[summary of the invention]
The objective of the invention is to overcome the deficiency of prior art, a kind of preparation method of graphene and the Graphene that uses this method preparation are provided.
The objective of the invention is to realize through following technical scheme:
A kind of preparation method of graphene is a raw material with graphite, makes compound between graphite layers through inserting metal in graphite layers, peels off said compound between graphite layers then and makes Graphene.
The selection of described graphite does not have particular restriction, can comprise natural graphite, synthetic graphite, specifically, comprises natural flake graphite, highly oriented pyrolytic graphite or special spherical graphite etc.Therefore can reach raw material sources purpose extensive, with low cost.
Described insertion metal be in basic metal, earth alkali metal, the rare earth metal a kind of, two or more:
Described basic metal is lithium (Li), sodium (Na), potassium (K), rubidium (Ru), caesium (Cs), francium (Fr);
Described earth alkali metal is beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra);
Described rare earth metal is lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), yttrium (Y);
Also can be to be selected from the aforementioned metal two or more, as: lithium (Li)/calcium (Ca), potassium (K)/magnesium (Mg), potassium (K)/scandium (Sc), magnesium (Mg)/calcium (Ca), lithium (Li)/magnesium (Mg)/lanthanum (La) etc.
Insert metal with in basic metal, the earth alkali metal a kind of, two or more serve as preferably, comparatively preferably basic metal, more preferably lithium (Li), potassium (K), rubidium (Ru), caesium (Cs), most preferably lithium (Li).
The preparation method of described compound between graphite layers is selected from a kind of, two or more the combination in the following method: solid phase pressurization, scorification, two warm area vapor transportation methods, liquid phase interpolation, molten salt electrolysis of metals method, battery charging and discharging method.
Wherein, described solid phase pressurization: metal-powder is mixed back reaction under pressurized conditions generate compound between graphite layers with graphite matrix, use this method key to be to have only when the vp of metal surpasses a certain threshold value, insertion reaction just can carry out.Be prone to cause metal and graphite to generate the side reaction of carbide but temperature is too high, so temperature of reaction must be controlled within the specific limits, for needs very high-temperature the metal of insertion reaction could take place, needs pressurize and reduce temperature of reaction.
Described scorification is for directly mixing graphite with metal-powder; Make compound between graphite layers with single thermal source reacting by heating, this method speed of response is fast, and reactive system and process are simple; Be suitable for a large amount of synthesizing, but the reactant that is attached to after the reaction on the compound between graphite layers is difficult to remove.
Described two warm area vapor transportation methods will be for being inserted into material and graphite is respectively charged into the heat-resistant glass tube both sides, and steam and graphite that the inset heating evaporation is produced react.The temperature of inserting material one side in the experiment will be higher than the temperature of graphite one side, is beneficial to insert material and forms steam, prevents that simultaneously the compound between graphite layers that generates from decomposition reaction taking place when temperature is too high.The advantage of this method is to be easy to separated product and reactant after reaction finishes, and shortcoming is that reaction unit is complicated, be difficult to carry out synthesize in a large number, and long reaction time, temperature is high, needs operation under vacuum condition.
The insertion metal that described liquid phase interpolation will be in a liquid state mixes with graphite, reacts and generates compound between graphite layers, and temperature, the stage structure of time to product have very big influence in the reaction.This method equipment is simple, and speed of response is fast, be suitable for a large amount of synthesizing, but because requirement must be with metal melting, temperature is big to the melting point metal dependency in the actually operating.
Described molten salt electrolysis of metals method is an ionogen to insert metal melting salt, is that electrode forms chemical system with graphite, is inserted into graphite as anode, prepares compound between graphite layers through the control of regulating current potential, electric weight.This method synthesis device is simple, and resultant quantity is big, and weak point is that the stability of synthetic product is than additive method difference.
Described battery charging and discharging method can know from name and specifically promptly be divided into two kinds, and a kind of is the battery discharge method, and another kind is the battery charge method.Wherein said battery discharge method is to be anodal with graphite, and metal is a negative pole, adds electrolytic solution and forms battery system.Move according to preset discharge step, metal is inserted into forms compound between graphite layers in the graphite;
Wherein said battery charge method is with agent structure in the process of charging not or rare variation, and the metal that does not react with electrolytic solution is intercalation compound, and graphite is negative pole for anodal, adds electrolytic solution and forms battery system.Move according to the preset charged step, metal is inserted into forms compound between graphite layers in the graphite.
This method technology is simple, and reaction conditions is gentle, and can discharge and recharge end condition through preset, obtains the controlled compound between graphite layers of exponent number, is suitable for suitability for industrialized production.
In a preferred embodiment; The method for preparing compound between graphite layers serves as preferred with solid phase pressurization, scorification, liquid phase interpolation, molten salt electrolysis of metals method and battery charging and discharging method; More preferably electrolytic process and battery charging and discharging method, most preferably battery charging and discharging method.
