CN105565297A - Graphene quantum dot prepared from tip surface of carbon fiber through electrochemical oxidation and cutting, and preparation method thereof - Google Patents
Graphene quantum dot prepared from tip surface of carbon fiber through electrochemical oxidation and cutting, and preparation method thereof Download PDFInfo
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Abstract
The invention provides a graphene quantum dot prepared from the tip surface of a carbon fiber through electrochemical oxidation and cutting, and a preparation method thereof. The method comprises the following steps: respectively connecting the carbon fiber used as a positive electrode and an inert electrode used as a negative electrode with the positive electrode and the negative electrode of a direct-current power source; totally immersing the inert electrode in an electrolyte solution; contacting the tip surface of the carbon fiber with the liquid level of the electrolyte solution before energization; allowing the working zone of the tip surface of the carbon fiber to be located in a range of 3 mm lower than the liquid level of the electrolyte solution to 5 mm higher than the liquid level of the electrolyte solution during energization; and discontinuously or continuously controlling the tip surface of the carbon fiber to be located in the working zone so as to allow a microcrystalline graphite flake layer on the tip surface of the carbon fiber to be expanded and dissociated through electrochemical oxidation and to be cut into graphene quantum dots. The graphene quantum dot prepared in the invention has a layer number of 1 to 10 and a particle size of 1 to 100 nm. The preparation method has higher oxidative expansion and dissociation capability and cutting capability and realizes preparation of the graphene quantum dot with a smaller layer number, uniform particle size distribution and a smaller particle size.
Description
Technical field
The invention belongs to technical field of nanometer material preparation, be specially the method that a kind of electrochemical oxidation cutting carbon fiber tip surface prepares graphene quantum dot, and then obtain a series of graphene quantum dot with different nano-scale, different carbon/oxygen ratio and different qualities.
Background technology
Graphene be a kind of by carbon atom with sp
2two dimension (2D) hexangle type of hybridized orbital composition is the planar monolayer of honeycomb lattice, and is the basic building module of other dimension graphite materials all.It can be packaged into the soccerballene of zero dimension (0D), is rolled into the nanotube of one dimension (1D) or is stacked into the graphite of three-dimensional (3D).Graphene is the thinnest in the world is at present the hardest nano material also, and it is almost completely transparent, only absorbs the light of 2.3%; Thermal conductivity is up to 5300W/mK, and higher than carbon nanotube and diamond, under normal temperature, its electronic mobility is more than 15000cm
2/ Vs, far above carbon nanotube or silicon crystal, and its resistivity only has 10
-6Ω cm, than copper or silver lower, be the material that at present resistivity is minimum in the world.Because its resistivity is extremely low, electric transmission speed is exceedingly fast, and is therefore expected to for development conduction rate electronic component of new generation or transistor faster.Graphene is in fact also a kind of transparent, good conductor, is applicable to very much for manufacturing transparent touch-sensitive panel, tabula rasa or even solar cell.Graphene also has an important characteristic, can observe quantum hall effect at normal temperatures, and the further investigation therefore in its field plays special effect by the development of future electronic device, and can be used for the high-speed electronic components preparing less energy-consumption.
Graphene quantum dot (Graphenequantumdot, GQD) is the nano material of accurate zero dimension, and the motion of its internal electron in all directions is all limited to, so quantum local effect is remarkable especially, has the character of many uniquenesses.It is compared with traditional semiconductor-quantum-point, and novel graphene quantum dot has following unique character: 1) do not contain highly toxic metallic element as cadmium, lead etc., belong to environment-friendly type quanta point material; 2) structure is highly stable, resistance to strong acid, highly basic, resistance to photoetch (conventional semiconductors quantum dot is applied to photoelectrochemicalcell cell and easily photoxidation occurs, and causes degradation and low device lifetime); 3) thickness can be thinned to monoatomic layer, and widthwise size can be reduced to the size of a phenyl ring, but still keeps the chemical stability of height; 4) band gap width scope is adjustable, regulate within the scope of 0-5eV by quantum local effect and side effect in principle, thus wavelength region is expanded to visible ray and dark purple outskirt from infrared region, meet the particular requirement of various technology to material energy gap and characteristic wavelength; 5) easily realize surface-functionalized, Absorbable organic halogens is scattered in common solvents, meets the demand of material low cost processing treatment.This maybe will bring revolutionary change for electronics, photoelectricity and electromagnetism field.It can be applied to the aspects such as solar cell, electronics, optical dye, biomarker and multiple microparticles system.Graphene quantum dot has important potential application in fields such as biology, medical science, material, semiconductor devices.It can realize monomolecular sensor, the chip communication that also may expedite the emergence of subminiature transistor or utilize semiconductor laser to carry out, and is used for making chemical sensor, solar cell, medical imaging apparatus or nanoscale circuit etc.
