阅读说明：本技术 一种具有氧还原活性氮硫共掺杂的类花菜结构碳材料、氧还原电极及制备方法、燃料电池 (Nitrogen-sulfur co-doped cauliflower-like structure carbon material with oxygen reduction activity, oxygen reduction electrode, preparation method and fuel cell ) 是由 王舜 李俊 王梦昆 金辉乐 于 2019-07-26 设计创作，主要内容包括：本发明涉及一种具有氧还原活性氮硫共掺杂的类花菜结构的碳材料,其制备方法包括如下步骤：S1：将六氯丁二烯、氮硫共源化合物加入溶剂内在高温高压下进行密闭反应；S2：反应结束后,泄压至常压,并自然冷却至室温,将所得固体进行离心、洗涤和干燥,得到干燥样品；S3：将所述干燥样品在惰性气体保护下进行高温焙烧处理,从而得到所述氮硫共掺杂类花菜结构碳材料；还涉及所述复合材料、用途和包含其的氧还原电极。所述氮硫共掺杂类花菜结构碳材料具有优异的性能,可用来制备燃料电池的氧还原电极,从而可用于燃料电池中,并表现出了良好的电化学性能,在电化学领域具有巨大的应用潜力和工业价值。(The invention relates to a carbon material with an oxygen reduction active nitrogen and sulfur co-doped cauliflower-like structure, and a preparation method of the carbon material comprises the following steps: s1: adding hexachlorobutadiene and a nitrogen-sulfur common source compound into a solvent to perform a closed reaction at high temperature and high pressure; s2: after the reaction is finished, releasing pressure to normal pressure, naturally cooling to room temperature, centrifuging, washing and drying the obtained solid to obtain a dried sample; s3: carrying out high-temperature roasting treatment on the dried sample under the protection of inert gas, thereby obtaining the nitrogen-sulfur co-doped cauliflower-like structural carbon material; it also relates to the composite material, use and an oxygen reduction electrode comprising the same. The nitrogen-sulfur co-doped cauliflower-like structural carbon material has excellent performance, can be used for preparing an oxygen reduction electrode of a fuel cell, can be used in the fuel cell, shows good electrochemical performance, and has great application potential and industrial value in the electrochemical field.)

1. A carbon material with an oxygen reduction active nitrogen and sulfur co-doped cauliflower-like structure is characterized in that the preparation method comprises the following steps:

S1: adding hexachlorobutadiene and a nitrogen-sulfur common source compound into a solvent, and carrying out a closed reaction at high temperature and high pressure;

S2: after the reaction is finished, releasing pressure to normal pressure, naturally cooling to room temperature, centrifuging, washing and drying the obtained solid to obtain a dried sample;

S3: and carrying out high-temperature roasting treatment on the dried sample under the protection of inert gas, thereby obtaining the nitrogen and sulfur co-doped carbon material with a cauliflower-like structure.

2. The carbon material having an oxygen-reducing active nitrogen-sulfur co-doped cauliflower-like structure of claim 1, wherein: in step S1, the nitrothiane compound is any one of tetramethylthiuram disulfide, dibenzothiazyl disulfide, tellurium diethyldithiocarbamate, or the like.

3. The carbon material having an oxygen-reducing active nitrogen-sulfur co-doped cauliflower-like structure of claim 2, wherein: in step S1, the nitrogen-sulfur-common source compound is tellurium diethyldithiocarbamate.

4. The carbon material having an oxygen-reducing active nitrogen-sulfur co-doped cauliflower-like structure of claim 1, wherein: in step S1, the solvent is a ketone compound.

5. The carbon material having an oxygen-reducing active nitrogen-sulfur co-doped cauliflower-like structure of claim 4, wherein: in step S1, the solvent is cyclohexanone.

6. The carbon material having an oxygen-reducing active nitrogen-sulfur co-doped cauliflower-like structure of claim 1, wherein: in step S1, the mass ratio of the NIS-S common source compound to hexachlorobutadiene is 1: 200-300.

7. The carbon material having an oxygen-reducing active nitrogen-sulfur co-doped cauliflower-like structure of claim 1, wherein: in step S1, the mass ratio of the NIS-S common source compound to the solvent is 1: 500-600.

8. An oxygen reduction electrode, characterized in that: the oxygen reduction electrode comprises the nitrogen and sulfur co-doped cauliflower-like structure carbon material of any one of claims 1-7.

9. The method for producing an oxygen-reducing electrode according to claim 8, characterized by comprising the steps of:

A. Grinding and polishing a glassy carbon electrode in alumina water slurry with the particle size of 1-0.05 mu m, then ultrasonically washing the glassy carbon electrode in acetone, absolute ethyl alcohol and high-purity water for 20-60 seconds in sequence, and drying the glassy carbon electrode by using nitrogen to obtain a pretreated glassy carbon electrode;

B. taking the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure in a mixed solution of ethanol, water and Nafion, and then carrying out ultrasonic dispersion for 30-60 minutes to obtain a uniformly mixed solution; and dripping the uniformly mixed solution onto the pretreated glassy carbon electrode, and drying at room temperature to obtain the oxygen reduction electrode.

10. A fuel cell comprising the oxygen-reducing electrode of claim 8.

Technical Field

The invention belongs to the technical field of new materials and electrochemical energy, and particularly provides a nitrogen and sulfur co-doped cauliflower-like structure carbon material with oxygen reduction activity, an oxygen reduction electrode, a preparation method and a fuel cell.

background

The fuel cell is a device for directly converting chemical energy existing in fuel and oxidant into electric energy, and has the advantages of high energy conversion efficiency, flexible installation site, fast load response, high operation quality, small environmental pollution and the like. Fuel cells suffer from the slow kinetics of cathode oxygen reduction (ORR), however, and have a long distance away from large-scale commercialization.

At present, noble metal catalysts such as platinum are good in catalytic performance in fuel cells, but the noble metals have the defects of poor methanol resistance, poor cycle stability and the like in the catalytic process. In addition, noble metals are relatively expensive. Greatly increasing the operating cost. Compared with noble metal catalysts, the porous carbon material doped with heteroatoms (such as N, S, P and the like) has the advantages of low price, methanol resistance and good cycling stability, so that the porous carbon material has wide application prospect in fuel cell catalysis.

In recent years, carbon materials such as carbon nanotubes, mesoporous carbons, and the like, which have a high specific surface area, excellent electrical conductivity, and stability, have been widely used in fuel cells, for example:

CN107887613A discloses an oxygen reduction electrode based on three-dimensional reticular nitrogen-phosphorus-sulfur co-doped porous carbon material, a preparation method and application thereof, and belongs to the field of inorganic functional materials. The preparation method comprises the following steps: and (2) carrying out closed reaction on a nitrogen source compound, a phosphorus source compound and a sulfur-containing compound in a high-pressure reaction kettle, after the reaction is finished, relieving the pressure to normal pressure, removing excessive reaction solvent to obtain a sample, and finally carrying out high-temperature treatment on the sample under the protection of inert gas to obtain the three-dimensional reticular nitrogen-phosphorus-sulfur co-doped porous carbon material. The porous carbon material has the advantages of uniform particle size distribution, high oxygen reduction catalytic activity, good stability, long service life and the like, thereby being applicable to the field of fuel cells.

CN105776178A discloses a method for preparing nitrogen and sulfur co-doped porous carbon by using heavy organic matters in coal direct liquefaction residues, which comprises the following steps: firstly, grinding a coal directly liquefied heavy organic matter into powder, obtaining a product A through hydroxylation, carboxylation or sulfonation processes, then reacting the product A with a carbon source and a sulfur source to obtain a product B, then mechanically mixing the product B with a certain proportion of a magnesium source, placing the mixture in a carbonization furnace for carbonization to obtain a mixture of magnesium oxide and nitrogen and sulfur co-doped porous carbon, and finally removing the magnesium oxide through an acid washing process to obtain the nitrogen and sulfur co-doped porous carbon. The nitrogen and sulfur co-doped carbon material obtained by the process has a large specific surface area, but the material has relatively low sulfur content, and has a low oxygen reduction peak potential and a small half-wave potential under an alkaline condition.

CN107482232A discloses a preparation method of a phosphorus and nitrogen co-doped carbon material of an oxygen reduction electrocatalyst of a fuel cell, which comprises the following process steps: 1. evenly mixing melamine, pyrophosphoric acid and deionized water through ultrasonic dispersion to prepare a solution; 2. transferring the solution into a microwave hydrothermal reaction kettle, and reacting in a microwave hydrothermal reaction instrument under a certain microwave condition; 3. washing the obtained product with deionized water until the filtrate becomes colorless, and drying in a vacuum drying oven to constant weight; and 4, calcining the dried sample at high temperature in an inert atmosphere to obtain the phosphorus and nitrogen co-doped carbon material of the oxygen reduction electrocatalyst of the fuel cell with the peanut-shaped structure. The process combines the unique heating characteristic of microwave and the advantages of a hydrothermal method, is simple to operate, high in reaction speed, short in synthesis time, mild in reaction condition and high in reaction efficiency, and compared with a carbon material only doped with nitrogen, the material has higher catalytic activity.

CN103007975A discloses a preparation method of a high-nitrogen-content carbon material, belonging to the technical field of carbon composite materials. The process comprises the following steps of 1, drying and ball-milling soybeans to obtain soybean meal; 2. mixing soybean meal and chloride salt in a certain mass fraction in a protic solvent, ultrasonically dispersing and stirring for a period of time, and evaporating the solvent to obtain mixed solid powder; 3. ball-milling the mixed solid powder in a zirconia ball milling tank; then placing the ball-milled powder in a tube furnace, and carbonizing under the protection of high-temperature inert gas to obtain a primary carbonized material; 4. continuously ball-milling the primary carbonized material in a zirconia ball-milling tank, fully dispersing the primary carbonized material into acetone, and refluxing the mixture for a period of time at a certain temperature; performing suction filtration, washing with deionized water, drying, performing oxidation treatment at room temperature by using a mixed aqueous solution of nitric acid and hydrogen peroxide, then washing, filtering and drying to obtain a secondary carbonized material; 5. placing the secondary carbonized material in a tubular furnace, and continuously carbonizing under the protection of high-temperature inert gas; then using mixed aqueous solution of nitric acid and hydrogen peroxide to perform oxidation treatment at room temperature, washing, filtering, drying and grinding to obtain the non-noble metal oxygen reduction electrocatalyst. The high-nitrogen-content carbon material prepared by the method has the advantages of good stability, high activity, difficult poisoning and the like when used as an oxygen reduction catalyst, and more importantly, the raw materials used in the preparation process of the carbon material are not noble metals, so that the non-noble metal of the oxygen reduction catalyst in the fuel cell is realized, the cost of the oxygen reduction catalyst is greatly reduced, and the industrialization of the fuel cell is facilitated.

CN104399508A discloses a nitrogen and sulfur co-doped carbon material with electrocatalytic oxygen reduction activity and a preparation method thereof, belonging to the technical field of new material application. According to the method, firstly, amino acid obtained by performing hydrothermal degradation on hair is used as a precursor, cheap and easily-obtained alkaline metal oxide is used as a template agent, and the nitrogen-sulfur co-doped carbon material is prepared through one-step thermal decomposition. The method has the advantages that the loss of miscellaneous elements in the pretreatment stage is avoided, the strong alkaline template agent is not adopted, the corrosivity to a reaction vessel and a quartz tube is reduced, the synthesis step of the hard template agent is avoided, the template agent removing step is simple, and the defects of time waste, labor waste and multiple steps in the traditional synthesis of the mesoporous carbon material by using the hard template agent are overcome.

CN105206849A discloses a nitrogen and sulfur co-doped carbon material with electrocatalytic oxygen reduction activity under acidic and alkaline conditions and a preparation method thereof, belonging to the technical field of new material application. The preparation process comprises the following steps: putting clean animal hair into a reaction kettle lining, adding analytically pure ammonia water, carrying out hydrothermal degradation reaction, drying and grinding a solution obtained by hydrothermal degradation to obtain bio-organic solid powder, dissolving the solid powder in methanol, adding zinc nitrate to obtain a suspension, magnetically stirring the suspension uniformly, pouring the suspension into the reaction kettle lining, after the solvent heating process is finished, obtaining a metal-organic coordination polymer as a precursor through centrifugal separation, and carrying out heat treatment on the precursor in an inert atmosphere; and cleaning the obtained sample with dilute hydrochloric acid, performing suction filtration and drying to obtain the nitrogen-sulfur co-doped carbon material. The material has larger specific surface area and abundant pore structure; the nitrogen and sulfur co-doped carbon material prepared by the method has excellent performance on the oxygen reduction catalysis of the cathode of the fuel cell under acidic and alkaline conditions.

CN107492670A discloses a preparation method of a fuel cell oxygen reduction electrocatalyst sulfur and nitrogen co-doped carbon material quantum dot, which comprises the following synthetic processes: 2-amino-1, 3, 5-triazine-4, 6-dithiol and formaldehyde solution are sufficiently mixed by ultrasound, then transferred to a microwave reaction kettle, reacted in a microwave reaction instrument under a certain microwave condition, and the obtained product is subjected to freeze-drying treatment to obtain solid powder with the particle size of 5-6 nm, namely the fuel cell oxygen reduction electrocatalyst sulfur and nitrogen co-doped carbon material quantum dots. The microwave preparation method adopted by the invention does not need to add other additives, synthesizes the target product in one step, and has the advantages of simple operation and high reaction efficiency. Compared with a nano carbon catalyst doped with nitrogen only, the catalyst has higher activity, more positively charged sites are created on the surface of the catalytic material by doping of sulfur atoms, the adsorption of oxygen molecules is enhanced, rich pi electrons in a carbon conjugated system are activated, and the sulfur and the nitrogen play a good synergistic effect on the carbon material together.

CN107910563A discloses an application of a three-dimensional sheet nitrogen and sulfur co-doped porous carbon material in preparation of an oxygen reduction electrode of a fuel cell. The process comprises the following steps: 1. adding pyridine, hexachlorobutadiene and trithiocyanuric acid into a reaction kettle, sealing for hydrothermal reaction, evaporating the obtained reaction mixed solution after the reaction is finished to remove the solvent, and drying to obtain a product A; 2. and mixing the obtained product A with a sulfur-containing compound, reacting under the protection of high-temperature inert gas, and carrying out ball milling treatment on the obtained product B to obtain the three-dimensional flaky nitrogen-sulfur co-doped porous carbon material. The material prepared by the method has excellent electrochemical performance, high catalytic activity, good stability and long service life, can be applied to the field of fuel cells, and has great application potential and industrial value in the electrochemical field.

CN109192997A discloses a nitrogen and sulfur co-doped carbon-supported non-noble metal oxygen reduction catalyst, which comprises the following process steps: firstly, preparing a solution of Fe ions and SCN ions by an ion exchange method, then reacting 2,2' -dipyridine amine with 1,3, 5-trichloro-s-triazine to obtain a compound A, then dropwise adding the solution of Fe ions and SCN ions into an organic solvent of A by a mixed solvent method, evaporating the solvent to obtain a complex B, and carrying out heat treatment on the complex B to obtain the nitrogen-sulfur co-doped carbon-supported non-noble metal oxygen reduction catalyst. Compared with other preparation methods, the method has the advantages of simple synthesis method, fast synthesis period, no need of adding additional carbon source, accurate control of the molar ratio of different elements and the like, and is favorable for promoting the research and development of the fuel cell field. In addition, the material has larger specific surface area, provides more catalytic active centers and is beneficial to the diffusion and transfer of electrolyte. In addition, the obtained catalyst not only has good ORR catalytic activity, but also has excellent stability and methanol resistance.

As described above, many prior arts disclose heteroatom-doped carbon materials, and due to the introduction of heteroatoms (e.g., N, S, P, etc.), the resulting carbon materials have catalytic performance equivalent to that of noble metal catalysts (e.g., platinum) and superior methanol resistance and cycle stability. In addition, the synthesis process of the material is complex, the synthesis conditions are strict, the large-scale production is difficult, and in addition, the electrochemical performance of the material needs to be further improved.

For the above reasons, the development of a heteroatom-doped porous carbon material which is green, environment-friendly and relatively simple in process is still of great significance, and in addition, the heteroatom-doped porous carbon material is a hot spot of research in the field of electrocatalysis, and the basis and the power of the invention are achieved.

Disclosure of Invention

the present inventors have conducted intensive studies in order to develop a novel heteroatom-doped porous carbon material, particularly a porous carbon material from which an oxygen reduction electrode is obtained, and after having paid a great deal of creative efforts, have completed the present invention.

Specifically, the technical scheme and content of the invention relate to a nitrogen and sulfur co-doped cauliflower-like structure carbon material with oxygen reduction activity, an oxygen reduction electrode, a preparation method and a fuel cell.

More specifically, the present invention relates to the following aspects.

The first aspect relates to a nitrogen and sulfur co-doped carbon material with a cauliflower-like structure, and the preparation method of the carbon material comprises the following steps:

S1: adding hexachlorobutadiene and a nitrogen-sulfur common source compound into a solvent, and carrying out a closed reaction at high temperature and high pressure;

S2: after the reaction is finished, releasing pressure to normal pressure, naturally cooling to room temperature, centrifuging, washing and drying the obtained solid to obtain a dried sample;

S3: and carrying out high-temperature roasting treatment on the dried sample under the protection of inert gas, thereby obtaining the nitrogen and sulfur co-doped carbon material with a cauliflower-like structure.

In the method for producing a carbon material having a nitrogen-sulfur co-doped cauliflower-like structure according to the present invention, in step S1, the nitrogen-sulfur common source compound is a linear or cyclic compound, and may be any one of tetramethylthiuram disulfide, dibenzothiazyl disulfide, tellurium diethyldithiocarbamate, and the like, and is most preferably tellurium diethyldithiocarbamate.

In the method for preparing the carbon material with a nitrogen and sulfur co-doped cauliflower-like structure, in step S1, the solvent is a ketone compound, such as any one of acetophenone, acetone, cyclohexanone, and the like, and most preferably cyclohexanone.

in the method for preparing the carbon material with nitrogen and sulfur co-doped cauliflower-like structure of the present invention, in step S1, the reaction temperature (i.e. the "high temperature") is 100-220 ℃, for example, 100 ℃, 120 ℃, 140 ℃, 160 ℃, 200 ℃ or 220 ℃, preferably 120-180 ℃, and most preferably 140 ℃.

In the method for preparing the carbon material of nitrogen and sulfur co-doped cauliflower-like structure of the present invention, in step S1, the reaction pressure (i.e. the "high pressure") is 1 to 6MPa, for example, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa or 6MPa, and most preferably 1.5 MPa.

In the method for preparing the carbon material with a nitrogen and sulfur co-doped cauliflower-like structure, in step S1, the reaction time is 2-10 hours, for example, 2 hours, 4 hours, 6 hours, 8 hours or 10 hours.

In the preparation method of the carbon material with a nitrogen-sulfur co-doped cauliflower-like structure, in step S1, the mass ratio of the nitrogen-sulfur common source compound to hexachlorobutadiene is 1:200-300, which may be 1:200, 1:273 or 1:300, for example.

In the preparation method of the carbon material with a nitrogen and sulfur co-doped cauliflower-like structure, in step S1, the molar ratio of the nitrogen and sulfur common source compound to hexachlorobutadiene is 1:1000-2000, which may be 1:1000, 1:1935 or 1:2000, for example.

In the preparation method of the carbon material with a nitrogen-sulfur co-doped cauliflower-like structure, in step S1, the mass ratio of the nitrogen-sulfur common source compound to the solvent is 1:500-600, which may be 1:500, 1:514, or 1:600, for example.

In the preparation method of the carbon material with a nitrogen and sulfur co-doped cauliflower-like structure, in step S1, the molar ratio of the nitrogen and sulfur common source compound to the solvent is 1:3000-4000, which may be 1:3000, 1:3872 or 1:4000, for example.

In the method for preparing the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure, in step S2, the rotation speed of the centrifuge is 8000-12000rpm/min, which may be 8000rpm/min, 9000rpm/min, 10000rpm/min, 11000rpm/min or 12000rpm/min, for example.

In the method for preparing the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure, in step S2, the drying temperature is 60-120 ℃, for example, 60 ℃, 80 ℃, 100 ℃ or 120 ℃; the drying time is 4 to 12 hours, and may be, for example, 4 hours, 6 hours, 8 hours, 10 hours, or 12 hours.

In the preparation method of the carbon material with a nitrogen and sulfur co-doped cauliflower-like structure, in step S3, the temperature of the high-temperature roasting treatment is 700-.

In the method for preparing the carbon material with a nitrogen and sulfur co-doped cauliflower-like structure, in step S3, the high-temperature roasting treatment time is 1-4 hours, and may be, for example, 1 hour, 2 hours, 3 hours, or 4 hours.

In the method for preparing the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure, in step S3, the inert gas is nitrogen or argon.

in summary, the high-temperature calcination treatment in step S3 is to place the dried sample at a high temperature in an inert gas atmosphere in this temperature range for 1 to 3 hours, so as to obtain the nitrogen and sulfur co-doped carbon material with a cauliflower-like structure of the present invention.

The present inventors have found that when the above preparation method of the present invention, especially some preferred process parameters therein, is adopted, a nitrogen and sulfur co-doped cauliflower-like structure carbon material with excellent electrical properties can be obtained, and an oxygen reduction electrode prepared therefrom has excellent electrochemical properties, such as high catalytic activity, good stability, long service life, and the like, and thus can be applied to the field of fuel cells.

The carbon material with the nitrogen and sulfur co-doped cauliflower-like structure prepared by the preparation method has excellent performances and a specific morphology, and the oxygen reduction electrode prepared by the carbon material has excellent electrochemical properties, such as high catalytic activity, good stability, long service life and the like, so that the carbon material can be applied to the field of fuel cells.

In a second aspect, the invention also relates to an oxygen reduction electrode comprising the nitrogen and sulfur co-doped cauliflower-like structure carbon material.

In a third aspect, the present invention also relates to a method for producing the oxygen reduction electrode, the method comprising the steps of:

A. Grinding and polishing a glassy carbon electrode in alumina water slurry with the particle size of 1-0.05 mu m, then ultrasonically washing the glassy carbon electrode in acetone, absolute ethyl alcohol and high-purity water for 20-60 seconds in sequence, and drying the glassy carbon electrode by using nitrogen to obtain a pretreated glassy carbon electrode;

B. Taking the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure in a mixed solution of ethanol, water and Nafion, and then carrying out ultrasonic dispersion for 30-60 minutes to obtain a uniformly mixed solution; and dripping the uniformly mixed solution onto the pretreated glassy carbon electrode, and drying at room temperature to obtain the oxygen reduction electrode.

In the method for preparing the oxygen reduction electrode, in the step A, the diameter of the glassy carbon electrode is 2-6mm, and for example, the diameter of the glassy carbon electrode can be 2mm, 3mm, 4mm, 5mm or 6 mm.

In the method for manufacturing an oxygen reduction electrode according to the present invention, in step a, the high purity water is deionized water, and preferably has a resistance of at least 18M Ω.

In the method for manufacturing an oxygen reduction electrode according to the present invention, in step a, the amounts of the acetone, the absolute ethyl alcohol, and the high purity water are not specifically defined, and may be appropriately selected by those skilled in the art, for example, the amount may be an amount that is sufficient to immerse the glassy carbon electrode and facilitates washing.

In the method for manufacturing an oxygen reduction electrode according to the present invention, in step B, the concentration of the ethanol aqueous solution may be 30 to 60% by mass, for example, 30%, 40%, 50%, or 60%.

In the method for manufacturing an oxygen reduction electrode according to the present invention, in step B, ultrasonic dispersion is performed for 30 to 60 minutes, for example, 30 minutes, 40 minutes, 50 minutes, or 60 minutes, preferably 60 minutes.

In the preparation method of the oxygen reduction electrode, in the step B, the mass volume concentration of the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure in the mixed homogeneous solution is 3-6mg/ml, that is, 3-6mg of the carbon material with the nitrogen and sulfur co-doped cauliflower-like structure is contained in 1ml of the mixed homogeneous solution, and the mass volume concentration can be 3mg/ml, 4mg/ml, 5mg/ml or 6mg/ml, for example.

In the method for manufacturing an oxygen reduction electrode according to the present invention, in step B, the mass percentage concentration of the Nafion ethanol and water mixed solution is 4 to 9%, that is, the mass percentage concentration of Nafion in the solution is 4 to 9%, and may be, for example, 4%, 5%, 6%, 7%, 8%, or 9%.

in the method for preparing the oxygen reduction electrode according to the present invention, the volume of the mixed homogeneous solution dropped onto the pretreated glassy carbon electrode in step B is not specifically defined, as long as it can uniformly cover the surface of the glassy carbon electrode, and it can be determined and selected by those skilled in the art as appropriate, and will not be described in detail herein.

In a fourth aspect, the invention also relates to a fuel cell comprising said oxygen reduction electrode.

As described above, the oxygen reduction electrode has various excellent electrochemical properties, so that it can be applied to a fuel cell, thereby obtaining a fuel cell having excellent properties.

As described above, the invention provides a nitrogen and sulfur co-doped carbon material with a cauliflower-like structure, a preparation method and application thereof, and an oxygen reduction electrode comprising the carbon material, wherein the nitrogen and sulfur co-doped carbon material with the cauliflower-like structure has excellent performance, can be used for preparing the oxygen reduction electrode of a fuel cell, can be used in the fuel cell, shows good electrochemical performance, and has great application potential and industrial value in the electrochemical field.

Drawings

Fig. 1 is a Scanning Electron Microscope (SEM) image of a carbon material of a nitrogen and sulfur co-doped cauliflower-like structure before and after firing in example 1 of the present invention.

Fig. 2 is a full scan XPS chart of the carbon material of the nitrogen and sulfur co-doped cauliflower-like structure prepared in example 1 of the present invention.

Fig. 3 is an XPS high-resolution C1s spectrum of the carbon material with nitrogen and sulfur co-doped cauliflower-like structure prepared in example 1 of the present invention.

FIG. 4 is an XPS high resolution N1s spectrum of a carbon material with a nitrogen and sulfur co-doped cauliflower-like structure prepared in example 1 of the invention.

Fig. 5 is an XPS high resolution S2p spectrum of the carbon material of nitrogen and sulfur co-doped cauliflower-like structure of example 1 of the present invention.

Fig. 6 is an XPS high resolution O1s spectrum of the carbon material of nitrogen and sulfur co-doped cauliflower-like structure of example 1 of the present invention.

FIG. 7 is a CV curve of oxygen reduction electrode prepared by using the carbon material of nitrogen and sulfur co-doped cauliflower-like structure of example 1 of the present invention, with a sweep rate of 10mv/s, for oxygen reduction under argon/oxygen saturation.

FIG. 8 is a linear scan graph of oxygen reduction at different rotation speeds in an oxygen saturation state of an oxygen reduction electrode manufactured by using the nitrogen and sulfur co-doped carbon material with a cauliflower-like structure in example 1 of the present invention, wherein the scan speed is 10 mv/s.

Fig. 9 is a koutech-Levich graph of an oxygen reduction electrode manufactured using the nitrogen and sulfur co-doped cauliflower-like structure carbon material of example 1 of the present invention at different potentials.

FIG. 10 is a CV curve of oxygen reduction electrodes prepared using the nitrogen and sulfur co-doped cauliflower-like structure carbon materials of example 1, comparative example 1 and example 2 of the present invention in an oxygen saturated state at a sweep rate of 10 mv/s.

Fig. 11 is a schematic view of hydrogen peroxide yield and electron transfer of an oxygen reduction electrode manufactured using the nitrogen and sulfur co-doped cauliflower-like structure carbon material of example 1 of the present invention.

Fig. 12 is a comparison graph of methanol poisoning resistance tests of an oxygen reduction electrode prepared using the nitrogen and sulfur co-doped cauliflower-like structure carbon material of example 1 of the present invention and a 20% Pt/C catalyst.

Fig. 13 is a stability test chart of an oxygen reduction electrode manufactured using the nitrogen and sulfur co-doped cauliflower-like structure carbon material of example 1 of the present invention.

fig. 14 is an impedance test chart of an oxygen reduction electrode prepared from the carbon material of nitrogen-sulfur co-doped cauliflower-like structure of example 1, comparative example 1 and example 2 of the present invention.

Fig. 15 is a nitrogen adsorption/desorption curve and a pore size distribution diagram before calcination of the carbon material of the nitrogen-sulfur co-doped cauliflower-like structure in example 1 of the present invention.

Fig. 16 is a nitrogen adsorption/desorption curve and a pore size distribution diagram of the carbon material of the nitrogen and sulfur co-doped cauliflower-like structure in example 1 of the present invention.

Detailed Description

The present invention is described in detail below with reference to specific drawings and examples, but the use and purpose of these exemplary drawings and embodiments are only to exemplify the present invention, not to limit the actual scope of the present invention in any way, and not to limit the scope of the present invention.