The described method of peeling off compound between graphite layers is selected from a kind of, two or more the combination in the following method: mechanically peel, stripper are peeled off, electrolytic stripping.
Described mechanically peel makes its bending, depression for compound between graphite layers used, the power of swiping, being pressed into or fracture, thus separate the method for Graphene.The instance of mechanically peel can be to utilize adhesive tape to tear repeatedly to take off compound between graphite layers, makes its attenuation, thereby obtains Graphene.Also can be the compound between graphite layers that utilizes the needleless pointed probe scraping of AFM (AFM) fixing, obtain the thin slice that scrapes and continue abovementioned steps, finally obtain Graphene.Also can be to utilize ball mill that the compound between graphite layers powder that is scattered in the organic solvent is carried out ball milling, thereby obtain Graphene.Use mechanically peel can on the gained Graphene, not introduce heteroatoms, but gained Graphene out-of-shape, and the preparation process is consuming time longer.
It is ionogen that described electrolytic stripping inserts metal melting salt; With graphite is that electrode forms chemical system; Compound between graphite layers makes Graphene as anode thereby through the control of regulating current potential, electric weight the metal continuation insertion compound between graphite layers interlayer of electrolysis generation is peeled off.Use the electrolytic stripping can the mass preparation Graphene, but can leave impurity, for example metal-salt on the gained Graphene.And entire reaction course needs higher temperature, reaction environment is required comparatively harsh.
Described stripper is peeled off and can be utilized two kinds of strippers to peel off: the one, utilize can with the stripper of compound between graphite layers reaction; The gas or the bulking effect that discharge through reaction further enlarge the graphite layers distance; Make graphite flake layer mutually away from obtaining Graphene to breaking away from the constraint of Van der Waals force to each other, finally peeling off; The 2nd, adopt the surface energy stripper close with graphite; Because can reduce the entropy of mixing of stripper and graphite under the close situation of surface energy; Be similar to " similar mixing " principle; So just can let stripper be inserted in the compound between graphite layers, continuing increases the graphite layers distance, obtains Graphene thereby peel off compound between graphite layers.The surface tension of selected stripper needs at 10-70mJ/m
2, more preferably at 20-50mJ/m
2Scope in; Above-mentioned surface tension numerical value all is at 20 ℃ of following sessile drop method test gained.Use the stripper strip operation simple, the stripper wide material sources, the chemical reagent for often having can not introduced heteroatoms on prepared Graphene mostly.
Stripping means most preferably stripper is peeled off.
Described stripper be selected from inorganic liquid and the organic liquid a kind of, two or more.
Described inorganic liquid is selected from water, inorganic acid aqueous solution, water phase surfactant mixture.
The aqueous solution that described inorganic aqueous acid instance is a hydrogenchloride, dilute sulphuric acid, rare nitric acid etc.
Described tensio-active agent instance is polyoxyethylene stearic acid ester (Brij 76); Cetyl trimethylammonium bromide (CTAB); TTAB (TTAB); 1-pyridine acid (PBA); Sodium lauryl sulphate (SDS); X 2073 (SDBS); Lithium dodecyl sulfate (LDS); Sodium cholic acid (SC); Sodium desoxycholate (DOC); Cow-bezoar Sodium desoxycholate (TDOC); Sodium (CHAPS) in 3-[3-(courage amido propyl) dimethylamino] propanesulfonic acid; Lewatit (PSS); Vinylpyrrolidone polymer (PVP); Dodecyl-β-D-maltoside (DBDM); Nonoxynolum (IGEPAL CO-890); Octadecanoic acid ester of polyethylene glycol (Tween 80) etc.
Described organic liquid is selected from alcohol, ketone, ester, amine, sulfone, chlorobenzene, organic acid, ionic liquid.
Wherein said alcohol is the alcohol that contains 1-6 carbon atom.Instance can be methyl alcohol, ethanol, terepthaloyl moietie, 1-propyl alcohol, 2-propyl alcohol, 1,2-Ucar 35,1, ammediol, USP Kosher, 1-butanols, 1-amylalcohol, 1-hexanol etc.;
Wherein said acid is the acid that fowl has 1-6 carbon atom.Instance can be formic acid, acetate, oxalic acid, 1-propionic acid, 2-propionic acid, 1,2-propanedioic acid, 1,3-propanedioic acid, the third three acid, 1-butyric acid, 1-valeric acid, 1-caproic acid etc.;
The instance of wherein said ketone can be acetone, 1-Methyl-2-Pyrrolidone, N-vinyl pyrrolidone, octylpyrrolidone, dodecyl pyrrolidone, 1,3-dimethyl--2-imidazolone etc.;
The instance of wherein said ester can be gamma-butyrolactone, peruscabin etc.;
The instance of wherein said amine can be N, N, accelerine, N, dinethylformamide etc.;
The instance of wherein said sulfone can be a DMSO 99.8MIN. etc.;
The instance of wherein said chlorobenzene can be an orthodichlorobenzene etc.;
Wherein said ion liquid instance can be [Bmim] [BF
4], [Bmim] [Tf
2N], [C
4Mim] [PF
6], [C
8Mim] [PF
6], [C
4Mim] Cl, [C
8Mim] Cl etc.
Also can be selected from the mixture of aforesaid two or more composition of liquid, as: water/methyl alcohol, water/ethanol, water/formic acid, ethanol/acetate, water/ethanol/acetate, N-Methyl pyrrolidone/water, [BMIm] [BF
4]/water, [C
4Mim] [PF
6]/N etc.
The length and the width of the Graphene that makes according to method of the present invention are 5~15000nm, and thickness is 0.3~15nm.The thickness of known single-layer graphene is about 0.335nm, so the thickness of Graphene can not be lower than 0.3nm.Because the thickness of Graphene of the present invention is to be recorded by AFM (AFM); But the interaction between AFM probe and substrate and the Graphene can bring measuring error; Therefore the Graphene thickness that records of AFM is generally than about the big 0.4~0.5nm of actual value, and specifically for instance, the single-layer graphene thickness that AFM records is about 0.8nm; The thickness of double-layer graphite alkene is about 1.1nm, and three layer graphene thickness are about 1.5nm.Based on this reason, after state the thickness of listed Graphene among the embodiment owing to all be that employing AFM records, so numerical value is all greater than 0.8.Gained Graphene thickness is at 0.3~15nm among the present invention, and the number of plies is between about 1~45 layer.
The productive rate of Graphene is the ratio of quality with the raw material graphite quality of obtained Graphene.The quality of the Graphene directly final solid graphite alkene of weighing obtains, and also can derive from the concentration of Graphene in the Graphene dispersion liquid.In the Graphene dispersion liquid concentration of Graphene be utilize the absorbancy measure the Graphene dispersion liquid (testing tool as: 722N visible spectrophotometer (Shanghai Precision Scientific Apparatus Co., Ltd's manufacturing)), follow that Law of Lambert-Beer calculates.
The structural information of compound between graphite layers X ray diffracting spectrum capable of using (XRD) measures that (testing tool is like D/MAX 2550 VB/PC (Japanese Rigaku manufactured), target source: the copper target).
The thickness number of plies of said Graphene and length and width size atomic force microscope images capable of using (AFM) are confirmed (testing tool as: NanoScope IIIa MultiMode AFM (U.S. Veeco manufactured), operator scheme: rap pattern).
The length and width size of said Graphene also can use sem (SEM) confirm (testing tool as: SEM (JSM-6360LV) (Japanese JEOL manufactured)).
Strength ratio (the I at D peak and G peak among the defect level of Graphene Raman spectrum capable of using (Raman) figure
D/ I
G) value confirms I
D/ I
GBe worth greatly more, Graphene contained defective is more, and (testing tool is like inVia+Reflex (Britain Renishaw manufactured), laser wavelength: 514nm).
Compared with prior art, positively effect of the present invention is:
(1) raw material sources are extensive, with low cost, and various types of graphite all can be used for preparing Graphene, and used stripper is also mostly to be chemical reagent commonly used; Conveniently be easy to get; Mostly used metal is common metal, particularly lithium, and its reactive behavior is moderate; The success that can guarantee stripping process is carried out, also can be as easy fire that causes of too active metal such as sodium, potassium;
(2) easy, the product performance stable and controllable of preparation method is fit to suitability for industrialized production;
Need Graphene to contain more defective when (3) being used for support of the catalyst and electrode materials, the Graphene of the inventive method preparation itself has more defective, need not further processing, promptly can be used as support of the catalyst or electrode materials.
[embodiment]
The embodiment of a kind of preparation method of graphene of the present invention below is provided.
Embodiment 1
The battery discharge legal system is equipped with compound between graphite layers
With special spherical graphite SSG (active material) (deriving from Loudi, Hunan brightness space Science and Technology Ltd.), acetylene black (static eliminator; About 10nm), pvdf PVDF (sticker) presses 8: 1: 1 mixed of mass ratio particle diameter:; Adding 1-Methyl-2-Pyrrolidone (NMP) makes PVDF concentration in 0.005~0.03g/ml scope; Stir the furnishing pasty slurry.It is evenly overlayed on the Copper Foil shop; After treating that solvent evaporates is studied carefully entirely; Utilize punch tool to make circular Graphite Electrodes sheet, after 12 hours, select for use metal lithium sheet 80 ℃ of following vacuum-dryings the Graphite Electrodes sheet that makes as GND; Graphite Electrodes is as anode; With lithium hexafluoro phosphate be dissolved in volume ratio be solution in 1: 1: 1 EC/EMC/DMC (NSC 11801/Methyl ethyl carbonate/methylcarbonate) ternary mixed solvent as electrolytic solution, barrier film adopts polypropylene porous film, water, oxygen level less than the glove box of 1ppm in assembled battery.
(testing tool is like: BTS high accuracy battery detection system (the new Weir Electronics Co., Ltd. of China makes) then the battery of assembling to be carried out impulsive discharge; Model: CT-3008W-5V10mA-S1); After being provided with according to parameter given below; Can carry out impulsive discharge: carried out constant-current discharge 5 minutes with the discharge rate of 0.05C in each circulation, left standstill 12 minutes, successively circulation.Pulse discharge time is 7 days, stops discharge then, in water, the glove box of oxygen level less than 1ppm, disassembles battery, takes out the single order lithium-compound between graphite layers of negative pole.After treating the electrolytic solution volatilization; Lithium-compound between graphite layers scraped from the copper sheet gently leave; Place in the agate mortar and grind to form uniform powder; Pour into rapidly the deionized water after in glove box, taking out powdered lithium-compound between graphite layers, deionized water described herein is as stripper, and the metallic lithium in lithium-compound between graphite layers is peeled off and made Graphene.
Utilize spectrophotometer to record the concentration of gained Graphene aqueous dispersions, thus the output of the Graphene that obtains making, and then obtain productive rate.Adopting the Graphene productive rate of preceding method gained present embodiment is 0.56%.
Fig. 2 is the single order compound between graphite layers of embodiment 1 gained lithium and the XRD figure of raw material graphite.Can find out: after graphite layers is inserted metallic lithium, originally disappeared at 26.6 ° of graphite characteristic peaks of locating, replacing is a tangible spike near 24 °, to have occurred.This phenomenon has proved the formation of single order lithium-compound between graphite layers.
Fig. 3 schemes for the AFM that embodiment 1 makes Graphene, and Graphene height that figure (c) is corresponding is 0.8nm, is individual layer.Graphene thickness is between 0.8~7nm, and the number of plies is between about 1~20 layer.Length and width are all between 100nm~5000nm.
Fig. 4 has provided the Raman spectrogram (X-coordinate is a wave number, and ordinate zou is an intensity) of the Graphene of embodiment 1 preparation, can find out the existence of graphite-structure in the G peak explanation Graphene, the existence of defective in the D peak explanation Graphene.The strength ratio I at D peak and G peak
D/ I
GValue is 0.69.
Embodiment 2
The battery discharge legal system is equipped with compound between graphite layers
Except pulse discharge time is 3 beyond the highest heavens, all the other operations are identical with embodiment 1, thereby obtain second order lithium-compound between graphite layers.Final gained Graphene productive rate is 0.59%, gained Graphene thickness between 2.1~9.2, promptly the number of plies between about 5~26 layers, length and width all between 100~6300nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.68.
Embodiment 3
The battery discharge legal system is equipped with compound between graphite layers
Except pulse discharge time is 2 beyond the highest heavens, all the other operations are identical with embodiment 1, thereby obtain three rank lithium-compound between graphite layers.Final gained Graphene productive rate is 0.45%, gained Graphene thickness between 4.5~11.3, promptly the number of plies between about 12~32 layers, length and width all between 130~7000nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.67.
Embodiment 4
The battery discharge legal system is equipped with compound between graphite layers
Except pulse discharge time is 32 hours, all the other operations are identical with embodiment 1, thereby obtain quadravalence lithium-compound between graphite layers.Final gained Graphene productive rate is 0.32%, gained Graphene thickness between 6.5~14.4, promptly the number of plies between about 18~42 layers, length and width all between 130~6800nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.66.
Embodiment 5
The battery discharge legal system is equipped with compound between graphite layers
The battery positive and negative polarities of the assembling described in the embodiment 1 are linked to each other, carried out short circuit dischange 48 hours, all the other operations are identical with embodiment 1.Final gained Graphene productive rate is 0.62%, gained Graphene thickness between 1.5~8.2, promptly the number of plies between about 3~24 layers, length and width all between 50~6500nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.71.
Embodiment 6
The battery charge legal system is equipped with compound between graphite layers.
With cobalt acid lithium (active material (Beijing Zhongxinguoan Mengguli Electric Source Technology Co., Ltd)), acetylene black (static eliminator; About 10nm), pvdf PVDF (sticker) presses 90: 5: 5 mixed of mass ratio particle diameter:; Adding 1-Methyl-2-Pyrrolidone (NMP) makes pvdf PVDF concentration in 0.005~0.03g/ml scope; Stir the furnishing pasty slurry.It is evenly overlayed on the aluminium foil shop; After treating that solvent evaporates fully; Utilize punch tool to make the positive electrical pole piece; After 12 hours, select for use natural graphite (particle diameter 20~30 μ m) as GND 120 ℃ of following vacuum-dryings the positive electrical pole piece that makes, it is that solution in 1: 1: 1 EC/EMC/DMC (NSC 11801/Methyl ethyl carbonate/methylcarbonate) ternary mixed solvent is as electrolytic solution that lithium hexafluoro phosphate is dissolved in volume ratio; Barrier film adopts polypropylene porous film, water, oxygen level less than the glove box of 1ppm in assembled battery.
Then the battery of assembling is carried out constant current charge to cell voltage with the charge rate of 0.2C and rise to 4.2V.Carry out constant voltage charge to charge rate afterwards and reduce to 0.02C; After shelving 30min; Again battery is carried out constant current charge with the charge rate of 0.2C and be charged to 4.35V earlier; Constant voltage charge to charge rate is reduced to 0.02C (testing tool is like: BTS high accuracy battery detection system (the new Weir Electronics Co., Ltd. of China makes), model: CT-3008W-5V10mA-S1) again.Stop charging then, in water, the glove box of oxygen level, disassemble battery, take out the single order lithium-compound between graphite layers of negative pole less than 1ppm.After treating the electrolytic solution volatilization; Lithium-compound between graphite layers scraped from the copper sheet gently leave; Place in the agate mortar and grind to form uniform powder; Pour into rapidly the deionized water after in glove box, taking out powdered lithium-compound between graphite layers, deionized water described herein is as stripper, and the metallic lithium in lithium-compound between graphite layers is peeled off and made Graphene.Final gained Graphene productive rate is 0.61%, gained Graphene thickness between 0.8~12nm, promptly the number of plies between about 1~35 layer, length and width all between 100~15000nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.74.
The SEM figure of the wherein a slice Graphene that makes for embodiment 6 shown in Figure 5.Can find out that by this SEM figure this Graphene has taken place by folding curling to a certain degree.This Graphene is studied carefully being about behind the full expand and is 10600nm, the wide 10000nm that is about.
Embodiment 7
A, solid phase pressurization prepare compound between graphite layers.
In water, the glove box of oxygen level less than 1ppm, graphite (particle diameter 40~50 μ m) 1.44g and lithium (particle diameter 200~400 μ m) 2g are mixed, place tightness system to be forced into 15kbar.Be heated to 200 ℃ afterwards, kept this pressure and temperature 24 hours, can make lithium-compound between graphite layers.
B, prepare Graphene by the compound between graphite layers that makes.
Remove the residual raw material of lithium-compound between graphite layers surface attachment, place in the agate mortar and grind to form uniform powder, in glove box, pour into rapidly the deionized water behind taking-up powdered lithium-compound between graphite layers, react immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.61%, gained Graphene thickness between 1.8~9.0nm, promptly the number of plies between about 4~26 layers, length and width all between 90~8000nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.75.
Embodiment 8
A, solid phase pressurization prepare compound between graphite layers.
In water, the glove box of oxygen level less than 1ppm, graphite (particle diameter 40~50 μ m) 1.44g and ytterbium (particle diameter 300~500 μ m) 4g are mixed, place tightness system to be forced into 20kbar.Be heated to 390 ℃ afterwards, keep two weeks of this pressure and temperature, can get ytterbium-compound between graphite layers.
B, prepare Graphene by the compound between graphite layers that makes.
Remove the residual raw material of ytterbium-compound between graphite layers surface attachment; Place in the agate mortar and grind to form uniform powder; Pour into rapidly the deionized water after in glove box, taking out powdered ytterbium-compound between graphite layers, ytterbium-compound between graphite layers and deionized water react, and deionized water is as stripper here; Metallic lithium in ytterbium-compound between graphite layers is peeled off, thereby obtains Graphene.Final gained Graphene productive rate is 0.42%, gained Graphene thickness between 5.6~14nm, promptly the number of plies between about 15~40 layers, length and width all between 200~7600nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.79.
Embodiment 9
A, solid phase pressurization prepare compound between graphite layers.
In water, the glove box of oxygen level less than 1ppm, graphite (diameter 40~50 μ m) 1.44g and thulium (particle diameter 300~500 μ m) 4g are mixed, place tightness system to be forced into 20kbar.Be heated to 500 ℃ afterwards, keep two weeks of this pressure and temperature, can get thulium-compound between graphite layers.
B, prepare Graphene by the compound between graphite layers that makes.
Remove the residual raw material of thulium-compound between graphite layers surface attachment, place the powder that grinds to form homogeneous in the agate mortar, in glove box, pour into rapidly the deionized water behind taking-up powdered thulium-compound between graphite layers, react immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.40%, gained Graphene thickness between 4.7~14.8nm, promptly the number of plies between about 13~43 layers, length and width all between 340~7000nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.78.
Embodiment 10
A, scorification prepare compound between graphite layers.
In water, the glove box of oxygen level less than 1ppm; To place flat 100ml there-necked flask with the potassium 3.9g that is cut into irregular bulk and a stirrer at 400 ℃ of degassing natural graphite (graphitiferous carbon 97~98%, particle diameter 90~145 μ m) 9.6g after 12 hours of constant temperature under the vacuum.With the there-necked flask sealing, take out glove box, connect vacuum line, vacuumize, and feed helium, make bottle internal gas pressure a little more than normal atmosphere.Begin heating afterwards, temperature potassium to about 100 ℃ the time melts fully, begins to carry out fierce stirring this moment.Insulation is 45 minutes after temperature rises to 170 ℃, and cooling afterwards obtains the potassium-compound between graphite layers of single order.
B, prepare Graphene by the compound between graphite layers that makes.
Remove the residual raw material of potassium-compound between graphite layers surface attachment, place in the agate mortar and grind to form uniform powder, in glove box, pour into rapidly the deionized water behind taking-up powdered potassium-compound between graphite layers, react immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.45%, gained Graphene thickness between 0.9~6.0nm, promptly the number of plies between about 1~17 layer, length and width all between 95~9500nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.77.
Embodiment 11
A, liquid phase interpolation prepare compound between graphite layers.
In water, the glove box of oxygen level, highly oriented pyrolytic graphite is cut into the parallelpiped of 1 * 2 * 0.3cm, at 400 ℃ of temperature, air pressure 10 less than 1ppm
-3Outgas under the torr.In 304 Stainless Steel Crucibles (internal diameter 25mm, height 17mm), hold molten lithium, the height of molten lithium is about 15mm, and the temperature of crucible is remained on 350 ± 5 ℃.Highly oriented pyrolytic graphite bar after the degassing finished is submerged in the molten lithium 6-8 hour, can obtain single order lithium-compound between graphite layers.Single order lithium-compound between graphite layers is taken out, with the stainless steel substrates residual lithium of its coated outside of pruning while hot.
B, prepare Graphene by the compound between graphite layers that makes.
Lithium-compound between graphite layers is placed the powder that grinds to form homogeneous in the agate mortar, in glove box, pour into rapidly the deionized water behind taking-up powdered lithium-compound between graphite layers, react immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.42%, gained Graphene thickness between 0.8~8.3nm, promptly the number of plies between about 1~25 layer, length and width all between 140~12000nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.75.
Embodiment 12
A, liquid phase interpolation prepare compound between graphite layers.
In the glove box of water, oxygen fowl amount, highly oriented pyrolytic graphite is cut into the parallelpiped of 1 * 2 * 0.3cm, at 400 ℃ of temperature, pressure 10 less than 1ppm
-3Outgas under the torr.Calcium (purity >=99.99%) and lithium (purity >=99.99%) are added in 304 Stainless Steel Crucibles (internal diameter 25mm, height 17mm) according to 1: 2 mol ratio, and fusion also stirs, and add-on guarantees that the height of molten metal is about 15mm.Graphite bar after will outgasing afterwards is immersed in the liquid metal, and tightly covers crucible cover.Be incubated 10 days down at 350 ℃, take out the graphite bar afterwards while hot, scrape off top kish, can obtain triple lithium-calcium-compound between graphite layers.
B, prepare Graphene by the compound between graphite layers that makes.
Lithium-calcium-compound between graphite layers placed grind to form uniform powder in the agate mortar, pour into rapidly the deionized water after in glove box, taking out powdered lithium-calcium-compound between graphite layers, react immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.39%, gained Graphene thickness between 5.8~13.6nm, promptly the number of plies between about 15~40 layers, length and width all between 130~6700nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.78.
Embodiment 13
A, molten salt electrolysis of metals legal system are equipped with compound between graphite layers.
As negative electrode (diameter 6mm), high purity graphite (impurity is less than 35ppm) crucible (high 140mm, internal diameter 20mm, external diameter 30mm) is as anode with high purity graphite (impurity is less than 35ppm) rod for electrolyzer, and fusion sodium-chlor is as ionogen.Use one can temperature control vertical heater and the sealing corundum tubular reactor that is connected with water cooling plant.99% pure sodium-chlor is adding in the reactor drum after super-dry, and the speed with 150ml/min pours into high-purity argon in reactor drum then, is used for the gas of purge reactor, and the inert atmosphere that keeps reactor drum is in case the generation of oxidation reaction.After continue feeding high-purity argon, begin to heat up, reach 850 ℃ after about 3 hours, treat the sodium-chlor fusing after, negative electrode is slowly inserted in the melting salt.The length of inserting in the fused salt is remained a constant.Continuous current with 5A carried out electrolysis 3 hours afterwards.After electrolysis finishes, treat the device cooling after, take out sealed reactor and transfer in water, the glove box of oxygen level less than 1ppm, scrape off sodium-chlor residual on the negative electrode, can obtain sodium-compound between graphite layers.
B, prepare Graphene by the compound between graphite layers that makes.
Sodium-compound between graphite layers placed grind to form uniform powder in the agate mortar, pour into rapidly the deionized water after in glove box, taking out powdered sodium-compound between graphite layers, react immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.39%, and gained Graphene thickness is between 3.8~9.2nm, and promptly the number of plies is between about 10~27 layers.Length and width all between 150~6700nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.76.
