CN102992303A - Preparation method of few-layer graphene by gradient oxidation process - Google Patents
Preparation method of few-layer graphene by gradient oxidation process Download PDFInfo
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- CN102992303A CN102992303A CN2012102365152A CN201210236515A CN102992303A CN 102992303 A CN102992303 A CN 102992303A CN 2012102365152 A CN2012102365152 A CN 2012102365152A CN 201210236515 A CN201210236515 A CN 201210236515A CN 102992303 A CN102992303 A CN 102992303A
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Abstract
The invention discloses a preparation method of few-layer graphene by a gradient oxidation process, which comprises the following steps: (1) preparing a manganese oxide/graphene compound: taking a carbon raw material-oxidizer mixture, uniformly dispersing in distilled water, stirring to react at room temperature, adding strong acid in an ice bath, and continuing stirring to react; heating to 80 DEG C, and continuing stirring to react; after the reaction finishes, adding distilled water to dilute the reaction solution, filtering to obtain a filter cake, and cleaning the filter cake to a neutral state; drying to obtain the manganese oxide/graphene compound; and (2) preparing graphene: dispersing the manganese oxide/graphene compound prepared in the step (1) in distilled water, adding dilute hydrochloric acid, stirring at room temperature for 1-6 hours to remove manganese oxide coated on the graphene surface, filtering, and cleaning the filter residue with distilled water to a neutral state, thereby obtaining the graphene. The method has the advantages of simple equipment, simple steps and low strong acid consumption, is easy to operate, and is very beneficial to environmental protection in large-scale production.
Description
Technical field
The present invention relates to a kind of preparation method of Graphene, relate in particular to a kind of graded oxidation method preparation method of few layer graphene.
Background technology
Graphene is to be arranged by the latticed dot matrix of six sides by carbon atom, is the thinnest in the world two-dimensional material, and its thickness only is 0.34nm.This special construction has contained abundant and novel physical phenomenon, makes Graphene show many excellent properties, and intensity is the highest in the test material, reaches 130Gpa, is more than 100 times of steel; Its carrier mobility reaches 15000cm
2V
-1s
-1, be present known twice with indium antimonide material of high mobility, surpass more than 10 times of silicon chip mobility, under the specified conditions such as cryogenic quenching, its mobility even can reach 250000cm
2V
-1s
-1Its thermal conductivity can reach 5000Wm
-1K
-1, be adamantine 3 times; Also have the special propertys such as room temperature quantum hall effect and room-temperature ferromagnetic.Because Graphene has the many merits such as excellent performance, workability be good, people predict that generally Graphene has great application prospect in fields such as electronics, information, the energy, material and biological medicines, is expected to start a new technological revolution in 21 century.
The method for preparing at present Graphene is more, mainly contains chemical Vapor deposition process, epitaxial growth method, mechanically peel method and chemical oxidation graft process.The additive method of comparing, take natural flake graphite as the carbon raw material, use the method for chemical oxidation intercalation to use the most extensive, the method is the carbon raw material, strong oxidizer and relatively large high density strong acid mix for 10mg:50mg:100ml in proportion, successively experience low temperature, middle gentle high temperature three-step reaction, make strong oxidizer in the strong acid of high density, bring into play the effect of oxidation, give graphite surface, the various oxy radicals of edge and interlayer, reach the purpose of the interlayer Van der Waals force that destroys graphite, make the interlamellar spacing of graphite 0.34nm be increased to 0.6-0.9nm, be beneficial to the intercalation of all kinds of SOLVENTS, peel off the formation graphene oxide, then at high temperature sonic oscillation is removed oxy radical with reductive agent under processing, and finally obtains Graphene, and wherein strong oxidizer is often referred to potassium permanganate, potassium perchlorate etc.High density strong acid is take the vitriol oil as main, and nitric acid, phosphoric acid etc. are auxiliary.。The Graphene output that this method obtains is that cost is minimum in all methods, and output is the highest.But the chemical oxidation graft process prepares Graphene and has following problem: (1) needs low temperature, middle gentle high temperature three-step reaction, complex steps, and the time of cost is long.(2) ultrasonic wave is peeled off and can be caused Graphene to reunite again.(3) a large amount of uses of high density strong acid have proposed high requirement to security, have also caused the aftertreatment difficulty, and environmental pollution is also very serious.
