Co-Cu Bimetallic ZIF Materials, Co-Cu Bimetallic Carbon Materials and Their Preparation Methods and Applications

Abstract

The present invention relates to a Co-Cu bimetallic ZIF material, a Co-Cu bimetallic carbon material, and their preparation methods and applications. The Co-Cu bimetallic ZIF material provided by the present invention comprises first composite particles composed of a plurality of nanosheets, and the nanosheets comprise cobalt ions, copper ions, and imidazole ligands. The Co-Cu bimetallic carbon material derived from the Co-Cu bimetallic ZIF material of the present invention can, while enriching phenolic substances, achieve the efficient and rapid degradation of phenolic substances through the synergistic effect of multi-metal active sites.

Description

Technical Field

[0001] The present invention relates to the field of environmental green catalysis, and particularly relates to a Co-Cu bimetallic ZIF material, a Co-Cu bimetallic carbon material, and their preparation methods and applications. Background Art

[0002] Metal-organic frameworks (MOFs) are a new milestone in the development of nanoporous materials and are a class of novel highly crystalline porous materials. MOFs materials have some desirable properties, such as high porosity, adjustable pore structures, and the ability to endow specific functions or active substances without changing the framework topology, making them very promising materials that can be widely used in fields such as adsorption, gas storage / separation, catalysis, etc. In addition to these intuitive applications, MOFs materials are also used as templates and platforms for preparing porous carbon materials. Zeolitic imidazolate frameworks (ZIFs) are an important branch of metal-organic framework MOFs materials and are used as precursors for synthesizing transition metal and N-doped porous carbon (TM-N-C) composites. During the formation of ZIFs, bimetallic active sites can be introduced by adding two kinds of cations. The introduction of heteroatoms can not only regulate the coordination environment of metal atoms in ZIFs, but also provide a certain steric hindrance to alleviate the agglomeration phenomenon during the pyrolysis process. However, there are still great challenges in the multi-scale preparation and control of nanoscale transition metals.

[0003] 4-Nitrophenol (4-NP) is a common organic pollutant in industries such as chemical engineering, dyes, and pharmaceuticals. It widely exists in various wastewaters and is an important persistent pollutant. Due to the good chemical and biological stability of phenolic compounds and their difficulty in degradation, it has always been a difficult problem in wastewater treatment. Currently, biological degradation, chemical oxidation, photocatalysis, and physical adsorption and other means play important roles in the degradation of 4-nitrophenol. How to combine multiple treatment methods to develop highly efficient and multifunctional catalysts remains a challenge. Summary of the Invention

[0004] To solve the problems in the prior art, the present invention provides a Co-Cu bimetallic ZIF material, a Co-Cu bimetallic carbon material, and their preparation methods and applications. The Co-Cu bimetallic carbon material derived from the Co-Cu bimetallic ZIF material provided by the present invention can enrich phenolic substances and achieve the efficient and rapid degradation of phenolic substances through the synergistic effect of multi-metal active sites.

[0005] In the first aspect, the present invention provides a Co-Cu bimetallic ZIF material, which includes a first composite particle composed of a plurality of nanosheets, and the nanosheets include cobalt ions, copper ions, and imidazole ligands.

[0006] In some embodiments, the Co-Cu bimetallic ZIF material comprises first composite particles having a bird's nest-like structure composed of a plurality of nanosheets.

[0007] In the present invention, the first composite particles have a unique "bird's nest-like" morphology assembled by nanosheets and a cobalt-copper bimetal, and also have good hydrothermal stability and high crystallinity. The bird's nest-like morphology is a three-dimensional structure formed by self-assembly of nanosheets, and hierarchical pores can be easily fabricated during the derivation of nanomaterials. The structural superiority of MOFs synthesized based on bimetals lies in that more catalytically active sites can be derived, and the structure is stable and not prone to collapse. The introduction of Co element makes the C species during the heat treatment tend to epitaxially grow on the outer surface of the carbon tube structure, enabling better contact and capture of catalytic substrates.

[0008] In some embodiments, the particle size range of the first composite particles is 5 μm - 15 μm. In some embodiments, the particle size of the first composite particles is 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or any value therebetween. In some embodiments, the particle size range of the first composite particles is 8 μm - 12 μm.

[0009] In some embodiments, the imidazole ligand is 2-methylimidazole.

[0010] In a second aspect, the present invention provides a method for preparing a Co-Cu bimetallic ZIF material, which includes subjecting a solution containing a copper source, a cobalt source, and an imidazole ligand to ultrasonic treatment, and subjecting the ultrasonically treated solution to heat treatment.

[0011] The preparation method provided by the present invention adjusts the coordination environment of Co ions by additionally introducing Cu ion sites, and utilizes the energy in ultrasonic waves to promote the coordination of the two metal ions with 2-methylimidazole in deionized water to form a coordination framework structure. A CoCu bimetallic-based ZIF material with good hydrothermal stability, high crystallinity, and a nano bird's nest-like shape can be obtained without adding a surfactant.

[0012] In some embodiments, the ultrasonic frequency of the ultrasonic treatment is 20 kHz - 55 kHz, such as 23 kHz, 25 kHz, 27 kHz, 30 kHz, 33 kHz, 35 kHz, 37 kHz, 40 kHz, 43 kHz, 45 kHz, 47 kHz, 50 kHz, 53 kHz, or any value therebetween. In some embodiments, the ultrasonic frequency of the ultrasonic treatment is 30 kHz - 40 kHz.

[0013] In some embodiments, the temperature of the ultrasonic treatment is less than or equal to 35°C, such as 5°C, 10°C, 15°C, 20°C, 25°C or 30°C. In some embodiments, the temperature of the ultrasonic treatment is 10°C - 35°C. In some embodiments, the ultrasonic treatment is carried out at room temperature.