Embodiment 14
A, two warm area vapor transportation legal systems are equipped with compound between graphite layers.
Natural graphite (diameter<30 μ m) 1.92g and potassium 0.78g are respectively charged into the heat-resistant glass tube both sides, vacuumize, reach about 1.33Pa to vacuum tightness.Heat with two groups of electrothermal ovens, first heating graphite end, treat graphite end temperature rise to 450 ℃ after reheat potassium end, and make potassium end temperature maintenance at 250 ℃.Begin slowly to reduce graphite end temperature this moment, makes it remain on 280~300 ℃, heated 3 days, finally obtains bronze spherical product at the graphite end, is the potassium-compound between graphite layers that makes.Heat-resistant glass tube is transferred in water, the glove box of oxygen level less than 1ppm, taken out potassium-compound between graphite layers wherein.
B, prepare Graphene by the compound between graphite layers that makes.
Heat-resistant glass tube is transferred in water, the glove box of oxygen level less than 1ppm; Take out potassium-compound between graphite layers; Remove the residual raw material of potassium-compound between graphite layers surface attachment, place the powder that grinds to form homogeneous in the agate mortar, in glove box, pour into the deionized water rapidly behind taking-up powdered potassium-compound between graphite layers; React immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.45%, and gained Graphene thickness is between 0.8~6.7nm, and promptly the number of plies is between about 1~20 layer.Length and width all between 110~6700nm, the ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.79.
Embodiment 15
A, two warm area vapor transportation legal systems are equipped with compound between graphite layers.
(median size: 220 μ m) 1.92g and strontium 1.94g are respectively charged into the heat-resistant glass tube both sides, vacuumize, and reach about 0.1MPa to vacuum tightness with natural graphite.Heat with two groups of electrothermal ovens, first heating graphite end, treat graphite end temperature rise to 600 ℃ after reheat strontium end, and make strontium end temperature maintenance at 450 ℃.Begin slowly to reduce graphite end temperature this moment, makes it remain on 480~500 ℃, heated for two weeks, finally obtains the spherical product of reddish-brown at the graphite end, is the strontium-compound between graphite layers that makes.
B, prepare Graphene by the compound between graphite layers that makes.
Heat-resistant glass tube is transferred in water, the glove box of oxygen fowl amount less than 1ppm; Take out strontium-compound between graphite layers; Remove the residual raw material of strontium-compound between graphite layers surface attachment, place the powder that grinds to form homogeneous in the agate mortar, in glove box, pour into the deionized water rapidly behind taking-up powdered strontium-compound between graphite layers; React immediately, thereby obtain Graphene.Final gained Graphene productive rate is 0.44%, gained Graphene thickness between 4.2~13.8nm, promptly the number of plies between about 11~40 layers, length and width all between 80~7800nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.77.
Embodiment 16
The mechanically peel method is peeled off compound between graphite layers and is prepared Graphene
With the prepared lithium-compound between graphite layers of embodiment 5 said battery discharge methods is raw material, in water, the glove box of oxygen level less than 1ppm, gets 0.02g lithium-compound between graphite layers powder and is scattered in the dimethyl benzene acid amides (DMF), stirs.Then and zirconia ball (diameter 2.0-2.5mm, heavy 200g) put into a tetrafluoroethylene bottle together, the tetrafluoroethylene bottle is sealed.Utilize ball mill (use instrument as: QM-3SP2 planetary ball mill (Nanjing Univ. Instrument Factory)) with the rotating speed ball milling 30h of 300rpm.Take out the gained dispersion liquid afterwards with 4000rpm, carried out centrifugal 30 minutes, finally obtain containing the upper strata dispersion liquid of Graphene.Final gained Graphene productive rate is 0.61%, gained Graphene thickness between 0.9~4.6nm, promptly the number of plies between about 1~13 layer, length and width all between 70~8600nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.75.
Embodiment 17
The electrolytic stripping method is peeled off compound between graphite layers and is prepared Graphene
Electrolyzer is used as negative electrode with the compound between graphite layers electrode that embodiment 5 said battery discharge methods make, and high purity graphite (impurity is less than 35ppm) crucible (high 140mm, internal diameter 20mm, external diameter 30mm) is as anode, and the fusion lithium chloride is as ionogen.Use one can temperature control vertical heater and the sealing corundum tubular reactor that is connected with water cooling plant.99% pure lithium chloride is adding in the reactor drum after super-dry, and the speed with 150ml/min pours into high-purity argon in reactor drum then, is used for the gas of purge reactor, and the inert atmosphere that keeps reactor drum is in case the generation of oxidation reaction.After continue feeding high-purity argon, begin to heat up, reach 850 ℃ after about 3 hours, treat the sodium-chlor fusing after, negative electrode is slowly inserted in the melting salt.Continuous current with 10A carried out electrolysis 3 hours afterwards.After electrolysis finishes, treat the device cooling after, take out sealed reactor and transfer in water, the glove box of oxygen level less than 1ppm, scrape off sodium-chlor residual on the negative electrode, negative electrode is cleaned with deionized water repeatedly obtains Graphene after removing impurity.Final gained Graphene productive rate is 0.61%, gained Graphene thickness between 4.5~13nm, promptly the number of plies between about 12~38 layers, length and width all between 69~5400nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.75.