From size, graphene quantum dot and Graphene something in common are thickness to be individual layer or few layer (is no more than 10 layers, the thickness of every layer is at about 0.34-0.40nm), difference is varying in size on planar orientation, the former is less than 100nm, and latter is more than micron order yardstick.The former preparation difficult point is how to obtain less nano level quantum dot, and the preparation difficult point of the latter is that the number of plies controls.This causes the two in the selection and preparation method of raw material, there is very large difference.Such as top-down preparation method, from raw material, the former adopts microcrystalline carbon material advantageously, the crystallite yardstick of such as carbon fiber only has tens nanometer (" carbon fiber and graphite fibre ", He Fu writes, Beijing: Chemical Industry Press, 2010), as long as therefore suitable being easy to of dissociating method obtains graphene quantum dot, difficult point in preparation method be how as far as possible by each crystallite from body mutually independently cut out, then relatively be easy to (to only have few tens of nanometers based on microwafer footpath and thickness as obtaining individual layer yardstick, interlayer Van der Waals force is less), and the latter adopts and high-graphitized has large stretch of layer crystal body structure carbon material advantageously, such as crystalline flake graphite, difficult point in preparation method is how independently to be cut out from crystalline phase by each lamella as far as possible (the interlayer Van der Waals force based on large size graphite crystal is larger), then relatively easy as the big scale obtaining planar orientation, therefore the product that the top-down preparation method of current existing employing often obtains is (as US7658901 based on the few layer of big scale or multi-layer graphene, CN103935999A, preparation method in CN101634032A), and adopt preparation method from bottom to top to obtain the single-layer graphene of big scale more relatively easily, such as CVD chemical gaseous phase depositing process (preparation method as in US2009110627A1), but batch preparation is a difficult point.
The main angle from materialogy below, the thinking continued to use from top to bottom and from bottom to top introduces existing graphene quantum dot preparation method.Top-to-bottom method refers to, by physics or chemical process, large-sized graphene platelet is cut into undersized graphene quantum dot.Such as: CN102660270A " solvent-thermal method prepares the method for fluorescence graphene quantum dot " first prepares graphene oxide, then utilize solvent thermal that graphene oxide is cut into quantum dot, CN102616774A " a kind of method preparing graphene quantum dot " adds amine passivator at hydro-thermal cutting process, and their shortcoming is high heat, high energy, yields poorly; CN102336404A " preparation method based on the graphene oxide quantum dot of photochemical catalytic oxidation ", graphene oxide quantum dot is prepared in conjunction with uv-radiation under ultrasonic, hydrogen peroxide and catalyst action, quantum dot distribution prepared by this method is improved, but be difficult to the preparation carrying out high yield, and quantum dot shape and edge pattern are difficult to control; The Facilesynthesisofwater-soluble of Electrochemicalpreparationofluminescentgraphenequantumdo tsfrommultiwalledcarbonnanotubes and J.Mater.Chem. of Chem.Eur.J. in 2012, highlyfluorescentgraphenequantumdotsasarobustbiologicall abelforstemcells, electrochemical stripping is adopted to prepare water-soluble good graphene quantum dot, the length consuming time but early stage of starting material graphite deals with the work, later-period purification step is consuming time also longer, and product yield is not high; The Graphene that CN102208755A " method of UV-light etching dry process graphene quantum dot " utilizes UV-light to etch on sheet mica obtains graphene quantum dot, the shortcoming of this method be have radiation, power consumption is large, preparation amount is little; The Graphenequantumdotsatroomtemperaturecarvedoutfromfew-lay ergraphene that NanoLetter in 2012 delivers, the Graphene adopting electron beam lithography to obtain prepares graphene quantum dot.These methods all through oxidization-reduction, then are cut, and a point a few step is carried out, and preparation process is numerous and diverse, and the cycle is long, yields poorly, and condition is harsh, are difficult to promote.CN103265020A " a kind of method of macroscopic preparation of graphene quantum dot powder " is from natural flake graphite, the first step changes natural flake graphite into graphite nanoparticles, graphite nanoparticles is changed into single order intercalation nano graphite oxide by second step, single order intercalation nano graphite oxide is placed in non-tight crucible with cover by the 3rd step, thermal treatment obtains graphene quantum dot powder in atmosphere, a large amount of strong acid and strong oxidizer to be used in second step, whole preparation process is complicated, length consuming time, seriously polluted, particle diameter and number of plies distributed controll poor, and the 3rd step thermal treatment product hydrophilicity can be caused to be deteriorated.In addition, also be used with the preparation method that microcrystalline carbon material is carbon source: the Graphenequantumdotsderivedfromcarbonfibers that NanoLetter in 2012 delivers, employing carbon fiber is carbon source, by acid treatment, the graphite of stacking in fiber is peeled off, only a step just can obtain the graphene quantum dot of a large amount of different-grain diameter distribution, this method advantage is that step is simple and raw material is cheap, but shortcoming is preparation process will use a large amount of sulfuric acid and nitric acid, length consuming time, seriously polluted, and particle size distribution range is very wide, follow-up dialysis separating treatment is needed to obtain less granularity, cause effectively preparing productive rate low, the One-stepandhighyieldsimultaneouspreparationofsingle-andm ulti-layergraphenequantumdotsfromCX-72carbonblack that J.Mater.Chem. in 2012 delivers, use 30nm carbon black pellet as raw material, at HNO
3in long-time high temperature reflux, the then centrifugal graphene quantum dot obtaining two kinds of sizes, but carbon black feed stock complex structure, non-sp
2structure is many, therefore makes the quantum dot defect that obtains many, poor product quality.
