阅读说明：本技术 一种由金属单原子及其金属衍生物负载的多孔碳基纳米纤维薄膜材料及其制备方法和应用 (Porous carbon-based nanofiber film material loaded by metal single atom and metal derivative thereof, and preparation method and application thereof ) 是由 芮琨 王文青 朱纪欣 武凯利 于 2021-07-12 设计创作，主要内容包括：本发明公开了一种由金属单原子及其金属衍生物负载的多孔碳基纳米纤维薄膜材料的制备方法与应用,属于功能纳米材料的制备技术领域。将金属有机骨架前驱体MOF与聚合物充分混合制备纺丝液,借助静电纺丝技术获得MOF纳米颗粒掺杂的聚合物纤维薄膜,通过浸渍使金属离子吸附于纤维表面和内部,进一步在惰性气氛中进行热处理,获得金属/氮掺杂多孔碳基杂化纳米纤维薄膜材料。该方法制备的碳基薄膜材料具有活性位点丰富、导电率高、离子传输通道充足、柔性好及自支撑结构优良等物理特性,在电化学催化反应和电存储的应用中,具备高活性、高容量、高稳定性的优势。整个材料的制备工艺简单,能耗低,环境友好,适合工业化大规模生产。(The invention discloses a preparation method and application of a porous carbon-based nanofiber membrane material loaded by metal single atoms and metal derivatives thereof, belonging to the technical field of preparation of functional nanomaterials. Fully mixing a metal organic framework precursor MOF and a polymer to prepare a spinning solution, obtaining a polymer fiber film doped with MOF nano particles by means of an electrostatic spinning technology, adsorbing metal ions on the surface and inside of the fiber by impregnation, and further performing heat treatment in an inert atmosphere to obtain the metal/nitrogen-doped porous carbon-based hybrid nanofiber film material. The carbon-based thin film material prepared by the method has the physical characteristics of rich active sites, high conductivity, sufficient ion transmission channels, good flexibility, excellent self-supporting structure and the like, and has the advantages of high activity, high capacity and high stability in the application of electrochemical catalytic reaction and electrical storage. The whole material has simple preparation process, low energy consumption and environmental protection, and is suitable for industrial large-scale production.)

1. A preparation method of a porous carbon-based nanofiber membrane material loaded by metal single atoms and metal derivatives thereof is characterized by comprising the following steps:

a. metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

b. dissolving ZIF-8 obtained in the step a in N, N-dimethylformamide, and fully stirring at room temperature to form a white solution; adding Polyacrylonitrile (PAN) polymer into the solution, so that the mass ratio of PAN to ZIF-8 is as follows: PAN (ZIF-8) is 1-4: 1-5; fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution; obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

c. soaking the fiber membrane PAN/ZIF-8 in methanol solution of metal salt with different concentrations, wherein the metal salt is Fe (NO)₃)₃、Co(NO₃)₂Or Ni (NO)₃)₂Soaking for 1-5 h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Fe, PAN/ZIF-8/Co and PAN/ZIF-8/Ni, and then carrying out heat treatment at the temperature rise rate of 2-10 ℃/min and the temperature of more than or equal to 500 ℃ for 1-5 h to obtain a porous carbon-based nanofiber membrane loaded with a metal monoatomic atom or a metal derivative thereof;

wherein, the fiber membrane PAN/ZIF-8 is kept still at 0.1-1 g L^-1Fe(NO₃)₃、Co(NO₃)₂、Ni(NO₃)₂In the methanol solution, the metal monatomic nitrogen-loaded carbon nanofiber SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C can be obtained through subsequent operation;

standing the fiber membrane PAN/ZIF-8 at 1-3 g L^-1Fe(NO₃)₃The metal carbide nano particles loaded with nitrogen-doped carbon nano fiber NP-Fe can be obtained through subsequent operation in the methanol solution_xC-N-C；

Standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1Fe(NO₃)₃In the methanol solution, the carbon tube can be coated with the nitrogen-doped carbon nano-fiber CNT @ Fe loaded by the metal derivative through subsequent operation_xC-N-C；

Standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1Co(NO₃)₂、Ni(NO₃)₂The metal simple substance nano-particle loaded nitrogen-doped carbon nano-fiber NP-Co-N-C, NP-Ni-N-C can be obtained through subsequent operations in the methanol solution.

