Graphene composite material and preparation method thereof

Abstract

The application provides a graphene composite material and a preparation method thereof, and relates to the technical field of graphene composite materials.Compared with the prior art, the preparation method can combine graphene on a gel formed by the reaction of chitosan and acrylic acid, and the three-dimensional structure formed by the combination of graphene and the gel can effectively improve the adsorption capacity.Furthermore, the sintering action can further improve the combination capacity between the graphene and the gel material, and can further improve the pores in the graphene composite material, so that the adsorption capacity is stronger.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of graphene composite material, in particular to a graphene composite material and a preparation method thereof. BACKGROUND

[0002] Traditional industries such as textile, printing and dyeing, papermaking and other industries are accompanied by wastewater discharge in the industrial production process, and high-toxicity and high-color dyes in the wastewater will cause adverse effects on the environment. At present, the methods for removing dyes from wastewater include biological degradation method, photocatalytic degradation method, flocculation precipitation method, chemical oxidation method and adsorption method, etc. Among them, the adsorption method is a water treatment method with high efficiency, low cost, convenient operation and wide application, and the biggest challenge of the adsorption method is to select and develop high-efficiency adsorption materials. Although there are many reports on the preparation method of dye adsorption materials at present, there are still disadvantages such as slow adsorption rate and low adsorption efficiency. Based on the above, it is of great significance to propose a high-efficiency adsorption material. SUMMARY

[0003] The present application aims to provide a preparation method of graphene composite material, and the graphene composite material prepared by the above preparation method has high adsorption capacity, is easy to separate from water after adsorption, and the main material is non-toxic and will not cause secondary pollution.

[0004] Another object of the present application is to provide a graphene composite material, which has all the above beneficial effects.

[0005] The technical problem of the present application is solved by adopting the following technical solutions.

[0006] In one aspect, the present application provides a preparation method of graphene composite material, mainly comprising the following steps:

[0007] Dissolve graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of a dispersant; completely dissolve a compound or hydrate containing divalent iron ions in deionized water to obtain an iron ion solution; mix the iron ion solution with the graphene dispersion liquid under an oxygen-free environment after adding a surfactant to the iron ion solution to prepare a mixed solution one; react chitosan and acrylic acid under the action of a dispersant two and an initiator to prepare a reaction liquid one; mix the mixed solution one and the reaction liquid one under an oxygen-free environment, and stir for 10-12 hours to prepare a mixed solution two; and sinter the mixed solution two in a tube furnace to obtain the graphene composite material.

[0008] In another aspect, the present application provides a graphene composite material, which is prepared by the above preparation method.

[0009] The graphene composite material and the preparation method thereof have at least the following beneficial effects:

[0010] Firstly, the application provides a preparation method of a graphene composite material. The preparation method can combine graphene on a gel formed by the reaction of chitosan and acrylic acid. The three-dimensional structure formed by graphene and the gel can effectively improve the adsorption capacity. Moreover, the sintering action can further improve the combination capacity between graphene and the gel material, and further improve the pores in the graphene composite material, so that the adsorption capacity is stronger.

[0011] Secondly, the graphene composite material uses graphene oxide and chitosan to be prepared together. The graphene composite material has no toxicity to the environment, has strong ecological compatibility, and has no secondary pollution problem.

[0012] Thirdly, the preparation method has the advantages of simple preparation, and is beneficial to the industrial application of the preparation method. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0014] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to specific embodiments.

[0015] In one aspect, the application provides a graphene composite material, which mainly comprises the following steps:

[0016] Dissolve the graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of a dispersant I;

[0017] Completely dissolve the compound or hydrate containing divalent iron ions in deionized water to obtain an iron ion solution;

[0018] After adding a surfactant to the iron ion solution, mix the graphene dispersion liquid in an oxygen-free environment to obtain a mixed solution I;

[0019] React chitosan and acrylic acid under the action of a dispersant II and an initiator to obtain a reaction solution I;

[0020] Mix the mixed solution I and the reaction solution I in an oxygen-free environment, and stir for 10-12 hours to obtain a mixed solution II;

[0021] The mixed solution two is placed in a tube furnace for sintering to obtain the graphene composite material.

