CN103950926B

CN103950926B - A kind of method preparing single-layer graphene fast

Info

Publication number: CN103950926B
Application number: CN201410202200.5A
Authority: CN
Inventors: 吴湘锋; 张�杰; 庄亚芳; 李婧; 韩刘春
Original assignee: Shijiazhuang Tiedao University
Current assignee: Shijiazhuang Tiedao University
Priority date: 2014-05-14
Filing date: 2014-05-14
Publication date: 2016-02-10
Anticipated expiration: 2034-05-14
Also published as: CN103950926A

Abstract

The invention provides a kind of method preparing single-layer graphene fast, comprise the steps: A, take 1-5g natural graphite, 40-200ml weight percent is the vitriol oil of 98%, be placed in the hydrothermal synthesis reaction still of 100-500ml inner liner polytetrafluoroethylene, fully stir 10-30min; B, slowly add 5-25g potassium permanganate to reaction system, add in 10-30min; C, temperature of reaction kettle is increased to 120-180 DEG C, soaking time controls, for 1-4h, to naturally cool to room temperature after reaction terminates; D, to be moved in 300ml deionized water by product, add the hydrogen peroxide that 20-50ml weight percent is 30%, the system that stirs, to colour stable, is filtered, with deionized water repetitive scrubbing to neutral; E, ultrasonic disperse are in organic solvent ethanol, acetone, tetrahydrofuran (THF) or DMF, and ultrasonic power controls as 100-500w, and time controling is 30-120min, namely obtains single-layer graphene product after filtration.

Description

A kind of method preparing single-layer graphene fast

Technical field

The present invention relates to a kind of method preparing single-layer graphene fast, belong to field of material synthesis technology.

Background technology

Since Graphene came out from 2004 (within 2010, this field is awarded the Nobel prize), it has been the hot research object of field of new always.As the up-to-date member of carbon atom family, single-layer graphene possesses unique physicochemical property and makes this material very bright in the actual application prospect in future.But being limited to current limited graphene preparation method, the application especially mass-producing application feature of Graphene is also pessimistic.By the end of at present, the preparation method of Graphene mainly contains: 1) mechanically peel method; 2) chemical Vapor deposition process; 3) chemical synthesis; 4) chemical stripping method.Wherein chemical stripping method is graphene preparation method the most frequently used at present; it is mainly raw material with graphite; strong acid and strong oxidizer is utilized to obtain graphene oxide to its oxidation; carry out reduction to it again after washing, filtration and obtain Graphene, the method to prepare the method for Graphene.Although existing chemical stripping method can prepare single-layer graphene, be Hummers method or its improved method mostly, preparation cycle is longer, and output is lower.Therefore, research and develop out the graphene preparation technology that a kind of technique is simple, efficiency is high, cost is low and become the key realizing Graphene application leap.

Summary of the invention

The object of the present invention is to provide a kind of method preparing single-layer graphene fast, utilize hydrothermal synthesis reaction that graphite, the vitriol oil, potassium permanganate are placed in reactor, in certain temperature with in the time, a step obtains Graphene.Effective solution single-layer graphene preparation efficiency is low, complex process, cycle length, high in cost of production problem.

The technical scheme that the present invention prepares the method for single-layer graphene fast comprises the steps:

A, take 1-5g natural graphite, 40-200ml weight percent is the vitriol oil of 98%, be placed in the hydrothermal synthesis reaction still of 100-500ml inner liner polytetrafluoroethylene, fully stir 10-30min;

B, slowly add 5-25g potassium permanganate to reaction system, add in 10-30min;

C, temperature of reaction kettle is increased to 120-180 DEG C, soaking time controls, for 1-4h, to naturally cool to room temperature after reaction terminates;

D, to be moved in 300ml deionized water by product, add the hydrogen peroxide that 20-50ml weight percent is 30%, the system that stirs, to colour stable, is filtered, with deionized water repetitive scrubbing to neutral;

E, ultrasonic disperse are in organic solvent ethanol, acetone, tetrahydrofuran (THF) or DMF, and ultrasonic power controls as 100-500w, and time controling is 30-120min, namely obtains single-layer graphene product after filtration.