2. The preparation method of the metal monoatomic and metal derivative-supported porous carbon-based nanofiber membrane material according to claim 1, wherein the preparation method comprises the following steps: the mass ratio of the metal salt to the organic ligand used in the step a is as follows: zn (NO)₃)₂2-methylimidazole is 1: 8.

3. The preparation method of the metal monoatomic and metal derivative-supported porous carbon-based nanofiber membrane material according to claim 1, wherein the preparation method comprises the following steps: in the electrostatic spinning process in the step b, a 10mL injector is used, the electrostatic spinning voltage is set to be 13kV, and the advancing speed is set to be: 1mL h^-1。

4. The preparation method of the metal monoatomic and metal derivative-supported porous carbon-based nanofiber membrane material according to claim 1, wherein the preparation method comprises the following steps: the inert gas under the heat treatment condition in the step c is nitrogen or argon.

5. The application of the porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof according to claim 1, wherein the porous carbon-based nanofiber membrane material is characterized in that: the nano material SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xThe application of C-N-C, NP-Co-N-C or NP-Ni-N-C in electrocatalysis, metal-air batteries, metal ion batteries, super capacitors and other energy storage and conversion.

6. The application of the porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof according to claim 5, wherein the porous carbon-based nanofiber membrane material is characterized in that: the nano material can be used as an electrocatalytic electrode material and comprises the following steps:

a. porous carbon-based nanofiber film material loaded with metal single atoms and metal derivatives of metal single atoms SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xPlacing C-N-C, NP-Co-N-C or NP-Ni-N-C in a centrifuge tube, and ultrasonically mixing with 5% Nafion/ethanol mixed solution (Nafion: ethanol is 1:19 Vol%) to obtain catalyst ink;

b. dripping 10 μ L of the catalyst ink solution on polished glassy carbon electrode, drying at room temperature for more than or equal to 20min, and loading the catalyst at 0.2mg cm^-2；

c. Testing by using a standard three-electrode system, wherein the rotating speed of a rotating disc is set to 1600 rpm;

d. and testing the electrocatalytic activity of oxygen reduction and hydrogen evolution and the like in 0.1-1.0M KOH solution at room temperature.

7. The application of the porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof according to claim 5, wherein the porous carbon-based nanofiber membrane material is characterized in that: the preparation method of the nanofiber membrane material used as the metal-air battery positive electrode material comprises the following steps:

a. porous carbon-based nanofiber film material loaded with metal single atoms and metal derivatives of metal single atoms SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xC-N-C, NP-Co-N-C or NP-Ni-N-C was sufficiently ground in a mortar, and then ultrasonically mixed with a 5% Nafion/ethanol mixture (Nafion: ethanol 1:19 Vol%) to obtain a catalyst ink, which was sprayed on hydrophobic carbon paper with an area of 1cm²Drying the electrode slice coated with the electrode material in a vacuum drying oven at 60 ℃ for more than or equal to 24 hours, and taking the prepared electrode as a battery anode;

b. using a metal zinc sheet as a negative electrode, 6.0M KOH and 2.0M Zn (Ac)₂The electrolyte is a self-made zinc-air battery assembled under air condition.

8. The application of the porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof according to claim 5, wherein the porous carbon-based nanofiber membrane material is characterized in that: the preparation method of the nanofiber membrane material used as the negative electrode material of the ion battery comprises the following steps:

a. porous carbon-based nanofiber film material SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe loaded with working electrode metal single atom and metal derivative thereof_xC-N-C、[email protected]_xC-N-C, NP-Co-N-C or NP-Ni-N-C is dried in a vacuum drying oven at 60 ℃ for more than or equal to 24 hours;

b. a metal lithium sheet is used as a reference/counter electrode, 1.0M LiPF6 in EC: DMC: EMC is 1:1:1Vol, 1.0M LiPF6 in an EC, DMC and EMC mixed solution with a volume ratio of 1:1:1 is used as an electrolyte, a polypropylene film is used as a diaphragm, and the button cell is assembled in a glove box.

Technical Field

The invention relates to a large-scale preparation method of a porous carbon-based nanofiber membrane material loaded by metal monatomic and metal derivatives thereof, which can be used as an electrochemical catalysis and energy storage material, and belongs to the technical field of preparation of functional nanomaterials.