Bottom-to-top method then refers to that making precursor with small molecules prepares graphene quantum dot by series of chemical.CN103320125A " preparation method of multicolor fluorescence graphene quantum dot material " selects pyrene to be precursor, at low temperatures oxygen functionalization is carried out on the surface of pyrene crystal grain, then carry out under the effect of catalyzer hydrazine hydrate and ammoniacal liquor the hydro-thermal dehydrogenation of low temperature, growth and original position surface-functionalized.Generally speaking, the most controllability of bottom-to-top method is comparatively strong, but complex steps troublesome poeration, productive rate is lower, and the synthetic method not still being applicable to industrial volume production at present occurs.
In sum, exploitation one is taken into account that particle diameter is little, the number of plies is low and distributes controlled, abundant raw material source and inexpensive, production unit is simple, preparation process is simple and easy, it is low to consume energy, production efficiency is high, productive rate is high and free of contamination can the preparation method of high-quality graphene quantum dot of industrial volume production, be still in technical field of nanometer material preparation the key issue being badly in need of solving.
Summary of the invention
For solving the problems of the technologies described above, the graphene quantum dot that the object of the present invention is to provide a kind of electrochemical oxidation cutting carbon fiber tip surface to prepare and method thereof.Graphene quantum dot preparation method of the present invention has higher oxidation compared to Conventional electrochemical preparation method and expands and dissociate and cutting power, can realize that the number of plies is lower, the preparation of even particle size distribution and the less graphene quantum dot of size.
For achieving the above object, the invention provides the method that a kind of electrochemical oxidation cutting carbon fiber tip surface prepares graphene quantum dot, it comprises the following steps:
Using a flocked carbon fibers (monofilament or multifibres) as anode, using a noble electrode as negative electrode, be connected with the positive pole of direct supply, negative pole respectively;
Described noble electrode is dipped in entirely in an electrolyte solution;
The working face of carbon fibre anode is made up of neat tow tip surface, contacts before energising by parallel with described electrolyte solution liquid level for carbon fiber tip surface;
Then start energising, during energising, the operation interval of carbon fiber tip surface is positioned at the scope to the-3mm of top to 5mm below electrolyte solution liquid level;
Be in described operation interval by being interrupted or controlling carbon fiber tip surface continuously, make the micro crystal graphite lamella on carbon fiber tip surface be electrochemically oxidized expansion dissociate and cut into graphene quantum dot, and be dissolved in described electrolyte solution, obtain graphene quantum dot solution.
In the methods described above, preferably, selected material carbon fiber is made up of micro crystal graphite laminated structure, crystallite three-dimensional dimension is at 10-100nm, micro crystal graphite lamellar orientation is not less than 60% compared to fibre axis orientation, be through the conductive carbon material of the different shape that high temperature cabonization obtains, the filament diameter of tow is 1-15 μm.Micro crystal graphite lamella size is little, is conducive to the effect of subsequent electrochemical oxygen cutting, makes it be dissociated into the graphene quantum dot of 1-10 layer, particle diameter 1-100nm; And high orientation is conducive to Electrochemical Cutting process controls for the size and dimension of graphene quantum dot; The carbon fiber guiding obtained through high temperature cabonization is electrically good, is conducive to the electric transmission needed for electrochemical oxidation and cutting process, is also conducive to reducing the fever phenomenon in preparation process; Tow shape form be conducive to distribution of current evenly, be also conducive to electric current and directly act on each microlitic structure and complete oxidation and cutting process fast, and regular form can prevent the uncontrolled fracture of wire of fiber, is favourable for the effective productive rate improving product.