[0014] In some embodiments, the time of the ultrasonic treatment is 5 min - 60 min, such as 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or any value therebetween. In some embodiments, the time of the ultrasonic treatment is 10 min - 30 min.

[0015] In some embodiments, the ultrasonic treatment is carried out in an ultrasonic cleaner.

[0016] In some embodiments, the temperature of the heat treatment is 5°C - 40°C, such as 10°C, 15°C, 20°C, 25°C, 30°C or 35°C. In some embodiments, the temperature of the heat treatment is 10°C - 30°C. In some embodiments, the heat treatment is carried out at room temperature.

[0017] In some embodiments, the time of the heat treatment is 5 h - 36 h, such as 5 h, 12 h, 15 h, 20 h, 24 h, 28 h, 30 h, 32 h or 34 h. In some embodiments, the time of the heat treatment is 10 h - 20 h.

[0018] In some embodiments, the heat treatment is carried out in a constant temperature water bath.

[0019] In some embodiments, the preparation method further includes centrifuging, washing and drying the product of the heat treatment to obtain the Co-Cu bimetallic ZIF material.

[0020] In some embodiments, the rotation speed of the centrifugation is 8000 r / min - 12500 r / min, such as 9000 r / min, 10000 r / min, 11000 r / min or 12000 r / min.

[0021] In some embodiments, the solvent used for washing is methanol or ethanol.

[0022] In some embodiments, the temperature of the drying is 50°C - 70°C. In some embodiments, the time of the drying is 6 h - 12 h.

[0023] In some embodiments, based on the copper element and the cobalt element, the molar ratio of the cobalt source to the copper source is (0.1 - 0.8):1, such as 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1 or any value therebetween. In some embodiments, the molar ratio of the cobalt source to the copper source is (0.1 - 0.5):1. In some embodiments, the molar ratio of the cobalt source to the copper source is (0.2 - 0.4):1.

[0024] In some embodiments, based on the copper element, the molar ratio of the imidazole ligand to the copper source is (3 - 15):1, such as 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1 or any value therebetween. In some embodiments, the molar ratio of the imidazole ligand to the copper source is (5 - 10):1.

[0025] In some embodiments, after mixing an aqueous solution of the copper source, an aqueous solution of the cobalt source, and an aqueous solution of the imidazole ligand, a solution containing the copper source, the cobalt source, and the imidazole ligand is obtained.

[0026] In some embodiments, based on the copper element, the concentration of the copper source in the aqueous solution of the copper source is 0.01 mol / L - 0.1 mol / L, such as 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L or any value therebetween. In some embodiments, the concentration of the copper source in the aqueous solution of the copper source is 0.03 mol / L - 0.07 mol / L.

[0027] In some embodiments, based on the cobalt element, the concentration of the cobalt source in the aqueous solution of the cobalt source is 0.01 mol / L - 0.1 mol / L, such as 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L or any value therebetween. In some embodiments, the concentration of the cobalt source in the aqueous solution of the cobalt source is 0.03 mol / L - 0.07 mol / L.

[0028] In some embodiments, in the aqueous solution of the imidazole ligand, the concentration of the imidazole ligand is 0.1 mol / L - 1 mol / L, for example, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L or any value therebetween. In some embodiments, the concentration of the imidazole ligand is 0.2 mol / L - 0.6 mol / L.

[0029] In some embodiments, the copper source is selected from one or more of soluble copper salts, preferably selected from one or more of copper nitrate, copper acetate, copper chloride, and copper sulfate.

[0030] In some embodiments, the cobalt source is selected from one or more of soluble cobalt salts, preferably selected from one or more of cobalt nitrate, cobalt acetate, cobalt chloride, and cobalt sulfate.

[0031] In some embodiments, the imidazole ligand is 2-methylimidazole.

[0032] In some embodiments, the method for preparing the Co-Cu bimetallic ZIF material comprises the following specific steps:

[0033] 1) Dissolve cobalt salt, copper salt, and 2-methylimidazole in solvents of deionized water to obtain an aqueous copper salt solution, an aqueous cobalt salt solution, and an aqueous solution of the organic ligand.

[0034] 2) Mix the aqueous cobalt salt solution and the aqueous copper salt solution evenly according to a certain volume ratio to obtain a mixed solution A.

[0035] 3) Pour the mixed solution A in step 2) into the aqueous solution of the organic ligand to obtain a mixed solution B.

[0036] 4) Perform temperature-controlled ultrasonic treatment on the mixed solution B for a fixed time and keep it warm in a constant temperature water bath to obtain a turbid solution C.

[0037] 5) Centrifuge, wash, and separate the system, and then vacuum dry to obtain a purple-black solid product, namely CoCu-ZIFs nanocrystals.

[0038] In the above solution, preferably in step 1), the cobalt salt is selected from cobalt nitrate, cobalt acetate, cobalt chloride, cobalt sulfate, etc. The copper salt is selected from copper nitrate, copper acetate, copper chloride, copper sulfate, etc.

[0039] In the above solution, preferably in step 1), the solvent is deionized water, the concentration of the cobalt salt solution is 0.05 mol / L, the concentration of the copper salt solution is 0.05 mol / L, and the concentration of the 2-methylimidazole solution is 0.3 - 0.4 mol / L.

[0040] In the above solution, preferably, the volume ratio of the 2-methylimidazole solution, cobalt salt solution, and copper salt in the system is 4:1:(2-5).

[0041] In the above solution, preferably, in step 4), the ultrasonic treatment is carried out in an ultrasonic cleaner, and the temperature of the ultrasonic cleaner needs to be maintained at 20-35°C.

[0042] In the above solution, preferably, in step 4), the frequency of the ultrasonic cleaner is 35-53 kHz.

[0043] In the above solution, preferably, in step 4), the time of ultrasonic treatment is 15-30 min.

[0044] In the above solution, preferably, in step 4), the holding time in the constant temperature water bath is 8-15 h, and the temperature of the constant temperature water bath is 25-30°C.