Background

The phenomena of environmental pollution and energy exhaustion are becoming more serious due to the excessive use of fossil energy, and thus, the use of clean energy instead of fossil energy is urgently required. Fuel cells, metal-air cells, metal-ion cells, and the like are considered ideal next-generation energy storage or conversion technologies. Metal air batteries are receiving increasing attention due to their high energy density, low cost, environmental friendliness and safety. However, the cathode oxygen reduction reaction is very slow in kinetics, and the current commercial noble metal catalyst suffers from the disadvantages of low storage capacity and high cost, so that the development of high-performance and low-cost oxygen reduction catalysts is urgent. Lithium ion batteries have the characteristics of high discharge voltage, high energy density and long cycle life, are widely applied in the field of portable electronic equipment, and are favored by some high-technology application fields such as military, aerospace, electric automobiles and the like. Therefore, it is of great research interest to search for and design electrocatalyst materials with high activity and low cost and battery electrode materials with high capacity and long lifetime.

Metal-organic frameworks (MOFs) are hybrid organic-inorganic materials with intramolecular pores formed by self-assembly of organic ligands and metal ions or clusters through coordination bonds. The method has the advantages of high porosity, low density, large specific surface area, regular pore channels, adjustable pore diameter, diversity of topological structure, tailorability and the like. The MOFs derivative material (metal oxide or sulfide) can retain the characteristics of porosity, large specific surface area, specific structure and the like of a precursor of the MOFs derivative material, so that the MOFs derivative material can be used as a battery electrode material and an electro-catalytic material to show excellent electrochemical performance.

The electrostatic spinning is a simple and effective processing technology capable of producing nano-fibers, and polymer solution is subjected to jet spinning in a strong electric field and solidified into polymer filaments with nano-scale diameters. The material obtained based on the electrostatic spinning technology has the excellent physical characteristics of small aperture, high porosity, good fiber uniformity and the like. The carbonized fiber is in a net-shaped intercommunicating structure and has excellent electrical conductivity and mechanical ductility. The electrostatic spinning technology is widely applied in the fields of energy, environment, biomedicine, photoelectricity and the like.

Disclosure of Invention

The technical problem solved by the invention is as follows: the method for synthesizing the carbon-based functional nano material has the advantages of excellent performance, simple process and large-scale preparation, and the prepared porous carbon-based nano fiber film material loaded by the metal monoatomic atom and the metal derivative thereof has stable performance, high capacity and long service life, has high activity in electrocatalytic oxygen reduction reaction, and can be applied to energy storage and conversion devices (such as metal air batteries, metal ion batteries, super capacitors and the like).

In order to solve the technical problems, the technical scheme provided by the invention is as follows: the preparation method of the porous carbon-based nanofiber film material loaded by the metal single atom and the metal derivative thereof comprises the following steps:

a. metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

b. and d, dissolving the ZIF-8 obtained in the step a in N, N-dimethylformamide, and fully stirring at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

c. soaking the fiber membrane PAN/ZIF-8 in methanol solution of metal salt with different concentrations, wherein the metal salt is Fe (NO)₃)₃、Co(NO₃)₂Or Ni (NO)₃)₂Soaking for 1-5 h, and vacuum drying to obtainAnd (2) carrying out heat treatment on metal ion adsorbed PAN/ZIF-8/Fe, PAN/ZIF-8/Co and PAN/ZIF-8/Ni at the temperature rising rate of 2-10 ℃/min and the temperature being more than or equal to 500 ℃ for 1-5 h to obtain the porous carbon-based nanofiber membrane loaded with the metal monoatomic atom or the metal derivative thereof. Wherein, the fiber membrane PAN/ZIF-8 is kept still at 0.1-1 g L^-1In the methanol solution of the metal salt, the metal monatomic nitrogen-loaded carbon nanofiber SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C can be obtained through subsequent operation; standing the fiber membrane PAN/ZIF-8 at 1-3 g L^-1Fe(NO₃)₃The metal carbide nano particles loaded with nitrogen-doped carbon nano fiber NP-Fe can be obtained through subsequent operation in the methanol solution_xC-N-C; standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1 Fe(NO₃)₃In the methanol solution, the carbon tube can be coated with the nitrogen-doped carbon nano-fiber CNT @ Fe loaded by the metal derivative through subsequent operation_xC-N-C, standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1In the methanol solution of the metal salt, the nitrogen-doped carbon nanofiber NP-Co-N-C, NP-Ni-N-C loaded by the metal simple substance nanoparticles can be obtained through subsequent operations.

