention aims to solve the technical problem that it is difficult to prepare high-performance and high-stability three-dimensional porous graphene at present, thereby providing a preparation method and application of a three-dimensional porous graphene skeleton.

The preparation method of a kind of three-dimensional porous graphene framework of the present invention is to carry out according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 8×10 ^-4 ~ 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and vacuum or fill it with gas sealed quartz tube;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 5-20°C/min to a temperature of 500-1200°C and keep it warm for 5-30 minutes, then take out the quartz tube and Quickly soak in ice water for 1-3 minutes;

3. Repeat the heating-quenching process of step 2 for 1 to 9 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene skeleton prepared by the above method can be combined with titanium dioxide (TiO ₂ ), tin dioxide (SnO ₂ ), ferric oxide (Fe ₃ O ₄ ), cobalt oxide (CoO), manganese oxide (MnO ₂ ), Copper oxide (CuO), molybdenum sulfide (MoS ₂ ), gold nanoparticles (Au), platinum nanoparticles (Pt) or palladium nanoparticles (Pd) are combined to obtain three-dimensional porous graphene composite materials and applied to lithium-ion batteries , fuel cells, solar cells, photocatalysis, catalytic oxidation, gas sensors, drug delivery fields.

The present invention comprises following beneficial effect:

1. The specific capacity of the lithium-ion battery assembled by the three-dimensional porous P25/graphene composite material prepared by the present invention is 2.3 times that of the lithium-ion battery assembled with pure P25 under the same conditions, indicating that the three-dimensional porous P25 prepared by the present invention The P25/graphene composite has high performance and high stability.

2. The present invention does not use any chemical reagents and produces no chemical waste, and is an environmentally friendly method for preparing a three-dimensional graphene skeleton;

3. The present invention uses a heating-quenching process to peel off graphite oxide, the method is simple, and graphite oxide of more than gram levels can be processed at one time, which is suitable for large-scale production;

4. The graphene prepared by the present invention effectively increases the specific surface area of graphite oxide, improves its quality, has a three-dimensional porous structure, and is beneficial to the improvement of material properties.

Description of drawings

Fig. 1 is the scanning electron microscope picture of graphite oxide;

Fig. 2 is the scanning electron microscope picture of the three-dimensional porous graphene that embodiment one prepares;

Fig. 3 is the X-ray diffraction figure of the three-dimensional porous graphene that embodiment one prepares;

Fig. 4 is the scanning electron micrograph of the P25/graphene composite material of three-dimensional hole shape prepared by test one;

The charge-discharge curve comparison diagram of the lithium-ion battery assembled by the three-dimensional porous P25/graphene composite material prepared in Figure 5 Test 1 and the lithium-ion battery assembled by pure P25; wherein, 1 is the three-dimensional porous P25/graphene composite material The charging curve of the assembled lithium-ion battery; 2 is the discharge curve of the lithium-ion battery assembled by the three-dimensional porous P25/graphene composite; 3 is the charging curve of the pure P25 assembled lithium-ion battery; 4 is the pure P25 Discharge curve graph of the assembled Li-ion battery.

Detailed ways

Specific embodiment one: the preparation method of a kind of three-dimensional porous graphene skeleton of the present embodiment is to carry out according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 8×10 ^-4 ~ 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and vacuum or fill it with gas sealed quartz tube;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 5-20°C/min to a temperature of 500-1200°C and keep it warm for 5-30 minutes, then take out the quartz tube and Quickly soak in ice water for 1-3 minutes;

3. Repeat the heating-quenching process of step 2 for 1 to 9 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

This embodiment includes the following beneficial effects:

1. The specific capacity of the lithium-ion battery assembled with the three-dimensional porous P25/graphene composite material prepared in this embodiment is 2.3 times that of the lithium-ion battery assembled with pure P25 under the same conditions, indicating that the three-dimensional porous prepared by the present invention The P25/graphene composite material has high performance and high stability.