In above-mentioned preparation process, using a flocked carbon fibers as anode, using a noble electrode as negative electrode, respectively with the positive pole of direct supply, negative pole is connected, wherein noble electrode is dipped in the electrolyte solution of electrolyzer entirely, and carbon fibre anode working face is neat tow tip surface composition, should by parallel with electrolyte solution liquid level for carbon fiber tip surface contact (error allowing tip surface to enter solution be that relative liquid surface is no more than 3mm) before energising, under surface tension and anodic oxidation generate the mechanical effect of bubble, occur that liquid level climbs after energising, cause carbon fiber tip surface also can be operated in the top of the electrolyte solution liquid level before energising, during energising, the operation interval of carbon fiber tip surface is positioned at below electrolyte solution liquid level that (negative value represents below liquid level to the-3mm of top to 5mm, on the occasion of expression at ullage) in scope, above-mentioned energising liquid level mobile working interval is in by being interrupted or controlling carbon fiber tip surface continuously, micro crystal graphite lamella on carbon fiber tip surface is electrochemically oxidized expand to dissociate and cut into the graphene quantum dot of 1-10 layer, particle diameter 1-100nm, and is dissolved in electrolyte solution, also further graphene quantum dot can be separated with solution, obtain colloidal attitude or solid-state graphene quantum dot.This preparation method is different from traditional electrochemistry preparation process, current concentration can be acted on a very little region by it, not only achieve being uniformly distributed of current density, avoid working electrode different sites (end face in Conventional electrochemical preparation method, side, in solution, liquid level place) due to uneven the caused fracture of wire of electric current distribution, product form and size difference problem, and obtain high energy density, compared to Conventional electrochemical preparation method, there is higher oxidation expansion to dissociate and cutting power, thus it is lower to achieve the number of plies, grain size is less, be more evenly distributed, size is controlled, the preparation of the graphene quantum dot of high-yield quick.
In the methods described above, preferably, described carbon fiber can be the one in PAN-based carbon fiber, asphalt base carbon fiber, viscose-based carbon fiber and graphite fibre.
In the methods described above, preferably, described noble electrode is the conductive electrode with potential resistance to electrolyte contamination solution corrosion; More preferably, described noble electrode can be the one in conventional stainless steel, titanium, platinum, nickel-base alloy, copper, lead, graphite and titanium supported oxide electrode.
In the methods described above, preferably, described electrolyte solution is the solution with ion conductivity, and the specific conductivity of this electrolyte solution is not less than 10mS/cm.The too low meeting of electrical conductivity of solution is that electro-chemical machining efficiency is reduced, and solution temperature rise is too fast, and energy consumption increases, and quality product declines.
In the methods described above, preferably, described electrochemical oxidation cutting process electrochemical control parameter be the operating voltage of direct supply not higher than 80V, be 1-30A/cm relative to the working current density on carbon fiber tip surface
2, can be constant voltage or constant current output control mode meeting direct supply under working current density requirement.Working volts direct current are in order to the enough working current requirements of satisfied output.The low meeting of working current density on carbon fiber tip surface causes oxygen cutting ability to decline, and not only efficiency is low, also can affect the quality of product; Although working current density is high can improve oxygen cutting ability, too high meeting causes the ablation of carbon fiber, and solution temperature rise is seriously decomposed even in a large number, and productive rate declines, and energy consumption increases, and then affects the quality of product.
According to the specific embodiment of the present invention, preferably, aforesaid method is further comprising the steps of: by described graphene quantum dot solution by vacuum filtration and/or dialysis treatment to narrow the size distribution of graphene quantum dot further.
According to the specific embodiment of the present invention, preferably, aforesaid method is further comprising the steps of: be separated with liquid by the graphene quantum dot in described graphene quantum dot solution, obtains colloidal attitude or solid-state graphene quantum dot.More preferably, the method that the graphene quantum dot in described graphene quantum dot solution and liquid carry out being separated is comprised the combination of one or more in centrifugal, vacuum-drying and lyophilize.
In the methods described above, preferably, the productive rate of preparing of described 1-10 layer, the graphene quantum dot of particle diameter 1-100nm is not less than 90%.
In the methods described above, preferably, the carbon/Sauerstoffatom of the graphene quantum dot prepared is than being 2:1-20:1.
According to the specific embodiment of the present invention, preferably, aforesaid method is further comprising the steps of: processed by one or more in liquid phase chemical reduction and electrochemical reduction, thermal reduction, ultraviolet irradiation reduction, microwave reduction, active metal reduction and vapour phase reduction to improve carbon/Sauerstoffatom ratio further by described graphene quantum dot (solution or colloidal attitude or solid-state).
In the methods described above, preferably, when adopting PAN-based carbon fiber to be raw material, the graphene quantum dot obtained contains N doping, and nitrogen-atoms is 1-6% than content (atom number content).
