A kind of preparation method of graphene oxide/nano-gold particulate composite material with mono-atomic thickness
Technical field
The present invention relates to Graphene preparation field, is a kind of preparation method of graphene oxide/nano-gold particulate composite material with mono-atomic thickness.
Background technology
Graphene, since University of Manchester in 2004 finds that it has excellent physicals, has been subject to extensive concern in fields such as physics, chemistry.Graphene, as a kind of honeycomb reticulated structure of monolayer carbon atom, can be considered to extensively be present in a lot of carbon-based materials.As graphite can be seen as the accumulation of graphene sheet layer, although these graphene sheet layers are to be deposited in together by faint intermolecular forces in graphite, this makes it carry out easily interlayer to move, but these a large amount of weak intermolecular forces make it still be difficult to be isolated completely each other graphene sheet layer.From the researchist K.S.Novoselov of The College of Physics of University of Manchester in 2004 and Russian Microelectronic Institute, A.K.Geim, S.V.Morozov etc. find Graphene as a kind of carbon atom lamella of individual layer can stable existence under room temperature environment, and it has large electron hole density and mobility at room temperature reaches 10000cm
2/ V.S.Graphene is considered to find now the thinnest and material that intensity is maximum, Yenny Hernandez, et al, High-yield production of graphene by liquid-phase exfoliation of graphite. nature anotechnology, 3,563-568,2008: the mobility of current carrier on Graphene, there is zero virtual mass, can at room temperature transmit several microns and without scattering.Graphene can bear the current density that exceeds 6 orders of magnitude than copper, has very high thermal conductivity and hardness, gas is not seen through, and fragility and ductility moderate.The transmission of electronics in Graphene can be described with dirac equation.
Because Graphene is in preparation process, can adopt chemistry route to be oxidized to be isolated the Graphene oxidation lamella of isolated individual layer, its edge or surface have epoxy or hydroxyl or carboxyl and exist, and this is just for chemically modified is provided convenience.
The matrix material of Graphene or graphene oxide and metal or metal oxide has been used to absorbing material, fuel cell field, semiconductor doping, catalyzer; As catalystic material, in Publication about Document, there is description: Titelman, G. I., et al, USSR Patent SU 1806005,1993; Kyotani, T. et al, A. Tanso 1993,160. Mastalir, A ' .et al, Carbon 2008,46,1631 – 1637. Mastalir, A '.; Notheisz, F.et al. Appl. Catal., A 1996,144,237 – 248. Gil M. Scheuermann, et al. Palladium Nanoparticles on Graphite Oxide and Its Functionalized Graphene Derivatives as Highly Active Catalysts for the Suzuki-Miyaura Coupling Reaction, J.AM.CHEM.SOC.XXX.X
Other similar preparation method has: Chao Xu, Xin Wang, Junwu Zhu. Graphene-Metal Particle Nanocomposites. J. Phys. Chem. C 2008,112,19841 – 19845.Ryan Muszynski, Brian Seger, and Prashant V. Kamat. Decorating Graphene Sheets with Gold Nanoparticles J. Phys. Chem. C, Vol. 112, No. 14,2008,255 – 265.
Summary of the invention
An object of the present invention is as solving above-mentioned prior art manufacture order atomic thickness graphene oxide/nm gold particles composite process loaded down with trivial details, need specific equipment, cannot realize the problems such as suitability for industrialized production, a kind of simple preparation method of graphene oxide/nano-gold particulate composite material with mono-atomic thickness is efficiently provided.
For achieving the above object, a technical scheme of the present invention provides a kind of preparation method of graphene oxide/nano-gold particulate composite material with mono-atomic thickness: 1) obtained graphene oxide is carried out to acylation reaction; 2) graphene oxide of acylation reaction reacts with chlorauric acid solution; 3) regulate ph value, precipitation is filtered, obtain graphene oxide/gold nano grain composite materials.
