High-energy catalytic physical stripping preparation method of graphene

Abstract

The invention relates to a high-energy catalytic physical stripping preparation method of graphene, relates to the technical field of graphene materials, and solves the problem that a conventional physical stripping method is high in cost and not easy to be mass-produced. The method specifically comprises the following steps: performing preliminary infiltration on pure water, performing first high-energy ultrasonic preliminary stripping, adding SiC for ball milling, then performing second high-energy catalysis for stripping, classifying graphene flakes by gas flow classification and spray-drying to obtain the graphene; by infiltration, ultrasonic treatment, SiC ball milling, addition of a surfactant and the secondary high-energy ultrasonic treatment, the graphene is stripped layer by layer, the process is mild, and basically no crushing and wear phenomena occur; the prepared graphene crystal lattice structure is complete and processed by a physical stripping method, the graphene flakesare present in a completely powdery form, the storage and use environments are not restricted, and the industrial production cost is relatively low, thereby facilitating the wider application of graphene in various industries.

Description

technical field [0001] The invention belongs to the technical field of graphene materials, in particular to a method for preparing graphene by high-energy catalytic physical exfoliation. Background technique [0002] Since Andre K. Geim of the University of Manchester in the UK prepared graphene materials in 2004, it has attracted widespread attention due to its unique structure and photoelectric properties. Graphene is hailed as a rising "new star" in the field of materials science and condensed matter physics. Its many novel and unique properties and potential applications are attracting many scientific and technological workers. Graphene has a large specific surface area, excellent electrical and thermal conductivity and low thermal expansion coefficient. [0003] At present, the preparation methods of graphene mainly include: 1) micromechanical exfoliation method, that is, directly exfoliate graphene flakes from larger crystals. For example, Chinese patent application C...

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Problems solved by technology

[0003] At present, the preparation methods of graphene mainly include: 1) micromechanical exfoliation method, that is, directly exfoliate graphene flakes from larger crystals. For example, Chinese patent application CN101817516A discloses a method for preparing graphene or graphene oxide by mechanical exfoliation. Using solid particles and liquid working medium (or gas working medium) to mechanically peel off the carbon material and separate it to obtain graphene or graphene oxide, the carbon material is graphite powder, expanded graphite, expandable graphite or graphite oxide powder; This method is simple, but only produces a very limited number of graphene sheets

2) Ultra-high vacuum graphene epitaxial growth method, that is, epitaxial growth of graphene from the surface of silicon carbide or metal in an ultra-high vacuum and high temperature environment. For example, Chinese patent application CN101798706A discloses a new type of semiconductor thin film material graphene on silicon carbide Epitaxial growth on (SiC) substrates, this kind of graphene is forced to nucleate and grow controllably under the bombardment of electron beams, the number of layers of graphene can be controlled below 6 layers, and the average diameter of the generated region can reach the order of centimeters; The cost of this method is high and the structure of the small wafer limits its application

3) Oxidation-reduction method, the whole process involves oxidizing graphite into graphite oxide, exfoliating graphite oxide to produce graphene oxide, and then reducing it to graphene through chemical or thermal reduction. For example, Chinese patent application CN103342904A discloses a titanate couple A method for preparing water-soluble graphene by the coupling agent modification method, the graphene oxide is obtained by the oxidation method, and the graphene is reduced to obtain the titanate coupling agent at the same time, the obtained modified graphene can be stably dispersed in water, and through The bridging effect of titanate coupling agent, the synthesis process of this method is cumbersome and the synthesized graphene is prone to defects

4) Chemical Vapor Deposition (CVD), which uses carbon-containing compounds such as methane as a carbon source to prepare graphene through pyrolysis and growth on the surface of the substrate. For example, Chinese patent application CN103409728A discloses a method for preparing graphene by chemical vapor deposition. The method comprises the following steps: washing the cobalt-nickel alloy substrate three times with an ethanol solution with a mass fraction of 75%, and drying at 50°C to 80°C; putting the cobalt-nickel alloy substrate into a quartz furnace, and heating the substrate to 880 ℃~890℃, flow helium, the helium flow rate is 50sccm; keep the temperature at 880℃~890℃, add ethylbenzene evenly into the quartz furnace; cool the quartz furnace to room temperature, take out the sample; ultrasonically treat the sample, The processing power is 800w, and the time is 60-90min to obtain graphene; this method can meet the requirements of large-scale preparation of high-quality graphene, but the cost is high and the process is complicated

5) Solvent stripping method, that is, graphite powder is oxidized and stripped in a solvent, and then reduced to obtain graphene. The disadvantage of this method is that the yield is very low, which limits its large-scale preparation and application

[0004] However, the method of industrialized production in the prior art is mainly realized by CVD (chemical vapor deposition method). Through chemical vapor deposition method, a large-area, continuous, transparent, high-conductivity few-layer graphene film can be made, mainly It is used in the anode of photovoltaic devices, and the energy conversion efficiency is as high as 1.71%. Compared with the components made of indium tin oxide materials, it is about 55.2% of its energy conversion efficiency. The disadvantage is that the production is difficult and the production cost is high. It is difficult to make graphene widely used, and it is of revolutionary significance to study the low-cost physical method to produce graphene

[0005] Graphene is obtained by repeated sticking and tearing with tape, from the friction method to the CVD method, all of which have either low efficiency or high production costs, which is not conducive to the popularization of graphene applications.