CN109305671A - A method of graphene is prepared using low layer number graphene oxide - Google Patents
A method of graphene is prepared using low layer number graphene oxide Download PDFInfo
- Publication number
- CN109305671A CN109305671A CN201811493454.1A CN201811493454A CN109305671A CN 109305671 A CN109305671 A CN 109305671A CN 201811493454 A CN201811493454 A CN 201811493454A CN 109305671 A CN109305671 A CN 109305671A
- Authority
- CN
- China
- Prior art keywords
- graphene oxide
- graphene
- low layer
- layer number
- reaction zone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/184—Preparation
Abstract
The present invention provides a kind of methods for preparing graphene using low layer number graphene oxide, which comprises carries out purification process to purifying object, obtains graphene oxide after purification；Freeze-drying process is carried out to the graphene oxide after purification, obtains low layer number graphene oxide；Reduction treatment is carried out to the low layer number graphene oxide, obtains graphene.The completeness of graphene oxide purifying can be improved in the present invention, so that graphene oxide and impurity is separated, remove impurity；Obtain the graphene oxide of low layer number by the method for freeze-drying, the structure of oxidized graphite flake layer will not be destroyed, preferably preservation functional group, it is freeze-dried after graphite oxide be not susceptible to agglomeration；So that the graphene oxide of low layer number is reacted under different temperature, pressure region by force using high-temperature low-pressure, takes full advantage of graphene and melt the high feature of boiling point, metal, the nonmetallic inclusion in graphene can be removed very well.
Description
Technical field
The present invention relates to technical field of new material preparation, more particularly, are related to a kind of utilization low layer number graphene oxide
The method for preparing graphene.
Background technique
In current industrial production, graphene oxide powder can be produced on a large scale using oxidation graft process.Aoxidize intercalation
Contain a large amount of foreign ion in the graphene oxide slurry of method production, existing graphene oxide has effect in purification process
The problems such as rate is low, and washing effect is poor；The number of plies is also more in the graphene oxide of production, that is, the graphene oxide quality produced
It is not high.Moreover, because the thermal stability of graphite oxide is poor, it often just will appear pyrolysis phenomenon during the drying process, and be heated
Graphite oxide after drying is easy to be agglomerated into lump, is unfavorable for subsequent dispersion.
Currently, the graphene preparation method of mainstream has mechanical stripping method, oxidation-reduction method, epitaxial growth method, chemical vapor
Sedimentation etc., wherein oxidation-reduction method due to its is low in cost, production equipment is simple, single yield is maximum, in gas producing formation manifold,
The advantages that lateral dimension is uniform becomes industrialized production most popular method.But in the method for preparing graphene, on the one hand, use
The graphene of oxidation-reduction method preparation, since during aoxidizing intercalation, the crystal structure of its own is easily broken, and is led
It causes graphene internal flaw to increase, significantly affects the performance of graphene；On the other hand, it is produced using oxidation-reduction method
Graphene there is also a large amount of metals, nonmetallic inclusion, this also further affects large-scale development and the application of graphene.
Summary of the invention
It is above-mentioned existing in the prior art it is an object of the present invention to solving for the deficiencies in the prior art
One or more problems.For example, one of the objects of the present invention is to provide one kind can reduce graphene impurity content, graphite is improved
Alkene purity reduces the graphene preparation method of graphene number of plies.
The present invention provides a kind of method for preparing graphene using low layer number graphene oxide, the preparation method can be with
The following steps are included: carrying out purification process to purifying object, graphene oxide after purification is obtained；To the oxidation after purification
Graphene carries out freeze-drying process, obtains low layer number graphene oxide；Also original place is carried out to the low layer number graphene oxide
Reason, obtains graphene, wherein
The purifying object is to be combined with foreign ion in functional group and have the graphene oxide of first number of plies or contain
There is the slurry that foreign ion and the graphene oxide with first number of plies are combined in functional group, first number of plies is ten several layers
To tens of layers；
The step of described pair of purifying object carries out purification process may include: by purifying object, complexing agent and acid solution
Mixing forms mixed liquor；Ultrasonic vibration is carried out to the mixed liquor, so that the foreign ion removing that graphene oxide is combined is simultaneously
With complexing agent stable bond；Filtering, obtains graphene oxide after purification；
Described the step of carrying out freeze-drying process to graphene oxide after purification may include: by oxidation after purification
Graphene dispersion in water, and forms graphene oxide hydrogel；Graphene oxide hydrogel is placed in the first temperature and first
It under pressure, molecule and sublimates so that the hydrone in graphene oxide hydrogel congeals into ice, to obtain that there is second number of plies
Graphene oxide, second number of plies be less than first number of plies；
Described the step of carrying out reduction treatment to low layer number graphene oxide may include: by the low layer number graphite oxide
Alkene sequence experience the i-th reaction zone and the n-th reaction zone, obtains low layer number graphene, and by the temperature and pressure of n-th reaction zone
It is controlled as T by forcenAnd Pn, the temperature of i-th reaction zone and pressure are controlled as TiAnd Pi, wherein Ti=w1·i/
n·Tn, Pi=(P0-Pn) (1-i/n), wherein w1It is selected between 0.80~1.20, P0For 1 standard atmospheric pressure, TnAnd PnPoint
Wei not be 1250 DEG C or more and 30Pa~500Pa, n is natural number and >=2, i gets all natural numbers less than n.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
State complexing agent may include citric acid, sodium citrate, sodium thiosulfate, sodium sulfite, sodium ethylene diamine tetracetate, polyacrylic acid,
Sodium gluconate or sodium alginate.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
The pH of acid solution can be 0.1~6.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
Stating filtration step includes being filtered by filter membrane, and suction filtration mechanism is arranged to carry out decompression suction filtration in the lower section of filter membrane.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
Stating first number of plies can be 20~30 layers, and second number of plies can be 5~7 layers.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
State the first temperature can be selected within the scope of -55~-65 DEG C and temperature change be no more than ± 2 DEG C.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
State the first pressure can be selected in the range of 10~100Pa and pressure change be no more than ± 10Pa.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
The solid content for stating graphene oxide hydrogel can be 0.1~50wt%.