Furthermore, a kind of preparation method of graphene oxide/nano-gold particulate composite material with mono-atomic thickness, the method comprises the steps:
(1) Graphene carries out acylation reaction: in graphene oxide, add solvent, then add reaction reagent, under the condition of protectiveness nitrogen, adjusting temperature of reaction is 50-85 degree Celsius, stir, use oil bath to reflux, return time is 1-24h, after backflow, carry out underpressure distillation processing;
(2) the THF solution of hydrochloro-auric acid is joined in the functionalization solution of above-mentioned monatomic lamella graphene oxide, then carry out stirring reaction, temperature is 50-65 degree Celsius;
(3) regulate ph value, obtain mixture solution precipitation, this precipitation is filtered, obtain graphene oxide/gold nano grain composite materials.
Described in step (1), solvent is N, dinethylformamide DMF and/or tetrahydrofuran THF and/or N, N " in-N,N-DIMETHYLACETAMIDE any one or multiple, add-on is 10-250ml/ part; reaction reagent comprises sulfur oxychloride; phosphorus oxychloride, phosphorus pentachloride, oxalyl chloride; phosgene; trichloromethylchloroformate, any one in triphosgene or multiple, add-on is 40-100g/ part; In described step (2), use the THF solution of the hydrochloro-auric acid of 0.001M to join in above-mentioned single-layer graphene functionalization lamella solution, the mass ratio of hydrochloro-auric acid and monoatomic layer graphene oxide is 1:15.In described step (3), the adjusting of ph value regulates by ammoniacal liquor, and the ph value after adjusting is 8-10.
More preferably scheme: be the single-layer graphene oxide powder of getting 100mg in described step (1), be dissolved in the DMF of 15ml.
Described every part for graphene oxide, and every part is 0.1g.
Described graphene oxide preparation method step is as follows:
(1.1) graphite is oxidized: the mixture of the strong acid of 50-150ml and 1-10g nitrate is added in reactor, add 10g graphite, under ice bath state, with strong oxidizer oxidation, after oxidation, add 150-300ml deionized water post-heating solution to 100 ℃ and be incubated 0.5-2h; Remove water-bath, reactant is stirred, make reaction at room temperature carry out 24-96h, after reaction finishes, mixture is added in the deionized water of 0.5-4L;
(1.2) graphite oxide after oxidation is carried out to ultrasonic peeling off: above solution is used to 28kHz-59kHz frequency, the processing of 500W power ultrasonic, the treatment time is 5-60min;
(1.3) the graphene oxide colloidal sol obtaining is carried out to deionization: utilize dialysis tubing graphene oxide colloidal sol to be carried out under agitation condition to dialysis, every 2h changes deionized water one time, and this process duration is 2-24h;
(1.4) graphene oxide obtaining being carried out to ph value regulates: use the aqueous solution of ammoniacal liquor, sodium hydroxide or sodium carbonate to carry out the adjusting of ph value, ph value is adjusted to 6-11;
(1.5) the monatomic lamella graphene oxide obtaining is carried out to washing and filtering: this filter cake is carried out to vacuum-drying, and drying temperature is 15-120 degree Celsius, dry 10-24h; The monatomic lamella of graphene oxide obtaining is dried to ball milling: ball milling is to use planetary type ball-milling, and ball milling speed is 450 revs/min, uses nitrogen protection, and Ball-milling Time is 10-30min, obtains monatomic thickness graphene oxide powder solid.
Described graphite is acid inflatable or acid graphite; Described strong acid is the vitriol oil, concentrated nitric acid and perchloric acid; Described nitrate is saltpetre, SODIUMNITRATE; Described strong oxidizer is potassium permanganate, potassium perchlorate, and the consumption of strong oxidizer is 2-25g; Before adding raw material graphite in described step (1.1), need, by the cooling 15min of solution ice bath in reactor, then to add graphite in mixed solution, high-speed stirring; While adding strong oxidizer, need in 1h, add the strong oxidizer powder through 200 mesh sieves, require little deal successively to add to guarantee to mix; After having added, remove ice bath; Slowly add after the deionized water of 150-300ml, solution is heated, make solution temperature be elevated to 100 ℃, keep 0.5-2h;
In described (1.2) step, the graphene oxide after oxidation is carried out to the step that ultrasonic wave peels off as follows: above solution is used to 28kHz-59kHz frequency, the processing of 500W power ultrasonic, the treatment time is 5-60min;
The deionization that described step (1.3) is carried out graphene oxide is to use the semi-permeable membranes that molecular weight cut-off is 12000-14000 to carry out, this semi-permeable membranes is carried out to dialysis to above-mentioned graphene oxide colloidal sol under agitation condition, this process duration is 2-24h, during end of processing, the ph value of this graphene oxide colloidal sol is about 6.5-8;
Described step (1.4), the adjusting of the ph value that graphene oxide colloidal sol is carried out, is that functional quality mark is 20-30% ammoniacal liquor, the aqueous sodium hydroxide solution of 0.5-1.0mol/L, or the aqueous sodium carbonate of 0.5-2.0mol/L carries out, the ph value of the graphene oxide after adjusting is 6.2-9;
Described step (1.5): after graphene oxide solution filters, obtain filter cake, this filter cake is carried out to vacuum-drying, drying temperature is 60-80 degree Celsius; The graphene oxide obtaining is dried to ball milling, and ball milling is used planetary type ball-milling, and ball milling speed is 450 revs/min, uses nitrogen protection, and Ball-milling Time is 15-25min, obtains the graphene oxide powder solid of monatomic thickness.
Also comprise dilution process step, after described dilution process step is positioned at step (1.4), step (1.5) is front, and the graphene oxide colloidal sol of gained after step (1.4) is processed is diluted, and Dilution ratio is 1:30-1:200; Described dilution is that water carries out, and described Dilution ratio refers to the 1/30-1/200 that is diluted to original content.Above-mentioned solution is carried out to supersound process, the supersound process time is 5-30min simultaneously.Now, obtain the graphene oxide nanoscale twins aqueous solution of certain density monoatomic layer.
Beneficial effect:
The present invention, through a large amount of tests, sums up a set of effective preparation method, and the usage quantity of the saving concentrated acid that present method can be larger, compared with traditional chemical method, can save the usage quantity 50% of concentrated acid.In particular preferred example, the usage quantity of the vitriol oil reduces 50%.Be applicable to suitability for industrialized production.
The utilization of the present invention cheap commercially available acid expansible black lead that is easy to get is prepared graphene oxide by redox method and is had sizable advantage, the graphene oxide productive rate that simultaneously uses this method to make is high, and also contain a large amount of active groups as hydroxyl, carboxyl and epoxy group(ing) etc. on the graphene oxide lamella of the monatomic thickness making, there is good chemically reactive, be easy to carry out chemically modified, the various functional groups of grafting, monatomic thickness graphene oxide/nm gold particles matrix material of preparing by the inventive method.The mixture of carbon nanotube loaded nanoparticle has been shown potential application performance at aspects such as catalysis, nanoelectronics, optics, biotechnologys, compared with carbon nanotube, Graphene has higher physical strength, larger specific surface area, surface treatment easily and cheap preparation cost, make Graphene become the Potential Vector of nanoparticle.Due to performances such as the special electronics of Graphene, optics, also make graphene nano particle composite show the performance of many excellences and potential application in fields such as catalysis, biosensor, spectroscopy, stored energies simultaneously.In article Enhanced Electrocatalytic Activity of Pt Subnanoclusters on Graphene Nanosheet Surface on the surface of people at Graphene such as Yoo E load there is the Ya Na meter Pt bunch of particular electrical minor structure, and this mixture has good catalytic activity to methanol oxidation.In article Palladium nanoparticles on graphite oxide and its functionalized graphene derivatives as highly active catalysts for the suzuki-miyaura coupling reaction, the people such as Mulhaupt R utilizes graphene oxide in acetic acid handle and water to carry out ion-exchange, and then utilize hydrogen to reduce, can obtain Graphene one Pd nano-particle compound, compared with other carbon material supported Pd nanoparticles mixtures, Graphene-Pd nano-particle compound has very high catalytic activity in Suzuki-Miyaura coupling chemosynthesis, its unit time molecule transformation frequency value has reached 39000h
-1.Graphene composite nanoparticle also has potential application prospect aspect the energy.Take graphene film as electrode materials, in lithium cell, there is good loading capacity (680mAh/g), but its cyclicity discharging and recharging is poor, secondary loading capacity can only reach 15% (86mAh/g) of loading capacity first, but in ethylene glycol mechanically mixing Graphene and SnO
2nanoparticle, the mixture of preparing has extraordinary cell container, its for the second time loading capacity also can reach 860mAh/g, after the charge and discharge cycles of 30 times, still there is good specific storage.Except load Sn0
2pass through TiCL outward,
3hydrolysis and the graphene-supported different crystal forms Ti0 for preparing of high-temperature heat treatment
2mixture, has higher storage capacity, and by comparing Graphene and carbon nanotube loaded Ti0
2find Graphene Ti0
2mixture has and better discharges and recharges character.