[0022] In the present application, the method for preparing the reaction solution one from chitosan and acrylic acid is as follows:

[0023] In a double-layer glass reactor equipped with a stirrer, a condenser, a thermometer and a nitrogen inlet, a proper amount of chitosan is prepared into a solution with 1% acetic acid solution. After 30 minutes of nitrogen deoxygenation, the chitosan solution is heated to 60°C. Then, an initiator is added to the reactor to generate active free radicals from chitosan, and then acrylic acid is added dropwise, and the temperature is raised to 70°C for 3 hours. During the experiment, the mass fraction of chitosan and initiator in the reaction system is 10% and 2% respectively. After the reaction is completed, the above-mentioned reaction solution one is prepared.

[0024] Further, the above preparation method further comprises the following steps: the eggshell is made into a powder, mixed with the reaction solution one and the mixed solution one to prepare the mixed solution two.

[0025] In the present application, the eggshell is ground into a powder of 120-200 mesh, mixed with the reaction solution one and the mixed solution one, and stirred. During the stirring process, the eggshell powder and the graphene oxide can also be attached to the main substances in the reaction solution one to improve the adsorption capacity of the graphene composite material.

[0026] Further, the pH of the mixed solution two is 6-7.

[0027] Further, the stirring speed of the obtained mixed solution two is 290 rpm-310 rpm, and the stirring temperature is 65°C±3°C.

[0028] Further, the surfactant is polyethylene glycol.

[0029] Further, the dispersant one is anhydrous ethanol.

[0030] Further, the dispersant two is polyvinylpyrrolidone.

[0031] Further, the mixed solution two is subjected to solid-liquid separation by vacuum filtration to obtain a precipitate, and the precipitate is placed in a vacuum drying oven for drying for 5-10 hours and then placed in a tube furnace for sintering.

[0032] In the present application, the water in the mixed solution two can be removed by pre-drying to improve the practicability of the above method.

[0033] In the present application, the drying temperature in the vacuum drying oven is 80-85°C. The sintering temperature in the tube furnace is 130-150°C. On the other hand, the present application provides a graphene composite prepared by the above preparation method, which has all the beneficial effects described above.

[0034] The features and properties of the present application are further described in detail below in combination with the examples.

[0035] Example 1

[0036] The purpose of the present embodiment is to provide a preparation method of a graphene composite, which is as follows:

[0037] Dissolve the graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of dispersant one;

[0038] Completely dissolve the compound or hydrate containing divalent iron ions in deionized water to obtain an iron ion solution;

[0039] After adding a surfactant to the iron ion solution, mix it with the graphene dispersion liquid in an oxygen-free environment to obtain a mixed solution one (the volume ratio of graphene solution to iron ion solution is 4:1, and the concentration ratio of graphene solution to iron ion solution is 5:1);

[0040] React chitosan and acrylic acid under the action of dispersant two and initiator to obtain a reaction solution one;

[0041] After mixing the mixed solution one and the reaction solution one in an oxygen-free environment, stir for 10-12 hours to obtain a mixed solution two;

[0042] Place the mixed solution two in a tube furnace for sintering (sintering temperature is 140°C, and sintering time is 30 minutes) to obtain the graphene composite.

[0043] Example 2

[0044] The purpose of the present embodiment is to provide a preparation method of a graphene composite, which is as follows:

[0045] Dissolve the graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of dispersant one;

[0046] Completely dissolve the compound or hydrate containing divalent iron ions in deionized water to obtain an iron ion solution;

[0047] After adding a surfactant into the iron ion solution, the graphene dispersion liquid is mixed in an oxygen-free environment to obtain a mixed liquid one (the volume ratio of the graphene solution to the iron ion solution is 4:1, and the concentration ratio of the graphene solution to the iron ion solution is 5:1);

[0048] The chitosan and the acrylic acid are reacted under the action of a dispersant two and an initiator to obtain a reaction liquid one;

[0049] The eggshell is made into a 180-mesh powder to obtain an eggshell powder;

[0050] The mixed liquid one, the eggshell powder and the reaction liquid one are mixed in an oxygen-free environment, and stirred for 10-12 hours to obtain a mixed liquid two;

[0051] The mixed liquid two is placed in a tube furnace for sintering (the sintering temperature is 130°C, and the sintering time is 30 minutes) to obtain the graphene composite material.