In an exemplary embodiment of the method for the invention for preparing graphene using low layer number graphene oxide, institute
Stating the step of carrying out reduction treatment to low layer number graphene oxide may include: that will be contained with first low layer number graphene oxide
Feed bin sequence undergo the first reaction member the i-th reaction zone and the n-th reaction zone, collect the graphene in the feed bin；To institute
It states feed bin and holds second batch low layer number graphene oxide, and its sequence is made to undergo the jth reaction zone of the second reaction member and m anti-
Area is answered, the graphene in the feed bin is collected；Third batch low layer number graphene oxide is held to the feed bin, and its sequence is undergone
The i-th reaction zone and the n-th reaction zone of first reaction member, collect the graphene in the feed bin, wherein n-th reaction zone
Temperature and pressure be controlled as TnAnd Pn, the temperature and pressure of i-th reaction zone be controlled as TiAnd Pi, wherein Ti
=w1·i/n·Tn, Pi=(P0-Pn) (1-i/n), wherein w1It is selected between 0.80~1.20, P0For 1 normal atmosphere
Pressure, TnAnd PnRespectively 1250 DEG C or more and 30Pa~500Pa, n is natural number and >=2, i gets all natural numbers less than n；
The temperature and pressure of the m reaction zone are controlled as tmAnd Pm, the temperature and pressure of the jth reaction zone be controlled as
tjAnd Pj, wherein tj=k1·j/m·tm, Pj=(P0-Pm) (1-j/m), wherein k1It is selected between 0.80~1.20, P0For
1 standard atmospheric pressure, tmAnd PmRespectively 1250 DEG C or more and 30Pa~500Pa, m is natural number and >=2, j is got less than m's
All natural numbers.Further, the feed bin can be graphite feed bin or the feed bin for being internally provided with graphite coating.
Compared with prior art, the beneficial effect comprise that
(1) completeness of graphene oxide purifying can be improved in the present invention, can effectively make graphene oxide and impurity
Separation, removes impurity, and purification efficiency is high, at low cost；
(2) present invention obtains the graphene oxide of low layer number by the method being freeze-dried, and will not destroy oxidized graphite flake
Layer structure, preferably preservation functional group, it is freeze-dried after graphite oxide be not susceptible to agglomeration；
(3) dry greater than other drying means by the lamella interlamellar spacing of freeze-dried obtained low layer number graphene oxide
Graphene oxide product after dry has superior dispersion performance, the less number of plies and bigger specific surface area；
(4) present invention by force sends out under different temperature, pressure region the graphene oxide of low layer number using high-temperature low-pressure
Raw reaction prepares graphene, takes full advantage of graphene and melts the high feature of boiling point；In low pressure environment, it can be gone by high temperature
Except metal, the nonmetallic inclusion in graphene, and a large amount of oxygen-containing functional groups of graphene oxide institute band are removed simultaneously, repair oxidation
Graphene during the preparation process caused by SP3Hydridization defect；
(5) present invention can pre-process to reduce energy consumption graphene oxide in lower temperature region, can effectively close
Reason utilizes waste heat, can significantly improve reduction efficiency, can be realized the continuous production of graphene；
(6) the low layer number graphene impurity content that the present invention is prepared is low, and fault of construction is few, and the number of plies is lower, comprehensive
It can be excellent.
Detailed description of the invention
By the description carried out with reference to the accompanying drawing, above and other purpose of the invention and feature will become more clear
Chu, in which:
Fig. 1 show an illustrative embodiment of the invention to the reaction zone in low layer number graphene oxide reduction step
Arrangement schematic diagram.
Specific embodiment
Hereinafter, utilization low layer number according to the present invention will be described in detail in conjunction with attached drawing and exemplary embodiment to aoxidize
The method that graphene prepares graphene.
Fig. 1 show an illustrative embodiment of the invention to the reaction zone in low layer number graphene oxide reduction step
Arrangement schematic diagram.
The present invention provides a kind of method for preparing graphene using low layer number graphene oxide, utilizes low layer in of the invention
In one exemplary embodiment of the method that number graphene oxide prepares graphene, the method may include:
Step S100 carries out purification process to purifying object, obtains graphene oxide after purification.Wherein, the purifying
Object can be containing functional group and to contain the graphene oxide of impurity with first number of plies.First number of plies can be ten
Several layers can be 22~28 layers further for example, can be 20~30 layers to tens of layers.Containing oxygen-containing in graphene oxide
Functional group.For example, the graphene oxide with first number of plies can be by being prepared using Bronsted acid intercalated graphite.
The impurity may include metal impurities and/or nonmetallic inclusion.For example, the impurity may include iron, manganese,
One of impurity such as potassium, sodium, sulphur, silicon or two kinds of combinations.The functional group may include carboxyl, hydroxyl, carbonyl, ehter bond and
One of epoxy group or a variety of functional groups.Certainly, functional group of the invention is without being limited thereto, such as functional group can also be ester
Base etc..
Step S200 carries out freeze-drying process to graphene oxide after purification, obtains low layer number graphene oxide.
Step S300 restores low layer number graphene oxide, obtains graphene.
In the present embodiment, for step S100, the step of graphene oxide obtained after purification, may include:
Purifying object, complexing agent are mixed with acid solution, form mixed liquor by S110.
The complexing agent may include citric acid, sodium citrate, sodium thiosulfate, sodium sulfite, sodium ethylene diamine tetracetate, gather
The combination of one or more of acrylic acid, sodium gluconate and sodium alginate.
Liquid reactions environment needed for the acid solution is capable of providing reaction.Acid solution may include that concentration is 0.005
The hydrochloric acid solution or concentration of~0.02mol/L is the dilution heat of sulfuric acid of 0.01~0.04mol/L, further, dilute hydrochloric acid concentration
It can be 0.01mol/L, dilute sulfuric acid concentration can be 0.02mol/L.Further, acid solution may include dilute hydrochloric acid solution, this is
It, can be faster using dilute hydrochloric acid because a certain amount of sulfuric acid can be contained in the graphene oxide ontology of intercalation oxidizing process preparation
Clean graphene oxide.
S120 carries out ultrasonic vibration to the mixed liquor.
Under the action of having children outside the state plan wave, the foreign ion in conjunction with graphene oxide can be detached from and better with associativity with it
Complexing agent combines, simultaneously because the effect of ultrasound, graphene oxide can preferably disperse and and H+In conjunction with will not be to network
Mixture fights for metal ion.
When carrying out ultrasound, the frequency of ultrasonic wave can be 50~750Hz, and the supersonic frequency of the range can make graphite oxide
Foreign ion in alkene functional group preferably removes.
The weight percent of the foreign ion on graphene oxide after purification can be not higher than 0.01%；The removal rate of impurity
Up to 99% or more.
S130, filtering, obtains graphene oxide after purification.
The filtering can be filtered by filter membrane, so that graphene oxide after purification and the solution comprising impurity
To separation.Wherein, graphene oxide stays on filter layer, and the solution containing impurity can penetrate filter membrane.The filter membrane can
Including polycarbonate membrane (i.e. PC film).Further, also pressure-reduction filter device can be set in the lower section of filter layer, so that containing miscellaneous
The solution of matter preferably penetrates filter layer.Wherein, it can realize that decompression filters by the way that vacuum pump is arranged under filter membrane.
When being filtered using filter membrane, the method may further comprise the step of: is arranged buffer protection on filter membrane
Layer, influence of the ultrasonic wave to filter membrane when absorbing and buffer ultrasonic vibration.Buffer protection layer may include sponge.
More than, the purification process, which may further comprise the step of:, carries out detection ion concentration to the obtained graphene oxide
Detection, to determine whether graphene oxide also needs to continue to purify.Wherein, ICP (Inductively can be passed through
Coupled Plasma, inductively coupled plasma) ion concentration detector detected.
In the present embodiment, for step S200, may include: in described the step of obtaining low layer number graphene oxide
Step S210 forms graphene oxide hydrogel.
The graphene oxide of purifying is dispersed in water, and forms graphene oxide hydrogel.In dispersion process, preferably
Further strengthen dispersion effect by ultrasonic disperse, thus make hydrone well into the lamellar structure to graphene oxide or
In person's fold, or with the functional groups of surface of graphene oxide graphene oxide hydrogel is formed at hydrated ion.Oxidation
Graphene hydrogel, which has, is combined with structure of water molecules in the lamella or fold of the graphene oxide of its own.Aoxidize stone
The solid content of black alkene hydrogel can be 0.1~50wt%.Water for dispersing graphene oxide is preferably secondary deionized water.
Step S220 carries out cryogenic vacuum freeze-drying to graphene oxide hydrogel.
Graphene oxide hydrogel is placed at the first temperature and the first pressure, so that the water in graphene oxide hydrogel
Molecule, which congeals into ice, molecule and sublimates, to obtain the graphene oxide with second number of plies.Also, the first temperature is controlled as
Not higher than -50 DEG C and the temperature change of the first temperature is no more than ± 4 DEG C always, and the first pressure is controlled as lower than 1 atmospheric pressure
And first the variation of pressure be no more than ± 100Pa always.Further, the first temperature can select within the scope of -55~-65 DEG C
And temperature change is no more than ± 2 DEG C.First pressure can be selected in the range of 10~100Pa and pressure change be no more than ±
10Pa。
Wherein, second number of plies is less than first number of plies.Under second number of plies can have significantly compared to first number of plies
Drop.Here, second number of plies can be the 1/3~1/6 of first number of plies.For example, second number of plies can be 5~7 layers.