Preferably, the mass ratio of the metal salt to the organic ligand used in the step a is: zn (NO)₃)₂2-methylimidazole is 1: 8.

Preferably, the mass ratio of PAN to ZIF-8 in the step b is: PAN, ZIF-8, 1-4: 1-5.

Preferably, in the electrospinning process in the step b, a 10mL syringe is used, the electrospinning voltage is set to 13kV, and the advancing speed is set to: 1mL h^-1。

Preferably, the inert gas under the heat treatment conditions in step c is nitrogen or argon.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: the porous carbon-based nanofiber film material loaded by the metal single atom and the metal derivative thereof is SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xThe application of C-N-C, NP-Co-N-C or NP-Ni-N-C in electrocatalysis, metal-air batteries, metal ion batteries, super capacitors and other energy storage and conversion.

Preferably, the porous carbon-based nanofiber membrane material loaded by the metal single atom and the metal derivative thereof can be used as an electrocatalytic electrode material, and the method comprises the following steps:

a. porous carbon-based nanofiber film material loaded with metal single atoms and metal derivatives of metal single atoms SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xPlacing C-N-C, NP-Co-N-C or NP-Ni-N-C in a centrifuge tube, and ultrasonically mixing with 5% Nafion/ethanol mixed solution (Nafion: ethanol is 1:19 vol%) to obtain catalyst ink;

b. dripping 10 μ L of the catalyst ink solution on polished glassy carbon electrode, drying at room temperature for more than or equal to 20min, and loading the catalyst at 0.2mg cm^-2；

c. Testing by using a standard three-electrode system, wherein the rotating speed of a rotating disc is set to 1600 rpm;

d. and testing the electrocatalytic activity of oxygen reduction and hydrogen evolution and the like in 0.1-1.0M KOH solution at room temperature.

Preferably, the porous carbon-based nanofiber membrane material loaded by the metal single atom and the metal derivative thereof can be used as a manufacturing method of a metal-air battery positive electrode material, and the steps are as follows:

a. porous carbon-based nanofiber film material SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe loaded with working electrode metal single atom and metal derivative thereof_xC-N-C、[email protected]_xC-N-C, NP-Co-N-C or NP-Ni-N-C was sufficiently ground in a mortar, and then ultrasonically mixed with a 5% Nafion/ethanol mixture (Nafion: ethanol 1:19 Vol%) to obtain a catalyst ink, which was sprayed on hydrophobic carbon paper with an area of 1cm²Drying the electrode slice coated with the electrode material in a vacuum drying oven at 60 ℃ for more than or equal to 24 hours, and taking the prepared electrode as a battery anode;

b. using a metal zinc sheet as a negative electrode, 6.0M KOH and 2.0M Zn (Ac)₂The electrolyte is a self-made zinc-air battery assembled under air condition.

Preferably, the preparation method of the porous carbon-based nanofiber membrane material loaded by the metal single atom and the metal derivative thereof can be used as the negative electrode material of the ion battery, and comprises the following steps:

a. porous carbon-based nanofiber film material SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe loaded with working electrode metal single atom and metal derivative thereof_xC-N-C、[email protected]_xC-N-C, NP-Co-N-C or NP-Ni-N-C is dried in a vacuum drying oven at 60 ℃ for more than or equal to 24 hours;

b. using a metal lithium sheet as a reference/counter electrode and 1.0M LiPF₆in EC DMC EMC 1:1:1Vol, 1:1:1 volume ratio of EC, DMC, EMC mixed solution containing 1.0M LiPF₆And (3) as an electrolyte, taking a polypropylene film as a diaphragm, and assembling the button cell in a glove box.

Advantageous effects

The preparation method comprises the steps of soaking the fiber membrane PAN/ZIF-8 in methanol solutions of metal salts with different concentrations to obtain PAN/ZIF-8/Fe, PAN/ZIF-8/Co and PAN/ZIF-8/Ni adsorbed by metal ions, then carrying out heat treatment, wherein the heating rate is 2-10 ℃/min, the temperature is more than or equal to 500 ℃, and the temperature is kept for 1-5 hours to obtain the porous carbon-based nanofiber membrane loaded with metal monoatomic atoms or metal derivatives thereof. Therefore, finding the optimum metal concentration and different metal salts is one of the creative efforts of the present invention. In practical cases, the method is suitable for preparing various metal species and various metal particle geometric sizes, including metal monoatomic atoms, metal carbides, metal simple substances and the like, and no harmful gas is discharged into the atmosphere in the preparation reaction process, so that the method accords with the concept of green chemistry. Simple operation stage, short test period and extremely high specific surface area of the porous material. The chemical reagent has high utilization rate in the experimental process, can be produced in large scale and is suitable for industrial application. Secondly, experimental results show that the incorporation ratios of different MOFs and PANs have significant effects on the sample morphology and material properties. Therefore, finding the optimal ratio is also one of the creative efforts. Through a large number of experimental screenings, the mass ratio of PAN to ZIF-8 in the step b is as follows: PAN, ZIF-8, 1-4: 1-5.

Besides, the porous carbon-based nanofiber membrane material loaded by metal single atoms and metal derivatives thereof is SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xThe catalyst ink prepared by C-N-C, NP-Co-N-C or NP-Ni-N-C ultrasonic is coated on a glassy carbon electrode, and the effective area is 0.19625cm²The electrode material shows better electrocatalytic oxygen reduction performance results at the rotating speed of 1600 rpm. Experimental results show that the porous carbon-based nanofiber membrane material SA-Fe-N-C, SA-Co-N-C and SA-Ni-N-C loaded by metal single atoms and metal derivatives thereof have oxygen reduction catalytic performance superior to that of commercial platinum carbon, and the limiting current density can reach 6mA cm^-2Exceeding the catalytic performance of commercial platinum carbon (5.5mA cm)^-2)。

The porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof prepared by the invention can be used as a zinc-air battery anode material. In the assembled zinc-air cell test, the current density was 2mA cm^-2Under the condition of (2), the specific capacity of the electrode material can reach 800mAh g^-1Above, these properties are consistent with practical applications for low cost production of materials compared to commercial platinum carbon. Experimental results show that the metal monoatomic and metal derivative-loaded porous carbon-based nanofiber membrane material SA-Fe-N-C shows excellent electrochemical performance and has good stability and rate capability. In contrast, commercial platinum carbon exhibits significant performance degradation at high current densities.

The porous carbon-based nanofiber membrane material loaded by the metal single atom and the metal derivative thereof can be used as a negative electrode material of an ion battery. Carbon tube coated metal derivative loaded nitrogen-doped carbon nanofiber CNT @ Fe_xC-N-C showed the best performance.

Drawings

The invention will be further explained with reference to the drawings.

FIG. 1 is a scanning electron microscope image of a ZIF-8 doped nanofiber film in example 1 of the present invention;

FIG. 2 is a scanning electron microscope image of a nanofiber membrane material adsorbing ferric nitrate in example 1 of the present invention;

FIG. 3 is a transmission electron microscope image of a porous carbon nanofiber film material loaded with iron monoatomic ions in example 1 of the present invention;

FIG. 4 is a spherical aberration electron microscope image of the porous filamentous nanocarbon material loaded with iron monoatomic atoms in example 1 of the invention;

FIG. 5 is an optical image photograph of a nanofiber thin film loaded with iron monoatomic ions according to example 1 of the present invention;

FIG. 6 is an X-ray diffraction image of a nanofiber membrane loaded with iron monoatomic ions according to example 2 of the present invention;

fig. 7 is a raman image of a porous carbon-based nanofiber membrane material supported by an iron monoatomic atom and an iron derivative in example 3 of the present invention;

fig. 8 is a transmission electron microscope image and an X-ray diffraction image of a carbon tube/metal nanoparticle hybrid loaded nanofiber thin film in example 3 of the present invention;

FIG. 9 is an LSV polarization curve of electrocatalytic oxygen reduction reaction of carbon-based nanofibers prepared in examples 1, 2, 3 of the present invention;

fig. 10 is a graph showing rate performance of a metal-air battery based on porous filamentous nanocarbon supporting iron monoatomic atoms, prepared in example 1 of the present invention;

fig. 11 is a diagram showing practical application of the zinc-air battery based on the porous filamentous nanocarbon supporting iron monoatomic ions prepared in example 1 of the present invention.

Detailed Description

The technical solution of the invention is further illustrated below with reference to examples, which are not to be construed as limiting the technical solution.

Example 1

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 0.1-1 g L^-1 Fe(NO₃)₃Soaking in the methanol solution for 1-5 h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Fe, then carrying out heat treatment at the temperature rise rate of 2-10 ℃/min at the speed of more than or equal to 500 ℃, and keeping for 1-5 h to obtain the metal monatomic nitrogen-loaded carbon nanofiber SA-Fe-N-C.