[0052] Example 3

[0053] The purpose of the embodiment is to provide a preparation method of a graphene composite material, and the method specifically comprises the following steps:

[0054] The graphene oxide powder is dissolved in deionized water, and a graphene dispersion liquid with a specific concentration is obtained under the action of a dispersant one;

[0055] A compound or hydrate containing divalent iron ions is completely dissolved in deionized water to obtain an iron ion solution;

[0056] After adding a surfactant into the iron ion solution, the graphene dispersion liquid is mixed in an oxygen-free environment to obtain a mixed liquid one (the volume ratio of the graphene solution to the iron ion solution is 4:1, and the concentration ratio of the graphene solution to the iron ion solution is 5:1);

[0057] The chitosan and the acrylic acid are reacted under the action of a dispersant two and an initiator to obtain a reaction liquid one;

[0058] The eggshell is made into a 180-mesh powder to obtain an eggshell powder;

[0059] The mixed liquid one, the eggshell powder and the reaction liquid one are mixed in an oxygen-free environment, and stirred for 10-12 hours to obtain a mixed liquid two;

[0060] The mixed liquid two is placed in a tube furnace for sintering (the sintering temperature is 130°C, and the sintering time is 30 minutes) to obtain the graphene composite material.

[0061] Example 4

[0062] The embodiment is to provide a preparation method of a graphene composite material, and specifically as follows.

[0063] Dissolve the graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of a dispersant one.

[0064] Completely dissolve a compound or a hydrate containing divalent iron ions in deionized water to obtain an iron ion solution.

[0065] After adding a surfactant to the iron ion solution, mix the graphene dispersion liquid in an oxygen-free environment to obtain a mixed liquid one (the volume ratio of the graphene solution to the iron ion solution is 3:1, and the concentration ratio of the graphene solution to the iron ion solution is 3:1).

[0066] React chitosan and acrylic acid under the action of a dispersant two and an initiator to obtain a reaction liquid one.

[0067] After mixing the mixed liquid one and the reaction liquid one in an oxygen-free environment, stir for 10-12 hours to obtain a mixed liquid two.

[0068] Place the mixed liquid two in a tube furnace for sintering (the sintering temperature is 140°C, and the sintering time is 30 minutes) to obtain the graphene composite material.

[0069] Embodiment 5

[0070] The embodiment is to provide a preparation method of a graphene composite material, and specifically as follows.

[0071] Dissolve the graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of a dispersant one.

[0072] Completely dissolve a compound or a hydrate containing divalent iron ions in deionized water to obtain an iron ion solution.

[0073] After adding a surfactant to the iron ion solution, mix the graphene dispersion liquid in an oxygen-free environment to obtain a mixed liquid one (the volume ratio of the graphene solution to the iron ion solution is 7:1, and the concentration ratio of the graphene solution to the iron ion solution is 4:1).

[0074] React chitosan and acrylic acid under the action of a dispersant two and an initiator to obtain a reaction liquid one.

[0075] After mixing the mixed liquid one and the reaction liquid one in an oxygen-free environment, stir for 10-12 hours to obtain a mixed liquid two.

[0076] The mixed solution two is placed in a tube furnace for sintering (sintering temperature is 140℃, sintering time is 30min), and the graphene composite material is obtained.

[0077] Comparative Example

[0078] The difference between the present comparative example and Example 1 is that the mixed solution two does not contain iron ion solution.