Accompanying drawing explanation
Fig. 1 is schematic flow sheet of the present invention;
Fig. 2 is monatomic lamella graphene oxide TEM photo.
Embodiment
Below in conjunction with embodiment, further illustrate the present invention, but not as a limitation of the invention.
Embodiment 1:
As described in preparation process schema 1, first acidifying expansible black lead is oxidized, by following steps, undertaken: 1 joins the vitriol oil strong 100ml in flask, is placed with magnet rotor in flask.Flask is by ice bath.2 concentrated acids are stirred the then cooling 15min of ice bath, then add 20g acidifying expansible black lead in concentrated acid, high-speed stirring.3 add the potassium permanganate powder of 15g certain particle size in 1h, and adition process needs slowly, to avoid occurring violent intensification, controls and adds speed, keep fluid temperature in beaker to be no more than 3 ℃.After 4 potassium permanganate have added, remove ice bath.5 slowly add the deionized water of 400ml, and solution is heated, and make solution temperature be elevated to 100 ℃.Keep 0.5-2h.6 remove water-bath, and reactant is stirred, and make reaction at room temperature carry out 24h.After 7 reactions finish, mixture is added in the deionized water of 0.5L.Then, the graphene oxide after oxidation is carried out to ultrasonic wave and peel off, above solution is used to 50KHz frequency, the processing of 500W power ultrasonic, the treatment time is 15min.
Then, the deionization that graphene oxide is carried out is used a kind of semi-permeable membranes to carry out, use a kind of method that above-mentioned graphene oxide colloidal sol is carried out separate with 2L deionized water this semi-permeable membranes, then under agitation condition, carry out dialysis, this process duration is 2h, during end of processing, the ph value of this graphene oxide colloidal sol is about 6.1.Use the aqueous solution of 5% concentration of sodium carbonate to regulate the ph value of colloidal sol.The ph value of the graphene oxide after adjusting is 10.
Then above-mentioned graphene oxide colloidal sol is diluted, Dilution ratio is 1:80.Above-mentioned solution is carried out to supersound process, the supersound process time is 18min simultaneously.Meanwhile, use coarse filter paper to filter above-mentioned solution.This filter cake is carried out to vacuum-drying, and drying temperature is 30 degrees Celsius.The monatomic lamella of graphene oxide obtaining is dried to ball milling.Ball milling is used planetary type ball-milling, and ball milling speed is 450 revs/min, uses nitrogen protection, and Ball-milling Time is 10min, sieves, and obtains the monoatomic layer graphene oxide powder solid of particle diameter below 60 microns.
As described in Figure 1; dried monatomic lamella graphene oxide is carried out to the processing of functionalization; use one or more reagent and the graphene solution of the monatomic lamella obtaining to carry out acylation reaction, thereby obtain the functional intermediate product of acylations of the monatomic lamella of a kind of Graphene.As get the single-layer graphene oxide powder of 100mg, be dissolved in the DMF of 15ml.Then add 40ml sulfur oxychloride or 50g phosphorus trichloride to carry out functionalization to above-mentioned monoatomic layer graphene oxide, temperature of reaction is 85 degrees Celsius, stirs, and passes into protectiveness nitrogen, uses oil bath to reflux.Return time is 24h.After backflow, the remaining chloride reagent of underpressure distillation.
Then, use the THF solution of the hydrochloro-auric acid of 0.001M to join in above-mentioned single-layer graphene functionalization lamella solution, carry out stirring reaction, temperature is 65 degrees Celsius, and the mass ratio of hydrochloro-auric acid and monoatomic layer graphene oxide is 1:15.