Summary of the invention
Purpose of the present invention aims to provide a kind of graded oxidation method preparation method of few layer graphene, and the method equipment is simple, and step is simple, easy handling, and the strong acid consumption of employing is few, is beneficial to very much the protection to environment in large-scale production.
The objective of the invention is to realize by following technical measures: a kind of graded oxidation method preparation method of few layer graphene may further comprise the steps:
(1) preparation manganese oxide/graphene complex: the mixture of getting carbon raw material and oxygenant is dispersed in the distilled water, and stirring reaction is 3 ~ 12 hours under the room temperature, then adds 100 ~ 500ul strong acid under ice bath, continues stirring reaction 30min ~ 90min; Then be warming up to 80 ℃ and continue stirring reaction 0.5 ~ 2h; Add the distilled water diluting reaction soln after reaction finishes, filter to get filter cake, the gained filter cake is cleaned to neutral; Drying obtains manganese oxide/graphene complex;
(2) preparation Graphene: manganese oxide/graphene complex of getting preparation in the step (1), pulverize, then manganese oxide/graphene complex is scattered in the distilled water, add dilute hydrochloric acid, at room temperature stir 1 ~ 6 h, be coated on the manganese oxide on Graphene surface with removal, filter, with distilled water filter residue is cleaned to neutral, obtain Graphene.
Carbon raw material in the described step (1): oxygenant: the proportioning of distilled water is 0.1 ~ 0.5g: 1 ~ 5g: 20 ~ 100 ml.
Carbon raw material in the described step (1) is graphite, carbon nanotube or acetylene black.
Strong acid in the described step (1) is the mixture that the vitriol oil, concentrated nitric acid or the vitriol oil and concentrated nitric acid mix with arbitrary proportion.When adopting strong acid to be the mixture of the vitriol oil and concentrated nitric acid, the ratio of institute's vitriol oil and concentrated nitric acid is 5:1.
Oxygenant in the described step (1) is one or more the mixing in potassium permanganate, SODIUMNITRATE and the manganous sulfate.
Further, when described oxygenant is potassium permanganate, after reaction is finished in the adding hydrogen peroxide and excessive potassium permanganate.
The amount of the distilled water that is used for diluting reaction solution in the described step (1) is 200 ~ 500ml.
Hydrochloric acid in the described step (2) is dilute hydrochloric acid, described dilute hydrochloric acid by concentrated hydrochloric acid: water by volume 1:10 is formulated.
Ratio in the described step (2) between dilute hydrochloric acid and the manganese oxide/graphene complex is 1:10 (g:ml).
Described step is at room temperature carried out in (2).
Compared with prior art, the present invention has following beneficial effect:
(1) the present invention has utilized diluted acid to prepare Graphene with the preparation of graded oxidation realization Graphene, the total concn of acid＜5% in the reaction soln, and the amount of used strong acid is the 0.5-5% of traditional chemical method, has reduced the consumption of strong acid; Also convenient follow-up processing to sample; Environmental pollution reduces.
(2) the present invention need not mechanical ultrasonic and peels off, thereby has avoided because the Graphene that the impact of ultrasonic power, time and strength of solution causes agglomeration again.
(3) need not middle temperature reaction in the preparation process of the present invention, reduced the reaction times, compare with conventional graphite alkylene length of schooling Preparation Method, simplified experimental procedure.
(4) the whole preparation method's desired reaction temperature of the present invention is low, operational safety, and technique is simple, and is with low cost and be applicable to the what is said or talked about raw material of various Gao Jingdu, is easy to accomplish scale production.
Description of drawings
Fig. 1 is the XRD diffraction spectrogram of manganese oxide/Graphene of the present invention and Graphite Powder 99.
Fig. 2 is the spectrogram of the Raman spectrum of manganese oxide/Graphene of the present invention and Graphite Powder 99.
Fig. 3 A is the scanning electron microscope (SEM) photograph of original crystalline flake graphite.
The scanning electron microscope (SEM) photograph on the manganese oxide that Fig. 3 B the present invention makes/graphene complex surface.
Fig. 3 C is the transmission electron microscope picture of the resolving power 5nm of Fig. 3 B.
Fig. 3 D is the scanning electron microscope (SEM) photograph of the resolving power 500nm of Fig. 3 B.
Fig. 4 is the Graphene transmission electron microscope picture that the present invention makes.
Fig. 5 is the XRD figure of the Graphene that makes of the present invention.