2. This embodiment does not use any chemical reagents and does not generate any chemical waste. It is an environmentally friendly method for preparing a three-dimensional graphene skeleton;

3. In this embodiment, the heating-quenching process is used to peel off graphite oxide. The method is simple, and graphite oxide of more than gram levels can be processed at one time, which is suitable for large-scale production;

4. The graphene prepared in this embodiment effectively increases the specific surface area of graphite oxide, improves its quality, and has a three-dimensional porous structure, which is beneficial to the improvement of material properties.

Embodiment 2: This embodiment differs from Embodiment 1 in that: In Step 1, the vacuum inside the quartz tube is evacuated to 9×10 ⁻⁴ Pa. Others are the same as in the first embodiment.

Embodiment 3: The difference between this embodiment and Embodiment 1 or 2 is that the gas charged in step 1 is argon or nitrogen. Others are the same as in the first or second embodiment.

Embodiment 4: This embodiment is different from Embodiment 1 to Embodiment 3 in that: in step 2, heating is performed at a rate of 10° C./min. Others are the same as those in the first to third specific embodiments.

Embodiment 5: This embodiment is different from Embodiment 1 to Embodiment 4 in that: in step 2, heat to a temperature of 600-1100° C. and keep it warm for 5-20 minutes. Others are the same as one of the specific embodiments 1 to 4.

Specific embodiment six: a three-dimensional porous graphene skeleton of this embodiment can be combined with titanium dioxide, tin dioxide, ferric oxide, cobalt oxide, manganese oxide, copper oxide, molybdenum sulfide, gold nanoparticles, platinum nanoparticles or Palladium nanoparticles are compounded to obtain a three-dimensional porous graphene composite material, which is used in the fields of lithium-ion batteries, fuel cells, solar cells, photocatalysis, catalytic oxidation, gas sensors, and drug delivery.

Verify the beneficial effects of the present invention through the following examples:

Embodiment one: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 3 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The scanning electron microscope picture of graphite oxide is as shown in Figure 1; The scanning electron microscope picture of the three-dimensional porous graphene skeleton prepared by the present embodiment is as shown in Figure 2, as can be seen from Figure 2, the three-dimensional porous graphene prepared by the present embodiment The pore diameter of the skeleton is about 200nm, and the wall thickness is about 3nm. Comparing Figure 1 and Figure 2, it can be seen that graphite oxide is a thicker sheet structure, and the graphene skeleton obtained after treatment is a pore structure with thinner pore walls. .

The X-ray diffraction figure of the three-dimensional porous graphene skeleton prepared by the present embodiment is as shown in Figure 3, as can be seen from Figure 3, the three-dimensional porous graphene prepared by the present embodiment is pure-phase graphene, without graphite phase or Graphene oxide phase.

Utilize the three-dimensional porous graphene framework that test one prepares to do following test:

Test 1: Take 100 mg of the obtained three-dimensional porous graphene and 200 mg of P25 particles and ultrasonically in 40 ml of ethanol for 30 minutes, seal the mixed solution in a hydrothermal kettle at 120 ° C for 10 hours, wash and dry the obtained product with deionized water, and obtain three-dimensional pores Shaped P25/graphene composite material; The resulting three-dimensional porous P25/graphene composite material is mixed with polytetrafluoroethylene and conductive acetylene black (TIMREXKS-15, TIMCAL, Switzerland) according to a mass ratio of 85:5:10, Apply on both sides of the nickel mesh as the working electrode, dry at 60°C for 6 hours, press and dry at 120°C for 24 hours; use metal lithium as the counter electrode, microporous polypropylene membrane (Celgard 2300) as the separator, 1mol/L LiPF ₆ ethylene carbonate and diethyl carbonate (volume ratio 1:1) solution is used as electrolyte to assemble lithium-ion battery.

The scanning electron microscope photo of the three-dimensional porous P25/graphene composite material prepared in this test is shown in Figure 4.