Graphene quantum dot preparation method of the present invention has higher oxidation compared to Conventional electrochemical preparation method and expands and dissociate and cutting power, thus achieves that the number of plies is lower, grain size is less, be more evenly distributed, size is controlled, the preparation of the graphene quantum dot of high-yield quick.
The present invention also provides a kind of graphene quantum dot, and it cuts carbon fiber tip surface by above-mentioned electrochemical oxidation to prepare the method for graphene quantum dot preparation-obtained.
According to the specific embodiment of the present invention, preferably, described graphene quantum dot is the graphene quantum dot of 1-10 layer, particle diameter 1-100nm.
According to the specific embodiment of the present invention, preferably, the carbon/Sauerstoffatom of described graphene quantum dot is than being 2:1-20:1.
According to the specific embodiment of the present invention, preferably, described graphene quantum dot contains N doping, and nitrogen-atoms is 1-6% than content.
Graphene quantum dot preparation method of the present invention has higher oxidation expansion compared to Conventional electrochemical preparation method and dissociates and cutting power, that one has that particle diameter is little, the number of plies is low simultaneously and distributes controlled, abundant raw material source and inexpensive, production unit is simple, preparation process is simple and easy, it is low to consume energy, production efficiency is high, productive rate is high and free of contamination can the preparation method of high-quality graphene quantum dot of the advantage such as industrial volume production.
Accompanying drawing explanation
Fig. 1 is the Method And Principle schematic diagram that electrochemical oxidation provided by the invention cutting carbon fiber tip surface prepares graphene quantum dot;
Fig. 2 is the microlitic structure schematic diagram on the carbon fibre tow that adopts of the present invention and its monofilament;
The atomic force microscope images of the graphene quantum dot that Fig. 3 a provides for embodiment 1;
The Elevation Analysis curve of the graphene quantum dot that Fig. 3 b provides for embodiment 1;
The grain size distribution curve of the graphene quantum dot that Fig. 4 provides for embodiment 1;
The uv absorption spectra of the graphene quantum dot that Fig. 5 provides for embodiment 1;
The fluorescence spectrum figure of the graphene quantum dot that Fig. 6 provides for embodiment 1.
Primary clustering nomenclature:
Anode 1 negative electrode 2 direct supply 3 electrolyzer 4 electrolyte solution 5 tow tip surface 6 bubble 7 climbs liquid level 8 graphene quantum dot 9
Embodiment
In order to there be understanding clearly to technical characteristic of the present invention, object and beneficial effect, existing following detailed description is carried out to technical scheme of the present invention, but can not be interpreted as to of the present invention can the restriction of practical range.
Electrochemical oxidation cutting carbon fiber tip surface provided by the invention prepares the Method And Principle schematic diagram of graphene quantum dot as shown in Figure 1, using a tow carbon fiber as anode 1, using a noble electrode as negative electrode 2, respectively with the positive pole of direct supply 3, negative pole is connected, wherein noble electrode is dipped in the electrolyte solution 5 of electrolyzer 4 entirely, and carbon fibre anode working face is neat tow tip surface 6 forms, should contact parallel with electrolyte solution liquid level for carbon fiber tip surface before energising, under surface tension and anode generate the mechanical effect of bubble 7, the liquid level 8 that climbs has been there is after energising, carbon fiber tip surface also can be operated in the top of electrolyte solution liquid level, during energising, the operation interval of carbon fiber tip surface to be positioned at below electrolyte solution liquid level the scope to the-3mm of top to 5mm, above-mentioned energising liquid level mobile working interval is in by being interrupted or controlling carbon fiber tip surface continuously, micro crystal graphite lamella on carbon fiber tip surface is electrochemically oxidized expand to dissociate and cut into the graphene quantum dot 9 of 1-10 layer, particle diameter 1-100nm, and be dissolved in electrolyte solution, thus obtain graphene quantum dot solution.Wherein said carbon fibre tow and the microlitic structure schematic diagram on its monofilament are as shown in Figure 2, the material carbon fiber selected is made up of micro crystal graphite laminated structure, crystallite three-dimensional dimension is at 10-100nm, micro crystal graphite lamellar orientation is not less than 60% compared to fibre axis orientation, be through the conductive carbon material of the different shape that high temperature cabonization obtains, preferred tow shape form, filament diameter is 1-15 μm.
Below by embodiment, technical scheme of the present invention is further described.
Embodiment 1
With T30012K (12000 monofilament) PAN-based carbon fiber tow for raw material, the filament diameter of this carbon fiber is 7 μm, it is made up of micro crystal graphite laminated structure, and crystallite three-dimensional dimension is at 10-40nm, and micro crystal graphite lamellar orientation is oriented to 80% compared to fibre axis.The tip surface of above-mentioned 78 bundle carbon fibre tows is had one's hair trimmed, and is vertically placed in and fills above electrolyzer that concentration is 0.5M aqueous sodium hydroxide solution, be connected with the positive pole of direct supply as anode; Be 100cm by an area again
2sS304 stainless (steel) wire be entirely dipped in solution, be connected with the negative pole of direct supply as negative electrode; The tip surface carefully regulating carbon fibre tow neat before energising and the parallel distance of liquid level of solution, be as the criterion just to touch liquid level, the error allowing tip surface to enter solution is that relative liquid surface is no more than 3mm; Open direct supply subsequently, control constant voltage 32V, start working, anode has a large amount of bubble formation, under surface tension and anodic oxidation generate the effect of bubble, visible solution climbs, now also adjustable carbon fiber tip surface is no more than the operated within range of 5mm at ullage, and now the working current density fluctuation range of opposite tip face area is 1-10A/cm
2; Along with the carrying out of electrolytic process is when current density is lower than 1A/cm
2time (phenomenon is that tip surface and liquid level distance widen), can regulate further tip surface and liquid level distance that electrolytic process is carried out continuously, also tip surface can first be tuned up and liquid level distance makes to have no progeny in reaction, again further tip surface and liquid level distance again at-3mm to 5mm operated within range, thus realize the intermitten service of electrolytic process; Along with the carrying out of electrolytic process, micro crystal graphite lamella on carbon fibre tow tip surface is electrochemically oxidized expansion and dissociates and cut, continuous dissolving enters into solution, solution colour change in time gradually by yellowish, bright orange, dark yellow, yellowish-brown to chocolate, the corresponding graphene quantum dot concentration generated increases gradually, finally obtains concentration not higher than the graphene quantum dot solution of 10mg/mL.
Graphene quantum dot solution obtained above is transferred on smooth silicon chip, atomic force microscope observation is carried out after seasoning, as Fig. 3 a and Fig. 3 b, quantum dot maximum height is 0.706nm, be equivalent to the thickness of two layer graphenes, its size distribution center line average is 0.339nm, is equivalent to the height of single-layer graphene, and distribution is more even.Graphene quantum dot solution obtained above is directly carried out the analysis of dynamic light scattering (DLS) size distribution, as Fig. 4, obtaining its particle size distribution range is 10-20nm, and distributed area is narrower; Carry out ultraviolet absorption spectroscopy further, as Fig. 5, there is significant optical absorption characteristics in it as seen; And then by fluorescent spectroscopy, as Fig. 6, under excitation wavelength is 480nm, its emission wavelength is 540nm; By graphene quantum dot solution obtained above through 2000D film dialysis treatment, obtain the graphene quantum dot solution of size distribution 5-10nm.By the graphene quantum dot solution of size distribution 5-10nm obtained above by obtaining gluey graphene quantum dot after vacuum-drying, by its further under nitrogen protection 500 DEG C of thermal reductions obtain solid-state graphene quantum dot powder, photoelectron spectrum (XPS) analysis obtains its carbon/oxygen and compares 11:1; XPS shows it also containing nitrogen element, and nitrogen-atoms is 2.6% than content, and this is that the graphene quantum dot therefore obtained here is containing N doping because PAN-based carbon fiber raw material is inherently containing nitrogen element.By the weightless quality of relatively obtained graphene quantum dot quality and carbon fibre tow, the productive rate of preparing obtaining graphene quantum dot is 93%.
Embodiment 2
Be with the Main Differences of embodiment 1: with T70012K PAN-based carbon fiber tow for raw material, the filament diameter of this carbon fiber is 7 μm, it is made up of micro crystal graphite laminated structure, and crystallite three-dimensional dimension is at 15-50nm, and micro crystal graphite lamellar orientation is oriented to 90% compared to fibre axis; The electrolyte solution adopted is 0.5M volatile salt; Negative electrode is 100cm
2nickel sheet; Control constant voltage 40V, working current density fluctuation range is 1-20A/cm
2.The graphene quantum dot obtained is 1-2 layer, and particle size distribution range is 7-15nm.By graphene quantum dot solution obtained above by obtaining spongiform solid graphite alkene quantum dot after lyophilize.In graphene quantum dot solution obtained above, add hydrazine hydrate reduction obtain reduction state graphene quantum dot, its carbon/oxygen brings up to 20:1 than by the 3:1 before not reducing.The productive rate of preparing of graphene quantum dot is 95%.
Embodiment 3
Be with the Main Differences of embodiment 2: adopt current constant control mode, working current density is 15A/cm
2, scope range of the fluctuation of voltage is 30-50V.The graphene quantum dot obtained is 1-2 layer, and particle size distribution range is 5-10nm, and without the carbon/oxygen reduced than 9:1, preparing productive rate is 98%.
Embodiment 4
Be with the Main Differences of embodiment 1: restraint M55J3K celion tow for raw material with 100, the filament diameter of this carbon fiber is 5 μm, it is made up of micro crystal graphite laminated structure, and crystallite three-dimensional dimension is at 30-80nm, and micro crystal graphite lamellar orientation is oriented to 99% compared to fibre axis; The electrolyte solution adopted is 0.2M sulfuric acid; Negative electrode is 200cm
2tA2 titanium net; Adopt current constant control mode, working current density is 25A/cm
2, scope range of the fluctuation of voltage is 50-80V.The graphene quantum dot obtained is 1-2 layer, and particle size distribution range is 15-25nm, and without the carbon/oxygen reduced than 15:1, preparing productive rate is 96%.
Embodiment 5
Be with the Main Differences of embodiment 1: restraint HM1104K asphalt base carbon fiber tow for raw material with 220, the filament diameter of this carbon fiber is 10 μm, it is made up of micro crystal graphite laminated structure, and crystallite three-dimensional dimension is at 50-100nm, and micro crystal graphite lamellar orientation is oriented to 98% compared to fibre axis; The electrolyte solution adopted is 1.0M sodium sulfate; Negative electrode is 50cm
2netted titanium base iridium oxide coated electrode; Adopt current constant control mode, working current density is 10A/cm
2, scope range of the fluctuation of voltage is 20-50V.The graphene quantum dot obtained is 1-2 layer, and particle size distribution range is 3-7nm, and without the carbon/oxygen reduced than 5:1, preparing productive rate is 93%.
Embodiment 6
Be with the Main Differences of embodiment 5: the electrolyte solution of employing is the mixed solution of 1.0M sodium sulfate and 0.1M sulfuric acid; Adopt current constant control mode, working current density is 3A/cm
2, scope range of the fluctuation of voltage is 10-20V.The graphene quantum dot obtained is layer 2-4, and particle size distribution range is 30-50nm, and without the carbon/oxygen reduced than 2:1, preparing productive rate is 90%.
Finally, the graphene quantum dot obtained by the embodiment of the present invention 5, embodiment 3 and embodiment 1 is irradiated by burst of ultraviolel optical wavelength 365nm in aqueous, can show blueness, green and yellow fluorescence (this may be relevant with the size distribution of graphene quantum dot) respectively.
Claims (10)
1. electrochemical oxidation cutting carbon fiber tip surface prepares a method for graphene quantum dot, and it comprises the following steps:
Using a flocked carbon fibers as anode, using a noble electrode as negative electrode, be connected with the positive pole of direct supply, negative pole respectively;
Described noble electrode is dipped in entirely in an electrolyte solution;
The working face of carbon fibre anode is made up of neat tow tip surface, contacts before energising by parallel with described electrolyte solution liquid level for carbon fiber tip surface;
Then start energising, during energising, the operation interval of carbon fiber tip surface is positioned at the scope to the-3mm of top to 5mm below electrolyte solution liquid level;
Be in described operation interval by being interrupted or controlling carbon fiber tip surface continuously, make the micro crystal graphite lamella on carbon fiber tip surface be electrochemically oxidized expansion dissociate and cut into graphene quantum dot, and be dissolved in described electrolyte solution, obtain graphene quantum dot solution.
2. method according to claim 1, it is further comprising the steps of: by described graphene quantum dot solution by vacuum filtration and/or dialysis treatment to narrow the size distribution of graphene quantum dot further.
3. method according to claim 1 and 2, it is further comprising the steps of: be separated with liquid by the graphene quantum dot in described graphene quantum dot solution, obtains colloidal attitude or solid-state graphene quantum dot; Preferably, the method that the graphene quantum dot in described graphene quantum dot solution and liquid carry out being separated is comprised the combination of one or more in centrifugal, vacuum-drying and lyophilize.
4. the method according to any one of claim 1-3, it is further comprising the steps of: processed by one or more in liquid phase chemical reduction and electrochemical reduction, thermal reduction, ultraviolet irradiation reduction, microwave reduction, active metal reduction and vapour phase reduction to improve carbon/Sauerstoffatom ratio further by described graphene quantum dot.
5. method according to claim 1, wherein, described carbon fiber is made up of micro crystal graphite lamella, the three-dimensional dimension of described micro crystal graphite lamella is 10-100nm, described micro crystal graphite lamellar orientation is not less than 60% compared to carbon fiber axle orientation, and described carbon fiber is through the conductive carbon fibre that high temperature cabonization obtains, be the one in PAN-based carbon fiber, asphalt base carbon fiber, viscose-based carbon fiber and graphite fibre, the filament diameter of tow is 1-15 μm.