Fig. 6 is reaction principle figure of the present invention.
Embodiment
Below in conjunction with accompanying drawing specific embodiments of the invention are described in further detail.See also Fig. 1 to Fig. 6.
Embodiment 1
(1) preparation of Graphene/manganese oxide mixture
Using first ball mill that diameter is pulverized at 200 microns crystalline flake graphite (purity is 99.99%) is 50 microns Graphite Powder 99, then gets the Graphite Powder 99 of 10 mg and the KMnO of 100 mg
4Mix, grind 20 min with mortar after, adopts ultrasonic making in the distilled water that mixture is dispersed in 20 ml, the stirring 6h that continues at room temperature (to be no more than 30 ℃).Subsequently, under ice bath, add the vitriol oil of 500 μ l, and continue to stir 30 ~ 90min.Solution moves in the oil bath, is warming up to 80 ℃ by 40 ℃, and behind the reacting by heating 1h, with the distilled water diluting solution of 500 ml, subsequently, using the aperture is the PEFT filtering with microporous membrane of 0.22 μ m, and water cleans removal of contamination repeatedly.Final product is 60
oIn the C vacuum drying oven dry 12 hours, obtain the Graphene of brown/manganese oxide mixture.The Graphene of gained/manganese oxide mixture is detected, and the result is shown in Fig. 1 ~ 3D.
Transformation has occured by Graphite Powder 99 to manganese oxide in the phase that shows product of Fig. 1, and the X diffractogram that its medium and small figure is original Graphite Powder 99 appears at 12 in the X-ray diffractogram
o, 37
o, 41
O,48
o, 54
o, 62
o, 66
oWith 68
oEight diffraction peaks of position correspond to respectively (110), (211), (301), (510), (600), (521) of alpha-oxidation manganese, the diffraction peak of (002) and (541) crystal face, the most approximate with 44-0141 in the JCPDS card.It can also be seen that among the figure that the position is 26
oNear the diffraction peak intensity that represents graphite (200) crystal face reduces, and is positioned at 44
oWith 54
oAbout represent graphite (001) and (004) crystal face diffraction peak disappear, shown greatly reducing through carbonizing degree after the chemical treatment of Graphite Powder 99.As shown in Figure 2, Raman spectrum is the result further show, the Graphite Powder 99 surface coverage manganese oxide, the Raman collection of illustrative plates that its medium and small figure is original Graphite Powder 99 is at ~ 1310 cm
-1The raman characteristic peak that represents the crystallization degree G of carbon graphite powder significantly weakens, and at ~ 1580 cm
-1The raman characteristic peak that represents the G of Graphite Powder 99 defective strengthens, and its D:G value becomes 2.77 from 1.126 of original Graphite Powder 99.At ~ 1623 cm
-1There is distortion structure near the D '-band peak of finding in conjunction with D and D ' characteristic peak explanation crystalline flake graphite, and degree increases slightly.At ~ 2607 cm
-1Near 2D-band peak (G ') become very a little less than, and the broadening effect is fairly obvious.At 0 ~ 1000 cm
-1Several New Characteristics peaks occur, all reflected the constructional feature of manganese oxide.Wherein ~ 575cm
-1And 649cm
-1Characteristic peak the most obvious, the former the representative be MnO
6The flexible vibrations of the Mn-O key in the plane, the latter is MnO
6The symmetry of Mn-O key is flexible in the group.
Can see in the scanning electron microscope (SEM) photograph shown in Fig. 3 A ~ 3D that a large amount of thin slices has appearred in graphite surface, and is interlaced, form size, different hole.Examine the sheet of generation, very thin, transparent and surperficial very smooth, its size range changes greatly.Except smooth sheet, the sheet of quite a few exists crooked and overlapping, and its reason may have several aspects: the one, and the limited space of graphite surface, and the density of thin slice is excessive too crowded; The 2nd, because the high-energy-density of slice surfaces, these thin slices have the tendency that changes from two dimension to three-dimensional, form and curl or pile up so more stable three-dimensional structure.Because thin slice stands upright on the graphite face, the diameter of product increases severely to 250 ~ 450 nm, the edge roughness of these sheets, and be " protruding " type.Simultaneously, we also can observe, and these staggered thin slice roots have separated with graphite.