In the same way, pure P25 was used to replace the three-dimensional porous P25/graphene composite to assemble lithium-ion batteries.

The charge-discharge curve comparison chart of the lithium-ion battery assembled by the three-dimensional porous P25/graphene composite material prepared in this test and the lithium-ion battery assembled by pure P25 is shown in Figure 5; wherein, 1 is the three-dimensional porous P25/graphene 2 is the discharge curve of the lithium-ion battery assembled by three-dimensional porous P25/graphene composite; 3 is the charging curve of the lithium-ion battery assembled by pure P25; 4 Discharge profile of Li-ion cells assembled for pure P25. It can be seen from Figure 5 that the lithium-ion battery assembled with three-dimensional porous P25/graphene composite material has a specific capacity of 150mAh/g at 0.1C discharge, and the lithium-ion battery assembled with pure P25 has a specific capacity of 65mAh at 0.1C discharge /g. That is, the specific capacity of the lithium-ion battery assembled with the three-dimensional porous P25/graphene composite material at 0.1C discharge is 2.3 times that of the lithium-ion battery assembled with pure P25 at 0.1C discharge.

Experiment 2: Take 100 mg of the obtained three-dimensional porous graphene and 200 mg of SnO ₂ particles in 40 ml of ethanol for 30 minutes of ultrasonication, seal the mixed solution in a hydrothermal kettle at 120 ° C for 10 hours, wash and dry the obtained product with deionized water, and obtain a three-dimensional Porous SnO ₂ /graphene composite material; the resulting three-dimensional porous SnO ₂ /graphene composite material with polytetrafluoroethylene and conductive acetylene black (TIMREXKS-15, TIMCAL, Switzerland) according to the mass ratio of 85:5:10 Mix evenly, apply on both sides of the nickel mesh as the working electrode, dry at 60°C for 6 hours, press and dry at 120°C for 24 hours; use metal lithium as the counter electrode, microporous polypropylene membrane (Celgard 2300) as the diaphragm, 1mol/ The ethylene carbonate and diethyl carbonate (volume ratio 1:1) solution of LiPF ₆ in L is used as the electrolyte to assemble the lithium-ion battery.

The obtained battery had a specific capacity of 820mAh/g when discharged at 0.1C.

Experiment 3: Take 50 mg of the obtained three-dimensional porous graphene and 200 mg of FeCl ₃ in 40 ml of deionized water and sonicate for 30 minutes, seal the mixed solution in a hydrothermal kettle at 150 ° C for 10 hours, wash and dry the obtained product with deionized water, and obtain a three-dimensional Porous Fe ₃ O ₄ /graphene composite material; the obtained three-dimensional porous Fe ₃ O ₄ /graphene composite material and polytetrafluoroethylene and conductive acetylene black (TIMREXKS-15, TIMCAL, Switzerland) according to the mass ratio of 85 : 5:10 mixed evenly, spread on both sides of the nickel mesh as the working electrode, dried at 60°C for 6 hours, pressed into tablets and dried at 120°C for 24 hours; metal lithium was used as the counter electrode, and the microporous polypropylene membrane (Celgard 2300) was Diaphragm, ethylene carbonate and diethyl carbonate (volume ratio 1:1) solution of 1mol/L LiPF ₆ is the electrolyte, and the lithium-ion battery is assembled.

The specific capacity of the obtained battery was 600mAh/g when discharged at 0.1C.

Experiment 4: Take 10mg of three-dimensional porous graphene skeleton and 200mg of P25 particles and ultrasonically 30min in 40ml of ethanol, seal the mixed solution in a hydrothermal kettle at 160°C for 10 hours, wash and dry the obtained product with deionized water to obtain three-dimensional pores Shaped P25/graphene composite material; add 100mg three-dimensional hole-shaped P25/graphene composite material into an agate mortar, add 80ml of ethanol and appropriate amount of anhydrous terpineol and ethyl cellulose and grind for 1h, and use a rotary evaporator to dissolve the ethanol Evaporate to dryness to obtain the slurry, prepare the absorbing layer on the ITO glass with a doctor blade method, anneal at 450°C for 1 h, soak in 0.5 mM N719 dye for 20 h, take it out and assemble it with a platinum electrode to form a battery.