Embodiment 18~38
Stripper is peeled off method and is peeled off compound between graphite layers and prepare Graphene
With the prepared lithium-compound between graphite layers of embodiment 5 said battery discharge methods is raw material; Lithium-compound between graphite layers powder is dropped in the stripper; (use instrument at UW like ultrasonic cleaner (Chinese Shanghai section leads ultrasonic instrument ltd and makes); Model: SK2510LHC) under the 53Hz environment ultrasonic 30 minutes; Under the 500rpm rotating speed, (use instrument afterwards like flying pigeon board whizzer (Chinese Shanghai peace booth scientific instrument factory makes), model: TDL80-2B) centrifugal 90 minutes, obtain Graphene.The used stripper of present embodiment is selected from alcohol, ketone, ester, amine, sulfone, chlorobenzene, organic acid, the ionic liquid in inorganic acid aqueous solution, water phase surfactant mixture and the organic liquid in the aforementioned inorganic liquid.NMP:1-N-methyl-2-2-pyrrolidone N-wherein, DMF: dimethyl benzene acid amides.
Embodiment 39~47
Stripper is peeled off method and is peeled off compound between graphite layers and prepare Graphene.
With the prepared lithium-compound between graphite layers of embodiment 5 said battery discharge methods is raw material; Lithium-compound between graphite layers powder is dropped in the stripper; (use instrument at the 53Hz UW like ultrasonic cleaner (Chinese Shanghai section leads ultrasonic instrument ltd and makes); Model: SK2510LHC) under the environment ultrasonic 30 minutes; Under the 500rpm rotating speed, (use instrument afterwards like flying pigeon board whizzer (Chinese Shanghai peace booth scientific instrument factory makes), model: TDL80-2B) centrifugal 90 minutes, obtain Graphene.The used stripper of present embodiment is selected from two or more the mixture of component of aforementioned inorganic liquid and organic liquid.
Embodiment 48
A, scorification/solid phase pressurization combined preparation compound between graphite layers.
In water, the glove box of oxygen level less than 1ppm, graphite (particle diameter 40~50 μ m) 1.44g and potassium (particle diameter 200~400 μ m) 2g are mixed, place tightness system to be forced into 15kbar.Be heated to 200 ℃ afterwards, kept this pressure and temperature 10 hours, afterwards cooling.Utilize agate mortar that the gained solid is clayed into power.
In glove box, the gained pressed powder is placed flat 100ml there-necked flask with the potassium 1.9g that is cut into irregular bulk and a stirrer then.With the there-necked flask sealing, take out glove box, connect vacuum line, vacuumize, and feed helium, make bottle internal gas pressure a little more than normal atmosphere.Begin heating afterwards, temperature potassium to about 100 ℃ the time melts fully, begins to carry out fierce stirring this moment.After temperature rises to 150 ℃ the insulation 20 minutes, get final product potassium-compound between graphite layers.
B, stripper peel off/and the combination of mechanically peel method peels off compound between graphite layers and prepares Graphene
In glove box, remove the residual raw material on the potassium-compound between graphite layers surface of gained; Getting potassium-compound between graphite layers powder 0.02g drops in the dimethyl benzene acid amides (DMF); (use instrument at the 53Hz UW like ultrasonic cleaner (Chinese Shanghai section leads ultrasonic instrument ltd and makes); Model: SK2510LHC) under the environment ultrasonic 40 minutes; Afterwards this dispersion liquid and zirconia ball (diameter 2.0-2.5mm, heavy 200g) are put into a tetrafluoroethylene bottle together, the tetrafluoroethylene bottle is sealed.Utilize ball mill (use instrument as: QM-3SP2 planetary ball mill (Nanjing Univ. Instrument Factory)) with the rotating speed ball milling of 300rpm 25 hours.Take out the gained dispersion liquid afterwards with 4000rpm, carry out centrifugally (using instrument like flying pigeon board whizzer (Chinese Shanghai peace booth scientific instrument factory makes), model: TDL80-2B) 30 minutes, finally to obtain containing the upper strata dispersion liquid of Graphene.Final gained Graphene productive rate is 0.70%, gained Graphene thickness between 0.8~8.7nm, promptly the number of plies between about 1~25 layer, length and width all between 65~13000nm, the strength ratio I at D peak and G peak in the Raman spectrum
D/ I
GValue is 0.78.
The above only is a preferred implementation of the present invention; Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the present invention's design; Can also make some improvement and retouching, these improvement and retouching also should be regarded as in protection scope of the present invention.