(2) preparation of Graphene
Get above-mentioned Graphene/manganese oxide composite powder 100 mg and again be scattered in the distilled water of 20 ml, add subsequently rare HCl of 10 ml, dilute hydrochloric acid by concentrated hydrochloric acid: water by volume 1:10 is formulated.At room temperature stir 6 h.Subsequently, using the aperture is the PEFT micropore worry membrane filtration of 0.22 μ m, and water repeatedly cleans until neutral pH=7.Final product in 60 ℃ of vacuum drying ovens dry 12 hours obtains the black graphene powder.The productive rate of this embodiment is 35%, and the number of plies of the Graphene that obtains is 3 ~ 5 layers.
The edge of transparent sheet be " convex and coarse, crooked part is found from the side, thin slice only has 4 layers thickness, less than 5 nm (shown in Fig. 3 C).The transmission electron microscope of Fig. 4 shows the size of Graphene about 100 nm, and the XRD diffractogram is 26
oNear the diffraction peak of obvious graphite (200) crystal face has appearred again, the contrast Graphite Powder 99, the intensity of this diffraction peak reduces and broadening greatly, and this mainly is because the interlamellar spacing increase that the number of plies of graphite reduces and intercalation causes is caused, and is very identical with bibliographical information.Calculate by schroedinger equation and Bragg equation, can learn that our Graphene product mean thickness is 3.3 layers.Comprehensive above-mentioned test analysis has shown that last products therefrom is few layer graphene.
(1) manganese oxide/graphene complex
Getting 5 mg diameters is the multi-walled carbon nano-tubes of 100nm and the KMnO of 30 mg
4Mix, grind 20 min with mortar after, adopts ultrasonic making in the distilled water that mixture is dispersed in 20 ml, 9h is at room temperature stirred in continuation.Subsequently, in ice bath, add the vitriol oil of 300 μ l, and continue to stir 30 ~ 90min.Solution moves in the oil bath, is warming up to 80 ℃ by 40 ℃, and behind reacting by heating 1 ~ 2h, with the distilled water diluting solution of 500 ml, subsequently, using the aperture is that the PEFT micropore of 0.22 μ m is considered membrane filtration, and water cleans removal of contamination repeatedly.Final product in 60 ℃ of vacuum drying ovens dry 12 hours obtains the manganese oxide of brown/graphene complex powder.
(2) preparation of Graphene
Get above-mentioned Graphene/manganese oxide composite powder 100 mg and again be scattered in the distilled water of 20 ml, add subsequently rare HCl of 10 ml, dilute hydrochloric acid by concentrated hydrochloric acid: water by volume 1:10 is formulated.At room temperature stir 6 h.Subsequently, using the aperture is the PEFT micropore worry membrane filtration of 0.22 μ m, and water repeatedly cleans until neutral pH=7.Final product in 60 ℃ of vacuum drying ovens dry 12 hours obtains the black graphene powder.The productive rate of this embodiment is 30%.
Embodiment 3
(1) manganese oxide/graphene complex
Get the acetylene black of 5 mg and the KMnO of 30 mg
4Mix, grind 20 min with mortar after, adopts ultrasonic making in the distilled water that mixture is dispersed in 20 ml, 12h is at room temperature stirred in continuation.Subsequently, the H that adds 100 μ l
2SO
4, and continue to stir 30 min.Solution moves in the oil bath, is warming up to 80 ℃ by 40 ℃, and behind reacting by heating 30 min, with the distilled water diluting solution of 500 ml, subsequently, using the aperture is that the PEFT micropore of 0.22 μ m is considered membrane filtration, and water cleans removal of contamination repeatedly.Final product in 60 ℃ of vacuum drying ovens dry 12 hours obtains the manganese oxide of brown/graphene complex powder.
(2) preparation of Graphene
Get above-mentioned Graphene/manganese oxide composite powder 100 mg and again be scattered in the distilled water of 20 ml, add subsequently rare HCl of 10 ml, dilute hydrochloric acid by concentrated hydrochloric acid: water by volume 1:10 is formulated.At room temperature stir 6 h.Subsequently, using the aperture is the PEFT micropore worry membrane filtration of 0.22 μ m, and water repeatedly cleans until neutral pH=7.Final product in 60 ℃ of vacuum drying ovens dry 12 hours obtains the black graphene powder.The productive rate of this embodiment is 20%.