The present invention utilizes the advantage of hydrothermal synthesis reaction still, graphite, the vitriol oil, potassium permanganate are placed in one, under certain temperature and time, one step obtains Graphene, do not need extra reduction step, solve existing utilize in chemical stripping technology of preparing need first to prepare that graphene oxide carries out filtering in reduction process to it again, washing difficulty and the large problem of product loss, provide a kind of safety, gentle, cheap, fast method prepare single-layer graphene, increase substantially production efficiency.

Accompanying drawing explanation

Fig. 1 is the transmission electron microscope figure of product in embodiment 2.

Fig. 2 is the atomic force microscope figure of product in embodiment 2.

Fig. 3 is the X-ray diffractogram of product in embodiment 2.

Fig. 4 is the infrared spectrogram of product in embodiment 2.

Embodiment

Embodiment 1:

First by 1g natural graphite (325 orders, AlfaAesar (Tianjin) Chemical Co., Ltd., down together), the 40ml vitriol oil (98wt%) is placed in hydrothermal synthesis reaction still (Dongtai City of Zhejiang Province Zhong Kaiya Stainless Steel Products factory of 100ml inner liner polytetrafluoroethylene, lower same), abundant stirring 30min. takes 5g potassium permanganate and join reaction system in 10min, then reactor is warming up to 120 DEG C, insulation 1h; After naturally cooling to room temperature, the sample in reactor is poured in 300ml deionized water, add the hydrogen peroxide that 20ml concentration is 30wt%, be stirred to colour stable; Filter, with deionized water repetitive scrubbing to ultrasonic after neutral (Ningbo new sesame ultrasonic cell disrupte machine, model: JY-92-IIN, lower with) dispersion in ethanol, ultrasonic power is 500W, and the time is 30min, can obtain 1g single-layer graphene after filtration.In above-mentioned reaction, the effect of the vitriol oil is: the intercalation ability utilizing it stronger makes that the interlamellar spacing of graphite flake layer becomes large, Van der Waals force between adjacent layers dies down; The effect of potassium permanganate is: the oxidation capacity utilizing it stronger becomes large graphite to interlamellar spacing and is oxidized, and generates oxy radical, increase interlamellar spacing further, become graphite oxide in each carbon atom plane; Adopt hydrothermal synthesis reaction under higher temperature and pressure, remove the functional groups such as the hydroxyl on graphite oxide surface, graphite oxide is reduced; The effect of employing ultrasonic disperse is: the product lamella of hydrophobic oleophilic oil is fully stripped in organic solvent, obtains single-layer graphene.

Embodiment 2:

First 2g natural graphite, the 80ml vitriol oil are placed in the hydrothermal synthesis reaction still of 150ml inner liner polytetrafluoroethylene, fully stir 20min. and take 10g potassium permanganate join reaction system in 20min, then reactor is warming up to 155 DEG C, insulation 2h; After naturally cooling to room temperature, the sample in reactor is poured in 300ml deionized water, add the hydrogen peroxide that 40ml concentration is 30wt%, be stirred to colour stable; Filter, in acetone, ultrasonic power is 200W, and the time is 30min, can obtain 2g single-layer graphene after filtration with ultrasonic disperse after deionized water repetitive scrubbing to neutrality.

Further test result as shown in drawings.Fig. 1 is the transmission electron microscope figure (be placed in by product on micro-grid and observe) of embodiment 2 product, and as can be seen from Figure 1, the Graphene obtained has many fine folds, illustrates that product thickness is very thin.

Fig. 2 is the atomic force microscope figure of product in example 2, the width scanned in figure is 3 μm, the mean thickness of sample is about 0.4nm as we know from the figure, difference of altitude between mark A place and mark 2, B place, 100pm=0.1nm, the theoretic throat of single-layer graphene is 0.34nm, all thinks single-layer graphene generally lower than 1nm, the theoretic throat of the closely Graphene of the product in embodiment 2.

