阅读说明：本技术 一种基于碳量子点的质子交换膜及其制备方法 (Proton exchange membrane based on carbon quantum dots and preparation method thereof ) 是由 田文迪 王永霞 田丙伦 傅婧 乔锦丽 于 2019-11-08 设计创作，主要内容包括：本发明涉及一种基于碳量子点的质子交换膜的制备方法,其特征在于,包括以下步骤：步骤S1、基膜材料的制备；步骤S2、碳量子点掺杂；步骤S3、浇注成膜。本发明还公开了根据所述基于碳量子点的质子交换膜的制备方法制备得到的基于碳量子点的质子交换膜。本发明公开的基于碳量子点的质子交换膜具有更加优异的氧化稳定性和力学性能,更高的质子传导率。(The invention relates to a preparation method of a proton exchange membrane based on carbon quantum dots, which is characterized by comprising the following steps of: step S1, preparation of a base film material; step S2, doping carbon quantum dots; and step S3, casting to form a film. The invention also discloses the proton exchange membrane based on the carbon quantum dots, which is prepared according to the preparation method of the proton exchange membrane based on the carbon quantum dots. The proton exchange membrane based on the carbon quantum dots disclosed by the invention has more excellent oxidation stability and mechanical property and higher proton conductivity.)

1. A preparation method of a proton exchange membrane based on carbon quantum dots is characterized by comprising the following steps:

step S1, preparation of base film material: adding 6-sulfonaphthalene-1, 4-dicarboxylic acid and 2, 4-diamino-5-fluoroquinazoline into a high-boiling-point solvent, and stirring for 20-40 minutes to form a mixed solution; adding a catalyst into the mixed solution, carrying out ultrasonic treatment for 15-25 minutes to obtain a mixed material, transferring the mixed material into a high-pressure reaction kettle, replacing air in the kettle with nitrogen or inert gas, keeping the temperature in the high-pressure reaction kettle at 285 ℃ and the pressure at 2-3MPa, carrying out stirring reaction for 8-10 hours, slowly exhausting and reducing the pressure to 1.0MPa within 1-2 hours, simultaneously heating the temperature in the high-pressure reaction kettle to 310 ℃ and carrying out stirring reaction for 0.2-0.5 hours, finally controlling the temperature to 250 ℃ under the vacuum condition, carrying out stirring reaction for 12-16 hours, then cooling to room temperature, and carrying out precipitation, washing and drying in sequence to obtain a base membrane material;

step S2, carbon quantum dot doping: dispersing the carbon quantum dots in N-methylpyrrolidone to obtain a dispersion liquid, adding the base membrane material prepared in the step S1, and performing ultrasonic treatment for 10-20 minutes to obtain a base membrane material dispersion liquid doped with the carbon quantum dots;

step S3, casting to form a film: and (4) pouring the base membrane material dispersion liquid doped with the carbon quantum dots prepared in the step S2 into a mold, and then placing the mold in a forced air drying oven at 80-90 ℃ for drying until the weight is constant, so as to obtain the proton exchange membrane based on the carbon quantum dots.

2. The method for preparing a proton exchange membrane based on carbon quantum dots as claimed in claim 1, wherein the molar ratio of the 6-sulfonaphthalene-1, 4-dicarboxylic acid, the 2, 4-diamino-5-fluoroquinolizoline, the high boiling point solvent and the catalyst in step S1 is 1:1 (7-12): 1-2.

3. The method for preparing a proton exchange membrane based on carbon quantum dots as claimed in claim 1, wherein the high boiling point solvent is at least one of dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide and N-methylpyrrolidone.

4. The method for preparing the proton exchange membrane based on the carbon quantum dots as claimed in claim 1, wherein the catalyst is at least one of aluminum trichloride, boron trifluoride and dicyclohexylcarbodiimide.

5. The method for preparing a proton exchange membrane based on carbon quantum dots as claimed in claim 1, wherein the inert gas is one of neon, helium and argon.

6. The method for preparing the proton exchange membrane based on the carbon quantum dots as claimed in claim 1, wherein the mass ratio of the carbon quantum dots, the N-methylpyrrolidone and the base membrane material in the step S2 is 0.1 (80-100): 2.

7. The method for preparing a proton exchange membrane based on carbon quantum dots as claimed in claim 1, wherein the carbon quantum dots are at least one of sulfonated carbon quantum dots or phosphorylated carbon quantum dots.

8. A carbon quantum dot-based proton exchange membrane prepared by the method for preparing a carbon quantum dot-based proton exchange membrane according to any one of claims 1 to 6.

Technical Field

The invention belongs to the technical field of fuel cells, relates to a fuel cell component, and particularly relates to a proton exchange membrane based on carbon quantum dots and a preparation method thereof.

Background

In recent years, with the increasing environmental and energy problems, the desire to improve the living environment and to search for clean energy devices is more and more urgent, and it is in this form that proton exchange membrane fuel cells are in the sight of people and attract extensive attention in the industry. The proton exchange membrane fuel cell is a high-efficiency, clean and environment-friendly power generation device, can directly convert chemical energy in fuel and oxidant into electric energy in an electrochemical reaction mode without combustion, is an ideal power source of an electric automobile, can also be used as a military power source or a portable power source of a dispersive power station, a submarine, a spacecraft and the like, and has very wide application prospect.

The proton exchange membrane is one of the key parts of the proton exchange membrane fuel cell, plays the double roles of obstructing raw materials and transferring protons in the fuel cell, and directly influences the working performance and the cycle service life of the proton exchange membrane fuel cell. A commonly used commercial proton exchange membrane in the prior art is Nafion membrane manufactured by dupont, usa, which has excellent low-temperature conductivity and performance stability, however, it is mainly imported and expensive. In addition, the membrane is easily attacked by OH free radicals in the operation process of the fuel cell, so that sulfonate is separated, the proton conductivity of the perfluorinated sulfonic acid resin is reduced, the mechanical performance of the membrane is reduced, the comprehensive performance of the membrane is generally reduced, and the reduction speed is higher. Therefore, it is important to find a proton exchange membrane with better performance.

In recent years, carbon nanomaterials represented by graphene oxide, carbon nanotubes and the like are widely applied to the field of hybrid proton exchange membranes due to rich structural morphology, unique barrier capability and excellent transmission characteristics. However, due to the compatibility and the large size, graphene oxide and carbon nanotubes are easily agglomerated in the polymer matrix, and the capability of regulating the aggregation state structure of the polymer is limited. Compared with graphene oxide and carbon nanotubes, the carbon quantum dots are used as a novel carbon nanomaterial, the size of the carbon quantum dots is similar to the size of ion clusters in a polymer film matrix, the carbon quantum dots can have better dispersibility in the polymer matrix, have stronger regulation and control capability on a polymer aggregation state structure, and are more efficient under the same doping amount.

The Chinese patent with the publication number of CN 106532091B discloses a Nafion^TMA modified carbon quantum dot-polymer hybrid proton exchange membrane and a preparation method thereof. The hair is usedFirstly, the polymer Nafion is utilized^TMMixing with citric acid and reacting under nitrogen protection to obtain Nafion^TMA modified carbon quantum dot; and then blending the obtained carbon quantum dots with a polymer solution to prepare the hybrid proton exchange membrane. Due to the presence of Nafion^TMThe carbon quantum dots have good dispersibility in a polymer matrix, and the proton conductivity of the prepared hybrid proton exchange membrane is improved by one order of magnitude; the carbon quantum dots also enable the methanol permeation channel in the membrane to be more tortuous through the interaction with the membrane matrix, so that the methanol permeability of the hybrid membrane is reduced by 50%. The method is simple and convenient to operate, environment-friendly, easy for batch and large-scale production, and has a good industrial production basis and a wide application prospect. However, Nafion is still used as the proton exchange membrane, the price is still high, the wide use of Nafion is still remarkable, and the proton conductivity and the oxidation resistance are required to be further improved.

Therefore, it is imperative to develop a proton exchange membrane with better comprehensive performance, higher proton conductivity, better oxidation resistance, more excellent chemical resistance, mechanical property and lower preparation cost.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a proton exchange membrane based on carbon quantum dots and a preparation method thereof, wherein the preparation method is simple and easy to implement, has high preparation efficiency and high qualification rate of finished products, and is suitable for industrial production; the prepared proton exchange membrane has high proton conductivity, good oxidation resistance, good performance stability and mechanical property and long service life.

In order to achieve the purpose, the invention adopts the technical scheme that:

a preparation method of a proton exchange membrane based on carbon quantum dots is characterized by comprising the following steps:

step S1, preparation of base film material: adding 6-sulfonaphthalene-1, 4-dicarboxylic acid and 2, 4-diamino-5-fluoroquinazoline into a high-boiling-point solvent, and stirring for 20-40 minutes to form a mixed solution; adding a catalyst into the mixed solution, carrying out ultrasonic treatment for 15-25 minutes to obtain a mixed material, transferring the mixed material into a high-pressure reaction kettle, replacing air in the kettle with nitrogen or inert gas, keeping the temperature in the high-pressure reaction kettle at 285 ℃ and the pressure at 2-3MPa, carrying out stirring reaction for 8-10 hours, slowly exhausting and reducing the pressure to 1.0MPa within 1-2 hours, simultaneously heating the temperature in the high-pressure reaction kettle to 310 ℃ and carrying out stirring reaction for 0.2-0.5 hours, finally controlling the temperature to 250 ℃ under the vacuum condition, carrying out stirring reaction for 12-16 hours, then cooling to room temperature, and carrying out precipitation, washing and drying in sequence to obtain a base membrane material;

step S2, carbon quantum dot doping: dispersing the carbon quantum dots in N-methylpyrrolidone to obtain a dispersion liquid, adding the base membrane material prepared in the step S1, and performing ultrasonic treatment for 10-20 minutes to obtain a base membrane material dispersion liquid doped with the carbon quantum dots;

step S3, casting to form a film: and (4) pouring the base membrane material dispersion liquid doped with the carbon quantum dots prepared in the step S2 into a mold, and then placing the mold in a forced air drying oven at 80-90 ℃ for drying until the weight is constant, so as to obtain the proton exchange membrane based on the carbon quantum dots.

Further, the molar ratio of the 6-sulfonaphthalene-1, 4-dicarboxylic acid, the 2, 4-diamino-5-fluoroquinazoline, the high boiling point solvent and the catalyst in the step S1 is 1:1 (7-12) to (1-2).

Further, the high boiling point solvent is at least one of dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide and N-methylpyrrolidone.

Preferably, the catalyst is at least one of aluminum trichloride, boron trifluoride and dicyclohexylcarbodiimide; the inert gas is one of neon, helium and argon.

Furthermore, in the step S2, the mass ratio of the carbon quantum dots, the N-methyl pyrrolidone and the base film material is 0.1 (80-100): 2.

Preferably, the carbon quantum dots are at least one of sulfonated carbon quantum dots or phosphorylated carbon quantum dots.

Another object of the present invention is to provide a carbon quantum dot-based proton exchange membrane prepared according to the above method for preparing a carbon quantum dot-based proton exchange membrane.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: the proton exchange membrane based on the carbon quantum dots and the preparation method thereof have the advantages of simple and easy operation, high preparation efficiency and high qualification rate of finished products, and are suitable for industrial production; the prepared proton exchange membrane has high proton conductivity, good oxidation resistance, good performance stability and mechanical property and long service life; the addition of the carbon quantum dots can improve the moisture retention and moisture absorption effects of the membrane, enhance the membrane, improve the oxidation resistance of the membrane, form a specific proton channel and improve the proton conductivity; the naphthalene structure and the fluorine-containing quinazoline structure of the base film enable the comprehensive performance of the film to be better.

Detailed Description

The invention relates to a preparation method of a proton exchange membrane based on carbon quantum dots, which is characterized by comprising the following steps of:

step S1, preparation of base film material: adding 6-sulfonaphthalene-1, 4-dicarboxylic acid and 2, 4-diamino-5-fluoroquinazoline into a high-boiling-point solvent, and stirring for 20-40 minutes to form a mixed solution; adding a catalyst into the mixed solution, carrying out ultrasonic treatment for 15-25 minutes to obtain a mixed material, transferring the mixed material into a high-pressure reaction kettle, replacing air in the kettle with nitrogen or inert gas, keeping the temperature in the high-pressure reaction kettle at 285 ℃ and the pressure at 2-3MPa, carrying out stirring reaction for 8-10 hours, slowly exhausting and reducing the pressure to 1.0MPa within 1-2 hours, simultaneously heating the temperature in the high-pressure reaction kettle to 310 ℃ and carrying out stirring reaction for 0.2-0.5 hours, finally controlling the temperature to 250 ℃ under the vacuum condition, carrying out stirring reaction for 12-16 hours, then cooling to room temperature, and carrying out precipitation, washing and drying in sequence to obtain a base membrane material;

step S2, carbon quantum dot doping: dispersing the carbon quantum dots in N-methylpyrrolidone to obtain a dispersion liquid, adding the base membrane material prepared in the step S1, and performing ultrasonic treatment for 10-20 minutes to obtain a base membrane material dispersion liquid doped with the carbon quantum dots;

step S3, casting to form a film: and (4) pouring the base membrane material dispersion liquid doped with the carbon quantum dots prepared in the step S2 into a mold, and then placing the mold in a forced air drying oven at 80-90 ℃ for drying until the weight is constant, so as to obtain the proton exchange membrane based on the carbon quantum dots.

Further, the molar ratio of the 6-sulfonaphthalene-1, 4-dicarboxylic acid, the 2, 4-diamino-5-fluoroquinazoline, the high boiling point solvent and the catalyst in the step S1 is 1:1 (7-12) to (1-2); the high boiling point solvent is at least one of dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide and N-methylpyrrolidone; the catalyst is at least one of aluminum trichloride, boron trifluoride and dicyclohexylcarbodiimide; the inert gas is one of neon, helium and argon.

Further, in the step S2, the mass ratio of the carbon quantum dots, the N-methyl pyrrolidone and the base film material is 0.1 (80-100): 2; the carbon quantum dots are at least one of sulfonated carbon quantum dots or phosphorylated carbon quantum dots.

Another object of the present invention is to provide a carbon quantum dot-based proton exchange membrane prepared according to the above method for preparing a carbon quantum dot-based proton exchange membrane.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: the proton exchange membrane based on the carbon quantum dots and the preparation method thereof have the advantages of simple and easy operation, high preparation efficiency and high qualification rate of finished products, and are suitable for industrial production; the prepared proton exchange membrane has high proton conductivity, good oxidation resistance, good performance stability and mechanical property and long service life; the addition of the carbon quantum dots can improve the moisture retention and moisture absorption effects of the membrane, enhance the membrane, improve the oxidation resistance of the membrane, form a specific proton channel and improve the proton conductivity; the naphthalene structure and the fluorine-containing quinazoline structure of the base film enable the comprehensive performance of the film to be better.

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto.