A carbon black material loaded with carbon quantum dots, a preparation method thereof, and applications thereof, and a cathode catalyst for a proton exchange membrane fuel cell

Abstract

The present invention relates to the field of proton exchange membrane technology, and in particular to a carbon quantum dot-loaded carbon black material, its preparation method and application, and a cathode catalyst for a proton exchange membrane fuel cell. The preparation method provided by the present invention comprises the following steps: mixing carbon black with concentrated nitric acid and modifying it to obtain a carboxyl-modified carbon black carrier; mixing lignin, water, and ethylene glycol, performing a hydrothermal reaction, and then performing amino modification to obtain carbon quantum dots; and mixing the carboxyl-modified carbon black carrier, the carbon quantum dots, and water, and loading them to obtain the carbon quantum dot-loaded carbon black material. The carbon quantum dot-loaded carbon black material prepared by this preparation method can prevent Pt aggregation and improve catalytic activity.

Description

Technical Field

[0001] The present invention relates to the technical field of proton exchange membranes, and in particular to a carbon black material loaded with carbon quantum dots, a preparation method and application thereof, and a cathode catalyst for a proton exchange membrane fuel cell. Background Art

[0002] A fuel cell is a device that can directly convert the chemical energy in a fuel (such as hydrogen) and an oxidant (such as air) into electrical energy. Among them, proton exchange membrane fuel cells (PEMFCs) have the characteristics of high energy conversion efficiency, zero pollution, and low-temperature start-up, and have been rapidly developed in the transportation field, especially in the automotive industry. However, the high cost of fuel cells is the key to large-scale industrialization and commercialization. Among them, precious metal catalysts are one of the reasons for the high cost. Currently, the catalyst used in fuel cells is a Pt-based catalyst. From the perspective of reducing costs and limited platinum resources, reducing the Pt loading and developing highly active non-precious metal catalysts are important means to reduce the cost of fuel cells.

[0003] At present, the cathode catalyst widely used in PEMFCs is Pt / C catalyst. Under the actual working conditions of the battery, the aggregation of Pt catalyst is likely to occur, resulting in a decrease in oxygen reduction activity. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a carbon quantum dot-loaded carbon black material, its preparation method and application, and a cathode catalyst for a proton exchange membrane fuel cell. The carbon quantum dot-loaded carbon black material prepared by the preparation method can avoid the aggregation of Pt and improve the catalytic activity.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a carbon black material loaded with carbon quantum dots, comprising the following steps:

[0007] The carbon black is mixed with concentrated nitric acid to perform modification to obtain a carboxyl-modified carbon black carrier;

[0008] Lignin, water and ethylene glycol are mixed, subjected to hydrothermal reaction, and then amino modified to obtain carbon quantum dots;

[0009] The carboxyl-modified carbon black carrier, carbon quantum dots and water are mixed and loaded to obtain the carbon black material loaded with carbon quantum dots.

[0010] Preferably, the mass ratio of the carbon black to concentrated nitric acid is (20-40): (50-80);

[0011] The modification temperature is 50-70°C and the modification time is 2-6 hours;

[0012] The particle size of the carboxyl-modified carbon black carrier is 100 to 200 nm.

[0013] Preferably, the mass ratio of lignin, water and ethylene glycol is (10-20): (180-200): (40-50);

[0014] The temperature of the hydrothermal reaction is 180-240° C., and the time is 4-8 hours.

[0015] Preferably, the amination reagent used in the amination modification is preferably carbodiimide hydrochloride and / or N-hydroxysuccinimide.

[0016] Preferably, the mass ratio of the carboxyl-modified carbon black support, carbon quantum dots and deionized water is 1:10:(100-150);

[0017] The temperature of the load is 40 to 60° C., and the time is 12 to 24 hours.

[0018] The present invention also provides a carbon black material loaded with carbon quantum dots prepared by the preparation method described in the above technical solution.

[0019] The present invention also provides the use of the carbon black material loaded with carbon quantum dots described in the above technical solution in a proton exchange membrane fuel cell.

[0020] The present invention also provides a method for preparing a cathode catalyst for a proton exchange membrane fuel cell, comprising the following steps:

[0021] After mixing carbon black material loaded with carbon quantum dots, ionomer and dispersion solvent, the obtained dispersion is coated on the surface of the proton exchange membrane to obtain a support layer of the loaded carbon membrane;

[0022] Immersing the carbon membrane-loaded support layer in an aqueous solution containing a platinum precursor and a reducing agent to perform a reduction reaction to obtain the cathode catalyst;

[0023] The carbon black material loaded with carbon quantum dots is the carbon black material loaded with carbon quantum dots described in the above technical solution.

[0024] Preferably, the concentration of the ionomer in the dispersion is 5 to 10 wt %; the concentration of the carbon black material supported by the carbon quantum dots in the dispersion is 10 to 20 wt %;

[0025] The ionomer comprises PTFE and / or sulfonic acid resin;

[0026] The dispersing solvent includes one or more of methanol, ethanol, isopropanol, n-propanol, butanol, N,N-dimethylformamide and toluene.

[0027] Preferably, the concentration of the platinum precursor in the aqueous solution containing the platinum precursor and the reducing agent is 0.1 to 1 wt %, and the concentration of the reducing agent is 5 to 10 wt %;

[0028] The platinum precursor includes chloroplatinic acid and / or platinum nitrate; the reducing agent includes one or more of ascorbic acid, formic acid and acetic acid;

[0029] The reduction reaction temperature is 50-70° C. and the time is 24-36 hours.

[0030] The present invention provides a method for preparing a carbon black material loaded with carbon quantum dots, comprising the following steps: mixing carbon black with concentrated nitric acid and modifying the mixture to obtain a carboxyl-modified carbon black carrier; mixing lignin, water, and ethylene glycol, subjecting the mixture to a hydrothermal reaction, and then performing amino modification to obtain carbon quantum dots; and mixing the carboxyl-modified carbon black carrier, the carbon quantum dots, and deionized water, and loading the mixture to obtain the carbon black material loaded with carbon quantum dots. The preparation method of the present invention first performs amino modification on the carbon black carrier and then modifies the surface with carbon quantum dots. Through an amidation reaction between the amino and carboxyl groups, the catalyst can be prevented from aggregating on the carrier surface, providing a more effective three-phase interface for the Pt atoms and improving the electrocatalytic activity of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The cyclic voltammetry curves of the carbon black material supported by carbon quantum dots described in Examples 1 and 2 and the cathode catalyst described in Comparative Examples 1 and 2;

[0032] Figure 2 These are TEM images of the carbon black materials loaded with carbon quantum dots described in Examples 1 and 2 and the cathode catalysts described in Comparative Examples 1 and 2 after polarization testing. DETAILED DESCRIPTION

[0033] The present invention provides a method for preparing a carbon black material loaded with carbon quantum dots, comprising the following steps:

[0034] The carbon black is mixed with concentrated nitric acid to perform modification to obtain a carboxyl-modified carbon black carrier;

[0035] Lignin, water and ethylene glycol are mixed, subjected to hydrothermal reaction, and then amino modified to obtain carbon quantum dots;

[0036] The carboxyl-modified carbon black carrier, carbon quantum dots and water are mixed and loaded to obtain the carbon black material loaded with carbon quantum dots.

[0037] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well known to those skilled in the art.

[0038] The invention mixes carbon black and concentrated nitric acid, performs modification, and obtains a carboxyl-modified carbon black carrier.

[0039] In the present invention, the particle size of the carbon black is preferably 100 to 200 nm, more preferably 120 to 180 nm, and most preferably 140 to 160 nm.

[0040] The present invention does not have any particular limitation on the concentrated nitric acid, and any type well known to those skilled in the art may be used.

[0041] In the present invention, the mass ratio of the carbon black to concentrated nitric acid is preferably (20-40):(50-80), more preferably (25-35):(55-75), and most preferably (28-32):(60-70).

[0042] In the present invention, the mixing is preferably performed by adding carbon black to the concentrated nitric acid. The present invention does not have any particular limitation on the manner of adding, and the method well known to those skilled in the art can be used.

[0043] In the present invention, the modification temperature is preferably 50-70°C, more preferably 55-65°C, and most preferably 58-62°C; the modification time is preferably 2-6h, more preferably 3-5h, and most preferably 3.5-4.5h.

[0044] After the modification is completed, the present invention preferably further comprises filtering, washing, and drying, which are performed sequentially. The present invention does not have any particular limitations on the filtering process, and can be performed using a process well known to those skilled in the art. In the present invention, the washing is preferably performed using deionized water. In the present invention, the drying method is preferably oven drying. The present invention does not have any particular limitations on the drying process, and can be performed using a process well known to those skilled in the art.

[0045] In the present invention, the particle size of the carboxyl-modified carbon black carrier is preferably 100 to 200 nm.

[0046] The preparation method of the present invention further comprises mixing lignin, water and ethylene glycol, performing a hydrothermal reaction, and then performing amino modification to obtain carbon quantum dots.

[0047] In the present invention, the mass ratio of lignin, water and ethylene glycol is preferably (10-20): (180-200): (40-50), more preferably (12-18): (185-195): (42-48), and most preferably (13-16): (188-192): (43-46).

[0048] The present invention does not have any special limitation on the mixing process, and the mixing process may be carried out using a process well known to those skilled in the art.

[0049] In the present invention, the temperature of the hydrothermal reaction is preferably 180-240° C., more preferably 190-230° C., most preferably 200-210° C.; the time is preferably 4-8 h, more preferably 5-6 h.

[0050] After the hydrothermal reaction is completed, the present invention also preferably includes sequential solid-liquid separation and drying. The present invention does not have any special limitation on the solid-liquid separation and drying process, and the process can be carried out using a process well known to those skilled in the art.

[0051] In the present invention, the amination reagent used in the amino modification is preferably carbodiimide hydrochloride and / or N-hydroxysuccinimide. When the amination reagent is carbodiimide hydrochloride and N-hydroxysuccinimide, the present invention has no special limitation on the ratio of the carbodiimide hydrochloride and N-hydroxysuccinimide, and they can be mixed in any ratio.

[0052] The present invention has no special limitation on the process of the amino modification, and the process can be carried out using a process well known to those skilled in the art.

[0053] After obtaining the carboxyl-modified carbon black carrier and carbon quantum dots, the present invention mixes the carboxyl-modified carbon black carrier, carbon quantum dots and deionized water for loading to obtain the carbon quantum dot-loaded carbon black material.

[0054] In the present invention, the mass ratio of the carboxyl-modified carbon black carrier, carbon quantum dots and deionized water is preferably 1:10:(100-150), more preferably 1:10:(110-140), and most preferably 1:10:(120-130).

[0055] The present invention does not have any special limitation on the mixing process, and the mixing process may be carried out using a process well known to those skilled in the art.

[0056] In the present invention, the temperature of the load is preferably 40-60°C, more preferably 45-55°C, most preferably 48-52°C; the time is preferably 12-24h, more preferably 15-22h, most preferably 16-20h.

[0057] After the loading is completed, the present invention also preferably includes filtering, washing, and drying in sequence. The present invention does not have any particular limitations on the filtration process, and a process well known to those skilled in the art can be used. In the present invention, the washing is preferably performed with deionized water. In the present invention, the drying method is preferably oven drying. The present invention does not have any particular limitations on the drying process, and a process well known to those skilled in the art can be used.

[0058] The present invention also provides a carbon black material loaded with carbon quantum dots prepared by the preparation method described in the above technical solution.

[0059] In the present invention, the carbon quantum dot-loaded carbon black material comprises a carboxyl-modified carbon black carrier and carbon quantum dots loaded on the carboxyl-modified carbon black carrier; the carbon quantum dots are amino-modified carbon quantum dots.

[0060] In the present invention, the mass ratio of the carboxyl-modified carbon black support to the carbon quantum dots is preferably 1:10.

[0061] The present invention also provides the use of the carbon black material loaded with carbon quantum dots described in the above technical solution in a proton exchange membrane fuel cell.

[0062] The present invention also provides a method for preparing a cathode catalyst for a proton exchange membrane fuel cell, comprising the following steps:

[0063] After mixing carbon black material loaded with carbon quantum dots, ionomer and dispersion solvent, the obtained dispersion is coated on the surface of the proton exchange membrane to obtain a support layer of the loaded carbon membrane;

[0064] Immersing the carbon membrane-loaded support layer in an aqueous solution containing a platinum precursor and a reducing agent to perform a reduction reaction to obtain the cathode catalyst;

[0065] The carbon black material loaded with carbon quantum dots is the carbon black material loaded with carbon quantum dots described in the above technical solution.

[0066] The present invention mixes carbon black material loaded with carbon quantum dots, ionomer and dispersing solvent, and then coats the obtained dispersion on the surface of a proton exchange membrane to obtain a supporting layer of the loaded carbon membrane.

[0067] In the present invention, the ionomer preferably includes PTFE and / or a sulfonic acid resin; the sulfonic acid resin preferably includes one or more of a perfluorosulfonic acid resin, a parafluorosulfonic acid resin, and a non-fluorosulfonic acid resin. When the ionomer comprises two or more of the above-mentioned specific selections, the present invention does not impose any particular restrictions on the ratio of the above-mentioned specific materials; they can be mixed in any ratio.

[0068] In the present invention, the dispersing solvent preferably includes one or more of methanol, ethanol, isopropanol, n-propanol, butanol, N,N-dimethylformamide and toluene. When the dispersing solvent is two or more of the above-mentioned specific selections, the present invention has no special restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0069] The present invention does not have any special limitation on the mixing process, and the mixing process may be carried out using a process well known to those skilled in the art.

[0070] In the present invention, the concentration of the ionomer in the dispersion is preferably 5-10wt%, more preferably 6-8wt%; the concentration of the carbon black material loaded with carbon quantum dots in the dispersion is preferably 10-20wt%, more preferably 12-18wt%, and most preferably 15-16wt%.

[0071] In the present invention, the coating method is preferably spraying. The present invention does not have any special limitation on the spraying process, and the process well known to those skilled in the art can be used.

[0072] The present invention does not have any special limitation on the coating amount of the coating, and any coating amount well known to those skilled in the art can be used.

[0073] After the coating is completed, the present invention further preferably includes curing, and the curing method is preferably drying. The present invention has no special limitation on the drying process, and the drying process can be carried out using a process well known to those skilled in the art.

[0074] After obtaining the support layer of the loaded carbon membrane, the present invention immerses the support layer of the loaded carbon membrane in an aqueous solution containing a platinum precursor and a reducing agent to perform a reduction reaction to obtain the cathode catalyst.

[0075] In the present invention, the concentration of the platinum precursor in the aqueous solution containing the platinum precursor and the reducing agent is preferably 0.1-1 wt%, more preferably 0.3-0.9 wt%, and most preferably 0.4-0.6 wt%; the concentration of the reducing agent is preferably 5-10 wt%, more preferably 6-8 wt%.

[0076] In the present invention, the platinum precursor preferably includes chloroplatinic acid and / or platinum nitrate. When the platinum precursor includes chloroplatinic acid and platinum nitrate, the present invention has no special restrictions on the ratio of the chloroplatinic acid and platinum nitrate, and they can be mixed in any ratio; the reducing agent preferably includes one or more of ascorbic acid, formic acid and acetic acid. When the reducing agent is two or more of the above-mentioned specific selections, the present invention has no special restrictions on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio.

[0077] In the present invention, the temperature of the reduction reaction is preferably 50-70° C., more preferably 55-65° C., most preferably 58-62° C.; the time is preferably 24-36 h, more preferably 26-34 h.

[0078] After the reduction reaction is completed, the present invention also preferably includes sequential cleaning and drying; the cleaning is preferably performed by rinsing with deionized water; the drying method is preferably drying. The present invention does not have any special restrictions on the drying process, and the process familiar to those skilled in the art can be used.

[0079] The carbon black material loaded with carbon quantum dots and its preparation method and application, as well as the cathode catalyst for proton exchange membrane fuel cells provided by the present invention are described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present invention.

[0080] Example 1

[0081] 20 g of carbon black was added to 50 g of concentrated nitric acid with a concentration of 0.1 mol / L, and the mixture was heated to 50° C. and reacted for 2 h. The mixture was then filtered, washed with deionized water, and dried to obtain a carboxyl-modified carbon black carrier.

[0082] 10 g of lignin, 180 g of water, and 40 g of ethylene glycol were mixed, reacted in a reactor at 180 ° C for 4 h, dried, and amino-modified with N-hydroxysuccinimide to obtain carbon quantum dots;

[0083] The carboxyl-modified carbon black support, carbon quantum dots, and deionized water were mixed in a mass ratio of 1:5:100, reacted at 40° C. for 12 h, washed with deionized water, and dried to obtain a carbon black material loaded with carbon quantum dots;

[0084] After mixing 10 g of carbon black material loaded with carbon quantum dots, 20 g of PTFE and 2000 g of isopropyl alcohol, the resulting dispersion was evenly sprayed on the surface of the proton exchange membrane and then dried to obtain a support layer of the loaded carbon membrane;

[0085] The support layer of the loaded carbon membrane is immersed in an aqueous solution containing chloroplatinic acid and ascorbic acid (the concentration of chloroplatinic acid is 0.3wt%, and the concentration of ascorbic acid is 6wt%) for a reduction reaction (the temperature of the reduction reaction is 50°C and the time is 24h), and then rinsed with deionized water and dried to obtain the cathode catalyst.

[0086] Example 2

[0087] 25 g of carbon black was added to 60 g of concentrated nitric acid with a concentration of 0.2 mol / L, and the mixture was heated to 60° C. and reacted for 3 h. The mixture was then filtered, washed with deionized water, and dried to obtain a carboxyl-modified carbon black carrier.

[0088] 15 g of lignin, 180 g of water, and 50 g of ethylene glycol were mixed, reacted in a reactor at 180 ° C for 6 h, dried, and amino-modified with N-hydroxysuccinimide to obtain carbon quantum dots;

[0089] The carboxyl-modified carbon black support, carbon quantum dots, and deionized water were mixed in a mass ratio of 1:5:100, reacted at 50° C. for 18 h, washed with deionized water, and dried to obtain a carbon black material loaded with carbon quantum dots;

[0090] After mixing 15 g of carbon black material loaded with carbon quantum dots, 30 g of PTFE and 3000 g of isopropyl alcohol, the resulting dispersion was evenly sprayed on the surface of the proton exchange membrane and then dried to obtain a support layer loaded with carbon membrane;

[0091] The support layer of the loaded carbon membrane is immersed in an aqueous solution containing chloroplatinic acid and ascorbic acid (the concentration of chloroplatinic acid is 0.1wt%, the concentration of ascorbic acid is 5wt%) for reduction reaction (the temperature of the reduction reaction is 60°C and the time is 30h), and then rinsed with deionized water and dried to obtain the cathode catalyst.

[0092] Comparative Example 1

[0093] 20 g of carbon black was added to 50 g of concentrated nitric acid with a concentration of 0.1 mol / L, and the mixture was heated to 50° C. and reacted for 2 h. The mixture was then filtered, washed with deionized water, and dried to obtain a carboxyl-modified carbon black carrier.

[0094] After mixing 10 g of carboxyl-modified carbon black support, 20 g of PTFE and 2000 g of isopropyl alcohol, the resulting dispersion was evenly sprayed on the surface of the proton exchange membrane and then dried to obtain a support layer for the carbon membrane;

[0095] The support layer of the loaded carbon membrane is immersed in an aqueous solution containing chloroplatinic acid and ascorbic acid (the concentration of chloroplatinic acid is 0.3wt%, and the concentration of ascorbic acid is 6wt%) for a reduction reaction (the temperature of the reduction reaction is 50°C and the time is 24h), and then rinsed with deionized water and dried to obtain the cathode catalyst.

[0096] Comparative Example 2

[0097] 10 g of lignin, 180 g of water, and 40 g of ethylene glycol were mixed, reacted in a reactor at 180 ° C for 4 h, dried, and amino-modified with N-hydroxysuccinimide to obtain carbon quantum dots;

[0098] Carbon black, carbon quantum dots, and deionized water were mixed at a mass ratio of 1:5:100, reacted at 40°C for 12 hours, washed with deionized water, and dried to obtain a carbon black material loaded with carbon quantum dots.

[0099] After mixing 10 g of carbon black material loaded with carbon quantum dots, 20 g of PTFE and 2000 g of isopropyl alcohol, the resulting dispersion was evenly sprayed on the surface of the proton exchange membrane and then dried to obtain a support layer of the loaded carbon membrane;

[0100] The support layer of the loaded carbon membrane is immersed in an aqueous solution containing chloroplatinic acid and ascorbic acid (the concentration of chloroplatinic acid is 0.3wt%, and the concentration of ascorbic acid is 6wt%) for a reduction reaction (the temperature of the reduction reaction is 50°C and the time is 24h), and then rinsed with deionized water and dried to obtain the cathode catalyst.

[0101] Test Case

[0102] The carbon black material loaded with carbon quantum dots described in Examples 1 and 2 and the cathode catalyst described in Comparative Examples 1 and 2 were assembled into a fuel cell. The fuel cell consisted of a membrane electrode prepared with a cathode catalyst, a graphite bipolar plate, a current collecting plate and an end plate. The assembled fuel cell was then subjected to a cyclic voltammetry test under the conditions of a voltage range of 0.6-0.75 V and a scan rate of 10 mV / s. The test results were as follows: Figure 1 As shown by Figure 1 It can be seen that the curve area of ​​Example 2 is the largest, representing the highest electrocatalytic activity, followed by Example 1, Comparative Example 2, and Comparative Example 1;

[0103] Polarization test was conducted on the fuel cell assembled with the carbon black material loaded with carbon quantum dots described in Examples 1 and 2 and the cathode catalyst described in Comparative Examples 1 and 2. After the test, the catalyst in the membrane electrode was subjected to TEM test. The test results are as follows: Figure 2 As shown, wherein, (a) Example 2, (b) Example 1, (c) Comparative Example 2, (d) Comparative Example 1; Figure 2 It can be seen that Example 2 has the smallest particle size and no obvious aggregation phenomenon, while Comparative Example 1 has the largest particle size and large-scale aggregation occurs.

[0104] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a carbon black material loaded with carbon quantum dots for use as a Pt support for cathode catalysts in proton exchange membrane fuel cells, characterized in that: The following steps are involved: The carbon black is mixed with concentrated nitric acid to perform modification to obtain a carboxyl-modified carbon black carrier; Lignin, water and ethylene glycol are mixed, subjected to hydrothermal reaction, and then amino modified to obtain carbon quantum dots; The carboxyl-modified carbon black carrier, carbon quantum dots and water are mixed and loaded to obtain the carbon quantum dot-loaded carbon black material; The amination reagent used in the amination modification is carbodiimide hydrochloride and / or N-hydroxysuccinimide.

2. The preparation method according to claim 1, wherein The mass ratio of the carbon black to concentrated nitric acid is (20-40): (50-80); The modification temperature is 50-70°C and the modification time is 2-6 hours; The particle size of the carboxyl-modified carbon black carrier is 100-200 nm.

3. The preparation method according to claim 1, wherein The mass ratio of the lignin, water and ethylene glycol is (10-20): (180-200): (40-50); The temperature of the hydrothermal reaction is 180-240° C., and the time is 4-8 hours.

4. The preparation method according to claim 1, wherein The mass ratio of the carboxyl-modified carbon black carrier, carbon quantum dots and water is 1:10:(100-150); The load temperature is 40-60° C., and the time is 12-24 hours.

5. The carbon black material loaded with carbon quantum dots prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the carbon black material loaded with carbon quantum dots according to claim 5 in a proton exchange membrane fuel cell.

7. A method for preparing a cathode catalyst for a proton exchange membrane fuel cell, characterized in that: The following steps are involved: After mixing carbon black material loaded with carbon quantum dots, ionomer and dispersion solvent, the obtained dispersion is coated on the surface of the proton exchange membrane to obtain a support layer of the loaded carbon membrane; Immersing the carbon membrane-loaded support layer in an aqueous solution containing a platinum precursor and a reducing agent to perform a reduction reaction to obtain the cathode catalyst; The carbon quantum dot-loaded carbon black material is the carbon quantum dot-loaded carbon black material according to claim 6.

8. The preparation method according to claim 7, wherein The concentration of the ionomer in the dispersion is 5-10 wt %; the concentration of the carbon black material supported by the carbon quantum dots in the dispersion is 10-20 wt %; The ionomer comprises PTFE and / or sulfonic acid resin; The dispersing solvent includes one or more of methanol, ethanol, isopropanol, n-propanol, butanol, N,N-dimethylformamide and toluene.

9. The preparation method according to claim 8, wherein The aqueous solution containing a platinum precursor and a reducing agent has a platinum precursor concentration of 0.1 to 1wt%, the reducing agent concentration of 5 to 10wt%; The platinum precursor includes chloroplatinic acid and / or platinum nitrate; the reducing agent includes one or more of ascorbic acid, formic acid and acetic acid; The reduction reaction temperature is 50-70° C. and the time is 24-36 hours.

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