The photoelectric conversion efficiency (η) of the obtained solar cell was 7.5%.

Embodiment two: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 3 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 200 nm and a wall thickness of about 3 nm.

Embodiment three: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling nitrogen;

2. Transfer the sealed quartz tube in step 1 to the muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C and keep it warm for 5 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 3 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 80 nm and a wall thickness of about 4 nm.

Embodiment four: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C and keep it warm for 10 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 3 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 100 nm and a wall thickness of about 4 nm.

Embodiment five: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 once, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 80 nm and a wall thickness of about 4 nm.

Embodiment six: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to the muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C for 20 minutes, then take out the quartz tube and quickly immerse it in ice water for 1 minute;

3. Repeat the heating-quenching process of step 2 for 6 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 200 nm and a wall thickness of about 2 nm.

Embodiment seven: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 10°C/min to 900°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 9 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 220 nm and a wall thickness of about 2 nm.

Embodiment eight: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to the muffle furnace, heat the muffle furnace at a rate of 10°C/min to 600°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 3 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 50 nm and a wall thickness of about 4 nm.

Embodiment nine: the preparation method of a kind of three-dimensional porous graphene skeleton of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to the muffle furnace, heat the muffle furnace at a rate of 10°C/min to 1100°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 for 3 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 220 nm and a wall thickness of about 3 nm.

Embodiment ten: the preparation method of a kind of three-dimensional porous graphene framework of the present embodiment is to realize according to the following steps:

1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and seal the quartz tube under the condition of filling with argon;

2. Transfer the sealed quartz tube in step 1 to the muffle furnace, heat the muffle furnace at a rate of 10°C/min to 1100°C and keep it warm for 20 minutes, then take out the quartz tube and quickly immerse it in ice water to keep 1 minute;

3. Repeat the heating-quenching process of step 2 once, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton.

The three-dimensional porous graphene prepared in this embodiment has a pore diameter of about 100 nm and a wall thickness of about 3 nm.

Claims (5)

1. a preparation method of a three-dimensional porous graphene skeleton is characterized in that the preparation method of a three-dimensional porous graphene skeleton is carried out in the following steps: 1. Put 500mg of graphite oxide in a quartz tube, use a molecular pump to vacuum the inside of the quartz tube to 8×10 ^-4 ~ 9×10 ^-4 Pa, close the exhaust valve of the molecular pump, and vacuum or fill it with gas sealed quartz tube; 2. Transfer the sealed quartz tube in step 1 to a muffle furnace, heat the muffle furnace at a rate of 5-20°C/min to a temperature of 500-1200°C and keep it warm for 5-30 minutes, then take out the quartz tube and Quickly soak in ice water for 1-3 minutes; 3. Repeat the heating-quenching process of step 2 for 1 to 9 times, and finally collect the product in the quartz tube, and the obtained product is a three-dimensional porous graphene skeleton. 2. The preparation method of a three-dimensional porous graphene skeleton according to claim 1, characterized in that in step 1, the vacuum in the quartz tube is evacuated to 9×10 ⁻⁴ Pa. 3. The preparation method of a kind of three-dimensional porous graphene skeleton according to claim 1, characterized in that the filling gas in step 1 is argon or nitrogen. 4. The preparation method of a kind of three-dimensional porous graphene skeleton according to claim 1, characterized in that in step 2, heating at a rate of 10° C./min. 5. The preparation method of a three-dimensional porous graphene skeleton according to claim 1, characterized in that in step 2, heating to a temperature of 600-1100° C. and keeping the temperature for 5-20 minutes.