CN119411168A

CN119411168A - Carbon-coated cerium-doped NiFeP material and preparation method and use thereof

Info

Publication number: CN119411168A
Application number: CN202411530636.7A
Authority: CN
Inventors: 刘玉宝; 李国玲; 杨鹏飞; 苗旭晨; 兰袖章; 周建昊; 高日增; 李园; 张全军; 黄海涛; 张洋; 张红
Original assignee: Baotou Rare Earth Research Institute
Current assignee: Baotou Rare Earth Research Institute
Priority date: 2024-10-30
Filing date: 2024-10-30
Publication date: 2025-02-11

Abstract

The invention discloses a carbon-coated cerium-doped NiFeP material, a preparation method and application thereof. The preparation method comprises the steps of performing electrochemical deposition on foam nickel to obtain Ni/NF, coating carbon on the surface of the Ni/NF by adopting a plasma enhanced chemical vapor deposition method to obtain Ni@C/NF, wherein carbon source gas of the plasma enhanced chemical vapor deposition reaction is CH ₄, reacting reaction liquid containing an iron source and a cerium source with the Ni@C/NF in a reaction kettle to obtain Ce-NiFe-LDH@C/NF, wherein the molar ratio of iron element contained in the iron source to cerium element contained in the cerium source is 1 (0.01-0.4), and performing the plasma enhanced chemical vapor deposition reaction on the Ce-NiFe-LDH@C/NF and red phosphorus to obtain the carbon coated cerium doped NiFeP material. The preparation method can improve the oxygen precipitation reaction activity and stability of the material.

Description

Carbon-coated cerium-doped NiFeP material and preparation method and application thereof

Technical Field

The invention relates to a carbon-coated cerium-doped NiFeP material, a preparation method and application thereof.

Background

Electrocatalytic decomposition of water is considered one of the environmental and efficient hydrogen production technologies. The transition metal phosphide has the advantages of low price, rich reserves and high conductivity, and is used as an electrocatalytic material. However, the electrocatalytic activity of transition metal phosphides still falls behind that of noble metals and severe corrosion phenomena may occur in harsh environments.

CN113832494A discloses a preparation method of transition/rare earth multi-metal co-doped phosphide, which comprises the steps of dissolving soluble ferric salt, soluble nickel salt and hydrated rare earth chloride in water containing an organic ligand, stirring, completely dissolving to form a solution, cooling, washing and centrifuging after a hydrothermal method, drying to obtain a precursor, mixing the precursor with an organic nitrogen source compound, fully and uniformly grinding, placing a porcelain boat containing materials in a tubular furnace and calcining in a protective atmosphere environment to obtain an iron-nickel-rare earth three-metal co-doped nitrogen-doped carbon nano tube, subpackaging the iron-nickel-rare earth three-metal co-doped nitrogen-doped carbon nano tube and an inorganic phosphorus source compound in two porcelain boats, and phosphating in the tubular furnace to obtain the transition/rare earth multi-metal co-doped phosphide. The phosphide has poor stability to acid, alkali and salt, and toxic substances containing phosphorus can be generated in the preparation process.

CN115094456A discloses a preparation method of a cerium dioxide nano particle/ferronickel bimetal phosphide/foam nickel composite electrode, which comprises the steps of firstly soaking foam nickel in acetone, washing with deionized water, then soaking with acid, washing with deionized water and ethanol, then drying in a vacuum drying oven, preparing nickel iron layered double hydroxide on the foam nickel by adopting a standard three-electrode system through a constant voltage deposition method to obtain a NiFe LDH/NF electrode, loading cerium dioxide nano particles on the NiFe LDH/NF electrode by adopting the standard three-electrode system through a constant current deposition method, respectively placing porcelain boats containing sodium hypophosphite and CeO ₂/NiFe LDH/NF electrodes at the upstream and middle parts of a tube furnace, then preserving heat at 250-350 ℃ in an argon environment, and naturally cooling to obtain the CeO ₂/NiFeP/NF composite electrode. The composite electrode has poor stability to acid, alkali and salt, and toxic substances containing phosphorus can be generated in the preparation process.

CN117779102A discloses a preparation method of a coral-shaped N-doped porous carbon coated zinc oxide/cobalt iron phosphide composite catalyst, which comprises the steps of co-dissolving cobalt salt, zinc salt and isonicotinic acid ligand in an organic solvent, reacting for 3-15 h at 120-180 ℃, cooling the solution to room temperature, centrifuging to obtain precipitate, washing and drying to obtain a precursor A, dispersing the precursor A in ethanol, adding an iron salt solution under the protection of N ₂/Ar for cation exchange, centrifuging to obtain electricity, vacuum drying to obtain a precursor B, calcining the precursor B under the protection of N ₂/Ar to obtain a precursor C, and reacting the precursor C and the phosphorus salt under the protection of N ₂/Ar at 250-350 ℃ to obtain the coral-shaped N-doped porous carbon coated zinc oxide/cobalt iron phosphide composite catalyst. The catalyst can produce poisonous phosphorus-containing substances in the preparation process, the electrolysis rate is low, and the OER activity is poor.

Disclosure of Invention

Accordingly, an object of the present invention is to provide a preparation method of a carbon-coated cerium-doped NiFeP material, wherein the carbon-coated cerium-doped NiFeP material obtained by the preparation method has high oxygen precipitation reactivity and high stability. It is another object of the present invention to provide a carbon-coated cerium doped NiFeP material. It is a further object of the present invention to provide a use of the carbon-coated cerium doped NiFeP material.

The above object is achieved by the following scheme.

In one aspect, the invention provides a method for preparing a carbon-coated cerium-doped NiFeP material, comprising the following steps:

(1) Performing electrochemical deposition on the foam nickel to obtain Ni/NF;

(2) Coating carbon on the surface of Ni/NF by adopting a plasma enhanced chemical vapor deposition method to obtain Ni@C/NF, wherein the carbon source gas of the plasma enhanced chemical vapor deposition reaction is CH ₄;

(3) Reacting a reaction solution containing an iron source and a cerium source with Ni@C/NF in a reaction kettle to obtain Ce-NiFe-LDH@C/NF, wherein the molar ratio of iron element contained in the iron source to cerium element contained in the cerium source is 1 (0.01-0.4);

(4) And carrying out a plasma enhanced chemical vapor deposition reaction on the Ce-NiFe-LDH@C/NF and red phosphorus to obtain the carbon-coated cerium doped NiFeP material.

According to the preparation method of the present invention, preferably, in the step (2), the diluent gas is a group 0 element gas, the reaction temperature is 400 to 800 ℃, and the discharge power is 100 to 300w.

According to the preparation method of the present invention, preferably, the diluent gas is argon, and the volume ratio of the diluent gas to the carbon source gas is (6-12): 1.

According to the preparation method of the present invention, preferably, in the step (4), the discharge gas is hydrogen and a group 0 element gas, and the volume ratio of the hydrogen to the group 0 element gas is 1 (1.5 to 5).

According to the preparation method of the present invention, preferably, in the step (4), the reaction temperature is 200 to 350 ℃, and the discharge power is 100 to 300w.

According to the preparation method, in the step (1), preferably, the anode is a nickel plate, the cathode is foam nickel, the electrolyte contains a nickel source, ammonium chloride and water, the deposition voltage is 0.5-2V, and the concentration of nickel element provided by the nickel source in the electrolyte is 1-3 mol/L.

According to the preparation method of the invention, in the step (3), preferably, the reaction solution contains an iron source, a cerium source, ammonium fluoride, urea and water, wherein the molar ratio of the iron element, the ammonium fluoride and the urea contained in the iron source is 1 (2-8): 7-13%, and the reaction temperature is 100-150 ℃.

In another aspect, the invention provides a carbon-coated cerium doped NiFeP material, which is prepared by the preparation method.

In yet another aspect, the present invention provides the use of the above carbon-coated cerium-doped NiFeP material in the electrolysis of water.

In yet another aspect, the present invention provides the use of the above carbon-coated cerium-doped NiFeP material in the electrolysis of alkaline water.

According to the invention, niFeP is doped with proper cerium, and a plasma enhanced chemical vapor deposition method is adopted for carbon coating, so that the oxygen precipitation reaction activity and the stability to alkali, salt and other environments are improved. According to the invention, CH ₄ is used as a carbon source, a carbon coating layer is efficiently formed under a low-temperature condition, so that the poison of an organic carbon source and morphology collapse caused by high-temperature calcination are avoided, and the conductivity, corrosion resistance and cycle stability are improved. The invention takes red phosphorus as phosphorus source, which can avoid generating toxic phosphine in the preparation process and can improve the oxygen precipitation reaction activity.

Drawings

Fig. 1 shows raman spectra of carbon-coated cerium-doped NiFeP material obtained in example 1 of the present invention.

Fig. 2 is an SEM image of the carbon-coated cerium-doped NiFeP material obtained in example 1 of the present invention.

Fig. 3 is an SEM spectrum of the carbon-coated cerium-doped NiFeP material obtained in example 1 of the present invention.

Fig. 4 is a TEM image of the carbon-coated cerium doped NiFeP material obtained in example 1 of the present invention. Wherein, the images a, b and c are respectively obtained under different magnification, and the images d and e are enlarged images of partial areas of the image c.

FIG. 5 shows polarization curves of oxygen evolution reactivity of the carbon-coated cerium-doped NiFeP material obtained in example 1 of the present invention under different conditions.

FIG. 6 is a graph showing the stability of the carbon-coated cerium-doped NiFeP material obtained in example 1 of the present invention in a 1mol/L KOH aqueous solution.

FIG. 7 is a graph showing the stability of the carbon-coated cerium-doped NiFeP material obtained in example 1 according to the present invention in a mixed aqueous solution of KOH and NaCl (KOH concentration: 1mol/L, naCl concentration: 0.5 mol/L).

FIG. 8 is a graph showing the stability of the carbon-coated cerium-doped NiFeP material obtained in example 1 of the present invention in seawater having a KOH concentration of 1 mol/L.

Wherein 1M KOH represents a KOH aqueous solution of 1mol/L, 1M KOH alkaline 0.5M NaCl represents a KOH and NaCl mixed aqueous solution (KOH concentration is 1mol/L, naCl concentration is 0.5 mol/L), and 1M KOH alkaline seawater represents seawater of 1mol/L KOH concentration.

Detailed Description

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

< Preparation method of carbon-coated cerium-doped NiFeP Material >

The preparation method of the carbon-coated cerium-doped NiFeP material comprises the following steps of (1) nickel deposition, (2) carbon coating, (3) cerium-iron compounding and (4) phosphating.

Step of Nickel deposition

The invention carries out electrochemical deposition on foam nickel to obtain Ni/NF.

Preferably, the electrochemical deposition employs a dual electrode system. The foam nickel is used as a cathode, and the nickel plate is used as an anode.

The electrolyte contains a nickel source and water. Preferably, the electrolyte further contains ammonium chloride. In certain embodiments, the electrolyte consists of a nickel source, ammonium chloride, and water.

The nickel source may be a water-soluble inorganic nickel salt. Such as nickel chloride. In the electrolyte, the concentration of nickel element provided by the nickel source is 1-3 mol/L, preferably 1.5-2.5 mol/L, and more preferably 2-2.2 mol/L.

The concentration of ammonium chloride in the electrolyte may be 1 to 3mol/L, preferably 1.5 to 2.5mol/L, more preferably 1.85 to 2.25mol/L.

The deposition voltage may be 0.5 to 2v, preferably 0.8 to 1.5v, more preferably 1 to 1.2v. Electrochemical deposition is performed at a constant voltage.

The deposition time may be 50 to 250 seconds, preferably 80 to 200 seconds, more preferably 100 to 150 seconds.

Preferably, the nickel foam is cleaned nickel foam. In some embodiments, the method further comprises the steps of ultrasonically cleaning the nickel foam in a solvent and then drying to obtain the cleaned nickel foam.

The solvent can be one or more of inorganic acid aqueous solution, water and small molecule alcohol. The mineral acid is preferably aqueous HCl. The concentration of the HCl aqueous solution may be 2 to 7mol/L, preferably 4 to 6mol/L. The small molecule alcohol may be a monohydric alcohol. For example, methanol, ethanol, propanol may be used.

Preferably, the nickel foam is ultrasonically cleaned in an aqueous solution of mineral acid, water and a small molecule alcohol in sequence. The time of ultrasonic cleaning in each solvent can be 3-20 min, preferably 5-15 min, and more preferably 10-12 min.

Drying may be performed under vacuum. Vacuum means a gas pressure of less than 10Pa, preferably less than 1Pa, more preferably less than 0.1Pa.

The drying temperature may be 40 to 90 ℃, preferably 50 to 80 ℃, more preferably 60 to 70 ℃.

Carbon coating step

According to the invention, a plasma enhanced chemical vapor deposition method is adopted to coat carbon on the surface of Ni/NF, so that Ni@C/NF is obtained.

The process parameters of the plasma enhanced chemical vapor deposition method are as follows:

CH ₄ of carbon source gas. The diluent gas may be a group 0 element gas, preferably argon. The volume ratio of the diluent gas to the carbon source gas is (6-12): 1, preferably (7-10): 1, more preferably (8-9): 1.

The discharge power may be 100 to 300W, preferably 150 to 250W, more preferably 200 to 220W.

The reaction temperature is 400-800 ℃, preferably 450-700 ℃, and more preferably 500-600 ℃.

The reaction time is 15 to 50min, preferably 20 to 40min, more preferably 25 to 35min.

In some embodiments, the method includes the steps of placing Ni/NF in a reaction chamber of a plasma enhanced chemical vapor deposition system, and then introducing a diluent gas and a carbon source gas into the reaction chamber, and heating to a reaction temperature to effect a reaction.

Therefore, the carbon coating layer can be efficiently formed at a lower temperature, the appearance can be kept from collapsing, the poison of an organic carbon source is avoided, and the corrosion resistance, the circulation stability and the conductivity of the material are improved.

Cerium-iron composite step

The method comprises the step of reacting a reaction solution containing an iron source and a cerium source with Ni@C/NF in a reaction kettle to obtain Ce-NiFe-LDH@C/NF.

In the present invention, the iron source may be a water-soluble iron salt. For example, ferric nitrate. The cerium source may be a water-soluble cerium salt. For example cerium nitrate.

The molar ratio of the iron element contained in the iron source to the cerium element contained in the cerium source is 1 (0.01 to 0.4), preferably 1 (0.05 to 0.2), and more preferably 1 (0.1 to 0.15). This can improve the oxygen evolution reaction activity of the material.

Preferably, the reaction solution further contains ammonium fluoride, urea and water. In certain embodiments, the reaction solution is comprised of an iron source, a cerium source, ammonium fluoride, urea, and water.

The molar ratio of the iron element to ammonium fluoride contained in the iron source is 1 (2-8), preferably 1 (3-7), and more preferably 1 (4-6).

The molar ratio of the iron element to urea contained in the iron source is 1 (7 to 13), preferably 1 (8 to 12), and more preferably 1 (10 to 11).

The molar volume ratio of the iron element and water contained in the iron source is 0.005-0.02 mol/mL, preferably 0.075-0.15 mol/mL, and more preferably 0.01-0.0125 mol/mL.

The reaction temperature may be 100 to 150 ℃, preferably 110 to 140 ℃, more preferably 120 to 130 ℃.

The reaction time may be 3 to 10 hours, preferably 4 to 8 hours, more preferably 5 to 6 hours.

In certain embodiments, the method further comprises the steps of cooling the resulting reaction product, and then washing and drying to obtain Ce-NiFe-LDH@C/NF.

Step of phosphating

And carrying out a plasma enhanced chemical vapor deposition reaction on the Ce-NiFe-LDH@C/NF and red phosphorus to obtain the carbon-coated cerium doped NiFeP material. Specifically, ce-NiFe-LDH@C/NF and red phosphorus may be placed in a plasma enhanced chemical vapor deposition boat.

The discharge gas is H ₂ and 0 group element gas. Preferably, the group 0 element gas is argon. The volume ratio of the hydrogen gas to the group 0 element gas may be 1 (1.5 to 5), preferably 1 (2 to 4), and more preferably 1 (3 to 3.5).

The reaction temperature may be 200 to 350 ℃, preferably 250 to 300 ℃, more preferably 280 to 290 ℃.

The reaction time may be 30 to 100 minutes, preferably 40 to 80 minutes, more preferably 50 to 70 minutes.

With red phosphorus as the phosphorus source, the highly active hydrogen in the plasma can activate volatile phosphorus vapor to form PH radicals. The PH free radical reacts with the active Ni and Fe atoms in the nanoneedle to form NiFe-P nanoclusters. The red phosphorus is used as a phosphorus source, so that the generation of phosphine is effectively avoided, a foundation is laid for large-scale production, and the oxygen precipitation reaction activity of the material is improved.

< Carbon-coated cerium-doped NiFeP Material and use thereof >

The carbon-coated cerium-doped NiFeP material is prepared by the method. The carbon-coated cerium-doped NiFeP material takes foamed nickel as a substrate, and the foamed nickel substrate is provided with cerium-doped NiFeP in a two-dimensional nano sheet form. The two-dimensional nanoplatelet array of NiFeP doped with cerium is arranged on a foam nickel substrate. The foam nickel substrate and/or the cerium doped NiFeP nano-sheet are coated with carbon. In certain embodiments, at least a portion of the foamed nickel substrate and cerium doped NiFeP nanoplatelets are coated with carbon.

The carbon-coated cerium-doped NiFeP material has higher oxygen precipitation reaction activity and alkali and salt stability. Thus, the invention provides the use of a carbon-coated cerium doped NiFeP material in the electrolysis of water. The carbon-coated cerium-doped NiFeP material can be used as an electrocatalytic material for water electrolysis.

Preferably, the present invention provides the use of a carbon-coated cerium doped NiFeP material in the electrolysis of alkaline water. Alkaline water refers to an aqueous solution or dispersion that is alkaline. The pH of the alkaline water may be 9 to 14, preferably 10 to 14, more preferably 13 to 14. In certain embodiments, the alkaline water may be an aqueous solution of an alkali metal hydroxide. The alkaline water may contain a salt at a certain concentration. In some embodiments, the alkaline water contains 0.1 to 1mol/L NaCl. In some embodiments, the alkaline aqueous solution contains 0.3 to 0.7mol/L NaCl. The alkaline water may be seawater containing a certain alkaline substance.

Example 1

(1) And sequentially ultrasonically cleaning the foam nickel with the thickness of 20mm multiplied by 10mm in 6mol/L of HCl aqueous solution, deionized water and ethanol for 10min respectively, and then drying in vacuum at 60 ℃ to obtain the cleaned foam nickel.

And (3) performing electrochemical deposition by taking the cleaned foam nickel as a cathode and a nickel plate as an anode to obtain Ni/NF. The electrolyte consists of nickel chloride, ammonium chloride and water. In the electrolyte, the concentration of nickel chloride is 2mol/L, and the concentration of ammonium chloride is 2mol/L. The deposition voltage was 1V and the deposition time was 100s.

(2) Placing Ni/NF in a reaction chamber of a plasma enhanced chemical vapor deposition system, then introducing Ar and CH ₄ with the volume ratio of 9:1 into the reaction chamber, heating to 500 ℃, and treating for 30min under the condition that the discharge power is 200W to obtain Ni@C/NF;

(3) Ferric nitrate, cerous nitrate, ammonium fluoride and urea are dissolved in water to form a reaction solution. The molar ratio of ferric nitrate, ammonium fluoride and urea is 1:5:10. The molar volume ratio of ferric nitrate to water was 0.01mol/mL.

And (3) placing the reaction solution and Ni@C/NF in a reaction kettle, and reacting for 6 hours at 120 ℃ to obtain a reaction product. Naturally cooling the reaction product to 25 ℃, washing with deionized water, and vacuum drying at 60 ℃ after washing to obtain Ce-NiFe-LDH@C/NF.

(4) Placing Ce-NiFe-LDH@C/NF and a phosphorus source into a small ceramic boat for plasma enhanced chemical vapor deposition, taking Ar and H ₂ with the volume of 3:1 as discharge gas, reacting for 60min at 280 ℃ with the discharge power of 200W, and obtaining the carbon-coated cerium doped NiFeP material.

The molar ratio of ferric nitrate to cerium nitrate and the choice of phosphorus source are shown in table 1.

TABLE 1

Fig. 1 shows raman spectra of carbon-coated cerium doped NiFeP materials obtained in example 1. Peaks at 1350cm ^-1 and 1600cm ^-1 correspond to the D and G bands, respectively, of the carbon layer. The D and G peaks are due to defects in the graphene nanostructure and C-C bond stretching. The strength ratio (I _D/I_G) of the D band to the G band was about 0.85, and the graphitization degree of the surface carbon was high. The graphite carbon is beneficial to accelerating electron transfer, thereby improving electrocatalytic activity and improving corrosion resistance of electrolysis.

Fig. 2 is an SEM image of the carbon-coated cerium doped NiFeP material obtained in example 1. As can be seen in fig. 2, the carbon-coated cerium-doped NiFeP material has an open nanoplatelet structure of an array of vertically aligned nanoplatelets grown on a foam nickel substrate.

Fig. 3 is an SEM energy spectrum of the carbon-coated cerium doped NiFeP material obtained in example 1. As can be seen from fig. 3, the nanoplatelet array sheet consists of ultra-fine nano-grains with smooth surfaces. After phosphating, the nanoplatelets become thinner and the resulting phosphide retains a uniformly aligned nanoplatelet structure. The vertically aligned nanoplatelet arrays of the 3D open frame thus formed are able to diffuse reactants and products more easily, providing more active sites, improving water splitting efficiency.

Fig. 4 is a TEM image of the carbon-coated cerium doped NiFeP material obtained in example 1. FIG. 4 demonstrates that the phosphide on the foam nickel substrate had a two-dimensional nanoplatelet morphology with ultrafine nanocrystalline grains of about 5nm. NiFeP have a interplanar spacing of 0.222nm and 0.253nm, corresponding to the (111) and (020) crystal planes of NiFeP, respectively, demonstrating successful synthesis of NiFeP.

Comparative example 2

The procedure of example 1 was followed except that carbon coating was not performed, as follows:

(2) Ferric nitrate, cerous nitrate, ammonium fluoride and urea are dissolved in water to form a reaction solution. The molar ratio of the ferric nitrate to the cerium nitrate to the ammonium fluoride to the urea is 1:0.1:5:10. The molar volume ratio of ferric nitrate to water was 0.01mol/mL.

And (3) placing the reaction liquid and Ni/NF in a reaction kettle, and reacting for 6 hours at 120 ℃ to obtain a reaction product. Naturally cooling the reaction product to 25 ℃, washing with deionized water, and vacuum drying at 60 ℃ after washing to obtain Ce-NiFe-LDH/NF.

(3) Placing Ce-NiFe-LDH/NF and red phosphorus into a small porcelain boat of plasma enhanced chemical vapor deposition, taking Ar and H ₂ with the volume of 3:1 as discharge gas, enabling the discharge power to be 200W, and reacting for 60min at 280 ℃ to obtain the cerium doped NiFeP material.

Experimental example

1. Polarization curve of oxygen evolution reaction

Polarization curve measurements were performed at a scan rate of 1mVs ^-1 in 1mol/L KOH aqueous solution, KOH and NaCl mixed aqueous solution (KOH concentration 1mol/L, naCl concentration 0.5 mol/L) and KOH concentration 1mol/L seawater respectively at 25℃using CHI760 electrochemical workstation, hg/HgO as reference electrode, the materials of examples 1-3 and comparative examples 1-2 as working electrode, and platinum sheet as counter electrode. Prior to linear polarization curve measurement, 50 cyclic voltammograms were run at 50mVs ^-1 scan speed to reach steady state. The polarization curve is corrected by compensation for the 85% ir drop. The overpotential at 100mAcm ^-2 was obtained from the polarization curve.

Table 2 shows the overpotential of the different working electrodes at a current density of 100mAcm ^-2 under a 1mol/L KOH aqueous solution. FIG. 5 is a polarization curve of the material of example 1 as a working electrode under the conditions of aqueous KOH, aqueous KOH and NaCl mixed solution and KOH seawater. As can be seen from table 2, the carbon-coated cerium-doped NiFeP material of the present invention has excellent oxygen precipitation reactivity under alkaline conditions. As can be seen from fig. 5, the carbon-coated cerium-doped NiFeP material of the present invention also has high oxygen precipitation reactivity in an alkaline solution containing NaCl or alkaline seawater.

TABLE 2

Selection of working electrode	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						Overpotential (mV)	250	265	270	275	280

2. Stability test

The material prepared in example 1 was used as a working electrode and a platinum sheet was used as a counter electrode at 25℃in 1mol/L KOH aqueous solution, KOH and NaCl mixed aqueous solution (KOH concentration: 1mol/L, naCl concentration: 0.5 mol/L) and KOH concentration: 1mol/L seawater respectively at a current density of 100mAcm ^-2 using a CHI760 electrochemical workstation and Hg/HgO as a reference electrode for 64 hours, to obtain a stability curve. Prior to stability testing, 50 cyclic voltammograms were run at 50mVs ^-1 scan speed to reach steady state. The steady circulation curve is not corrected for iR drop compensation. The resulting stability curves are shown in figures 6-8. As can be seen from fig. 6 to 8, the carbon-coated cerium-doped NiFeP material of the present invention has excellent stability in alkaline solution, alkaline solution containing NaCl, or alkaline seawater.

The present invention is not limited to the above-described embodiments, and any modifications, improvements, substitutions, and the like, which may occur to those skilled in the art, fall within the scope of the present invention without departing from the spirit of the invention.

Claims

1. A method for preparing a carbon-coated cerium-doped NiFeP material, comprising the following steps:

(1) Electrochemical deposition is performed on nickel foam to obtain Ni/NF;

(2) using plasma enhanced chemical vapor deposition to coat carbon on the surface of Ni/NF to obtain Ni@C/NF; wherein the carbon source gas for the plasma enhanced chemical vapor deposition reaction is CH ₄ ;

(3) reacting a reaction solution containing an iron source and a cerium source with Ni@C/NF in a reactor to obtain Ce-NiFe-LDH@C/NF; wherein the molar ratio of the iron element contained in the iron source to the cerium element contained in the cerium source is 1:(0.01-0.4);

(4) Ce-NiFe-LDH@C/NF and red phosphorus are subjected to plasma enhanced chemical vapor deposition reaction to obtain carbon-coated cerium-doped NiFeP material.

2. The preparation method according to claim 1 is characterized in that in step (2), the dilution gas is a Group 0 element gas, the reaction temperature is 400-800°C, and the discharge power is 100-300W.

3. The preparation method according to claim 2 is characterized in that the dilution gas is argon, and the volume ratio of the dilution gas to the carbon source gas is (6-12):1.

4. The preparation method according to claim 1, characterized in that in step (4), the discharge gas is hydrogen and group 0 element gas, and the volume ratio of hydrogen to group 0 element gas is 1:(1.5-5).

5. The preparation method according to claim 4, characterized in that in step (4), the reaction temperature is 200-350°C and the discharge power is 100-300W.

6. The preparation method according to claim 1 is characterized in that in step (1), the anode is a nickel plate, the cathode is nickel foam, the electrolyte contains a nickel source, ammonium chloride and water, and the deposition voltage is 0.5 to 2 V; wherein the concentration of the nickel element provided by the nickel source in the electrolyte is 1 to 3 mol/L.

7. The preparation method according to claim 1, characterized in that in step (3), the reaction solution contains an iron source, a cerium source, ammonium fluoride, urea and water, and the molar ratio of the iron element contained in the iron source, ammonium fluoride and urea is 1:(2-8):(7-13); and the reaction temperature is 100-150°C.

8. A carbon-coated cerium-doped NiFeP material, characterized in that the carbon-coated cerium-doped NiFeP material is obtained by the preparation method according to any one of claims 1 to 7.

9. Use of the carbon-coated cerium-doped NiFeP material according to claim 8 in electrolysis of water.

10. Use of the carbon-coated cerium-doped NiFeP material according to claim 8 in electrolysis of alkaline water.