In an exemplary embodiment of the present invention, by by the control of the first temperature for not higher than -50 DEG C and by the first pressure
Control is not higher than 1 standard atmospheric pressure, and hydrone can be made to become ice molecule, by volume expansion, further widen stone
The lamellar structure of ink；And ice can sublimate volatilization under low-temp low-pressure, and temperature is low, and " entropy " value is low, enables to graphene oxide
The structure being softened is maintained, and makes graphene oxide composite material good dispersion, the large specific surface area of preparation.Moreover, by opposite
Constant cryogenic temperature (for example, not higher than -50 DEG C and controlling the intracorporal temperature change of chamber of entire cold dry chamber no more than ± 4 DEG C)
With relative constant vacuum degree (for example, lower than 1 atmospheric pressure and the entire intracorporal pressure change of chamber of control be no more than ±
100Pa), be conducive to keep the rate of set of hydrone and degree relatively stable, therefore, to " strutting " effect of graphene oxide layer
Stablize；And be conducive to make ice molecule sublimate speed and degree it is relatively stable, therefore, be also beneficial to be avoided to a certain degree because of oxygen
Local defect caused by the local stress of graphite alkene layer.Further say, it will be cold dry by control temperature unit and pressure control unit
The control climate of chamber is temperature within the scope of -55~-65 DEG C and the entire intracorporal temperature change of chamber of control is no more than ± 2 DEG C, with
And pressure control is in 10~100Pa and the entire intracorporal pressure change of chamber of control is no more than ± 10Pa, is more conducive to making moisture
The rate of set and degree of son are further stablized, thus to " strutting " effect stability of graphene oxide layer；And be conducive to make
Ice molecule sublimate speed and degree is further stablized, to be also beneficial to further avoid to answer because of the part of graphene oxide layer
Local defect caused by power.
In the present embodiment, described that low layer number graphene oxide is restored for step S300, it is higher to obtain purity
Graphene the step of may include:
The i-th reaction zone and the n-th reaction zone for successively undergoing temperature different with pressure in order low layer number graphene oxide
It is reacted, obtains graphene, wherein n is natural number and >=2, i gets all natural numbers less than n.
The temperature T of n-th reaction zonenIt indicates, pressure PnIt indicates.Here temperature TnIt can be 1250 DEG C or more,
Further, the temperature TnIt can be 1700 DEG C~2800 DEG C, further, 1700 DEG C~2800 DEG C, further,
Temperature TnIt can be 2200 DEG C.Since 2200 DEG C be carbon material graphitization temperature, and also help and repair graphene oxide
Self-defect.The pressure PnIt can be 30Pa~500Pa, further, the pressure PnCan be 60Pa~100Pa, more into
One step, the pressure PnIt can be 85Pa~95Pa.
The temperature T of i-th reaction zoneiIt indicates, pressure PiIt indicates.The temperature TiIt can be Ti=w1·i/n·
Tn, wherein w1It is selected between 0.80~1.20.The pressure PiIt can be Pi=(P0-Pn) (1-i/n), wherein P0It is 1
A standard atmospheric pressure.Different temperature and pressure is arranged in different reaction zones, can preferably carry out to low layer number graphene oxide
Pretreatment, can be more advantageous to low layer number graphene oxide impurity elimination and go functional group's process, can be improved the production effect of graphene
Rate.Further, w1It can be selected between 0.85~1.14, for example, w10.98 can be taken.For example, graphene oxide is distinguished
Undergo totally 3 reaction zones of the 1st, the 2nd and the 3rd.The temperature and pressure of 3rd reaction zone are respectively set to 1500 DEG C and 100Pa.According to
Above-mentioned temperature and pressure formula, take w1The temperature for being the 0.9, the 1st reaction zone is T1=0.9 × 1/3 × 1500=450 DEG C, pressure is
P1=(1.01 × 105- 100) (1-1/3)=0.67 × 105Pa, the temperature of the 2nd reaction zone are T2=0.9 × 2/3 × 1500
=900 DEG C, pressure P1=(1.01 × 105- 100) × (1-2/3)=0.34 × 105Pa。
It can based on experience value or actual field for reaction time of the low layer number graphene oxide in each reaction zone
Operation is determined.For example, it is assumed that the reaction time in the n-th reaction zone is tn, then the reaction time of the i-th reaction zone can be ti
=r1·i/n·tn, the r1It can be selected between 0.9~1.1.
In the present embodiment, described that low layer number graphene oxide is restored for step S300, it is higher to obtain purity
Graphene the step of may include:
Step S310, as shown in Figure 1, the feed bin sequence experience first for being contained with first low layer number graphene oxide is anti-
The i-th reaction zone and the n-th reaction zone for answering unit, collect the graphene in the feed bin.Wherein, the temperature of n-th reaction zone
It may be controlled to T respectively with pressurenAnd Pn, the temperature and pressure of i-th reaction zone may be controlled to T respectivelyiAnd Pi, wherein
Ti=w1·i/n·Tn, Pi=(P0-Pn) (1-i/n), wherein w1It is selected between 0.80~1.20, P0For 1 normal atmosphere
Pressure, n is natural number and >=2, i gets all natural numbers less than n.