[0045] In the above solution, preferably, in step 5), the solvent used for washing is ethanol or methanol, and the product is collected by centrifugation at a rotation speed of 8000-12500 r / min and vacuum dried at 60°C for 6-12 h.

[0046] In a third aspect, the present invention provides a Co-Cu bimetallic carbon material, which includes second composite particles, and the second composite particles include metal cobalt particles, metal copper particles, carbon nanotubes, and nitrogen-doped porous carbon.

[0047] The Co-Cu bimetallic carbon material provided by the present invention has abundant mesoporous and microporous structures. The active metal Co and Cu particles on the surface and inside the structure are nanoscale in size and evenly dispersed. The carbon nanotubes growing around have the effect of adsorbing and activating substrates. The synergistic effect of the bimetallic active sites and the Π electron structure of the carbon nanotubes plays an important role in the rapid and efficient degradation of p-nitrophenol.

[0048] In some embodiments, the carbon nanotubes are located on the surface of the nitrogen-doped porous carbon.

[0049] In some embodiments, the carbon nanotubes are selected from multi-walled carbon nanotubes.

[0050] In some embodiments, the wall thickness of the carbon nanotubes is 5 nm-15 nm, such as 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, or any value between them.

[0051] In some embodiments, the metal cobalt particles and metal copper particles are located on the surface of the nitrogen-doped porous carbon and / or doped inside the nitrogen-doped porous carbon.

[0052] In some embodiments, at least 60%, such as 65%, 70%, 75%, 80%, 85%, 90% or 95% of the metal copper and metal cobalt particles are located inside the nitrogen-doped porous carbon.

[0053] In some embodiments, the particle size range of the metal cobalt particles is 5 nm - 150 nm, such as 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or any value therebetween.

[0054] In some embodiments, the particle size range of the metal copper particles is 5 nm - 200 nm, such as 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or any value therebetween.

[0055] In some embodiments, the particle size range of the second composite particles is 3 μm - 10 μm, such as 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or any value therebetween. In some embodiments, the particle size range of the second composite particles is 5 μm - 8 μm.

[0056] In some embodiments, the Co-Cu bimetallic carbon material includes the Co-Cu bimetallic ZIF material described in the first aspect or the product obtained after carbonization treatment of the Co-Cu bimetallic ZIF material prepared by the preparation method described in the second aspect.

[0057] The present invention uses CoCu-ZIFs as a self-sacrificial template to in-situ reduce metal nodes at high temperature in an inert atmosphere. During the pyrolysis of the crystal, Co sites and Cu sites are reduced to nanoparticles and spatially confined in the carbon matrix and protected by the carbon layer from agglomeration, while the organic ligands are carbonized and radially grow into a multi-walled carbon nanotube structure, making the material have a high specific surface area. A large number of conjugated Π electrons are rich on the multi-walled carbon nanotubes, which can form Π-Π conjugation with the Π electrons of phenolic substances to achieve the enrichment of pollutants. The bimetallic active sites can all activate the substrate well, so that the Co-Cu bimetallic carbon material of the present invention shows excellent activity in the catalytic degradation process of p-nitrophenol.

[0058] In some embodiments, the carbonization treatment is carried out in an inert atmosphere. Preferably, the inert atmosphere is selected from an argon atmosphere and / or a nitrogen atmosphere.

[0059] In some embodiments, the temperature of the carbonization treatment is 700°C - 1000°C, for example, 750°C, 800°C, 850°C, 900°C, 950°C, or any value therebetween. In some embodiments, the temperature of the carbonization treatment is 800°C - 900°C.

[0060] In some embodiments, the time of the carbonization treatment is 1 h - 10 h, for example, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, or 9 h. In some embodiments, the time of the carbonization treatment is 3 h - 5 h.

[0061] In some embodiments, the temperature of the carbonization treatment is reached by means of programmed temperature increase. Preferably, the heating rate is 1°C / min - 5°C / min, for example, 2°C / min, 3°C / min, or 4°C / min.

[0062] Fourthly, the present invention provides a method for preparing a Co-Cu bimetallic carbon material, which comprises the following steps:

[0063] S1: Ultrasonically treating a solution containing a copper source, a cobalt source, and an imidazole ligand, and heat-treating the ultrasonically treated solution;

[0064] S2: Centrifuging, washing, and drying the product of the heat treatment to obtain a Co-Cu bimetallic carbon material precursor;

[0065] S3: Carbonizing the Co-Cu bimetallic carbon material precursor to obtain the Co-Cu bimetallic carbon material.

[0066] In some embodiments, the ultrasonic frequency of the ultrasonic treatment is 20 kHz - 55 kHz, for example, 23 kHz, 25 kHz, 27 kHz, 30 kHz, 33 kHz, 35 kHz, 37 kHz, 40 kHz, 43 kHz, 45 kHz, 47 kHz, 50 kHz, 53 kHz, or any value therebetween. In some embodiments, the ultrasonic frequency of the ultrasonic treatment is 30 kHz - 40 kHz.

[0067] In some embodiments, the temperature of the ultrasonic treatment is less than or equal to 35°C, for example, 5°C, 10°C, 15°C, 20°C, 25°C, or 30°C. In some embodiments, the temperature of the ultrasonic treatment is 10°C - 35°C. In some embodiments, the ultrasonic treatment is carried out at room temperature.

[0068] In some embodiments, the time of the ultrasonic treatment is 5 min - 60 min, for example, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, or any value therebetween. In some embodiments, the time of the ultrasonic treatment is 10 min - 30 min.

[0069] In some embodiments, the ultrasonic treatment is carried out in an ultrasonic cleaner.

[0070] In some embodiments, the temperature of the heat treatment is 5 °C - 40 °C, for example, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, or 35 °C. In some embodiments, the temperature of the heat treatment is 10 °C - 30 °C. In some embodiments, the heat treatment is carried out at room temperature.

[0071] In some embodiments, the time of the heat treatment is 5 h - 36 h, for example, 5 h, 12 h, 15 h, 20 h, 24 h, 28 h, 30 h, 32 h, or 34 h. In some embodiments, the time of the heat treatment is 10 h - 20 h.

[0072] In some embodiments, the heat treatment is carried out in a constant temperature water bath.

[0073] In some embodiments, the rotation speed of the centrifugation is 8000 r / min - 12500 r / min, for example, 9000 r / min, 10000 r / min, 11000 r / min, or 12000 r / min.

[0074] In some embodiments, the solvent used for washing is methanol or ethanol.

[0075] In some embodiments, the temperature of the drying is 50 °C - 70 °C. In some embodiments, the time of the drying is 6 h - 12 h.

[0076] In some embodiments, based on copper element and cobalt element, the molar ratio of the cobalt source to the copper source is (0.1 - 0.8):1, for example, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, or any value therebetween. In some embodiments, the molar ratio of the cobalt source to the copper source is (0.1 - 0.5):1. In some embodiments, the molar ratio of the cobalt source to the copper source is (0.2 - 0.4):1.

[0077] In some embodiments, based on the copper element, the molar ratio of the imidazole ligand to the copper source is (3 - 15):1, for example, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, or any value therebetween. In some embodiments, the molar ratio of the imidazole ligand to the copper source is (5 - 10):1.

[0078] In some embodiments, after mixing an aqueous solution of the copper source, an aqueous solution of the cobalt source, and an aqueous solution of the imidazole ligand, a solution containing the copper source, the cobalt source, and the imidazole ligand is obtained.

[0079] In some embodiments, based on the copper element, the concentration of the copper source in the aqueous copper source solution is 0.01 mol / L - 0.1 mol / L, for example, 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, or any value therebetween. In some embodiments, the concentration of the copper source in the aqueous copper source solution is 0.03 mol / L - 0.07 mol / L.

[0080] In some embodiments, based on the cobalt element, the concentration of the cobalt source in the aqueous cobalt source solution is 0.01 mol / L - 0.1 mol / L, for example, 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, or any value therebetween. In some embodiments, the concentration of the cobalt source in the aqueous cobalt source solution is 0.03 mol / L - 0.07 mol / L.

[0081] In some embodiments, in the aqueous solution of the imidazole ligand, the concentration of the imidazole ligand is 0.1 mol / L - 1 mol / L, for example, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, or any value therebetween. In some embodiments, the concentration of the imidazole ligand is 0.2 mol / L - 0.6 mol / L.

[0082] In some embodiments, the copper source is selected from one or more of soluble copper salts, preferably selected from one or more of copper nitrate, copper acetate, copper chloride, and copper sulfate.

[0083] In some embodiments, the cobalt source is selected from one or more of soluble cobalt salts, preferably selected from one or more of cobalt nitrate, cobalt acetate, cobalt chloride, and cobalt sulfate.

[0084] In some embodiments, the imidazole ligand is 2-methylimidazole.

[0085] In some embodiments, the carbonization treatment is carried out in an inert atmosphere. Preferably, the inert atmosphere is selected from an argon atmosphere and / or a nitrogen atmosphere.

[0086] In some embodiments, the temperature of the carbonization treatment is 700°C - 1000°C, such as 750°C, 800°C, 850°C, 900°C, 950°C or any value therebetween. In some embodiments, the temperature of the carbonization treatment is 800°C - 900°C.

[0087] In some embodiments, the time of the carbonization treatment is 1 h - 10 h, such as 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h or 9 h. In some embodiments, the time of the carbonization treatment is 3 h - 5 h.

[0088] In some embodiments, the temperature of the carbonization treatment is reached by a programmed temperature rise. Preferably, the heating rate is 1°C / min - 5°C / min, such as 2°C / min, 3°C / min or 4°C / min.

[0089] In some embodiments, the method for preparing the Co-Cu bimetallic carbon material comprises the following specific steps:

[0090] 1) Dissolve cobalt salt, copper salt and 2-methylimidazole in a solvent of deionized water respectively to obtain an aqueous copper salt solution, an aqueous cobalt salt solution and an aqueous solution of the organic ligand.

[0091] 2) Mix the aqueous cobalt salt solution and the aqueous copper salt solution evenly according to a certain volume ratio to obtain a mixed solution A.

[0092] 3) Pour the mixed solution A in step 2) into the aqueous solution of the organic ligand to obtain a mixed solution B.

[0093] 4) Carry out temperature-controlled ultrasonic treatment on the mixed solution B for a fixed time and keep it warm in a constant temperature water bath to obtain a turbid solution C.

[0094] 5) Centrifuge, wash and separate the system, and vacuum dry to obtain a purple-black solid product, namely CoCu-ZIFs nanocrystals;

[0095] 6) Carry out carbonization treatment on the CoCu-ZIFs nanocrystals under a protective atmosphere.

[0096] In the above scheme, preferably in step 1), the cobalt salt is selected from cobalt nitrate, cobalt acetate, cobalt chloride, cobalt sulfate, etc. The copper salt is selected from copper nitrate, copper acetate, copper chloride, copper sulfate, etc.

[0097] In the above solution, preferably in step 1), deionized water is used as the solvent, the concentration of the cobalt salt solution is 0.05 mol / L, the concentration of the copper salt solution is 0.05 mol / L, and the concentration of the 2-methylimidazole solution is 0.3 - 0.4 mol / L.

[0098] In the above solution, preferably in the system, the volume ratio of the 2-methylimidazole solution, cobalt salt solution, and copper is 4:1:(2 - 5).

[0099] In the above solution, preferably in step 4), the ultrasonic treatment is carried out in an ultrasonic cleaner, and the temperature of the ultrasonic cleaner needs to be maintained at 20 - 35 °C.