6. method according to claim 1, wherein, described noble electrode is the conductive electrode with potential resistance to electrolyte contamination solution corrosion; Preferably, described noble electrode is the one in stainless steel, titanium, platinum, nickel-base alloy, copper, lead, graphite and titanium supported oxide electrode.
7. method according to claim 1, wherein, described electrolyte solution is the solution with ion conductivity, and the specific conductivity of this electrolyte solution is not less than 10mS/cm.
8. method according to claim 1, wherein, the operating voltage of described direct supply, not higher than 80V, is 1-30A/cm relative to the working current density on carbon fiber tip surface
2, described direct supply is constant voltage or constant current output control mode.
9. a graphene quantum dot, it is preparation-obtained that it is that electrochemical oxidation cutting carbon fiber tip surface according to any one of claim 1-8 prepares the method for graphene quantum dot, it is the graphene quantum dot of 1-10 layer, particle diameter 1-100nm, and its carbon/Sauerstoffatom is than being 2:1-20:1.
10. graphene quantum dot according to claim 9, it contains N doping, and nitrogen-atoms is 1-6% than content.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018028004A1 (en) * | 2016-08-10 | 2018-02-15 | 玉灵华科技有限公司 | Quantum carbon and method and device for producing same |
| CN108977198A (en) * | 2018-07-12 | 2018-12-11 | 北京林业大学 | A kind of method that lignin prepares single crystal graphene quantum dot |
| WO2019028803A1 (en) * | 2017-08-11 | 2019-02-14 | 徐海波 | Method and device for electrochemically preparing graphene oxide |
| CN109594097A (en) * | 2018-12-14 | 2019-04-09 | 上海大学 | The method of graphene quantum dot is prepared under electric field and ultrasonic field coupling |
| CN110589813A (en) * | 2019-10-08 | 2019-12-20 | 杭州高烯科技有限公司 | Preparation method of three-dimensional graphene |
| CN110607174A (en) * | 2019-09-17 | 2019-12-24 | 杭州高烯科技有限公司 | Preparation method of graphene carbon dots |
| CN111864203A (en) * | 2019-04-28 | 2020-10-30 | 中国科学院上海硅酸盐研究所 | High-capacitance lithium-carbon negative electrode material and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014081117A1 (en) * | 2012-11-21 | 2014-05-30 | 주식회사 그래핀올 | Method for forming graphene quantum dot |
| CN103935998A (en) * | 2014-05-09 | 2014-07-23 | 中国科学院上海微***与信息技术研究所 | Preparation method of graphene water solution |
| CN104003379A (en) * | 2014-05-30 | 2014-08-27 | 中国工程物理研究院化工材料研究所 | Preparation method of graphene quantum dot |
-
2014
- 2014-10-13 CN CN201410538019.1A patent/CN105565297B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014081117A1 (en) * | 2012-11-21 | 2014-05-30 | 주식회사 그래핀올 | Method for forming graphene quantum dot |
| CN103935998A (en) * | 2014-05-09 | 2014-07-23 | 中国科学院上海微***与信息技术研究所 | Preparation method of graphene water solution |
| CN104003379A (en) * | 2014-05-30 | 2014-08-27 | 中国工程物理研究院化工材料研究所 | Preparation method of graphene quantum dot |
Non-Patent Citations (1)
| Title |
|---|
| YAN LI ET AL.，: "Nitrogen-Doped Graphene Quantum Dots with Oxygen-Rich Functional Groups", 《JOURNAL OF THE AMERICAN CHEMICAL SOCIETY》 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018028004A1 (en) * | 2016-08-10 | 2018-02-15 | 玉灵华科技有限公司 | Quantum carbon and method and device for producing same |
| WO2019028803A1 (en) * | 2017-08-11 | 2019-02-14 | 徐海波 | Method and device for electrochemically preparing graphene oxide |
| CN108977198A (en) * | 2018-07-12 | 2018-12-11 | 北京林业大学 | A kind of method that lignin prepares single crystal graphene quantum dot |
| CN109594097A (en) * | 2018-12-14 | 2019-04-09 | 上海大学 | The method of graphene quantum dot is prepared under electric field and ultrasonic field coupling |
| CN111864203A (en) * | 2019-04-28 | 2020-10-30 | 中国科学院上海硅酸盐研究所 | High-capacitance lithium-carbon negative electrode material and preparation method and application thereof |
| CN110607174A (en) * | 2019-09-17 | 2019-12-24 | 杭州高烯科技有限公司 | Preparation method of graphene carbon dots |
| CN110607174B (en) * | 2019-09-17 | 2022-11-25 | 杭州高烯科技有限公司 | Preparation method of graphene carbon dots |
| CN110589813A (en) * | 2019-10-08 | 2019-12-20 | 杭州高烯科技有限公司 | Preparation method of three-dimensional graphene |
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