Then, regulate ph value, obtain a mixture solution precipitation, this precipitation is filtered, obtain graphene oxide/gold nano grain composite materials.To the adjusting of ph value herein, be that working concentration is that 25% ammoniacal liquor carries out, according to the convention of prior art, the concentration of ammoniacal liquor refers to mass concentration.Ph value after adjusting is 10.The precipitation producing is carried out after filtration treatment, obtain described monatomic lamella graphene oxide/nm gold particles matrix material.
Embodiment 2:
As described in preparation process schema 1, first acidifying expansible black lead is oxidized, by following steps, undertaken: 1 joins the mixing acid of the vitriol oil strong 50ml and concentrated nitric acid 1:1 ratio in flask, is placed with magnet rotor in flask.Flask is by ice bath.2 concentrated acids are stirred the then cooling 15min of ice bath, then add 15g acidifying expansible black lead in concentrated acid, high-speed stirring.3 slowly add the potassium permanganate powder of 12g certain particle size in 45min, avoid occurring violent intensification, control and add speed, keep fluid temperature in beaker to be no more than 3 ℃.After 4 potassium permanganate have added, remove ice bath.5 slowly add the deionized water of 400ml, and solution is heated, and make solution temperature be elevated to 100 ℃.Keep 1h.6 remove water-bath, and reactant is stirred, and make reaction at room temperature carry out 24h.After 7 reactions finish, mixture is added in the deionized water of 0.5L.Then, the graphene oxide after oxidation is carried out to ultrasonic wave and peel off, above solution is used to 50KHz frequency, the processing of 500W power ultrasonic, the treatment time is 30min.8 add the H of 100ml
2o
2in above-mentioned solution.
Then, the deionization that graphene oxide is carried out is used a kind of semi-permeable membranes to carry out, use a kind of method that above-mentioned graphene oxide colloidal sol is carried out separate with 2L deionized water this semi-permeable membranes, then under agitation condition, carry out dialysis, this process duration is 2h, during end of processing, the ph value of this graphene oxide colloidal sol is about 6.1.Use the aqueous solution of 5% concentration of sodium carbonate to regulate the ph value of colloidal sol.The ph value of the graphene oxide after adjusting is 10.
Then above-mentioned graphene oxide colloidal sol is diluted, Dilution ratio is 1:200.Above-mentioned solution is carried out to supersound process, the supersound process time is 5-30min simultaneously.Meanwhile, use coarse filter paper to filter above-mentioned solution.This filter cake is carried out to vacuum-drying, and drying temperature is 30 degrees Celsius.The monatomic lamella of graphene oxide obtaining is dried to ball milling.Ball milling is used planetary type ball-milling, and ball milling speed is 450 revs/min, uses nitrogen protection, and Ball-milling Time is 15min, sieves, and obtains the monoatomic layer graphene oxide powder solid of particle diameter below 60 microns.
As described in Figure 1; dried monatomic lamella graphene oxide is carried out to the processing of functionalization; preferably; use one or more reagent and the graphene solution of the monatomic lamella obtaining to carry out acylation reaction, thereby obtain the functional intermediate product of acylations of the monatomic lamella of a kind of Graphene.The reagent that carries out acylation reaction with the Graphene of above-mentioned monoatomic layer is sulfur oxychloride, and DMF is solvent, gets the single-layer graphene oxide powder of 200mg, is dissolved in the DMF of 25ml.Above-mentioned monoatomic layer graphene oxide is carried out to functionalization, and temperature of reaction is 82 degrees Celsius, stirs, and passes into protectiveness nitrogen, uses oil bath to reflux.Return time is 24h.After backflow, the remaining chloride reagent of underpressure distillation.
Then, the THF solution of certain density hydrochloro-auric acid is joined in the functionalization solution of above-mentioned monatomic lamella graphene oxide, then carry out stirring reaction, temperature is 65 degrees Celsius.Preferably, use the THF solution of the hydrochloro-auric acid of 0.001M to join in above-mentioned single-layer graphene functionalization lamella solution, the mass ratio of hydrochloro-auric acid and monoatomic layer graphene oxide is 1:50.
Then, regulate ph value, obtain a mixture solution precipitation, this precipitation is filtered, obtain graphene oxide/gold nano grain composite materials.Preferably to the adjusting of ph value herein, use certain density ammoniacal liquor to carry out.Ph value after adjusting is 8-10.The precipitation producing is carried out after filtration treatment, obtain described monatomic lamella graphene oxide/nm gold particles matrix material.
Embodiment 3:
(1) Graphene carries out acylation reaction: in graphene oxide, add solvent, then add reaction reagent, under the condition of protectiveness nitrogen, adjusting temperature of reaction is 50-85 degree Celsius, stir, use oil bath to reflux, return time is 1-24h, after backflow, carry out underpressure distillation processing;
(2) the THF solution of hydrochloro-auric acid is joined in the functionalization solution of above-mentioned monatomic lamella graphene oxide, then carry out stirring reaction, temperature is 50-65 degree Celsius;
(3) regulate ph value, obtain mixture solution precipitation, this precipitation is filtered, obtain graphene oxide/gold nano grain composite materials.
Reactant used and proportioning are with embodiment 2.
Embodiment 4:
In in step (1), temperature of reaction is 85 degrees Celsius, and return time is 1h;
In step (2), temperature of reaction is 65 degrees Celsius; All the other are with embodiment 3.
Embodiment 5:
In in step (1), temperature of reaction is 60 degrees Celsius, and return time is 12h;
In step (2), temperature of reaction is 55 degrees Celsius; All the other are with embodiment 3.
Embodiment 6-12:
Step and operation are with embodiment 3, and reactant used and proportioning are as follows:
Embodiment 13:
First commercially available acid expansible black lead is oxidized, by following steps, is undertaken: the SODIUMNITRATE of the 200ml vitriol oil and 2g is joined in the flask that is placed with magnet rotor, flask is placed in to ice bath state.Concentrated acid is stirred the then cooling 15min of ice bath, then adds the commercially available acid expansible black lead of 20g in concentrated acid, stirs.In 40min, add the potassium permanganate powder of 30g, adition process needs slowly, to control and add speed, avoids occurring violent intensification, keeps fluid temperature in beaker to be no more than 5 ℃.After potassium permanganate has added, remove ice bath.The deionized water that slowly adds 500ml, then heats solution, makes solution temperature be elevated to 100 ℃ and keep 0.5-2h.Remove water-bath, reactant is stirred, make reaction at room temperature carry out 24h.After reaction finishes, mixture is added in the deionized water of 500ml.
Then, gained solution is used to 59kHz frequency, the processing of 500W power ultrasonic, the treatment time is 30min.Graphene oxide after being soon oxidized has carried out ultrasonic wave and has peeled off.
Use semi-permeable membranes to carry out deionization to graphene oxide colloidal sol.Detailed process is that to use a kind of method that above-mentioned graphene oxide colloidal sol and 2L deionized water are carried out this semi-permeable membranes separate, then under agitation condition, carries out dialysis, and every 2h changes deionized water one time, and this process duration is 4h.
With the sodium hydroxide solution of 0.5mol/L, regulate the ph value to 7 of graphene oxide solution.
Above-mentioned solution is carried out to supersound process, and the supersound process time is used coarse filter paper to carry out washing and filtering to above-mentioned solution after being 5-30min.This filter cake is carried out to vacuum-drying, and drying temperature is 80 degrees Celsius.The monatomic lamella graphene oxide obtaining is carried out to ball milling.Ball milling is used planetary type ball-milling, and ball milling speed is 450 revs/min, uses nitrogen protection, and Ball-milling Time is 10min, sieves to such an extent that be monatomic thickness or several atomic thickness graphene oxide powder solid of 325 mesh sieves.
The acid expansible black lead of commodity used is that Laixi, Qingdao oildag factory produces.Particle diameter specification was 325 mesh sieves.
Productive rate can reach 180.2%.
Embodiment 14-21:
Ph value conditioning agent refers in step (1.4) graphene oxide obtaining is carried out to the aqueous solution that ph value regulates.All the other are with embodiment 13.