The temperature TnIt can be 1250 DEG C or more, further, the temperature TnIt can be 1700 DEG C~2800 DEG C.More
Further, temperature TnIt can be 1700 DEG C~2500 DEG C.For example, temperature can be 2200 DEG C, since 2200 DEG C be carbon material
Graphitization temperature, and also help the self-defect for repairing graphene oxide.The pressure PnIt can be 30Pa~500Pa.
Further, the pressure PnIt can be 60Pa~100Pa.
More than, the feed bin for being loaded with first low layer number graphene oxide passes through the area of different temperatures and pressure respectively
Domain carries out heating reaction, then takes out the low layer number graphene that reaction is prepared in final reaction zone.Feed bin is due to having one
Fixed waste heat, it is not necessary to take out feed bin in final reaction zone, and be directly entered the 1st reaction zone of the second reaction member, such as Fig. 1 institute
Show.Feed bin waste heat can be efficiently used in this way, improve reaction efficiency, it is energy saving.
Further, w1It can be selected between 0.85~1.14, for example, w10.95 can be taken.
Step S320, after the n-th reaction zone of the first reaction member takes out the low layer number graphene being prepared, to institute
State addition second batch low layer number graphene oxide in feed bin.It, will since feed bin has had certain temperature in the n-th reaction zone
The feed bin for being contained with second batch low layer number graphene oxide is directly entered the first reaction zone of the second reaction member, can use material
The waste heat in storehouse preheats simultaneously second batch low layer number graphene oxide, and the jth for making its sequence undergo the second reaction member is anti-
Area and m reaction zone are answered, the low layer number graphene being prepared in the feed bin is collected in m reaction zone, it is low to obtain second batch
Number of plies graphene.Wherein, the temperature of the m reaction zone and pressure are controlled as tmAnd Pm, the temperature of the jth reaction zone
T is controlled as with pressurejAnd Pj.Wherein, tj=k1·j/m·tm, Pj=(P0-Pm) (1-j/m), wherein k10.80~
It is selected between 1.20, P0For 1 standard atmospheric pressure, m is natural number and >=2, j gets all natural numbers less than m.The temperature
TmIt can be 1250 DEG C or more, further, the temperature TmIt can be 1700 DEG C~2200 DEG C.The pressure PmIt can be
30Pa~500Pa, further, the pressure PmIt can be 85Pa~95Pa.Further, k1Can 0.83~1.16 it
Between select, for example, w10.92 can be taken.
More than, the discharge port of the n-th reaction zone of the first anti-unit and the 1st reaction zone of the second reaction member into
Material mouth is disposed adjacent.After first low layer number graphite oxide alkene reaction is completed to take out product low layer number graphene, it is added second
Low layer number graphene oxide is criticized, the feed bin for filling second batch low layer number graphene oxide enters the 1st reaction of the second reaction member
Area is reacted in the reaction zone of the second reaction member.Feed bin for just going out first the n-th reaction zone of reaction member has one
Fixed waste heat, when entering the second reaction member, the waste heat that can use feed bin carries out second batch low layer number graphene oxide
Heating, may be implemented the effective use to high temperature material waste heat, energy saving.
Step S330, when second batch low layer number graphene oxide the second reaction member after the reaction was completed, second reaction
The m reaction zone of unit takes out second batch low layer number graphene oxide, and third batch low layer number graphene oxide is added simultaneously, and
Its sequence undergoes the i-th reaction zone and the n-th reaction zone of the first reaction member, collects the graphene in the feed bin, is recycled with this,
Realize the continuous production of graphene.
More than, the discharge port of the m reaction zone of second reaction member and the 1st reaction zone of the first reaction member
Feed inlet is disposed adjacent, the 1st reaction zone of the discharge port and the second reaction member of the n-th reaction zone of first reaction member
Feed inlet is disposed adjacent, and can be formed a continuous circular response region in this way, be can be realized the continuous of low layer number graphene
Metaplasia produces.Likewise, third batch low layer is added after second batch low layer number graphite oxide alkene reaction is completed to take out product graphene
Number graphene oxide.The feed bin for filling third batch low layer number graphene oxide enters the 1st reaction zone progress of the first reaction member
Reaction.Graphene is taken out after the reaction was completed in first the n-th reaction zone of reaction member, and the 4th batch of low layer number graphite oxide is added
Alkene.
Likewise, the oxygen in reaction time and foregoing example embodiment in each reaction zone of low layer number graphene oxide
Graphite alkene can be identical in the time that each reaction zone reacts.
More than, due to may include at least one of manganese, iron, potassium, sodium, sulphur, silicon impurity in the purifying object.It is above-mentioned
Impurity is usually in the form of ions in graphene oxide.Complexing agent used in purification process can in impurity
Metal impurities be combined to remove metal impurities, for example, manganese, iron, potassium, sodium etc..At this point, the additional amount of the complexing agent is
It can be with 1.0~1.2 times of the theoretical amount of impurity complex reaction.Certainly, it is without being limited thereto that removable metal impurities are complexed, example
Such as, beavy metal impurity or other can be with the impurity in conjunction with complexing agent.After purifying removes partial impurities, in reduction step
In, metal and nonmetallic inclusion can be removed under high-temperature low-pressure environment, for example, manganese, iron, potassium, sodium, sulphur, silicon etc..In high temperature
Under, it can achieve the fusing point and boiling point of the metal impurities and nonmetallic inclusion that contain in graphene oxide, it can be from graphite oxide
It is separated in the form of a vapor in alkene.Under certain low pressure subsidiary conditions, the fusing point and boiling point of metal impurities and nonmetallic inclusion
Can further reduce, by the temperature and vacuum degree of setting be easy in removal graphene oxide the metal impurities that contain and
Nonmetallic inclusion.Cooperate to remove jointly by two stages of reaction of purification process and high-temperature vacuum reaction process and contain in raw material
Impurity can be good at removing oxygen-containing functional group under high-temperature vacuum degree, can obtain the graphene of low impurity content.Existing
It prepares in the method for graphene, the content of preparation-obtained graphene is generally all in 2000PPm or more, method system of the invention
Ferro element and manganese element content can achieve less than 20PPm in the graphene of standby obtained low impurity content, further, can be with
It is less than 15ppm, and the impurity such as nitrate ion, chloride ion can also be removed well, can be very good to be used in work
For lithium ion battery conductive additive.
For temperature T is arranged in any one embodiment of step S300nOr TmIt is advantageous in that for 1250 DEG C or more,
If temperature is lower than 1250 DEG C, the volatilization for being unfavorable for impurity is gone out, and the fusing point and boiling point of certain impurity may be not achieved.For example,
The temperature of setting can be 1250 DEG C~2500 DEG C.If the temperature of setting of the invention is higher than 2800 DEG C, the too high possibility of temperature
Can be serious to the loss of stove, energy consumption is larger, higher cost, also, higher temperature will lead to the low layer number stone being prepared
The specific surface area of black alkene becomes smaller.Further, temperature TnOr TmIt can be 2200 DEG C.Since 2200 DEG C be carbon material graphite
Change temperature, and also helps the self-defect for repairing graphene oxide.Pressure P is setnIt is advantageous in that for 30Pa~500Pa,
Under above-mentioned pressure vacuum degree, the fusing point and boiling point for the impurity that graphene oxide contains are lower, it is easier to volatilization removal.
For in any one embodiment of step S300, in the n-th reaction zone and can in the time of m reaction zone reaction
To be 60min~600min.Since the n-th reaction zone and m reaction zone are each reaction member temperature highest, pressure is the smallest
Reaction zone is the main reaction region of graphene oxide.If heating time is lower than 60min, the heating time of possible graphene oxide
Not enough, impurity cannot adequately be removed；Heating time is higher than 600min, and heating time is too long, and energy consumption consumption is too big.Further
, heating time is 120min~300min.
For the high temperature that in any one embodiment of step S300, purifying object institute's oxygen-containing functional group is arranged in the present invention
And carbon dioxide and water can be decomposed under pressure conditions, it can effectively remove the oxygen-containing functional group in graphene oxide.
Theoretically speaking can be removed functional group at 1000 DEG C of temperature and vacuum environment of the invention, but since impurity is gone
The temperature removed is higher, and therefore, the temperature that the present invention is arranged should be higher than 1250 DEG C.Certainly, oxygen-containing functional group of the invention is unlimited
In this, carbon dioxide and water can be decomposed at temperature and pressure of the invention.
In order to avoid graphene purity of the feed bin to preparation impacts, during processing, it should avoid in graphene
Other elements impurity is introduced because of feed bin material.Since the fusing point of graphite is up to 3652 DEG C, much higher than common metal impurity and
The molten boiling point of nonmetallic inclusion.Therefore, it is possible to use graphite feed bin or surface be coated with graphite linings feed bin, for example,
Graphite alms bowl.But the present invention is not limited to this, and the feed bin material also can be selected other molten higher materials of boiling point, such as tungsten foil,
Tantalum carbide feed bin or hafnium carbide feed bin etc..In order to keep the heating surface area of graphene oxide bigger, it is conducive to sufficiently removal impurity, simultaneously
In a certain amount of situation of graphene oxide, the bigger graphene of area is generated, it is preferable that pave the graphene oxide in institute
It states in feed bin.
The molten boiling point difference for containing impurity with it using graphene for the present invention, by the way that different humidity province and pressure is arranged
Strong area, subregion reaction, while effectively removing impurity, can repair the SP in graphene oxide3Fault of construction simultaneously removes
Its oxygen-containing functional group, and then the higher high-quality graphene of purity is prepared.Temperature range appropriate can make graphene oxide
In SP3Fault of construction is repaired, then is aided with low pressure condition, can remove a large amount of oxidation functions of graphene oxide institute band
Group, and metal and/or nonmetallic inclusion can be removed from graphene oxide in the form of a vapor.Be arranged different temperature and
Pressure area can carry out a pretreatment to graphene oxide, and can rationally utilize generated waste heat in preprocessing process,
It can be realized energy-efficient effect, can be realized the continuous production of graphene.Make graphite oxide alkene reaction under the conditions of low pressure,
It can reduce the fusing point and boiling point of impurity in graphene oxide, and then reduce requirement of the preparation process to temperature, can achieve section
It can be with the effect of cost squeeze.
