Iron-based perovskite nanofiber oxygen evolution catalyst material for in-situ dissolution of nanoparticles as well as preparation method and application of iron-based perovskite nanofiber oxygen evolution catalyst material

Abstract

The invention belongs to the technical field of catalysts, and particularly relates to an iron-based perovskite nanofiber oxygen evolution catalyst material for in-situ dissolution of nanoparticles as well as a preparation method and application of the iron-based perovskite nanofiber oxygen evolution catalyst material. The iron-based perovskite nanofiber oxygen evolution catalyst material provided by the invention is prepared into a nanofiber shape with a high specific surface area through electrostatic spinning, the electronic structure of the oxygen evolution catalyst material is changed by doping ruthenium (Ru), and ruthenium nanoparticles are dissolved in situ by calcining in a reducing atmosphere; the oxygen evolution catalyst material is improved by means of calcining in-situ dissolved amorphous ruthenium oxide nanoparticles in air and the like, that is, on the basis of doping ruthenium in the iron-based perovskite material, the surface of the iron-based perovskite material is reconstructed to form an epitaxial anchoring structure, so that the high-performance oxygen evolution catalyst is provided; the technical problem of low oxygen evolution catalytic performance of the perovskite material in the prior art is solved.

Description

Technical Field

[0001] The present application belongs to the field of catalyst technology, and in particular relates to an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles, a preparation method, and an application thereof. Background Art

[0002] Hydrogen (H2) has high energy density ( ), far exceeding gasoline and coal, and is environmentally friendly and carbon-free during use. It is an energy storage medium or carrier that is expected to replace traditional fossil fuels; however, hydrogen resources that exist alone as hydrogen molecules (H2) are very rare. Traditional hydrogen (H2) is mainly produced from hydrocarbons such as fossil fuels through reforming or thermal cracking, which limits the production and large-scale use of hydrogen (H2).

[0003] Hydrogen (H2) resources can be obtained from water (H2O) through water electrolysis technology. The hydrogen production technology in alkaline electrolysis cells is the most mature and has begun to be used in industry to prepare high-purity hydrogen. However, there is a problem of high energy consumption in the alkaline hydrogen production industry. In recent years, with the rapid development of new energy sources such as wind power generation and photovoltaic power generation, water electrolysis can realize the integration of new energy power generation and hydrogen production projects, produce hydrogen during the low electricity consumption period, improve the consumption of wind and solar clean energy, and realize the interconnection between the power grid and the gas grid. However, new energy power generation only provides cheap electricity during the low electricity consumption period, and it is difficult to effectively reduce the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OXYGENERATED RESULTS) at the anode in the process of water electrolysis hydrogen production. The energy consumption required for the anodic oxygen evolution reaction (OER) in hydrogen production by water electrolysis is greatly reduced. In the hydrogen evolution / oxygen evolution reaction of water electrolysis, the high reaction potential and slow reaction kinetics limit the reduction of energy consumption of hydrogen production by water electrolysis. Among them, the anodic oxygen evolution reaction (OER) with slow reaction kinetics is one of the bottleneck problems faced by the development of new energy-driven water electrolysis hydrogen production technology. Developing high-performance OER electrocatalysts to reduce the energy consumption of water electrolysis hydrogen production is an important way to promote the development of water electrolysis hydrogen production technology.

[0004] Some precious metals and their precious metal oxides are considered to be OER electrocatalysts. However, the high cost and poor stability of precious metals and their precious metal oxides in strong alkaline solutions limit their large-scale application as oxygen evolution catalysts used in alkaline electrolysis hydrogen production technology. Perovskite materials (ABO3) have many advantages such as low cost and stable structure. They are expected to replace traditional precious metals such as precious metals and their precious metal oxides in the future and become new OER electrocatalyst materials. However, the OER activity of the perovskite materials currently prepared is poor and it is difficult to meet the requirements of high-performance OER electrocatalysts. Summary of the Invention

[0005] In view of this, the application provides an in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, a preparation method and application thereof, and is used to solve the technical problem of low oxygen evolution catalytic performance of the perovskite material in the prior art.

[0006] The first aspect of the application provides an in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, comprising: an iron-based perovskite nanofiber and a ruthenium-based nanoparticle.

[0007] The chemical formula of the iron-based perovskite nanofiber is: Sr 1-2x Ce x Fe 1-x Ru x O3, 0.005 < x < 0.1.

[0008] The iron-based perovskite nanofiber exsolves the ruthenium-based nanoparticle in-situ.

[0009] Preferably, the ruthenium-based nanoparticle is selected from a ruthenium nanoparticle and / or a ruthenium oxide nanoparticle.

[0010] Preferably, the diameter of the in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material is 50-300 nm.

[0011] The second aspect of the application provides a preparation method of an in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, which can prepare the in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material of the first aspect, and comprises the following steps:

[0012] Step S1, according to the stoichiometric ratio in the chemical formula Sr 1-2x Ce x Fe 1-x Ru x O3, 0.005 < x < 0.1, the required strontium salt and cerium salt of the A site, the required iron salt and ruthenium salt of the B site are weighed;

[0013] Step S2, the strontium salt, the cerium salt, the iron salt and the ruthenium salt, the fiber-forming polymer and the organic solvent are uniformly mixed to obtain an electrospinning solution;

[0014] Step S3, the electrospinning solution is added to the injector of the electrospinning machine to perform electrospinning to obtain an iron-based perovskite nanofiber material;

[0015] Step S4, the iron-based perovskite nanofiber material is sequentially subjected to high-temperature calcination and reduction atmosphere calcination to obtain an in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material.

[0016] Preferably, after the reduction atmosphere calcination in step S4, the process further comprises an oxidation atmosphere calcination before obtaining the in-situ exfoliated nanoparticle-embedded iron-based perovskite nanofiber oxygen evolution catalyst material.

[0017] Preferably, the reduction atmosphere calcination in step S4 comprises calcination in a H2 / N2 mixed atmosphere at 600-1000℃ for 10-30h.

[0018] Preferably, the oxidation atmosphere calcination in step S4 comprises calcination in air at 400-800℃ for 0.5-2h.

[0019] Preferably, in step S1, the strontium salt is selected from at least one of chloride, nitrate, acetate, sulfate, a hydrate of chloride, a hydrate of nitrate, a hydrate of acetate, a hydrate of sulfate;

[0020] the cerium salt is selected from at least one of chloride, nitrate, acetate, sulfate, a hydrate of chloride, a hydrate of nitrate, a hydrate of acetate, a hydrate of sulfate;

[0021] the iron salt is selected from at least one of chloride, nitrate, acetate, sulfate, a hydrate of chloride, a hydrate of nitrate, a hydrate of acetate, a hydrate of sulfate;

[0022] the ruthenium salt is selected from at least one of chloride, nitrate, acetate, sulfate, a hydrate of chloride, a hydrate of nitrate, a hydrate of acetate, a hydrate of sulfate.

[0023] Preferably, in step S1, the strontium salt is strontium nitrate, the cerium salt is cerium nitrate hexahydrate, the iron salt is iron nitrate nonahydrate, and the ruthenium salt is ruthenium chloride hydrate.

[0024] Preferably, in step S2, the fiber-forming polymer is selected from polyvinylpyrrolidone;

[0025] the organic solvent is selected from N,N-dimethylformamide;

[0026] the mass ratio of the fiber-forming polymer to the organic solvent is 10-30:100.

[0027] Preferably, in step S3, the needle of the syringe loaded with the electrospinning solution is a 25G needle, and the pushing rate is set to 1-5μL / min.

[0028] The voltage applied between the needle and the receiving cylinder is 10-30kV, and the distance from the needle to the receiving cylinder is 10-30cm.

[0029] The third aspect of the present application provides an application of the in-situ exsolution of the nano-particle iron-based perovskite nanofiber oxygen evolution catalyst material in the field of hydrogen production by water electrolysis.

[0030] The fourth aspect of the present application provides an alkaline electrolytic cell, wherein the anode of the alkaline electrolytic cell is loaded with the in-situ exsolution of the nano-particle iron-based perovskite nanofiber oxygen evolution catalyst material of the first aspect.

[0031] The fifth aspect of the present application provides a new energy hydrogen production integrated system, wherein the electrolytic hydrogen production unit of the new energy hydrogen production integrated system comprises the alkaline electrolytic cell of the fourth aspect.

[0032] Compared with the prior art, the in-situ exsolution of the nano-particle iron-based perovskite nanofiber oxygen evolution catalyst material provided by the present application has at least the following beneficial effects:

[0033] 1. The nanofiber oxygen evolution catalyst provided by the present application changes the electronic structure of the original iron-based perovskite material by doping ruthenium (Ru) in the iron-based perovskite, thereby improving the oxygen evolution activity of the iron-based perovskite material.

[0034] 2. The nanofiber oxygen evolution catalyst provided by the present application further improves the oxygen evolution activity of the iron-based perovskite material by calcining the ruthenium-doped iron-based perovskite in a reducing atmosphere to make the ruthenium nano-particles in-situ adhere, and calcining in an air atmosphere to oxidize the in-situ adhered ruthenium nano-particles into amorphous ruthenium oxide nano-particles.

[0035] 3. The nanofiber oxygen evolution catalyst provided by the present application improves the specific surface area and the number of active adhesion sites, promotes the dispersion and adhesion of ruthenium-based nano-particles, reduces agglomeration, and improves the oxygen evolution activity of the iron-based perovskite material by being made into a nanofiber shape. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0037] Figure 1 X-ray diffraction patterns of the nanofiber oxygen evolution catalyst materials SCFR0.05, SCFR0.05-H, and SCFR0.05-H-O provided for Example 1 of the present application and the nanofiber oxygen evolution catalyst material SCF provided for Comparative Example 1 of the present application;

[0038] Figure 2The scanning electron microscope images and energy spectrum images of the nanofiber oxygen evolution catalyst material SCF provided for Comparative Example 1 of the present application before and after calcination, a figure is the scanning electron microscope image before calcination, b figure is the scanning electron microscope image after calcination, c figure is the energy spectrum image;

[0039] Figure 3 The scanning electron microscope images of the nanofiber oxygen evolution catalyst material SCFR0.05, SCFR0.05-H, SCFR0.05-H-O provided for Example 1 of the present application and the nanofiber oxygen evolution catalyst material SCF provided for Comparative Example 1 of the present application, a figure is the scanning electron microscope image of SCF, b figure is the scanning electron microscope image of SCFR0.05, c figure is the scanning electron microscope image of SCFR0.05-H, d figure is the scanning electron microscope image of SCFR0.05-H-O;

[0040] Figure 4 The transmission electron microscope image and high-resolution transmission electron microscope image of the nanofiber oxygen evolution catalyst material SCFR0.05-H provided for Example 1 of the present application, a figure is the transmission electron microscope image of SCFR0.05-H, b figure is the high-resolution transmission electron microscope image of SCFR0.05-H;

[0041] Figure 5 The energy spectrum image of the nanofiber oxygen evolution catalyst material SCFR0.05-H provided for Example 1 of the present application;

[0042] Figure 6 The transmission electron microscope image and high-resolution transmission electron microscope image of the nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided for Example 1 of the present application, a figure is the transmission electron microscope image of SCFR0.05-H-O, b figure is the high-resolution transmission electron microscope image of SCFR0.05-H-O;

[0043] Figure 7 The energy spectrum image of the nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided for Example 1 of the present application;

[0044] Figure 8 The overpotential, Tafel slope and polarization impedance test results of the nanofiber oxygen evolution catalyst materials SCFR0.05, SCFR0.05-H and SCFR0.05-H-O provided for Example 1 of the present application and the nanofiber oxygen evolution catalyst material SCF provided for Comparative Example 1 of the present application, a figure is the overpotential test result, b figure is the Tafel slope test result, c figure is the columnar chart of the overpotential / Tafel slope test result, d figure is the polarization impedance test result;

[0045] Figure 9Cyclic voltammetry (CV) curves of the nanofiber oxygen evolution catalyst material SCFR0.05, SCFR0.05-H and SCFR0.05-H-O provided in Example 1 of the present application and the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 at different scan rates;

[0046] Figure 10 Test results of electric double layer capacitance of the nanofiber oxygen evolution catalyst material SCFR0.05, SCFR0.05-H and SCFR0.05-H-O provided in Example 1 of the present application and the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1;

[0047] Figure 11 Test results of overpotential of the SCFR0.05-H-O nanoparticles prepared by the solid phase method provided in Comparative Example 2 of the present application;

[0048] Figure 12 Cyclic voltammetry (CV) curves of the SCFR0.05-H-O nanoparticles prepared by the solid phase method provided in Comparative Example 2 of the present application at different scan rates;

[0049] Figure 13 Test results of Tafel slope of the SCFR0.05-H-O nanoparticles prepared by the solid phase method provided in Comparative Example 2 of the present application;

[0050] Figure 14 Test results of polarization impedance of the SCFR0.05-H-O nanoparticles prepared by the solid phase method provided in Comparative Example 2 of the present application;

[0051] Figure 15 Test results of stability of the nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided in Example 2 of the present application, a figure is the change of current density with time, b figure is a transmission electron microscope image, and c figure is an energy spectrum. DETAILED DESCRIPTION

[0052] The present application provides an in-situ out-solution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, a preparation method and an application, and is used to solve the technical problem of low oxygen evolution catalytic performance of the perovskite material in the prior art.

[0053] The technical solutions of the present application will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0054] In view of the poor OER activity of ordinary iron-based perovskite and the low oxygen evolution catalytic performance, the application provides an in-situ out-dissolved nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, which comprises: iron-based perovskite nanofiber and ruthenium-based nanoparticles; the chemical formula of the iron-based perovskite nanofiber is: Sr 1-2x Ce x Fe 1-x Ru x O3, 0.005 < x < 0.1; the iron-based perovskite nanofiber in-situ out-dissolves ruthenium-based nanoparticles.

[0055] The oxygen evolution catalyst material provided by the application is an iron-based perovskite material, and the OER electrocatalytic activity of the iron-based perovskite material is closely related to the electronic structure of the transition metal element thereof. The electronic structure of the original iron-based perovskite material can be changed through A-site and B-site doping, so as to improve the oxygen evolution activity of the iron-based perovskite material. Moreover, on the basis of A-site doping of cerium and B-site doping of ruthenium of the iron-based perovskite material, the morphology and out-dissolution mode of the catalytic activity component are improved. The iron-based perovskite oxygen evolution catalyst material doped with cerium and ruthenium at the A site and the B site is made into an iron-based perovskite oxygen evolution catalyst material in the form of nanofiber. The nanofiber has a hollow structure and a large specific surface area, and increases the attachment sites, which is conducive to the dispersion and attachment of the ruthenium-based nanoparticles, reduces the agglomeration, promotes the oxygen evolution reaction, improves the oxygen evolution activity, and the metal nanostructure of the ruthenium nanoparticles is formed in the form of in-situ out-dissolution. The in-situ out-dissolution refers to that the ruthenium metal ions in the crystal lattice are reduced, the metal atoms produced by the reduction migrate from the inside of the crystal lattice to the surface, nucleate and grow at specific positions (such as steps and defects) on the surface to form metal particles. The application causes more oxygen vacancies by precipitating the ruthenium-based nanoparticles from the perovskite substrate, and the oxygen vacancies can be active sites for OER, which is conducive to improving the OER activity of the catalyst and improving the catalytic performance. Generally, the ruthenium-based nanoparticles are prepared in advance and then out-dissolved through impregnation and the like, and the catalytic performance is low. Therefore, the oxygen evolution catalyst material provided by the application is an iron-based perovskite material, which is made into nanofiber with a high specific surface area on the basis of A-site doping of cerium and B-site doping of ruthenium of the iron-based perovskite material, and the ruthenium-based nanoparticles are out-dissolved in-situ after being precipitated, so that the oxygen evolution activity of the iron-based perovskite material is significantly improved. The in-situ out-dissolved nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material provided by the application is a high-performance oxygen evolution catalyst, which can overcome the defect of low oxygen evolution catalytic performance of the perovskite material.

[0056] As preferred, in the in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material provided in the application, the form of the in-situ exsolved ruthenium-based nanoparticles can be selected from ruthenium nanoparticles and / or ruthenium oxide nanoparticles; both the ruthenium nanoparticles and the ruthenium oxide nanoparticles can improve the oxygen evolution catalytic performance of the perovskite material, and when the in-situ exsolved ruthenium oxide nanoparticles are in the form of amorphous ruthenium oxide, there are more surface defect sites that can become active centers for catalytic reactions, and the higher surface energy is conducive to enhancing the adsorption performance of the oxygen adsorption intermediates, so that the in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material provided in the application can reduce the OER oxygen evolution reaction overpotential, Tafel slope and polarization resistance, so that the oxygen evolution reaction is easier to occur, the reaction kinetics is faster, and the reaction resistance is smaller.

[0057] As preferred, the diameter of the in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material provided in the application is about 50-300 nm; and the particle size of the exsolved ruthenium-based nanoparticles is about 5-20 nm.

[0058] Correspondingly, the application also provides a preparation method of the above-mentioned in-situ exsolution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, and the process of the preparation method comprises the following steps: first, according to the stoichiometric ratio of Sr 1-2x Ce x Fe 1-x Ru x O3, 0.005

[0059] Correspondingly, the application also provides the application of the in-situ exsolution nanoparticle-containing iron-based perovskite nanofiber oxygen evolution catalyst material; the application is applied to the anode of an alkaline electrolytic cell, and the alkaline electrolytic cell generally comprises a tank body containing an alkaline electrolyte, an anode for generating an oxidation reaction, a cathode for generating a reduction reaction, a diaphragm and the like; when the in-situ exsolution nanoparticle-containing iron-based perovski te nanofiber oxygen evolution catalyst material is epitaxially anchored to the anode of the alkaline electrolytic cell, the energy consumption of the existing alkaline electrolytic cell for electrolysis of water to produce hydrogen can be reduced due to the good catalytic OER activity.

[0060] Correspondingly, the application also provides a new energy hydrogen production integrated system; conventional hydrogen production using thermal power as a power supply unit has poor economic benefits, while the application provides a new energy hydrogen production integrated system using a wind turbine, solar energy and the like as a power supply unit, which can provide cheap electricity for hydrogen production during the low electricity consumption valley period; in addition to the power supply unit, the hydrogen production integrated system also comprises an electrolytic hydrogen production unit, and the electrolytic hydrogen production unit comprises the above-mentioned alkaline electrolytic cell, a gas purification component for purifying hydrogen / oxygen, a gas compression / storage component and the like; since the anode in the alkaline electrolytic cell is loaded with the in-situ exsolution nanoparticle-containing iron-based perovskite nanofiber oxygen evolution catalyst material, the new energy hydrogen production integrated system provided by the application can efficiently produce hydrogen on a large scale, which is conducive to the large-scale use of hydrogen.

[0061] The in-situ exsolution nanoparticle-containing iron-based perovskite nanofiber oxygen evolution catalyst material provided by the application will be specifically described below in combination with examples and experimental examples.

[0062] Example 1

[0063] The example provides a preparation method of an in-situ exsolution nanoparticle-containing iron-based perovskite nanofiber oxygen evolution catalyst material, and the preparation method comprises the steps of weighing raw materials, preparing an electrospinning solution, electrospinning and calcining to prepare an oxygen evolution catalyst material.

[0064] The step of weighing the raw materials comprises: weighing 0.9 mmol of strontium nitrate SrNO3, 0.05 mmol of cerium nitrate hexahydrate Ce(NO3)3·6H2O, 0.95 mmol of iron nitrate nonahydrate Fe(NO3)3·9H2O and 0.05 mmol of ruthenium chloride trihydrate RuCl3·3H2O according to the stoichiometric ratio in the chemical formula SrCeFeRuO3; and weighing 7.5 milliliters of N,N-dimethylformamide (DMF, about 7.1 grams) and 1.07 grams of polyvinylpyrrolidone (PVP) as an organic solvent and a fiber-forming polymer, respectively. 0.9 Ce 0.05 Fe 0.95 Ru 0.05 O3; and weighing 7.5 milliliters of N,N-dimethylformamide (DMF, about 7.1 grams) and 1.07 grams of polyvinylpyrrolidone (PVP) as an organic solvent and a fiber-forming polymer, respectively.

[0065] The step of preparing the electrospinning solution includes: placing weighed strontium nitrate, cerium nitrate hexahydrate, iron nitrate nonahydrate, ruthenium trichloride trihydrate, N,N-dimethylformamide and polyvinylpyrrolidone on a magnetic stirrer to stir overnight until a certain viscosity of the glue is formed as an electrospinning solution.

[0066] The step of electrospinning includes: first, filling the electrospinning solution into the syringe of the electrospinning machine, connecting the syringe with a 25G needle through a plastic tube, and controlling the advancing rate of the micro-injection pump to be 2 μL / min to prepare the spinning solution supply system; then, wrapping a metal aluminum foil on the high-speed motorized yarn collection cylinder, controlling the rotating speed to be 300 rpm, and controlling the distance between the yarn collection cylinder and the needle to be 15 cm to prepare the spinning collection system; next, starting the electrospinning machine to apply a voltage of 18 kV between the needle and the yarn collection cylinder for electrospinning, and collecting the iron-based perovskite nanofiber material on the aluminum foil of the yarn collection cylinder.

[0067] The step of calcining to prepare the oxygen evolution catalyst material includes: tearing the iron-based perovskite nanofiber material collected on the aluminum foil of the yarn collection cylinder from the aluminum foil, first calcining at 850℃ for 3 hours at a temperature rising and falling rate of 2℃ / min to obtain an iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR0.05; then, placing the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR into the tube furnace again, reducing calcining at 800℃ in a 5% H2 / N2 mixed atmosphere for 20 hours to make the ruthenium nanoparticles in-situ precipitate, obtaining an in-situ precipitated ruthenium nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR0.05-H; next, oxidizing calcining the in-situ precipitated ruthenium nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material SCFR-H in air at 600℃ for 1 hour to oxidize the ruthenium nanoparticles, obtaining an in-situ precipitated oxidized ruthenium nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR0.05-H-O.

[0068] Example 2

[0069] The embodiment provides a preparation method of an in-situ precipitated nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, and the preparation method includes the steps of weighing raw materials, preparing an electrospinning solution, electrospinning, and calcining to prepare an oxygen evolution catalyst material.

[0070] The step of weighing raw materials includes: according to the chemical formula Sr 0.9 Ce 0.05 Fe 0.99 Ru 0.01The stoichiometric ratio in O3, 0.9 mmol of strontium nitrate SrNO3 and 0.05 mmol of cerium nitrate hexahydrate Ce(NO3)3·6H2O, 0.99 mmol of iron nitrate nonahydrate Fe(NO3)3·9H2O and 0.01 mmol of ruthenium chloride trihydrate RuCl3·3H2O were weighed; 7.5 milliliters of N,N-dimethylformamide (DMF, about 7.1 grams) and 1.07 grams of polyvinylpyrrolidone (PVP) were weighed as the organic solvent and the fiber-forming polymer, respectively.

[0071] The steps for preparing the electrospinning solution include: placing the weighed strontium nitrate, cerium nitrate hexahydrate, iron nitrate nonahydrate, ruthenium chloride trihydrate, N,N-dimethylformamide and polyvinylpyrrolidone on a magnetic stirrer and stirring overnight until a certain viscosity of the gel is formed as the electrospinning solution.

[0072] The steps of electrospinning include: first, the electrospinning solution is loaded into the syringe of the electrospinning machine, and the syringe is connected to a 25G needle through a plastic tube, while the push rate of the microsyringe pump is controlled at 2 μL / min, and the spinning solution supply system is prepared; then, a metal aluminum foil is wrapped around the high-speed motorized fiber collection cylinder, the rotating speed is controlled at 300 rpm, and the distance between the cylinder and the needle is 15 cm, and the spinning collection system is prepared; next, the electrospinning machine is turned on to apply a voltage of 18 kV between the needle and the cylinder for electrospinning, and the iron-based perovskite nanofiber material is collected on the aluminum foil of the cylinder.

[0073] The steps of calcining to prepare the oxygen evolution catalyst material include: tearing the iron-based perovskite nanofiber material collected on the aluminum foil of the cylinder from the aluminum foil, first calcining at 850℃ for 3 hours with a temperature rising and falling rate of 2℃ / min, obtaining the iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR; then, the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR is placed into the tube furnace again, and is reduced and calcined at 800℃ in a 5% H2 / N2 mixed atmosphere for 20 hours, so that ruthenium nanoparticles are in-situ precipitated, obtaining the iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ precipitated ruthenium nanoparticles, named SCFR-H; next, the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR-H with in-situ precipitated ruthenium nanoparticles is oxidized and calcined in air at 600℃ for 1 hour, so that the ruthenium nanoparticles are oxidized, obtaining the iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ precipitated oxidized ruthenium nanoparticles, named SCFR-H-O.

[0074] Example 3

[0075] The embodiment provides a preparation method of an in-situ out-solution nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, and the preparation method comprises the following steps: a step of weighing raw materials, a step of preparing an electrostatic spinning solution, a step of electrostatic spinning and a step of calcining to prepare an oxygen evolution catalyst material.

[0076] The step of weighing the raw materials comprises the following steps: according to the stoichiometric ratio of Sr 0.9 Ce 0.05 Fe 0.98 Ru 0.02 O3, 0.9 mmol of strontium nitrate SrNO3, 0.05 mmol of cerium nitrate hexahydrate Ce(NO3)3·6H2O, 0.98 mmol of iron nitrate nonahydrate Fe(NO3)3·9H2O and 0.02 mmol of ruthenium chloride trihydrate RuCl3·3H2O are weighed; 7.5 mL of N,N-dimethylformamide (DMF, about 7.1 g) and 1.07 g of polyvinylpyrrolidone (PVP) are weighed as an organic solvent and a fiber-forming polymer respectively.

[0077] The step of preparing the electrostatic spinning solution comprises the following steps: the weighed strontium nitrate, cerium nitrate hexahydrate, iron nitrate nonahydrate, ruthenium chloride trihydrate, N,N-dimethylformamide and polyvinylpyrrolidone are placed on a magnetic stirrer and stirred overnight until a certain viscosity of the colloidal substance is formed as the electrostatic spinning solution.

[0078] The step of electrostatic spinning comprises the following steps: first, the electrostatic spinning solution is loaded into a syringe of an electrostatic spinning machine, and the syringe is connected to a 25G needle through a plastic tube, while the push rate of a micro-injection pump is controlled to be 2 μL / min, and the spinning solution supply system is prepared; then, a metal aluminum foil is wrapped on a high-speed electric spinning cylinder, the rotating speed is controlled to be 300 r / min, and the distance between the spinning cylinder and the needle is 15 cm, and the spinning collection system is prepared; next, the electrostatic spinning machine is started to apply a voltage of 18 kV between the needle and the spinning cylinder for electrostatic spinning, and the iron-based perovskite nanofiber material is collected on the aluminum foil of the spinning cylinder.

[0079] The step of calcining to prepare the oxygen evolution catalyst material includes: tearing the iron-based perovskite nanofiber material collected on the aluminum foil of the spool from the aluminum foil, first calcining at 850°C for 3 hours at a temperature rising and falling rate of 2°C / min, obtaining an iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR; then placing the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR into a tube furnace again, reducing and calcining at 800°C for 20 hours in a 5% H2 / N2 mixed atmosphere, so that ruthenium nanoparticles are in-situ precipitated, obtaining an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ precipitated ruthenium nanoparticles, named SCFR-H; next, oxidizing and calcining the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR-H with in-situ precipitated ruthenium nanoparticles at 600°C in air for 1 hour, oxidizing the ruthenium nanoparticles, obtaining an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ precipitated oxidized ruthenium nanoparticles, named SCFR-H-O.

[0080] Example 4

[0081] The present embodiment provides a preparation method of an in-situ precipitated nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, which includes a step of weighing raw materials, a step of preparing an electrospinning solution, a step of electrospinning, and a step of calcining to prepare an oxygen evolution catalyst material.

[0082] The step of weighing raw materials includes: weighing 0.9 mmol of strontium nitrate SrNO3 and 0.05 mmol of cerium nitrate hexahydrate Ce(NO3)3·6H2O, 0.97 mmol of iron nitrate nonahydrate Fe(NO3)3·9H2O and 0.03 mmol of ruthenium chloride trihydrate RuCl3·3H2O according to the stoichiometric ratio in the chemical formula SrCeFeRuO3; weighing 7.5 milliliters of N,N-dimethylformamide (DMF, about 7.1 grams) and 1.07 grams of polyvinylpyrrolidone (PVP) as an organic solvent and a fiber-forming polymer, respectively. 0.9 Ce 0.05 Fe 0.97 Ru 0.03 O3.

[0083] The step of preparing an electrospinning solution includes: placing the weighed strontium nitrate, cerium nitrate hexahydrate, iron nitrate nonahydrate, ruthenium chloride trihydrate, N,N-dimethylformamide and polyvinylpyrrolidone on a magnetic stirrer and stirring overnight until a certain viscosity of the gel is formed as an electrospinning solution.

[0084] The steps of electrospinning include: first loading the electrospinning solution into the syringe of the electrospinning machine, and connecting the syringe to a 25G needle through a plastic tube, while controlling the microinjection pump propulsion rate to 2μL / min, and preparing the spinning solution supply system; then wrapping a metal aluminum foil on the high-speed electric winding drum, controlling the speed to 300 rpm, and the distance between the winding drum and the needle to 15cm, and preparing the spinning collection system; next, turning on the electrospinning machine and applying 18 kV voltage between the needle and the winding drum for electrospinning, and collecting the iron-based perovskite nanofiber material on the aluminum foil of the winding drum.

[0085] The steps of calcining to prepare the oxygen evolution catalyst material include: collecting the iron-based perovskite nanofiber material on the aluminum foil of the wire collection drum, tearing it off the aluminum foil, and first calcining it at 850°C for 3 hours at a heating and cooling rate of 2°C / min to obtain the iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR; then placing the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR into the tubular furnace again, and reducing and calcining it at 800°C in a 5% H2 / N2 mixed atmosphere for 20 hours to precipitate ruthenium nanoparticles in situ, thereby obtaining the iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ ruthenium nanoparticles dissolved therein, named SCFR-H; next, the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR-H with in-situ ruthenium nanoparticles dissolved therein is oxidized and calcined in air at 600°C for 1 hour to oxidize the ruthenium nanoparticles, thereby obtaining the iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ ruthenium oxide nanoparticles dissolved therein, named SCFR-HO.

[0086] Example 5

[0087] This embodiment provides a method for preparing an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles. The preparation method includes the steps of weighing raw materials, preparing an electrospinning solution, electrospinning, and calcining to prepare the oxygen evolution catalyst material.

[0088] The steps of weighing the raw materials include: according to the chemical formula Sr 0.9 Ce 0.05 Fe 0.96 Ru 0.04 In a stoichiometric ratio in O3, 0.9 mmol strontium nitrate SrNO3, 0.05 mmol cerium nitrate hexahydrate Ce(NO3)3·6H2O, 0.96 mmol iron nitrate nonahydrate Fe(NO3)3·9H2O and 0.04 mmol ruthenium chloride trihydrate RuCl3·3H2O were weighed; 7.5 ml N,N-dimethylformamide (DMF, about 7.1 g) and 1.07 g polyvinylpyrrolidone (PVP) were weighed as organic solvent and fiber-forming polymer, respectively.

[0089] The step of preparing the electrospinning solution includes: placing weighed strontium nitrate, cerium nitrate hexahydrate, iron nitrate nonahydrate, ruthenium trichloride trihydrate, N,N-dimethylformamide and polyvinylpyrrolidone on a magnetic stirrer to stir overnight until a certain viscosity of the glue is formed as an electrospinning solution.

[0090] The step of electrospinning includes: first, filling the electrospinning solution into the syringe of the electrospinning machine, connecting the syringe with a 25G needle through a plastic tube, and controlling the advancing rate of the microsyringe pump to be 2 μL / min to prepare the spinning solution supply system; then, wrapping a metal aluminum foil on the high-speed motorized bobbin, controlling the rotating speed to be 300 rpm, and controlling the distance between the bobbin and the needle to be 15 cm to prepare the spinning collection system; next, starting the electrospinning machine to apply a voltage of 18 kV between the needle and the bobbin to electrospin, and collecting the iron-based perovskite nanofiber material on the aluminum foil of the bobbin.

[0091] The step of calcining to prepare the oxygen evolution catalyst material includes: tearing the iron-based perovskite nanofiber material collected on the aluminum foil of the bobbin from the aluminum foil, first calcining at 850℃ for 3 hours at a temperature rising and falling rate of 2℃ / min to obtain an iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR; then, placing the iron-based perovskite nanofiber oxygen evolution catalyst material SCFR into the tube furnace again, reducing calcining at 800℃ in a 5% H2 / N2 mixed atmosphere for 20 hours to make ruthenium nanoparticles in-situ precipitate, obtaining an in-situ precipitated ruthenium nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR-H; next, oxidizing calcining the in-situ precipitated ruthenium nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material SCFR-H in air at 600℃ for 1 hour to oxidize the ruthenium nanoparticles, obtaining an in-situ precipitated oxidized ruthenium nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material, named SCFR-H-O.

[0092] Comparative Example 1

[0093] This comparative example provides a preparation method of an iron-based perovskite nanofiber oxygen evolution catalyst material, which does not contain ruthenium, and the preparation method includes the steps of weighing raw materials, preparing an electrospinning solution, electrospinning, and calcining to prepare an oxygen evolution catalyst material.

[0094] The step of weighing raw materials includes: according to the chemical formula Sr 0.9 Ce 0.05stoichiometric ratio in FeO3, 0.9 mmol of strontium nitrate SrNO3 and 0.05 mmol of cerium nitrate hexahydrate Ce(NO3)3·6H2O, 1 mmol of iron nitrate nonahydrate Fe(NO3)3·9H2O were weighed; 7.5 milliliters of N,N-dimethylformamide (DMF, about 7.1 grams) and 1.07 grams of polyvinylpyrrolidone (PVP) were weighed as an organic solvent and a fiber-forming polymer, respectively.

[0095] The step of preparing the electrospinning solution includes: placing the weighed strontium nitrate, cerium nitrate hexahydrate, iron nitrate nonahydrate, N,N-dimethylformamide and polyvinylpyrrolidone on a magnetic stirrer to stir overnight until a certain viscosity of the gel is formed as the electrospinning solution.

[0096] The step of electrospinning includes: first, the electrospinning solution is loaded into the syringe of the electrospinning machine, and the syringe is connected to a 25G needle through a plastic tube, while the push rate of the microsyringe pump is controlled at 2 μL / min, and the spinning solution supply system is prepared; then, a metal aluminum foil is wrapped on the high-speed motorized fiber collection cylinder, the rotating speed is controlled at 300 rpm, and the distance between the needle and the fiber collection cylinder is 15 cm, and the spinning collection system is prepared; next, the electrospinning machine is started to apply a voltage of 18 kV between the needle and the fiber collection cylinder for electrospinning, and the iron-based perovskite nanofiber material is collected on the aluminum foil of the fiber collection cylinder.

[0097] The step of calcining to prepare the oxygen evolution catalyst material includes: tearing the iron-based perovskite nanofiber material collected on the aluminum foil of the fiber collection cylinder from the aluminum foil, first calcining at 850℃ with a temperature rising and falling rate of 2℃ / min for 3 hours to obtain an iron-based perovskite nanofiber oxygen evolution catalyst material, named SCF.

[0098] Comparative Example 2

[0099] The present comparative example 2 provides a preparation method of an in-situ out-of-solution nanoparticle iron-based perovskite oxygen evolution catalyst material, and the prepared oxygen evolution catalyst material is a nanoparticle catalyst; the preparation method includes the step of weighing raw materials and the step of preparing a nanoparticle catalyst by a solid phase method.

[0100] The step of weighing raw materials includes: according to the chemical formula Sr 0.9 Ce 0.05 Fe 0.95 Ru 0.05 stoichiometric ratio in FeO3, 0.9 mmol of strontium nitrate SrNO3 and 0.05 mmol of cerium nitrate hexahydrate Ce(NO3)3·6H2O, 1 mmol of iron nitrate nonahydrate Fe(NO3)3·9H2O and 0.05 mmol of ruthenium chloride trihydrate RuCl3·3H2O were weighed.

[0101] The steps of preparing nanoparticle catalyst by solid phase method include: firstly, weighing strontium nitrate, cerium nitrate hexahydrate, ferric nitrate nonahydrate, ruthenium chloride trihydrate and a certain amount of anhydrous ethanol are mixed and then ball milled in a planetary ball mill for 24 hours to make the materials uniformly mixed; then, calcining at 850℃ for 3 hours at a heating and cooling rate of 2℃ / min to obtain iron-based perovskite nanoparticle oxygen evolution catalyst material, named SCFR nanoparticles; then, the iron-based perovskite nanoparticle oxygen evolution catalyst material SCFR is placed in a tube furnace again and heated in 5% H2 / N2 The material was reduced and calcined at 800°C in a mixed atmosphere for 20 hours to precipitate ruthenium nanoparticles in situ, thereby obtaining an iron-based perovskite nanoparticle oxygen evolution catalyst material with in-situ dissolution of ruthenium nanoparticles, which was named SCFR-H nanoparticles. Subsequently, the iron-based perovskite nanoparticle oxygen evolution catalyst material SCFR-H with in-situ dissolution of ruthenium nanoparticles was oxidized and calcined at 600°C in air for 1 hour to oxidize the ruthenium nanoparticles, thereby obtaining an iron-based perovskite nanoparticle oxygen evolution catalyst material with in-situ dissolution of ruthenium oxide nanoparticles, which was named SCFR-HO nanoparticles.

[0102] Experimental Example 1

[0103] In this experimental example, the oxygen evolution catalyst materials provided in Example 1 and Comparative Example 1 were tested, and the tests included structural characterization and elemental analysis tests.

[0104] The nanofiber oxygen evolution catalyst materials SCFR0.05, SCFR0.05-H and SCFR0.05-HO provided in Example 1 and the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 were structurally characterized using an X-ray diffractometer. The obtained X-ray diffraction patterns are shown in FIG. Figure 1 shown; from Figure 1 It can be seen that the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 exhibits a single-phase structure, with no impurity diffraction peaks appearing, and can be indexed to the typical SrFeO 3Perovskite is the same as the standard PDF card, indicating that the nanofiber oxygen evolution catalyst material SCF prepared by high-temperature calcination is a pure perovskite phase of ABO3; and the position of the characteristic diffraction peak of the nanofiber oxygen evolution catalyst material SCFR0.05 provided in Example 1 is slightly shifted to the left by a certain angle. This is mainly because the radius of the ruthenium ion (r=0.62Å) is larger than the radius of the iron ion (r0.59Å). When doped ruthenium replaces the position of ruthenium, the unit cell volume expands, causing the position of the diffraction peak to move to the left, reflecting that ruthenium is successfully doped into the perovskite. At the same time, the angle of the nanofiber oxygen evolution catalyst material SCFR0.05-H provided in Example 1 to the left is more obvious. This is because the reduction calcination in 5% H2 / N2 causes the in-situ dissolution of ruthenium nanoparticles, resulting in a large number of oxygen vacancies. At the same time, a new characteristic diffraction peak appears, which is the characteristic diffraction peak of ruthenium nanoparticles. In addition, the characteristic diffraction peak of ruthenium nanoparticles of the nanofiber oxygen evolution catalyst material SCFR0.05-HO provided in Example 1 disappears. This is because the ruthenium nanoparticles are oxidized to ruthenium oxide nanoparticles during calcination in air. During the calcination in air, the crystal structure of the ruthenium nanoparticles is gradually destroyed by oxidation, but the orderly arrangement of atoms is not promoted. The ruthenium oxide nanoparticles are an amorphous structure, so there is no characteristic diffraction peak. The in-situ dissolved amorphous ruthenium oxide nanoparticles are beneficial to improving the OER activity.

[0105] The structures and element types of the nanofiber oxygen evolution catalyst materials SCFR0.05, SCFR0.05-H and SCFR0.05-HO provided in Example 1 and the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 were analyzed using a scanning electron microscope and an energy dispersive spectrometer. The results are shown in FIG. Figures 2-3 As shown, from Figure 2 As can be seen from the ab diagram in the figure, the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 still maintains a nanofiber structure before and after calcination. At the same time, it can be seen from Figure c that the nanofiber oxygen evolution catalyst material SCF includes elements such as Sr, Ce, Fe, and O, while Figure 3 As can be seen from the electron microscope image shown in Figure a, no nanoparticles are dissolved from the surface of the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1, while from Figure b, it can be seen that no nanoparticles are dissolved from the nanofiber oxygen evolution catalyst material SCFR0.05 provided in Example 1 before calcination. As can be seen from Figures cd, after calcination in a H2 / N2 mixed atmosphere and an air atmosphere, the surface of the nanofiber oxygen evolution catalyst material becomes rough and ruthenium-based nanoparticles are precipitated.

[0106] To further analyze the nano-fiber oxygen evolution catalyst material SCFR0.05-H and SCFR0.05-H-O provided by Example 1, the structure and element species of SCFR0.05-H and SCFR0.05-H-O were analyzed using a transmission electron microscope image and an energy dispersive spectrometer, and the results are shown in FIGS. Figures 4-5 and 6-7; it can be clearly seen from the transmission electron microscope image of the nano-fiber oxygen evolution catalyst material SCFR0.05-H shown in FIG. Figure 4 It can be clearly seen from the transmission electron microscope image of the nano-fiber oxygen evolution catalyst material SCFR0.05-H shown in FIG. Figure 5 It can be clearly seen from the transmission electron microscope image of the nano-fiber oxygen evolution catalyst material SCFR0.05-H shown in FIG. Figure 6 It can be clearly seen from the transmission electron microscope image of the nano-fiber oxygen evolution catalyst material SCFR0.05-H shown in FIG. Figure 7 It can be clearly seen from the transmission electron microscope image of the nano-fiber oxygen evolution catalyst material SCFR0.05-H shown in FIG.

[0107] From the above structure characterization and element analysis, it can be known that calcination in a H2 / N2 mixed atmosphere can cause the nano-fiber oxygen evolution catalyst material SCFR0.05 to precipitate ruthenium nanoparticles on the surface, thereby obtaining the nano-fiber oxygen evolution catalyst material SCFR0.05-H with in-situ precipitated ruthenium nanoparticles. Further calcination of SCFR0.05-H in an air atmosphere can cause the precipitated ruthenium nanoparticles of the nano-fiber oxygen evolution catalyst material SCFR0.05-H to be oxidized into amorphous ruthenium oxide nanoparticles, thereby obtaining the nano-fiber oxygen evolution catalyst material SCFR0.05-H-O with in-situ precipitated ruthenium oxide nanoparticles, which is a nano-fiber oxygen evolution catalyst material with better OER activity.

[0108] Experimental Example 2

[0109] In this experimental example, the oxygen evolution catalyst materials provided by Example 1, Comparative Example 1 and Comparative Example 2 were tested, and the tests included structure characterization and element analysis and oxygen evolution performance tests.

[0110] Among them, the oxygen evolution electrocatalytic activity results of the nanofiber oxygen evolution catalyst materials SCFR0.05, SCFR0.05-H and SCFR0.05-HO provided in Example 1 and the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 in an oxygen-saturated 1M KOH electrolyte are as follows: Figure 8 shown; from Figure 8 From the overpotential test results in Figure a, it can be seen that the overpotentials of the nanofiber oxygen evolution catalyst materials SCF, SCFR0.05, SCFR0.05-H and SCFR0.05-HO gradually decrease, and the overpotentials are 391mV, 359mV, 353mV and 334mV respectively. This shows that among the four nanofiber oxygen evolution catalyst materials, SCFR0.05-HO reaches 10mA / cm 2 The potential is the lowest, about 1.23V+0.334V, and its oxygen evolution catalytic activity is the best, while SCFR0.05-H, SCFR0.05, and SCF reach 10mA / cm 2 The electric potential gradually increases, making it more difficult to produce hydrogen by electrolysis; Figure 8 The Tafel slopes of the four nanofiber oxygen evolution catalyst materials shown in Figure b, the overpotential / Tafel slope bar graph shown in Figure c, and the electrochemical impedance of the four nanofiber oxygen evolution catalyst materials shown in Figure d also show the same results. Among the four nanofiber oxygen evolution catalyst materials, the Tafel slope of SCFR0.05-HO is lower and the electrochemical impedance is smaller, while the Tafel slope and electrochemical impedance of SCFR0.05-H, SCFR0.05, and SCF gradually increase; This shows that the nanofiber oxygen evolution catalyst material provided by the present application is changed by doping ruthenium (Ru). The SCFR0.05 obtained by the electronic structure of perovskite has a higher oxygen evolution electrocatalytic activity, which further illustrates that the nanofiber oxygen evolution catalyst material provided by the present application dissolves ruthenium nanoparticles through reduction calcination, and in-situ dissolves them on the surface of the nanofiber oxygen evolution catalyst material, resulting in the generation of oxygen vacancies, and the oxygen evolution electrocatalytic activity is improved. It can also be further illustrated that the nanofiber oxygen evolution catalyst material provided by the present application is calcined in an air atmosphere so that the in-situ dissolved ruthenium nanoparticles are oxidized to amorphous ruthenium oxide, further improving the oxygen evolution electrocatalytic activity of the nanofiber oxygen evolution catalyst material, and the reaction kinetics are faster.

[0111] The cyclic voltammetry (CV) curves of the nanofiber oxygen evolution catalyst materials SCFR0.05, SCFR0.05-H and SCFR0.05-HO provided in Example 1 and the nanofiber oxygen evolution catalyst material SCF provided in Comparative Example 1 at different scan rates are as follows: Figure 9 As shown, by fitting Figure 9 The difference in current density and the slope of the scan rate curve give the double layer capacitance results as shown in Figure 10 shown; fromFigure 10 As can be seen, among the four nanofiber oxygen evolution catalyst materials, the SCFR0.05-H-O double-layer capacitance value is the largest, being C dl = 9.85 mF dec -1 , indicating that the greater the electrochemical active surface area, the more OER active sites can be provided, while the double-layer capacitance values of SCFR0.05-H, SCFR0.05, and SCF gradually decrease; this indicates that the nanofiber oxygen evolution catalyst material provided by the present application can improve the electrochemical active surface area by doping ruthenium, in-situ precipitating ruthenium nanoparticles by reduction calcination, and obtaining ruthenium oxide nanoparticles by oxidation calcination, so that the nanofiber oxygen evolution catalyst material has more OER active sites.

[0112] The oxygen evolution electrocatalytic activity results of the SCFR0.05-H-O nanoparticles prepared by the solid phase method provided in Comparative Example 2 in the oxygen-saturated 1M KOH electrolyte are shown in Figures 11-14 As can be seen from the overpotential, cyclic voltammetry (CV) curves at different scan rates, Tafel slope, and electrochemical impedance test results shown in Figures 11-14 , the SCFR0.05-H-O nanoparticles prepared by the solid phase method have an overpotential of 342 mV, poor symmetry of the cyclic voltammetry (CV) curve, a Tafel slope of 238 mV dec -1 , and a polarization impedance of 73.8 Ω, all of which are higher than those of the nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided in Example 1; this indicates that the nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided in Example 1 has a large specific surface area and more active attachment sites due to its nanofiber shape, which is conducive to the dispersion and attachment of ruthenium oxide nanoparticles, reduces agglomeration, promotes the progress of the oxygen evolution reaction, improves the oxygen evolution activity, and has faster reaction kinetics.

[0113] The nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided in Example 1 was tested for stability near a current density of 10 mA cm -2 using chronoamperometry, and the change in current density over time is shown in

[0114] As shown in a of Figure 15 , it can be seen from the a graph that the current density does not have significant fluctuations within two hours, indicating that the nanofiber oxygen evolution catalyst material SCFR0.05-H-O has good stability; further transmission electron microscopy and energy dispersive spectrometry were used to analyze the nanofiber oxygen evolution catalyst material SCFR0.05-H-O after chronoamperometry testing, and the results are shown in Figure 15As shown in the b and c diagrams in FIG. 6, in combination with the transmission electron microscopy diagram shown in the b diagram and the high-contrast energy spectrum diagram shown in the c diagram, it can be seen that the nanofiber oxygen evolution catalyst material SCFR0.05-H-O maintains the nanofiber shape, and the surface stably adheres to the ruthenium oxide nanoparticles; this indicates that the nanofiber oxygen evolution catalyst material SCFR0.05-H-O provided in the present application, which in-situ adheres to the ruthenium oxide nanoparticles, is expected to be practically applied to water electrolysis for hydrogen production, and in the hydrogen production process, the in-situ precipitated and adhered ruthenium oxide nanoparticles are not easy to fall off or aggregate.

[0115] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or one or more technical features can be replaced by equivalent features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0116] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or one or more technical features can be replaced by equivalent features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles, characterized in that: include: iron-based perovskite nanofibers and ruthenium-based nanoparticles; The chemical formula of the iron-based perovskite nanofiber is: Sr 1-2x Ce x Fe 1-x Ru x O3, 0.005<x<0.1; The iron-based perovskite nanofibers in-situ dissolve the ruthenium-based nanoparticles.

2. The iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to claim 1, characterized in that: The ruthenium-based nanoparticles are selected from ruthenium nanoparticles and / or ruthenium oxide nanoparticles.

3. The iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to claim 1, characterized in that: The diameter of the in-situ dissolved nanoparticle iron-based perovskite nanofiber oxygen evolution catalyst material is 50-300 nm.

4. A method for preparing an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles, characterized in that: The iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to any one of claims 1 to 3 can be prepared, comprising the following steps: Step S1, according to the chemical formula Sr 1-2x Ce x Fe 1-x Ru x O3, 0.005<x<0.1 in the stoichiometric ratio, weigh the corresponding strontium salt and cerium salt required for the A position, and the iron salt and ruthenium salt required for the B position; Step S2, uniformly mixing strontium salt, cerium salt, iron salt, ruthenium salt, fiber-forming polymer, and organic solvent to obtain an electrospinning solution; Step S3, adding the electrospinning solution into a syringe of an electrospinning machine, and performing electrospinning to obtain an iron-based perovskite nanofiber material; Step S4: calcining the iron-based perovskite nanofiber material at high temperature and in a reducing atmosphere in sequence to obtain an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolved nanoparticles.

5. The method for preparing an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to claim 4, characterized in that: In step S4, after the reducing atmosphere calcination, the oxidizing atmosphere calcination is also included.

6. The method for preparing an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to claim 4, characterized in that: Calcination in a reducing atmosphere includes: calcination at 600~1000℃ for 10~30h in a H2 / N2 mixed atmosphere.

7. The method for preparing an iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to claim 5, characterized in that: Calcination in an oxidizing atmosphere includes: calcining at 400~800℃ in air for 0.5~2h.

8. Use of the iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution of nanoparticles according to any one of claims 1 to 3 in the field of hydrogen production by electrolysis of water.

9. An alkaline electrolytic cell, characterized in that The anode in the alkaline electrolytic cell is loaded with the iron-based perovskite nanofiber oxygen evolution catalyst material with in-situ dissolution nanoparticles according to any one of claims 1 to 3.

10. A new energy hydrogen production integrated system, characterized in that: The electrolytic hydrogen production unit in the new energy integrated hydrogen production system includes an alkaline electrolytic cell as described in claim 9.

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