Example 2

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 0.5g L^-1 Fe(NO₃)₃Soaking in the methanol solution for 3h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Fe, and then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising rate of 800 ℃ for 3h to obtain the metal monatomic nitrogen-loaded carbon nanofiber SA-Fe-N-C.

Example 3

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 1-3 g L^-1 Fe(NO₃)₃Soaking the metal-doped carbon nano-fiber in the methanol solution for 3 hours, then drying the metal-doped carbon nano-fiber in vacuum to obtain PAN/ZIF-8/Fe adsorbed by metal ions, and then carrying out heat treatment at the temperature rising rate of 2-10 ℃/min and the temperature rising speed of more than or equal to 500 ℃ for 1-5 hours to obtain the metal carbide nano-particle loaded nitrogen-doped carbon nano-fiber NP-Fe_xC-N-C。

Example 4

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 2g L^-1 Fe(NO₃)₃Soaking in the methanol solution for 3h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Fe, then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising rate of 800 ℃, and keeping for 3h to obtain the metal carbide nano-particle loaded nitrogen-doped carbon nano-fiber NP-Fe_xC-N-C。

Example 5

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1 Fe(NO₃)₃Soaking the carbon nanotube-coated metal derivative in the methanol solution for 1-5 h, then drying the methanol solution in vacuum to obtain metal ion-adsorbed PAN/ZIF-8/Fe, and then carrying out heat treatment at the temperature rising rate of 2-10 ℃/min and the temperature rising speed of more than or equal to 500 ℃ for 1-5 h to obtain carbon tube-coated metal derivative-loaded nitrogen-doped carbon nanofiber CNT @ Fe_xC-N-C。

Example 6

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1 Fe(NO₃)₃Soaking in the methanol solution for 3h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Fe, then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising rate of 800 ℃, keeping for 3h to obtain carbon tube coated metal derivative loaded nitrogen-doped carbon nanofiber CNT @ Fe_xC-N-C。

Example 7

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

subjecting the fibrous membrane PAN/ZIF-8 to static agitationIs disposed at 0.1 to 1g L^-1 Co(NO₃)₂Soaking in the methanol solution for 1-5 h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Co, then carrying out heat treatment at the temperature rise rate of 2-10 ℃/min at the speed of more than or equal to 500 ℃, and keeping for 1-5 h to obtain the metal monatomic nitrogen-loaded carbon nanofiber SA-Co-N-C.

Example 8

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 0.5g L^-1 Co(NO₃)₂Soaking in the methanol solution for 3h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Co, then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising rate of 800 ℃, and keeping for 3h to obtain the metal monatomic nitrogen-loaded carbon nanofiber SA-Co-N-C.

Example 9

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 0.1-1 g L^-1 Ni(NO₃)₂Soaking in methanol solution for 1-5 h, and vacuum drying to obtain the product with metal ion adsorptionAnd (3) performing heat treatment on the PAN/ZIF-8/Ni, wherein the heating rate is 2-10 ℃/min, the heating speed is more than or equal to 500 ℃, and the temperature is kept for 1-5 h to obtain the metal monatomic nitrogen-loaded carbon nanofiber SA-Ni-N-C.

Example 10

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 0.5g L^-1 Ni(NO₃)₂Soaking in the methanol solution for 3h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Ni, and then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising rate of 800 ℃ for 3h to obtain the metal monatomic nitrogen-loaded carbon nanofiber SA-Ni-N-C.

Example 11

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1 Co(NO₃)₂Soaking the mixture in the methanol solution for 1-5 h, then drying the mixture in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Co, then carrying out heat treatment at the temperature rise rate of 2-10 ℃/min and the temperature rise rate of more than or equal to 500 ℃, and keeping the temperature for 1-5 h to obtain metal simple substance nano particlesAnd the loaded nitrogen-doped carbon nanofiber NP-Co-N-C.

Example 12

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 5g L^-1Co(NO₃)₂Soaking in the methanol solution for 3h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Co, then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising rate of 800 ℃, and keeping for 3h to obtain the nitrogen-doped carbon nanofiber NP-Co-N-C loaded by the metal simple substance nanoparticles.

Example 13

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 4-6 g L^-1 Ni(NO₃)₂Soaking in the methanol solution for 1-5 h, then drying in vacuum to obtain metal ion adsorbed PAN/ZIF-8/Ni, then carrying out heat treatment at the temperature rise rate of 2-10 ℃/min at the speed of more than or equal to 500 ℃, and keeping for 1-5 h to obtain the nitrogen-doped carbon nanofiber NP-Ni-N-C loaded with the metal simple substance nanoparticles.

Example 14

Metal salt Zn (NO)₃)₂Dissolving the mixture and 2-methylimidazole in methanol respectively, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8;

the obtained ZIF-8 was dissolved in N, N-dimethylformamide and stirred well at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, fully stirring and mixing for more than or equal to 24 hours to prepare spinning solution. Obtaining a ZIF-8 nanoparticle-doped polymer fiber film PAN/ZIF-8 by using an electrostatic spinning technology;

standing the fiber membrane PAN/ZIF-8 at 5g L^-1 Ni(NO₃)₂Soaking the metal-ion-adsorbed PAN/ZIF-8/Ni in the methanol solution for 1-5 h, then drying in vacuum to obtain metal-ion-adsorbed PAN/ZIF-8/Ni, and then carrying out heat treatment at the temperature rising rate of 5 ℃/min and at the temperature rising speed of 800 ℃ for 3h to obtain the nitrogen-doped carbon nanofiber NP-Ni-N-C loaded by the metal simple substance nanoparticles.

Example 15

The porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof prepared by the invention can be used as an electrocatalytic oxygen reduction reaction material. Porous carbon-based nanofiber film material loaded with metal single atoms and metal derivatives of metal single atoms SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xC-N-C, NP-Co-N-C or NP-Ni-N-C was placed in a centrifuge tube and mixed with 5% Nafion/ethanol mixture (Nafion: ethanol 1:19 vol%) by ultrasound to obtain catalyst ink. Dripping 10 μ L of the catalyst ink solution on polished glassy carbon electrode, drying at room temperature for more than or equal to 20min, and loading the catalyst at 0.2mg cm^-2. The test was performed using a standard three-electrode system with the rotating disc set at 1600 rpm. And testing the electrocatalytic activity of oxygen reduction and hydrogen evolution and the like in 0.1-1.0M KOH solution at room temperature. After the data acquisition is completed, the mapping analysis is carried out by origin data processing software. Experimental results show that the porous carbon-based nanofiber membrane material SA-Fe-N-C, SA-Co-N-C and SA-Ni-N-C loaded by metal single atoms and metal derivatives thereof show superior oxygen reduction catalytic performance and limiting current density to commercial platinum carbonCan reach 6mA cm^-2Exceeding the catalytic performance of commercial platinum carbon (5.5mA cm)^-2)。

The porous carbon-based nanofiber membrane material loaded by the metal monoatomic atom and the metal derivative thereof prepared by the invention can be used as a zinc-air battery anode material. Porous carbon-based nanofiber film material SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe loaded with working electrode metal single atom and metal derivative thereof_xC-N-C、[email protected]_xC-N-C, NP-Co-N-C or NP-Ni-N-C was sufficiently ground in a mortar, and then ultrasonically mixed with a 5% Nafion/ethanol mixture (Nafion: ethanol 1:19 Vol%) to obtain a catalyst ink, which was sprayed on hydrophobic carbon paper with an area of 1cm²And (3) drying the electrode slice coated with the electrode material in a vacuum drying oven at 60 ℃ for more than or equal to 24 hours, and taking the prepared electrode as a battery anode. Using metal zinc sheet as negative electrode, 6.0MKOH and 2.0M Zn (Ac)₂The electrolyte is a self-made zinc-air battery assembled under air condition. After the battery assembly is finished, performing constant current charge-discharge cycle test on a battery tester (Shenzhen New Wei battery test cabinet CT-4008-5V5mA), and setting the charge time and the discharge time to be 10 minutes; the specific capacity of the zinc-air battery is tested by testing constant current discharge on a battery tester (Shenzhen New Wei battery test cabinet CT-4008-5V5mA), and the current density is set to be 10mA cm^-2. After the data acquisition is completed, the mapping analysis is carried out by origin data processing software. Experimental results show that the metal monoatomic and metal derivative-loaded porous carbon-based nanofiber membrane material SA-Fe-N-C shows excellent electrochemical performance and has good stability and rate capability. In contrast, commercial platinum carbon exhibits significant performance degradation at high current densities.

The porous carbon-based nanofiber membrane material loaded by the metal single atom and the metal derivative thereof can be used as a negative electrode material of an ion battery. The working electrode SA-Fe-N-C, SA-Co-N-C, SA-Ni-N-C, NP-Fe_xC-N-C、[email protected]_xAnd drying the C-N-C, NP-Co-N-C or NP-Ni-N-C nanofiber membrane material in a vacuum drying oven at the temperature of 60 ℃ for more than or equal to 24 hours. Using metal lithium sheet as reference/counter electrode and 1.0MLiPF₆in EC DMC EMC 1:1:1 Vol% in a volume ratio of 1:1:1EC. The DMC and EMC mixed solution contains 1mol/L LiPF₆And (3) as an electrolyte, taking a polypropylene film as a diaphragm, and assembling the button cell in a glove box. The test is carried out on a battery tester (Shenzhen New Wei battery test cabinet CT-4008-5V5mA), and after the data acquisition is completed, the drawing analysis is carried out through origin data processing software. Wherein, the carbon tube is coated with the nitrogen-doped carbon nanofiber CNT @ Fe loaded by the metal derivative_xC-N-C showed the best performance.

Comparative example 1

Metal salt Zn (NO)₃)₂And respectively dissolving the mixture and 2-methylimidazole in methanol, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8. And dissolving the ZIF-8 obtained in the step into N, N-dimethylformamide, and fully stirring at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, so that the mass ratio of PAN to ZIF-8 is as follows: PAN: ZIF-8 ═ 3: 1. Fully stirring and mixing for more than or equal to 24 hours to prepare the spinning solution. By using an electrospinning technique, a ZIF-8 nanoparticle doped polymer fiber thin film (7:1) PAN/ZIF-8 was obtained. Soaking fibrous membrane PAN/ZIF-8 in 0.5g L^-1Fe(NO₃)₃In the methanol solution of metal salt, the metal salt is Fe (NO)₃)₃Soaking for 3h, then drying in vacuum to obtain PAN/ZIF-8/Fe adsorbed by metal ions, then carrying out heat treatment at the heating rate of 5 ℃/min and the temperature of more than or equal to 500 ℃ for 3h to obtain the fiber material (7:1) -SA-Fe-N-C with low surface roughness.

Comparative example 2

Metal salt Zn (NO)₃)₂And respectively dissolving the mixture and 2-methylimidazole in methanol, stirring and mixing at room temperature, washing a centrifuged product by using methanol, and drying in vacuum to obtain a white powder solid ZIF-8. And dissolving the ZIF-8 obtained in the step into N, N-dimethylformamide, and fully stirring at room temperature to form a white solution. Adding Polyacrylonitrile (PAN) polymer into the solution, so that the mass ratio of PAN to ZIF-8 is as follows: PAN: ZIF-8 ═ 1: 6. Fully stirring and mixing for more than or equal to 24 hours to prepare the spinning solution. By using an electrospinning technique, a ZIF-8 nanoparticle doped polymer fiber thin film (1:7) PAN/ZIF-8 was obtained. Soaking fiber membrane PAN/ZIF-8 in water at 0.5g L^-1Fe(NO₃)₃In the methanol solution of metal salt, the metal salt is Fe (NO)₃)₃Soaking for 3h, then drying in vacuum to obtain PAN/ZIF-8/Fe adsorbed by metal ions, and then carrying out heat treatment at the temperature rise rate of 5 ℃/min, wherein the temperature is more than or equal to 500 ℃, and keeping for 3h to obtain the fiber material (1:7) -SA-Fe-N-C in a fracture form.

The invention explores a method for synthesizing metal-loaded porous nano-fiber by taking an electrostatic spinning technology as a support and application thereof. The invention can simply and massively manufacture nano fiber structures and a series of hybrid materials doped with metal monoatomic atoms, and the obtained nano fibers not only show ultrahigh activity in electrocatalytic reaction, but also show the characteristics of high specific capacity and long service life in energy storage and conversion due to the structural advantages of high conductivity, high active sites, high loading capacity, carbon network structure interaction, thin transverse extension and the like.

The above-mentioned embodiments are intended to illustrate the technical solutions and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only the most preferred embodiments of the present invention, and are not intended to limit the present invention, and any modifications, additions, equivalents, etc. made within the scope of the principles of the present invention should be included in the scope of the present invention.