In conclusion the completeness of graphene oxide purifying can be improved in the present invention, it can effectively make graphene oxide
It is separated with impurity, purification efficiency is high, at low cost；The graphene oxide of low layer number is obtained by the method for freeze-drying, will not be broken
The structure of bad oxidized graphite flake layer, preferably preservation functional group, it is freeze-dried after graphite oxide be not susceptible to agglomeration；
The a large amount of impurity in used raw material and graphene preparation process can be removed by purification step and reduction step, it can be with
Improve the purity of graphene；The low layer number graphene impurity content being prepared is low, and fault of construction is few, and the number of plies is lower, comprehensive
It can be excellent.
Although those skilled in the art should be clear above by combining exemplary embodiment to describe the present invention
Chu can carry out exemplary embodiment of the present invention each without departing from the spirit and scope defined by the claims
Kind modifications and changes.
Claims (10)
1. a kind of method for preparing graphene using low layer number graphene oxide, which is characterized in that the method includes following steps
It is rapid:
Purification process is carried out to purifying object, obtains graphene oxide after purification；
Freeze-drying process is carried out to the graphene oxide after purification, obtains low layer number graphene oxide；
Reduction treatment is carried out to the low layer number graphene oxide, obtains graphene, wherein
The purifying object is that foreign ion and the graphene oxide with first number of plies, the first layer are combined in functional group
Number is ten several layers to tens of layers；
Described pair of purifying object carries out the step of purification process and includes:
Object will be purified, complexing agent is mixed with acid solution, formation mixed liquor；Ultrasonic vibration is carried out to the mixed liquor, so that
The removing of foreign ion that graphene oxide is combined and with complexing agent stable bond；Filtering, obtains graphene oxide after purification；
The step of graphene oxide to after purification carries out freeze-drying process include:
Graphene oxide after purification is dispersed in water, and forms graphene oxide hydrogel；By graphene oxide hydrogel
It is placed at the first temperature and the first pressure, molecule and sublimates so that the hydrone in graphene oxide hydrogel congeals into ice, from
And the graphene oxide with second number of plies is obtained, second number of plies is less than first number of plies, and first temperature is not
Higher than -50 DEG C and temperature change is no more than ± 4 DEG C, first pressure be lower than 1 atmospheric pressure and pressure change be no more than ±
100Pa；
It is described to low layer number graphene oxide carry out reduction treatment the step of include:
By low layer number graphene oxide sequence i-th reaction zone of experience and the n-th reaction zone, graphene is obtained, and will be described
The temperature and pressure of n-th reaction zone are controlled as TnAnd Pn, the temperature of i-th reaction zone and pressure are controlled as Ti
And Pi,
Wherein, Ti=w1·i/n·Tn, Pi=(P0-Pn) (1-i/n), wherein w1It is selected between 0.80~1.20, P0It is 1
Standard atmospheric pressure, TnAnd PnRespectively 1250 DEG C or more and 30Pa~500Pa, n is natural number and >=2, i gets owning less than n
Natural number.
2. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
Complexing agent includes citric acid, sodium citrate, sodium thiosulfate, sodium sulfite, sodium ethylene diamine tetracetate, polyacrylic acid, glucose
Sour sodium or sodium alginate.
3. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that institute's acid
Property solution pH be 0.1~6.
4. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
Filtration step includes being filtered by filter membrane, and suction filtration mechanism is arranged to carry out decompression suction filtration in the lower section of filter membrane.
5. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
First number of plies is 20~30 layers, and second number of plies is 5~7 layers.
6. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
First temperature selects within the scope of -55~-65 DEG C and temperature change is no more than ± 2 DEG C.
7. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
First pressure selects in the range of 10~100Pa and pressure change is no more than ± 10Pa.
8. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
The solid content of graphene oxide hydrogel is 0.1~50wt%.
9. the method according to claim 1 for preparing graphene using low layer number graphene oxide, which is characterized in that described
Include: to the step of low layer number graphene oxide progress reduction treatment
The feed bin sequence for being contained with first low layer number graphene oxide is undergone to the i-th reaction zone and n-th of the first reaction member
Reaction zone collects the graphene in the feed bin；
Second batch low layer number graphene oxide is held to the feed bin, and the jth for making its sequence undergo the second reaction member is reacted
Area and m reaction zone collect the graphene in the feed bin；
Third batch low layer number graphene oxide is held to the feed bin, and its sequence undergoes the i-th reaction zone of the first reaction member
With the n-th reaction zone, the graphene in the feed bin is collected, wherein
The temperature and pressure of n-th reaction zone are controlled as TnAnd Pn, the temperature and pressure of i-th reaction zone control respectively
It is made as TiAnd Pi, wherein Ti=w1·i/n·Tn, Pi=(P0-Pn) (1-i/n), wherein w1It is selected between 0.80~1.20,
P0For 1 standard atmospheric pressure, TnAnd PnRespectively 1250 DEG C or more and 30Pa~500Pa, n is natural number and >=2, i gets and is less than
All natural numbers of n；
The temperature and pressure of the m reaction zone are controlled as tmAnd Pm, the temperature and pressure of the jth reaction zone control respectively
It is made as tjAnd Pj, wherein tj=k1·j/m·tm, Pj=(P0-Pm) (1-j/m), wherein k1It is selected between 0.80~1.20,
P0For 1 standard atmospheric pressure, tmAnd PmRespectively 1250 DEG C or more and 30Pa~500Pa, m is natural number and >=2, j gets and is less than
All natural numbers of m.