[0079] Effect Example

[0080] Methylene blue solution and malachite green solution of 150mg / L are prepared respectively, and the graphene composite materials prepared in Comparative Example 1 and Examples 1-5 are placed in the methylene blue solution and malachite green solution, and vibrated at a frequency of 180rpm / min. After adsorption equilibrium, the absorbance of the above prepared solution is tested at the wavelength corresponding to methylene blue and the wavelength corresponding to malachite green by ultraviolet spectrophotometer, and the removal rate of methylene blue and malachite green is calculated. The results are as follows:

[0081] Table 1 Removal effect of methylene blue and malachite green

[0082]

[0083] From the above table, it can be seen that the removal effect of the composite material prepared in the comparative example on the above two dyes is poor, and the adsorption time is long. In the present application, the adsorption capacity of the graphene material can be further improved by adding eggshell powder, and the effect is better.

[0084] It should be noted that in the present application, the test time is 10min, 30min, 60min, 120min, 180min, 240min and 300min. The absorbance of the dye in the adsorption process is tested at each time point. When the absorbance does not change, the corresponding test time is the adsorption equilibrium time.

[0085] In summary, the application provides a preparation method of graphene composite material, which comprises the following steps: dissolving graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a specific concentration under the action of a dispersant; completely dissolving a compound or hydrate containing divalent iron ions in deionized water to obtain an iron ion solution; mixing the iron ion solution with the graphene dispersion liquid in an oxygen-free environment after adding a surfactant to the iron ion solution to obtain a mixed liquid one; reacting chitosan and acrylic acid in the presence of a dispersant two and an initiator to obtain a reaction liquid one; mixing the mixed liquid one and the reaction liquid one in an oxygen-free environment and stirring for 10-12 hours to obtain a mixed liquid two; and sintering the mixed liquid two in a tube furnace to obtain the graphene composite material. The graphene composite material can be combined on the gel formed by the reaction of chitosan and acrylic acid, and the three-dimensional structure formed by the combination of graphene and gel can effectively improve the adsorption capacity. Moreover, the sintering can further improve the combination between graphene and gel material, and further improve the porosity of the graphene composite material, so that the adsorption capacity is stronger.

[0086] The embodiments described above are part of the embodiments of the present application, but not all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

Claims

1. A method of preparing a graphene composite material, characterized by, The method comprises the following steps: dissolving graphene oxide powder in deionized water to obtain a graphene dispersion liquid with a certain concentration under the action of a dispersant; completely dissolving a compound or hydrate containing divalent iron ions in deionized water to obtain an iron ion solution; mixing the iron ion solution with the graphene dispersion liquid in an oxygen-free environment after adding a surfactant to the iron ion solution to obtain a mixed solution one; reacting chitosan and acrylic acid under the action of a dispersant two and an initiator to obtain a reaction liquid one; preparing eggshell powder from eggshells; mixing the mixed solution one, the eggshell powder, and the reaction liquid one in an oxygen-free environment, stirring for 10-12 hours to obtain a mixed solution two; sintering the mixed solution two in a tube furnace to obtain the graphene composite material.

2. The method of claim 1, wherein the graphene composite is prepared by a process comprising: The pH of the mixed solution two is 6-7.

3. The method for preparing the graphene composite material according to claim 1, characterized in that, The stirring speed of the obtained mixed solution two is 290 rpm-310 rpm, and the stirring temperature is 65℃±3℃.

4. The method of claim 1, wherein the graphene composite is prepared by a process comprising: The surfactant is polyethylene glycol.

5. The method for preparing the graphene composite material according to claim 1, characterized in that, The dispersant one is anhydrous ethanol.

6. The method of claim 1, wherein the graphene composite is prepared by a process comprising: The dispersant two is polyvinylpyrrolidone.

7. The method for preparing the graphene composite material according to claim 1, characterized in that, The mixed solution two is subjected to solid-liquid separation by vacuum filtration to obtain a precipitate, and the precipitate is dried in a vacuum drying box for 5-10 hours and then sintered in a tube furnace.

8. A graphene composite material, characterized by, The graphene composite material is prepared by the method for preparing the graphene composite material according to any one of claims 1-7.

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