The present invention can summarize with other the specific form without prejudice to spirit of the present invention or principal character.The above embodiment of the present invention can only think all that to explanation of the present invention rather than restriction every foundation essence technology of the present invention all belongs in the scope of technical solution of the present invention any trickle modification, equivalent variations and modification that above embodiment does.
Claims (10)
1. the graded oxidation method preparation method of a few layer graphene is characterized in that, may further comprise the steps:
(1) preparation manganese oxide/graphene complex: the mixture of getting carbon raw material and oxygenant is dispersed in the distilled water, and stirring reaction is 3 ~ 12 hours under the room temperature, then adds 100 ~ 500ul strong acid under ice bath, continues stirring reaction 30min ~ 90min; Then be warming up to 80 ℃ and continue stirring reaction 0.5 ~ 2h; Add the distilled water diluting reaction soln after reaction finishes, filter to get filter cake, the gained filter cake is cleaned to neutral; Drying obtains manganese oxide/graphene complex;
(2) preparation Graphene: manganese oxide/graphene complex of getting preparation in the step (1), pulverize, then manganese oxide/graphene complex is scattered in the distilled water, add dilute hydrochloric acid, at room temperature stir 1 ~ 6h, be coated on the manganese oxide on Graphene surface with removal, filter, with distilled water filter residue is cleaned to neutral, obtain Graphene.
2. the graded oxidation method preparation method of few layer graphene according to claim 1 is characterized in that, the carbon raw material in the described step (1): oxygenant: the proportioning of distilled water is 0.1 ~ 0.5g: 1 ~ 5g: 20 ~ 100 ml.
3. the graded oxidation method preparation method of few layer graphene according to claim 1 and 2 is characterized in that, the hydrochloric acid in the described step (2) is dilute hydrochloric acid, described dilute hydrochloric acid by concentrated hydrochloric acid: water by volume 1:10 is formulated.
4. the graded oxidation method preparation method of few layer graphene according to claim 3 is characterized in that, the carbon raw material in the described step (1) is for referring to graphite, carbon nanotube or acetylene black.
5. the graded oxidation method preparation method of few layer graphene according to claim 3 is characterized in that, the strong acid in the described step (1) is the mixture that the vitriol oil, concentrated nitric acid or the vitriol oil and concentrated nitric acid mix with arbitrary proportion.
6. the graded oxidation method preparation method of few layer graphene according to claim 5 is characterized in that, the ratio of institute's vitriol oil and concentrated nitric acid is 5:1.
7. the graded oxidation method preparation method of few layer graphene according to claim 3 is characterized in that, the oxygenant in the described step (1) is one or more the mixing in potassium permanganate, SODIUMNITRATE and the manganous sulfate.
8. the graded oxidation method preparation method of few layer graphene according to claim 7 is characterized in that, when described oxygenant is potassium permanganate, after reaction is finished in the adding hydrogen peroxide and excessive potassium permanganate.
9. the graded oxidation method preparation method of few layer graphene according to claim 3 is characterized in that, the amount of the distilled water that is used for diluting reaction solution in the described step (1) is 200 ~ 500ml.
10. the graded oxidation method preparation method of few layer graphene according to claim 3 is characterized in that, described step is at room temperature carried out in (2).
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106229164A (en) * | 2016-08-08 | 2016-12-14 | 南昌大学 | A kind of preparation method of manganese dioxide/graphene composite structure electrode material for super capacitor |
| CN107381551A (en) * | 2016-08-18 | 2017-11-24 | 成都中医药大学 | A kind of embedding manganese graphene and preparation method and application |
| CN107934946A (en) * | 2017-12-13 | 2018-04-20 | 北京大学 | Graphene powder and preparation method thereof |
-
2012
- 2012-07-09 CN CN2012102365152A patent/CN102992303A/en active Pending
Non-Patent Citations (1)
| Title |
|---|
| YING CHEN ET AL.: "One-pot synthesis of MnO2/graphene/carbon nanotube hybrid by chemical method", 《CARBON》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106229164A (en) * | 2016-08-08 | 2016-12-14 | 南昌大学 | A kind of preparation method of manganese dioxide/graphene composite structure electrode material for super capacitor |
| CN107381551A (en) * | 2016-08-18 | 2017-11-24 | 成都中医药大学 | A kind of embedding manganese graphene and preparation method and application |
| CN107934946A (en) * | 2017-12-13 | 2018-04-20 | 北京大学 | Graphene powder and preparation method thereof |
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Application publication date: 20130327 |