Fig. 3 is the X-ray diffractogram of embodiment 2 product, as we know from the figure, there is the distinctive diffraction peak of Graphene in sample, do not find the characteristic peak of graphene oxide at 11 ° of places, namely known graphene oxide is fully converted into Graphene under higher temperature and pressure when 2 θ=23.5 °.

Fig. 4 is the infrared spectrogram of example 2 product, at 1220cm in figure ^-1, 1562cm ^-1, 1740cm ^-13 comparatively significantly charateristic avsorption bands, the respectively C-O-C of corresponding Graphene, sp are there are ²c=O vibration absorption peak in C=C and carboxyl, at 2300cm ^-1the absorption peak at place is CO ₂absorption peak (normal phenomenon), in addition at 3400cm ^-1place does not find absorption peak, this product is described not containing oh group, and also illustrate that graphene oxide is reduced sufficiently under higher temperature and pressure, this result and XRD result are consistent simultaneously.

Embodiment 3:

First 5g natural graphite, the 200ml vitriol oil are placed in the hydrothermal synthesis reaction still of 500ml inner liner polytetrafluoroethylene, fully stir 18min. and take 25g potassium permanganate join reaction system in 30min, then reactor is warming up to 180 DEG C, insulation 4h; After naturally cooling to room temperature, the sample in reactor is poured in the deionized water of 300ml, add the hydrogen peroxide that 50ml concentration is 30wt%, be stirred to colour stable; Filter, ultrasonic disperse is in DMF with after deionized water repetitive scrubbing to neutrality, ultrasonic power is 100W, and the time is 120min, can obtain 5g single-layer graphene after filtration.

Embodiment 4:

First 3g natural graphite, the 160ml vitriol oil are placed in the hydrothermal synthesis reaction still of 300ml inner liner polytetrafluoroethylene, fully stir 20min. and take 10g potassium permanganate join reaction system in 20min, then reactor is warming up to 165 DEG C, insulation 3h; After naturally cooling to room temperature, sample in reactor is poured in 300ml deionized water, add the hydrogen peroxide that 30ml concentration is 30wt%, be stirred to colour stable, filter, use the extremely neutral rear ultrasonic disperse of deionized water repetitive scrubbing in tetrahydrofuran (THF), ultrasonic power is 300W, and the time is 70min, can obtain 3g single-layer graphene after filtration.

Embodiment 5:

First 4g natural graphite, the 140ml vitriol oil are placed in the hydrothermal synthesis reaction still of 250ml inner liner polytetrafluoroethylene, fully stir 10min. and take 10g potassium permanganate join reaction system in 30min, then reactor is warming up to 145 DEG C, insulation 2.5h; After naturally cooling to room temperature, the sample in reactor is poured in 300ml deionized water, add the hydrogen peroxide that 35ml concentration is 30wt%, be stirred to colour stable; Filter, in acetone, ultrasonic power is 200W, and the time is 50min, can obtain 4g single-layer graphene after filtration with ultrasonic disperse after deionized water repetitive scrubbing to neutrality.

Embodiment 6:

First 3g natural graphite, the 140ml vitriol oil are placed in the hydrothermal synthesis reaction still of 250ml inner liner polytetrafluoroethylene, fully stir 20min. and take 15g potassium permanganate join reaction system in 30min, then reactor is warming up to 155 DEG C, insulation 2h; After naturally cooling to room temperature, the sample in reactor is poured in 300ml deionized water, add the hydrogen peroxide that 30ml concentration is 30wt%, be stirred to colour stable; Filter, in ethanol, ultrasonic power is 400W, and the time is 80min, can obtain 3g single-layer graphene after filtration with ultrasonic disperse after deionized water repetitive scrubbing to neutrality.

Several enforceable technical scheme of method that foregoing description only prepares single-layer graphene fast as the present invention proposes, not as the single restricted condition to its technical scheme itself.

Claims

1. prepare a method for single-layer graphene fast, its feature comprises the steps:

B, slowly add 5-25g potassium permanganate to reaction system, add in 10-30min;

C, temperature of reaction kettle is increased to 120-180 DEG C, time controling is 1-4h, naturally cools to room temperature after reaction terminates;