10. the method according to claim 9 for preparing graphene using low layer number graphene oxide, which is characterized in that institute
Stating feed bin is graphite feed bin or the feed bin for being internally provided with graphite coating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811493454.1A CN109305671B (en) | 2018-12-07 | 2018-12-07 | Method for preparing graphene by using low-layer graphene oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811493454.1A CN109305671B (en) | 2018-12-07 | 2018-12-07 | Method for preparing graphene by using low-layer graphene oxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109305671A true CN109305671A (en) | 2019-02-05 |
| CN109305671B CN109305671B (en) | 2021-03-19 |
Family
ID=65223776
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811493454.1A Active CN109305671B (en) | 2018-12-07 | 2018-12-07 | Method for preparing graphene by using low-layer graphene oxide |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109305671B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103058179A (en) * | 2013-01-21 | 2013-04-24 | 张家港市东大工业技术研究院 | Method for preparing spongy graphene oxide by using freeze-drying method |
| CN103395780A (en) * | 2013-08-19 | 2013-11-20 | 济宁利特纳米技术有限责任公司 | Method for reducing manganese content in graphene oxide |
| CN106809821A (en) * | 2017-01-19 | 2017-06-09 | 广东烛光新能源科技有限公司 | The preparation method of Graphene |
| CN107815170A (en) * | 2017-11-07 | 2018-03-20 | 成都新柯力化工科技有限公司 | A kind of graphene coating masterbatch and preparation method |
-
2018
- 2018-12-07 CN CN201811493454.1A patent/CN109305671B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103058179A (en) * | 2013-01-21 | 2013-04-24 | 张家港市东大工业技术研究院 | Method for preparing spongy graphene oxide by using freeze-drying method |
| CN103395780A (en) * | 2013-08-19 | 2013-11-20 | 济宁利特纳米技术有限责任公司 | Method for reducing manganese content in graphene oxide |
| CN106809821A (en) * | 2017-01-19 | 2017-06-09 | 广东烛光新能源科技有限公司 | The preparation method of Graphene |
| CN107815170A (en) * | 2017-11-07 | 2018-03-20 | 成都新柯力化工科技有限公司 | A kind of graphene coating masterbatch and preparation method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109305671B (en) | 2021-03-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103407984A (en) | Carbon nano-tube purification method based on weak oxidizing atmosphere oxidation assisted acid treatment | |
| JPWO2006018985A1 (en) | Purification method of alkaline aqueous solution | |
| CN105197918A (en) | High-quality graphene and quick preparation method thereof | |
| CN111559743B (en) | Preparation method and application of graphene powder | |
| CN115057435B (en) | Method for preparing graphene oxide by recycling concentrated sulfuric acid and application of product obtained by method | |
| CN107699830A (en) | Method that is a kind of while improving industrially pure titanium intensity and plasticity | |
| CN109305671A (en) | A method of graphene is prepared using low layer number graphene oxide | |
| CN109305674A (en) | A method of graphene is prepared using low impurity content graphene oxide | |
| TW201422524A (en) | Low-temperature manufacturing method and system for spheroidal graphite | |
| CN109292762B (en) | Production method of low-structure-defect graphene | |
| CN106379896B (en) | A kind of graphene and preparation method thereof | |
| CN109292764B (en) | Preparation method of low-impurity-content graphene | |
| CN109264710B (en) | Method for improving quality of graphene oxide | |
| CN110282621B (en) | Preparation method of microcrystalline graphite negative electrode material with high cost performance | |
| CN109824036B (en) | Method for high-temperature carbonization of graphene of solid carbon material | |
| CN110743511A (en) | Preparation method of polysulfone resin-based lithium ion adsorption sieve membrane | |
| CN109437163B (en) | System for producing graphene through purification and continuous reduction | |
| CN109264699A (en) | A kind of low layer number graphene preparation method | |
| CN106756747B (en) | The preparation method of porous palladium material | |
| CN109264700A (en) | A method of graphene is prepared from graphene oxide | |
| CN115304064A (en) | Production method and application of physical activated carbon | |
| CN105712317B (en) | A kind of preparation method of the carbon material containing hollow nano | |
| CN110526238A (en) | The preparation method of redox graphene and the intermediate processing of graphene oxide colloidal sol | |
| CN112777600B (en) | Ultra-pure quartz and preparation method thereof | |
| CN111252769A (en) | Preparation method of solar polycrystalline silicon |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |