CN115863663A - Preparation method and application of heteroatom nitrogen-phosphorus-sulfur-doped carbon-coated cobalt-phosphorus-sulfur nanorod composite material - Google Patents
Preparation method and application of heteroatom nitrogen-phosphorus-sulfur-doped carbon-coated cobalt-phosphorus-sulfur nanorod composite material Download PDFInfo
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Abstract
The invention relates to a preparation method and application of a heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material. The invention adopts a method of firstly hydrothermal and then twice high-temperature calcination, namely irregular nano particles are crystallized into regular nano rods, and the sulfur source thiourea and the phosphorus source sodium hypophosphite are added and doped into a carbon substrate and a cobalt lattice to form the nitrogen-phosphorus-sulfur triple-doped carbon-coated cobalt-phosphorus-sulfur nano rod with better catalytic performance. The invention ensures that the large-particle cobalt metal forms cobalt nanorods with smaller sizes which are uniformly distributed in a carbon matrix, and the two elements of phosphorus and sulfur are doped into the crystal lattice of cobalt in the calcining process to form a new cobalt phosphorus sulfur nanorod, and the carbon matrix is doped with the elements of nitrogen, phosphorus and sulfur, so that the advantages of the cobalt phosphorus sulfur nanorod are more outstanding, the cobalt phosphorus sulfur nanorod has excellent oxygen reduction activity far exceeding that of the current commercial platinum carbon, and the application prospect is wide.
Description
The technical field is as follows:
the invention relates to the technical field of materials, in particular to preparation and application of a heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material.
Background
With the coming of global energy crisis and the increasing environmental pollution and greenhouse effect caused by the combustion of fossil fuels, the development of clean energy is urgently needed. There is an increasing concern about the storage and conversion of sustainable energy, and fuel cells are currently of high research value as one of the most promising clean energy converters. In a fuel cell, fuel is oxidized at the anode, the released electrons are transferred through an external circuit to the cathode, and oxygen is reduced at the cathode. However, since oxygen reduction ORR is a four-electron reaction, the kinetics are very slow, greatly limiting the energy output efficiency of the fuel cell. ORR is a very important reaction for fuel cells. It is well known that the best ORR catalyst at present is the Pt-based catalyst. Although the platinum-based catalyst has the most outstanding catalytic activity, the platinum-based catalyst has poor stability, and platinum is scarce, has a small reserve and is expensive. Therefore, it is necessary to develop a high-efficiency and high-stability catalyst of non-platinum group.
In recent years, researchers have developed a large number of transition metals and their compounds as highly efficient oxygen reduction catalysts. Of the many transition metal based catalysts, cobalt is one of the transition metals that was earlier used as an oxygen reduction catalyst in a basic medium. With the progress of research, most of the transition metal ORR electrocatalysts have good stability and good catalytic activity, but are still inferior to the noble metal catalysts. Although researchers have improved the performance of cobalt metal electrocatalysts, the inherent problem of poor electrical conductivity still exists, and the ultra-small structural feature makes the catalysts easy to aggregate during the reaction process to lose a large amount of active sites, which limits further application of the catalysts in the field of oxygen reduction. Therefore, the composite material can be effectively compounded with a cobalt metal electrocatalyst and other stable and highly conductive carrier materials, and can realize a synergistic catalytic effect, so that the oxygen reduction catalytic efficiency and the long-term stability are improved.
Carbon materials, particularly nano carbon materials, have received extensive attention from researchers due to their unique properties of large specific surface area, acid and alkali resistance, high electrical conductivity, wide sources, tunable surface groups, and the like. Heteroatoms such as nitrogen, sulfur, phosphorus and the like with atom sizes similar to that of carbon atoms can be doped into a carbon skeleton structure on the surface layer of the nano carbon material, so that the physicochemical function of the carbon material is modified. Among them, nitrogen atoms are the closest to carbon atoms in radius, so that doping is easier to realize. The modification mode of sulfur to the carbon material mainly comprises two modes of surface functional modification of various sulfur-containing functional groups formed on the surface of the carbon material and doped substitution modification entering the crystal lattice of the carbon material. Phosphorus is used as a heteroatom to dope in a carbon material to prepare an oxygen reduction catalyst, and the phosphorus-doped carbon material has good stability and methanol resistance. Atoms with different electronegativities and atomic sizes are doped, so that the charge distribution and the spin density of carbon can be improved, the adsorption capacity of the carbon to reactants is adjusted, the chemical activity of the material can be changed due to defects caused by doping, and the oxygen reduction catalytic performance of the material is further improved.
However, because the carbonization temperature has a significant influence on the number of doped non-metal heteroatoms, and unstable heteroatoms are usually lost in the heat treatment process (limited or complex), the doping technology of the carbon nano-material at the center of the current technology has the defects of insufficient total content of non-metal heteroatoms caused by single element doping, so that the catalytic performance of the catalytic material is limited, and there is no way to unify the optimum temperature for doping different heteroatoms during doping of various elements, such as: the preparation method comprises the steps of dissolving nitrilotriacetic acid, manganese chloride and cobalt nitrate, carrying out a hydrothermal reaction at 180 ℃ to generate a Co/Mn-NTA precursor, cooling and drying, and carrying out one-time calcination in the atmosphere of hydrogen-argon mixed gas to generate the Co/MnO @ NC nanowire; although the direct carbonization of the compound rich in non-metallic heteroatoms has the advantage of being capable of adapting to the optimum temperature of nitrogen doping of heteroatoms, the method still has the defects that two optimum temperatures of nitrogen doping of heteroatoms cannot be adopted in one-time calcination, the total content of non-metallic heteroatoms in a single-doped carbon material is relatively low, and the formed nano-particles are not regular in nano-morphology but irregular in nano-particles.
Disclosure of Invention
The invention aims to provide a preparation method of a heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt nanorod composite material and an application of the heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt nanorod composite material as an oxygen reduction catalyst, aiming at the defects in the prior art. The invention adopts a method of firstly hydrothermal treatment and then twice high-temperature calcination, namely irregular nano particles are crystallized into regular nano rods, and sulfur source thiourea and phosphorus source sodium hypophosphite are added and doped into a carbon substrate and a cobalt lattice to form the nitrogen-phosphorus-sulfur triple-doped carbon-coated cobalt-phosphorus-sulfur nano rod with better catalytic performance. The large-particle cobalt metal forms cobalt nanorods with smaller sizes and are uniformly distributed in a carbon matrix, and the two elements of phosphorus and sulfur are doped into the crystal lattice of cobalt in the calcining process to form a new cobalt phosphorus sulfur nanorod, and meanwhile, the carbon matrix is doped with nitrogen, phosphorus and sulfur elements, so that the cobalt phosphorus sulfur nanorod has more outstanding advantages, obtains excellent oxygen reduction activity far exceeding that of current commercial platinum carbon, and has wide application prospect.
The invention provides the following specific technical scheme:
a preparation method of a heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material comprises the following steps:
first, preparing a Co @ NTA precursor:
adding nitrilotriacetic acid and cobalt nitrate into a mixed solvent, heating to 60-80 ℃, stirring, immediately pouring into a reaction kettle after dissolving, and carrying out hydrothermal reaction for 6-9 hours at 160-180 ℃; naturally cooling, performing suction filtration, then respectively performing centrifugal washing by using deionized water and ethanol, and then performing suction filtration, and drying at 60-80 ℃ for 24-48h to obtain a Co @ NTA precursor;
wherein, the mass ratio of nitrilotriacetic acid to cobalt nitrate is 0.8 to 1.2, the mixed solvent comprises deionized water and isopropanol, and the volume ratio of the deionized water to the isopropanol is 6 to 8:1; 0.5-1g of nitrilotriacetic acid is added into every 50mL of mixed solvent;
second, preparation of CoS @ SNTA:
mixing and grinding the obtained Co @ NTA precursor and thiourea for 1-2 hours, pouring the mixture into a porcelain boat, transferring the porcelain boat into a muffle furnace which is filled with argon for 10-30 minutes, heating the mixture to 900-950 ℃ at a heating rate of 3-5 ℃/minute, and calcining the mixture for 3-4 hours to obtain the CoS @ SNTA, wherein the mass ratio of the Co @ NTA precursor to the thiourea is 1:8-12;
thirdly, preparing CoPS @ PSNTA
Cooling the obtained CoPS @ SNTA, immediately placing sodium hypophosphite at the front end of the muffle furnace, heating to 550-650 ℃ at the heating rate of 2-3 ℃/min, calcining for 2-3h, cooling, washing and drying for 24-48h by using deionized water and ethanol to obtain CoPS @ PSNTA;
wherein the mass ratio of the CoPS @ SNTA precursor to the sodium hypophosphite is 1:8-12.
The application of the heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material loads the composite material on the cathode of a fuel cell as a catalyst.
The invention has the following essential characteristics:
in the prior art, a single metal/metal oxide-single element doped carbon substrate is formed by one-time direct calcination under the atmosphere of hydrogen-argon mixture.
According to the invention, nitrilotriacetic acid and cobalt nitrate are selected, a Co @ NTA precursor is obtained through a hydrothermal reaction after dissolution, the Co @ NTA precursor and thiourea are mixed and calcined to obtain CoS @ SNTA, sodium hypophosphite is placed at the front end of a muffle furnace immediately after cooling, and the calcination is carried out to obtain the heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material, and the synthesized material is applied to an oxygen reduction reaction ORR for the first time.
Compared with other known preparation methods of carbon-coated metal two-dimensional composite materials, the method comprises the steps of firstly carrying out hydrothermal and then carrying out high-temperature calcination twice on nitrilotriacetic acid and cobalt nitrate to enable the cobalt metal in large particles to form cobalt nanorods with smaller sizes to be uniformly distributed in a carbon matrix, doping phosphorus and sulfur elements into crystal lattices of cobalt in the calcination process, forming new cobalt phosphorus sulfur nanorods, and doping nitrogen phosphorus and sulfur elements on the carbon matrix. The nitrogen-phosphorus-sulfur triple-doped carbon matrix has extremely strong conductivity, larger defect degree and larger specific surface area, and can better adsorb oxygen; the formed cobalt-phosphorus-sulfur nanorod has better catalytic reduction performance on oxygen compared with a cobalt nanorod, and the prepared catalyst has a coating structure which can greatly improve the stability, the conductivity, the acid-base resistance and the methanol resistance of the catalyst.
The beneficial effects of the invention are as follows:
compared with other metal catalysts, the catalyst adopts a transition metal cobalt compound and is combined with a non-metal material, so that the use of noble metal is avoided, and the cost is reduced. Meanwhile, compared with the common carbon substrate, the nitrogen-phosphorus-sulfur triple-doped carbon substrate has stronger conductivity, higher defect degree and more active sites, the cobalt-phosphorus-sulfur nanorod formed by doping phosphorus-sulfur elements into the crystal lattice of the cobalt nanorod has better catalytic reduction performance on oxygen compared with the cobalt nanorod, the cobalt-sulfur nanorod and the cobalt-phosphorus nanorod, and the carbon substrate can generate synergistic effect with the cobalt-phosphorus-sulfur nanorod, so that the effect is favorable for ORR activity; and the nitrogen-phosphorus-sulfur triple-doped carbon matrix further enhances the synergistic effect, so that the catalytic performance of the catalyst is further improved, the electron transfer rate is increased, the charge transfer resistance is reduced, and the catalytic active sites are effectively increased. In addition, the prepared catalyst has a coating structure which can enhance the stability of the cobalt-phosphorus-sulfur nanorod, ensure that the cobalt-phosphorus-sulfur nanorod is not easy to agglomerate and a metal central site drops, and can improve the conductivity, acid-base resistance and methanol resistance of the catalyst. Through electrochemical performance tests, the synthesized electrocatalytic composite material has excellent oxygen reduction catalytic activity. The initial potential and the half-wave potential are respectively as follows: 0.96V and 0.86V, better than 0.95V and 0.84V of commercial platinum carbon, and higher limiting current density.
Description of the drawings:
FIG. 1 is a TEM image of the heteroatom N-P-S doped carbon-coated cobalt-P-S nanorod composite material obtained in example 1
FIG. 2 is a TEM image of the heteroatom N-P-S doped carbon-coated cobalt-P-S nanorod composite material obtained in example 1
FIG. 3 is an XPS image of the elements of the heteroatom N-P-S doped carbon-coated cobalt-P-S nanorod composite material obtained in example 1
FIG. 4 is an XRD spectrum of the heteroatom nitrogen phosphorus sulfur doped carbon coated cobalt phosphorus sulfur nanorod composite material obtained in example 1
FIG. 5 is the linear voltammetry scan curve (sweep rate of 10mv/s, rotation speed of 1600 rpm) of the heteroatom N-P-S doped carbon-coated cobalt-P-S nanorod composite material obtained in example 1 and a commercial Pt-C catalyst in 0.1mol/L oxygen saturated KOH solution.
FIG. 6 is it curve of the heteroatom N-P-S doped carbon coated cobalt-P-S nanorod composite material obtained in example 1 and a commercial platinum-carbon catalyst in 6mol/L oxygen saturated KOH solution.
Fig. 7 is a test chart of methanol resistance of the heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material and the commercial platinum carbon catalyst obtained in example 1.
The specific implementation mode is as follows:
the following is a specific example for a ternary heterostructure FePc/Ti 3 C 2 /g-C 3 N 4 The preparation of the composite material and its use as an oxygen reduction catalyst are further described.
Example 1:
preparation of Co @ NTA precursor
1.2g of cobalt nitrate and 0.8g of nitrilotriacetic acid were placed in a clean beaker, followed by 35mL of deionized water and 5mL of isopropanol, and a clean rotor was added. Covering a preservative film to prevent external impurities from polluting the solution, putting the solution into an oil bath pan, heating the solution to 60 ℃, and electromagnetically stirring the solution for dissolution; and then pouring the hot mixture into a high-pressure reaction kettle, screwing the hot mixture into a drying oven, heating the mixture to 180 ℃ for 6 hours, naturally cooling the mixture, performing suction filtration to obtain a solid precipitate, taking the solid on the filter paper, putting the solid into a centrifuge tube, adding deionized water into the centrifuge tube, performing centrifugal washing for 2 times at 10000rpm, adding ethanol into the centrifuge tube, performing centrifugal washing for 2 times at 10000rpm, performing suction filtration, and then putting the filter tube into a drying oven at 60 ℃ for drying for 24 hours to obtain the CoS @ SNTA precursor.
Preparation of CoS @ SNTA precursor
Pouring 0.25g of the prepared Co @ NTA into an agate mortar, adding 2.5g of thiourea, carefully grinding for 1h, putting into a cleaned porcelain boat, putting into a muffle furnace, raising the temperature to 900 ℃ at a heating rate of 3 ℃/min under the protection of nitrogen, and keeping for 3h to obtain the CoS @ SNTA precursor.
Preparation of CoPS @ PSNTA composite material
2.5g of sodium hypophosphite is put into an agate mortar to be ground into fine powder, then the powder is put into a cleaned porcelain boat, 0.25g of CoS @ SNTA precursor is put into the front end of a muffle furnace immediately after being cooled to room temperature, the sodium hypophosphite and the CoS @ SNTA precursor are put into the muffle furnace in a tandem way relative to the flow of argon gas, the temperature is raised to 600 ℃ at the heating rate of 2 DEG/min under the protection of nitrogen, the mixture is kept for 2h, black solid is taken out after the temperature is reduced to room temperature, the black solid is put into a centrifuge tube, deionized water is added into the centrifuge tube, the mixture is centrifugally washed and filtered at 10000rpm, ethanol is added into the centrifuge tube, the mixture is centrifugally washed and filtered again at 10000rpm, the centrifugal washing and the filtering are repeated for three times, and the mixture is put into a 60 ℃ drying box to be dried for 24h, and then the carbon-coated cobalt-phosphorus-sulfur composite nanorod material doped with nitrogen and phosphorus sulfur is prepared.
Example 2:
preparation of Co @ NTA precursor
2.1g of cobalt nitrate and 1.4g of nitrilotriacetic acid were placed in a clean beaker, followed by 69mL of deionized water and 11mL of isopropanol, and a clean rotor was added. Covering with a preservative film to prevent external impurities from polluting the solution, and putting the solution into an oil bath pan to be heated to 80 ℃ for stirring and dissolving; and then pouring the mixture into a reaction kettle while the mixture is hot, screwing the mixture and placing the mixture into a drying oven, heating the mixture to 180 ℃ and keeping the mixture for 6 hours, naturally cooling the mixture, performing suction filtration on the mixture to obtain a solid precipitate, taking the solid on filter paper, placing the solid on the filter paper into a centrifuge tube, adding deionized water and ethanol, performing centrifugal washing for 3 times at 10000rpm respectively, performing suction filtration, and placing the filter paper into the drying oven at 80 ℃ for drying for 48 hours to obtain a CoS @ SNTA precursor.
Preparation of CoS @ SNTA precursor
Pouring 0.5g of the prepared Co @ NTA into an agate mortar, adding 6g of thiourea, carefully grinding for 1.5h, putting into a cleaned porcelain boat, putting into a muffle furnace, raising the temperature to 950 ℃ at a heating rate of 4 ℃/min under the protection of nitrogen, and keeping for 3h to obtain the CoS @ SNTA precursor.
Preparation of CoPS @ PSNTA composite material
Putting 6g of sodium hypophosphite into an agate mortar, grinding into fine powder, putting into a cleaned porcelain boat, cooling 0.5g of CoS @ SNTA precursor to room temperature, immediately putting into the front end of a muffle furnace, putting the sodium hypophosphite and the CoS @ SNTA precursor in the muffle furnace in tandem, raising the temperature to 600 ℃ at a heating rate of 3 DEG/min under the protection of nitrogen, keeping for 2h, cooling to room temperature, taking out black solid, putting into a centrifuge tube, adding deionized water, centrifugally washing and filtering at 10000rpm, adding ethanol, centrifugally washing and filtering at 10000rpm again, repeating for 5 times, filtering, and putting into a drying box at 80 ℃ for drying for 48h to obtain the CoPS @ PSNTA composite material.
Application examples
The application of the synthesized nitrogen-phosphorus-sulfur-doped carbon-coated cobalt-phosphorus-sulfur nanorod composite material as an oxygen reduction catalyst in ORR (organic oxygen reduction) is tested.
Electrocatalysis performance test is carried out by using an electrochemical workstation and an RDE rotating disk electrode, a three-electrode system (an auxiliary electrode is a platinum electrode; a reference electrode is a platinum electrode, and the composite material obtained in example 1 is used as a working electrode) is placed into 0.1mol/L KOH solution under the condition of oxygen saturationLSV test was performed at 1600rpm (as catalyst, the catalyzed reaction was O) 2 +2H 2 O +4e- → 4OH — (i.e., oxygen reduction reaction)). When in actual application, the catalyst is loaded on the cathode of the fuel cell to be used as a catalyst. The potentials herein were converted to standard hydrogen electrodes, oxygen was applied for 20 minutes prior to testing, the electrolyte was saturated, voltammetric cycling was performed at 1600rpm for 20 cycles of electrode material at a sweep rate of 50mv/s, followed by linear voltammetric testing at a sweep rate of 10mv/s in the range of 1-0.2V. Each experiment was repeated 3 times to ensure the reliability of the experimental data.
FIGS. 1 and 2 are transmission electron microscope scanning images of the heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material prepared by the invention, from which it can be seen that the prepared cobalt phosphorus sulfur nanorod has a diameter of about 50-60nm and a length of about 150nm. And the prepared cobalt-phosphorus-sulfur nano rods are uniformly distributed in the carbon matrix.
FIG. 3 is an XPS image of each element of a carbon-coated cobalt-phosphorus-sulfur nanorod composite material doped with nitrogen, phosphorus and sulfur heteroatoms, from a C spectrum, we can see the existence of a C-N bond, a C-P bond and a C-S bond, and prove that three heteroatoms of nitrogen, phosphorus and sulfur are successfully doped into a carbon matrix; from the N spectrum we can see pyridine nitrogen, pyrrole nitrogen, graphite nitrogen and nitrogen oxide, and we can see that the relative proportions of pyridine nitrogen and graphite nitrogen of our catalyst are large, according to the previous literature data, the existence of pyridine nitrogen and graphite nitrogen is very beneficial to oxygen reduction performance; from Co spectrum, we can see that cobalt divalent and cobalt trivalent coexist to prove that our cobalt exists in the form of compound, and the successful synthesis of our cobalt-phosphorus-sulfur nano rod is laterally proved; from the P spectrum and the S spectrum, we can respectively see that Co-P and C-P bonds and Co-S and C-S exist to prove that the phosphorus and sulfur are doped into the carbon matrix and the crystal lattice of cobalt, and the successful synthesis of the cobalt phosphorus and sulfur is proved.
Fig. 4 is an XRD spectrum of the heteroatom nitrogen phosphorus sulfur doped carbon coated cobalt phosphorus sulfur nanorod composite material obtained in example 1. From the figure we can see that the diffraction peaks at 44.1 °, 51.4 ° and 75.7 ° are attributed to the (111) crystal plane of Co, confirming the successful loading of Co onto the carbon matrix. The diffraction peaks at 32.9 °, 37 °, 48.1 ° and 57.4 ° attributed to the (112) crystal plane of CoP confirm successful doping of phosphorus into the crystal lattice of cobalt. By analyzing the XRD pattern of CoS, it can be seen that peaks at 30.1 °, 35.3 °, 47.1 °, 54.5 ° and 74.8 ° correspond to the (100) plane of CoS, indicating successful doping of elemental sulfur into the crystal lattice of cobalt. The peak of CoPS @ PSNTA is similar to that of CoS, but slightly shifted to a lower angle, which is the result of lattice expansion caused by doping phosphorus element into the lattice of CoS, and also proves the successful synthesis of the cobalt-phosphorus-sulfur nanorod.
Fig. 5 shows the results of performance tests, where the initial potential and the half-wave potential are important indicators for evaluating the performance of ORR, and the larger the values of the two potentials in the LSV curve, the better, and the platinum carbon electrode has the best effect as the evaluation standard of ORR, i.e., the initial potential of 0.97V and the half-wave potential of 0.85V. The ternary heterostructure FePc/Ti prepared by the method 3 C 2 /g-C 3 N 4 The composite material catalyst is used in ORR, and the initial potential and the half-wave potential are 0.98V and 0.852V, respectively. And the manufacturing cost of the catalyst is far lower than that of a platinum carbon electrode. In addition, ternary heterostructure FePc/Ti 3 C 2 /g-C 3 N 4 The final limiting current density of the composite material catalyst is-7.18 mA/cm -2 Limiting current density of-5.495 mA/cm with platinum carbon -2 Compared with the prior art, the prepared catalyst has excellent performance.
FIG. 6 is the it curve of heteroatom nitrogen phosphorus sulfur doped carbon coated cobalt phosphorus sulfur nano rod composite material and commercial platinum carbon catalyst in 6mol/L oxygen saturated KOH solution.
Fig. 7 is a methanol resistance test chart of the heteroatom nitrogen phosphorus sulfur doped carbon coated cobalt phosphorus sulfur nanorod composite material and a commercial platinum carbon catalyst. In the figure, 50mL of methanol is injected into 0.1mol/L oxygen saturated KOH solution at 380 seconds, the current drop of platinum and carbon is very small, and the catalyst prepared by the invention still has strong performance after slight fluctuation, which proves that the catalyst prepared by the invention has strong methanol resistance.
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that, while the invention has been described in detail with reference to the above-mentioned embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.
The invention is not the best known technology.
Claims (4)
1. A preparation method of a heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material is characterized by comprising the following steps:
first, preparing a Co @ NTA precursor:
adding nitrilotriacetic acid and cobalt nitrate into a mixed solvent, heating to 60-80 ℃, stirring, dissolving, then pouring into a reaction kettle, and carrying out hydrothermal reaction at 160-180 ℃ for 6-9 hours; after natural cooling and suction filtration, respectively using deionized water and ethanol for centrifugal washing, then carrying out suction filtration and drying to obtain a Co @ NTA precursor;
wherein, the mass ratio of nitrilotriacetic acid to cobalt nitrate is 0.8 to 1.2, the mixed solvent comprises deionized water and isopropanol, and the volume ratio of the deionized water to the isopropanol is 6 to 8:1; adding 0.5-1g of nitrilotriacetic acid into every 50mL of mixed solvent;
second, preparation of CoS @ SNTA:
mixing and grinding the obtained Co @ NTA precursor and thiourea for 1-2 hours, pouring the mixture into a porcelain boat, transferring the porcelain boat into a muffle furnace which is filled with argon for 10-30 minutes, heating to 900-950 ℃ and calcining for 3-4 hours to obtain CoS @ SNTA;
wherein the mass ratio of the Co @ NTA precursor to the thiourea is 1:8-12;
thirdly, preparing CoPS @ PSNTA
Cooling the obtained CoPS @ SNTA, placing sodium hypophosphite at the front end of the muffle furnace, heating to 550-650 ℃, calcining for 2-3h, cleaning with deionized water and ethanol after cooling, and drying for 24-48h to obtain CoPS @ PSNTA;
wherein the mass ratio of the CoPS @ SNTA precursor to the sodium hypophosphite is 1:8-12.
2. The method for preparing the heteroatom nitrogen phosphorus sulfur doped carbon coated cobalt phosphorus sulfur nanorod composite material of claim 1, wherein the temperature rise rate in the second step is 3-5 ℃/min; the temperature rise rate in the third step is 2-3 ℃/min.
3. The method for preparing the heteroatom nitrogen phosphorus sulfur doped carbon-coated cobalt phosphorus sulfur nanorod composite material of claim 1, wherein the drying in the first step is drying at 60-80 ℃ for 24-48h.
4. The use of the heteroatom nitrogen phosphorus sulfur doped carbon coated cobalt phosphorus sulfur nanorod composite material prepared by the method of claim 1, characterized in that the composite material is supported on the cathode of a fuel cell as a catalyst.
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