[0100] In the above solution, preferably in step 4), the frequency of the ultrasonic cleaner is 35 - 53 kHz.

[0101] In the above solution, preferably in step 4), the time of ultrasonic treatment is 15 - 30 min.

[0102] In the above solution, preferably in step 4), the holding time in the constant temperature water bath is 8 - 15 h, and the temperature of the constant temperature water bath is 25 - 30 °C.

[0103] In the above solution, preferably in step 5), the solvent used for washing is ethanol or methanol, and the product is collected by centrifugation at a rotation speed of 8000 - 12500 r / min and vacuum dried at 60 °C for 6 - 12 h.

[0104] In the above solution, preferably in step 6), the protective gas is argon or nitrogen, etc.

[0105] In the above solution, preferably in step 6), the temperature of the carbonization treatment is 800 - 900 °C, the time is 3 - 5 h, and the heating rate is 1 - 5 °C / min.

[0106] In the fifth aspect, the present invention provides the application of the Co-Cu bimetallic carbon material described in the third aspect or the Co-Cu bimetallic carbon material described in the fourth aspect in the catalytic degradation of phenolic compounds, especially p-nitrophenol.

[0107] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0108] The present invention uses a temperature-controlled ultrasonic hydrothermal synthesis method and cleverly selects Cu 2+As a regulator, it can not only introduce heteroatom active sites, but also regulate the coordination environment with the organic ligand dimethylimidazole, thereby obtaining special bird's nest-shaped bimetallic ZIFs nanocrystals. Using CoCu-ZIFs as a self-sacrificing template, under heat treatment in an inert atmosphere, a carbon material with bimetallic active sites is formed. During the process of reducing metal nodes to form nanoparticles, a local contraction effect will be caused, thereby deriving a hierarchical pore structure. The grown carbon nanotubes have a rich pore structure and greatly increase the specific surface area of the material. At the same time, the rich Π-electron structure on the multi-walled carbon nanotubes can form Π-Π conjugation with the Π-electrons of phenolic substances, thereby achieving effective enrichment of pollutants. Description of the Drawings

[0109] Figure 1 It is a scanning electron microscope image of CoCu-ZIFs prepared in Example 1 of the present invention.

[0110] Figure 2 It is an XRD pattern of CoCu-ZIFs prepared in Example 1 of the present invention.

[0111] Figure 3 It is a scanning electron microscope image of CoCu-CNTs-900 prepared in Example 1 of the present invention, where (b) is a partial enlarged view of (a).

[0112] Figure 4 It is a comparison chart of XRD of CoCu-CNTs-900 prepared in Example 1 of the present invention and the standard card.

[0113] Figure 5 It is a transmission electron microscope image of CoCu-CNTs-900 prepared in Example 1 of the present invention. Among them, Figure (a) is a low-magnification transmission electron microscope image, (b) is a high-magnification transmission electron microscope image, and the inset in b is a high-resolution transmission image of the carbon nanotubes.

[0114] Figure 6 It is a scanning electron microscope image of CoCu-ZIFs prepared in Comparative Example 1 of the present invention.

[0115] Figure 7 It is a scanning electron microscope image of CoCu-ZIFs prepared in Comparative Example 2 of the present invention.

[0116] Figure 8 It is an ultraviolet-visible spectrogram of the reduction of p-nitrophenol by sodium borohydride before and after adding CoCu-CNTs-900 prepared in Example 1 of the present invention as a catalyst.

[0117] Figure 9 It is a schematic diagram of the time tracking of the catalytic effect of CoCu-CNTs-900 prepared in Example 1 of the present invention as a catalyst on p-nitrophenol.

[0118] Figure 10 Schematic diagram of the catalytic cycle effect of CoCu-CNTs-900 prepared in Example 1 of the present invention as a catalyst for p-nitrophenol.

[0119] Figure 11 UV-visible spectrogram of sodium borohydride reducing p-nitrophenol before and after adding the material prepared in Comparative Example 3 of the present invention as a catalyst.

[0120] Figure 12 UV-visible spectrogram of sodium borohydride reducing p-nitrophenol before and after adding CoCu-CNTs-900 prepared in Comparative Example 4 of the present invention as a catalyst. Detailed implementation manners

[0121] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in combination with embodiments and drawings. The specific embodiments described herein are only used to explain the present invention and do not constitute any limitation to the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessarily confusing the concepts of the present disclosure. Such structures and technologies have also been described in many publications.

[0122] Example 1

[0123] (1) Weigh 1.243 g (0.005 mol) of cobalt acetate tetrahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 0.993 g (0.005 mol) of copper acetate monohydrate and dissolve it in 100 mL of deionized water to form a light blue transparent solution. Weigh 3.339 g (0.041 mol) of 2-methylimidazole solution and dissolve it in 100 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 20 mL of 2-methylimidazole solution, 5 mL of cobalt acetate solution and 20 mL of copper acetate solution in sequence according to the volume ratio of 4:1:4. Mix the two metal solutions and then pour them into a 100 mL round-bottom flask containing 2-methylimidazole solution.

[0124] (2) Place the whole system in an ultrasonic cleaner and ultrasonicate for 20 minutes, with an ultrasonic frequency of 35 kHz (the temperature is kept no higher than 35 °C during the ultrasonic treatment). After ultrasonication, the system is left standing in a constant temperature water bath at 30 °C for 15 hours. The upper layer is a purple clear liquid, and a dark blue precipitate precipitates at the bottom of the flask. Centrifuge to collect the product at a speed of 10,000 revolutions per minute, wash it three times with absolute ethanol, and place the obtained product in a vacuum drying oven at 60 °C for 12 h to obtain a dark blue powdery solid Co-Cu bimetallic ZIF material, denoted as CoCu-ZIFs.

[0125] (3) Place 150 mg of CoCu-ZIFs in an alumina boat and put it into a tube furnace. Use argon as an inert protective gas. After purging for 30 minutes, heat it to 900 °C at a rate of 2 °C / min, hold at 900 °C for 3 h, and then cool naturally to obtain a black powdered solid, namely Co-Cu bimetallic carbon material, denoted as CoCu-CNTs-900.

[0126] The scanning electron microscope image of the prepared CoCu-ZIFs material is as Figure 1 shown. It can be seen from Figure 1 that the morphology of the CoCu-ZIFs material is a bird's nest-like nanocrystal formed by intercalation of flakes, with good dispersion and uniform morphology. The size of a single particle is about 9 - 10 μm.

[0127] The XRD pattern of the prepared CoCu-ZIFs material is as Figure 2 shown. The sharp peaks on the spectrum indicate that the formed structure has long-range order and good crystallinity of the crystal.

[0128] The scanning electron microscope image of the prepared CoCu-CNTs-900 material is as Figure 3 shown. It can be seen from Figure (a) that the morphology structure of a single particle has no collapse, and the size has decreased, approximately 7 - 8 μm; it can be clearly seen from Figure (b) that metal nanoparticles and carbon nanotubes are formed on the surface of the material.

[0129] The XRD pattern of the prepared CoCu-CNTs-900 material is as Figure 4 shown. It can be seen from Figure 4 that after high-temperature treatment in an argon atmosphere, the nanocrystal structure of the CoCu-ZIFs material has been completely carbonized, and a characteristic broad peak absorption of graphite carbon appears at about 25°. At the same time, obvious phases of metallic Co and metallic Cu can also be seen on the spectrum, along with a weak Cu2O phase. This indicates that the two metal nodes in the CoCu-ZIFs material have been successfully reduced to metallic Co and Cu, and a very small number of Cu 2+ reacted with the adsorbed oxygen species during the synthesis process to form a by-product Cu2O.

[0130] The transmission electron microscope image of the prepared CoCu-CNTs-900 material is as Figure 5 shown. It can be seen from Figure (a) that the formed nano-sub-nanoparticles are uniformly distributed in the carbon matrix under the action of spatial confinement, and the particle size distribution range is 5 - 200 nm and there is a hierarchical pore structure; it can be seen from Figure (b) that carbon nanotubes grow on the surface of the material, the wall thickness of the nanotubes is about 6 - 10 nm, and metal nanoparticles are connected and wrapped at the ends of the nanotubes.

[0131] Example 2

[0132] (1) Weigh 1.488 g (0.005 mol) of cobalt nitrate hexahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 1.200 g (0.005 mol) of copper nitrate trihydrate and dissolve it in 100 mL of deionized water to form a light blue transparent solution. Weigh 3.350 g (0.041 mol) of 2-methylimidazole solution and dissolve it in 100 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 20 mL of 2-methylimidazole solution, 5 mL of cobalt nitrate solution, and 25 mL of copper nitrate solution in sequence according to the volume ratio of 4:1:5. Mix the two metal solutions and then pour them into a 100 mL round-bottom flask containing 2-methylimidazole solution.

[0133] (2) Place the entire system in an ultrasonic cleaner and ultrasonicate for 20 minutes at an ultrasonic frequency of 35 kHz (keep the temperature not higher than 35 °C during the ultrasonic treatment). After ultrasonication, let the system stand in a 30 °C constant temperature water bath for 15 hours. The upper layer is a purple clear liquid, and dark blue precipitate precipitates at the bottom of the flask. Centrifuge and collect the product at a speed of 10,000 revolutions per minute, wash it three times with absolute ethanol, and place the obtained product in a vacuum drying oven at 60 °C for drying for 12 h to obtain a dark blue powdery solid Co-Cu bimetallic ZIF material, denoted as CoCu-ZIFs.

[0134] (3) Place 150 mg of CoCu-ZIFs in an Al2O3 porcelain boat, put it into a tube furnace, use argon as an inert protective gas, after purging for 30 minutes, heat it to 900 °C at a rate of 5 °C / min, hold at 900 °C for 3 h, and then cool naturally to obtain a black powdery solid, namely Co-Cu bimetallic carbon material.

[0135] Example 3

[0136] (1) Weigh 1.490 g (0.005 mol) of cobalt nitrate hexahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 1.203 g (0.005 mol) of copper nitrate trihydrate and dissolve it in 100 mL of deionized water to form a light blue transparent solution. Weigh 6.688 g (0.081 mol) of 2-methylimidazole solution and dissolve it in 200 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 120 mL of 2-methylimidazole solution, 30 mL of cobalt nitrate solution, and 90 mL of copper nitrate solution in sequence according to the volume ratio of 4:1:3. Mix the two metal solutions and then pour them into a 250 mL round-bottom flask containing 2-methylimidazole solution.

[0137] (2) The whole system is placed in an ultrasonic cleaner and ultrasonically treated for 20 minutes at an ultrasonic frequency of 35 kHz (the temperature is kept no higher than 35 °C during the ultrasonic treatment). After the ultrasonic treatment, the system is left standing in a constant temperature water bath at 30 °C for 15 hours. The upper layer is a purple clear liquid, and a dark blue precipitate precipitates at the bottom of the flask. The product is collected by centrifugation at a speed of 10,000 revolutions per minute, washed three times with absolute ethanol, and the obtained product is placed in a vacuum drying oven at 60 °C and dried for 12 h to obtain a dark blue powdery solid Co-Cu bimetallic ZIF material, denoted as CoCu-ZIFs.

[0138] (3) Place 150 mg of CoCu-ZIFs in an Al2O3 porcelain boat, put it into a tube furnace, use argon as an inert protective gas, after purging for 30 minutes, heat it up to 800 °C at a rate of 5 °C / min, hold it at 800 °C for 3 h, and obtain a black powdery solid, namely Co-Cu bimetallic carbon material, after natural cooling.

[0139] Comparative Example 1

[0140] (1) Weigh 1.230 g (0.005 mol) of cobalt acetate tetrahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 0.998 g (0.005 mol) of copper acetate monohydrate and dissolve it in 100 mL of deionized water to form a light blue transparent solution. Weigh 3.337 g (0.041 mol) of 2-methylimidazole solution and dissolve it in 100 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 20 mL of 2-methylimidazole solution, 5 mL of cobalt acetate solution, and 5 mL of copper acetate solution in sequence according to the volume ratio of 1:1:4. Mix the two metal solutions and then pour them into a 100 mL round-bottom flask containing the 2-methylimidazole solution.

[0141] (2) The whole system is placed in an ultrasonic cleaner and ultrasonically treated for 20 minutes at an ultrasonic frequency of 35 kHz (the temperature is kept no higher than 35 °C during the ultrasonic treatment). After the ultrasonic treatment, the system is left standing in a constant temperature water bath at 30 °C for 15 hours. The upper layer is a purple clear liquid, and a dark blue precipitate precipitates at the bottom of the flask. The product is collected by centrifugation at a speed of 10,000 revolutions per minute, washed three times with absolute ethanol, and the obtained product is placed in a vacuum drying oven at 60 °C and dried for 12 h to obtain a dark blue powdery solid Co-Cu bimetallic ZIF material, denoted as CoCu-ZIFs.

[0142] The scanning electron microscope image of the prepared CoCu-ZIFs is as Figure 6 shown. It can be seen that changing the ratio of the synthesis precursors cannot synthesize a special morphology with a bird's nest shape.

[0143] Comparative Example 2

[0144] (1) Weigh 1.246 g (0.005 mol) of cobalt acetate tetrahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 0.991 g (0.005 mol) of copper acetate monohydrate and dissolve it in 100 mL of deionized water to form a light blue transparent solution. Weigh 3.337 g (0.041 mol) of 2-methylimidazole solution and dissolve it in 100 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 20 mL of 2-methylimidazole solution, 5 mL of cobalt acetate solution, and 20 mL of copper acetate solution in sequence according to the volume ratio of 4:1:4. Mix the two metal solutions and then pour them into a 100 mL round-bottom flask containing the 2-methylimidazole solution.

[0145] (2) Let the system stand still in a 30 °C constant temperature water bath for 15 hours. The upper layer is a purple clear liquid, and a dark blue precipitate precipitates at the bottom of the flask. Centrifuge and collect the product at a speed of 10,000 revolutions per minute, wash it three times with absolute ethanol, and place the obtained product in a vacuum drying oven at 60 °C for drying for 12 h to obtain a dark blue powdery solid Co-Cu bimetallic ZIF material, denoted as CoCu-ZIFs.

[0146] The scanning electron micrograph of the prepared CoCu-ZIFs is as Figure 7 shown. It can be seen that the material synthesized by replacing ultrasonic treatment with constant temperature standing is a flaky structure with only a small part of self-assembly.

[0147] Comparative Example 3

[0148] (1) Weigh 1.243 g (0.005 mol) of cobalt acetate tetrahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 1.097 g (0.005 mol) of zinc acetate dihydrate and dissolve it in 100 mL of deionized water to form a solution. Weigh 3.328 g (0.040 mol) of 2-methylimidazole solution and dissolve it in 100 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 20 mL of 2-methylimidazole solution, 5 mL of cobalt acetate solution, and 20 mL of zinc acetate solution in sequence according to the volume ratio of 4:1:4. Mix the two metal solutions and then pour them into a 100 mL round-bottom flask containing the 2-methylimidazole solution.

[0149] (2) Place the entire system in an ultrasonic cleaner and ultrasonicate for 20 minutes at an ultrasonic frequency of 35 kHz (keep the temperature not higher than 35 °C during the ultrasonic treatment). After ultrasonic treatment, let the system stand still in a 30 °C constant temperature water bath for 15 hours. The upper layer is a purple clear liquid, and a dark blue precipitate precipitates at the bottom of the flask. Centrifuge and collect the product at a speed of 10,000 revolutions per minute, wash it three times with absolute ethanol, and place the obtained product in a vacuum drying oven at 60 °C for drying for 12 h to obtain a dark blue powdery solid Co-Zn bimetallic ZIF material, denoted as CoZn-ZIFs.

[0150] (3) Place 150 mg of CoZn-ZIFs in an alumina boat and put it into a tubular furnace. Using argon as an inert protective gas, after purging for 30 minutes, heat it to 900 °C at a rate of 2 °C / min, hold at 900 °C for 3 h, and then cool naturally to obtain a black powdery solid.

[0151] Comparative Example 4

[0152] (1) Weigh 1.243 g (0.005 mol) of cobalt acetate tetrahydrate and dissolve it in 100 mL of deionized water to form a purple transparent solution. Weigh 0.993 g (0.005 mol) of copper acetate monohydrate and dissolve it in 100 mL of deionized water to form a light blue transparent solution. Weigh 3.341 g (0.041 mol) of 2-methylimidazole solution and dissolve it in 100 mL of deionized water to obtain a colorless 2-methylimidazole aqueous solution. Take 20 mL of the 2-methylimidazole solution, 5 mL of the cobalt acetate solution, and 20 mL of the copper acetate solution in sequence according to a volume ratio of 4:1:4. Mix the two metal solutions and then pour them into a 100 mL round-bottom flask containing the 2-methylimidazole solution.

[0153] (2) Pour the entire system into a polytetrafluoroethylene-lined stainless steel hydrothermal reactor and heat it at 120 °C for 4 hours. Centrifuge and collect the product at a speed of 10,000 revolutions per minute, wash it three times with absolute ethanol, and place the obtained product in a vacuum drying oven at 60 °C for drying for 12 h to obtain a dark blue powdery solid Co-Cu bimetallic ZIF material, denoted as CoCu-ZIFs.

[0154] (3) Place 150 mg of CoCu-ZIFs in an alumina boat and put it into a tubular furnace. Using argon as an inert protective gas, after purging for 30 minutes, heat it to 900 °C at a rate of 2 °C / min, hold at 900 °C for 3 h, and then cool naturally to obtain a black powdery solid, namely Co-Cu bimetallic carbon material, denoted as CoCu-CNTs-900.

[0155] Performance Test

[0156] Use the catalytic reduction of p-nitrophenol as a model reaction to study the catalytic activity of the catalyst. Specifically, in a cuvette: Take 1 mL of NaBH4 solution (0.18 mol·L -1 ) and add it to 2 mL of 4-nitrophenol solution with a concentration of 0.25 mmol·L -1 . The solution immediately turns bright yellow. Then add 200 μL of the catalyst (2 mg / mL) dispersed in deionized water in Example 1 and Comparative Examples 3-4 to start the reaction. Use a UV-visible spectrophotometer to measure the absorption spectrum during the reaction, and the results are as Figures 8 - 12 .

[0157] It can be seen from Figure 8 that before and after the addition of the CoCu-CNTs-900 catalyst, the solution in the cuvette faded from bright yellow to colorless, the characteristic peak of p-nitrophenol at 400 nm disappeared, and the characteristic peak of p-aminophenol at 300 nm was generated, indicating that p-nitrophenol was successfully reduced.

[0158] It can be seen from Figure 9 that under the experimental conditions, it took about 240 s to completely degrade 4-nitrophenol.

[0159] It can be seen from Figure 10 that after 5 catalytic cycles, the activity of the CoCu-CNTs-900 catalyst did not decrease, and the conversion rate could reach more than 99.6%.

[0160] Figure 11 is the UV-visible spectrum of the reduction of p-nitrophenol by sodium borohydride before and after the addition of the catalyst of Comparative Example 3. It can be seen from the figure that under the experimental conditions, it took about 600 s to completely degrade 4-nitrophenol.

[0161] Figure 12 is the UV-visible spectrum of the reduction of p-nitrophenol by sodium borohydride before and after the addition of the catalyst of Comparative Example 4. It can be seen from the figure that under the experimental conditions, part of 4-nitrophenol was still not completely degraded within 600 s.

[0162] Among them, the conversion rate of 4-nitrophenol was calculated using the following formula:

[0163] Conversion rate = C change / C initial × 100%, that is, (initial concentration - equilibrium concentration) / initial concentration × 100%.

[0164] For a relatively dilute solution, the absorbance is proportional to the concentration, that is, A = lg(1 / T) = Kbc, where A is the absorbance, T is the transmittance, K is the molar absorptivity, c is the concentration of the absorbing substance, and b is the thickness of the absorption layer.

[0165] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A Co-Cu bimetallic carbon material, which includes second composite particles, and the second composite particles include metallic cobalt particles, metallic copper particles, carbon nanotubes and nitrogen-doped porous carbon. The Co-Cu bimetallic carbon material includes the product after carbonization treatment of Co-Cu bimetallic ZIF material. The Co-Cu bimetallic ZIF material includes first composite particles composed of a plurality of nanosheets, and the nanosheets include cobalt ions, copper ions and imidazole ligands. The preparation method of the Co-Cu bimetallic ZIF material includes ultrasonic treatment of a solution containing a copper source, a cobalt source and an imidazole ligand, heat treatment of the ultrasonically treated solution, and centrifugation, washing and drying of the heat-treated product to obtain the Co-Cu bimetallic ZIF material. Among them, Based on copper element and cobalt element, the molar ratio of the cobalt source to the copper source is (0.1-0.5):1, and based on copper element, the molar ratio of the imidazole ligand to the copper source is (5-10):

1. The imidazole ligand is 2-methylimidazole. The carbon nanotubes are located on the surface of the nitrogen-doped porous carbon. The carbon nanotubes are selected from multi-walled carbon nanotubes, and the wall thickness of the carbon nanotubes is 5nm-15nm. The ultrasonic frequency of the ultrasonic treatment is 30kHz-40kHz, the temperature of the ultrasonic treatment is 10℃-35℃, and the time of the ultrasonic treatment is 10min-30min. The temperature of the heat treatment is 10℃-30℃, and the time of the heat treatment is 10h-20h. The carbonization treatment is carried out in an inert atmosphere. The temperature of the carbonization treatment is 800℃-900℃, and the time of the carbonization treatment is 3h-5h. The temperature of the carbonization treatment is reached by a programmed heating method, and the heating rate is 1℃ / min-5℃ / min.

2. The Co-Cu bimetallic carbon material according to claim 1, wherein The particle size range of the first composite particles is 5μm-15μm.

3. The Co-Cu bimetallic carbon material according to claim 2, wherein The particle size range of the first composite particles is 8μm-12μm.

4. The Co-Cu bimetallic carbon material according to any one of claims 1-3, wherein the copper source is selected from one or more of soluble copper salts; and / or the cobalt source is selected from one or more of soluble cobalt salts.

5. The Co-Cu bimetallic carbon material according to any one of claims 1-3, characterized in that, The molar ratio of the cobalt source to the copper source is (0.2-0.4):1; and / or the copper source is selected from one or more of copper nitrate, copper acetate, copper chloride and copper sulfate; and / or the cobalt source is selected from one or more of cobalt nitrate, cobalt acetate, cobalt chloride and cobalt sulfate.

6. The Co-Cu bimetallic carbon material according to any one of claims 1-3, characterized in that The metallic cobalt particles and metallic copper particles are located inside the nitrogen-doped porous carbon; and / or the particle size range of the metallic cobalt particles is 5nm-150nm; and / or the particle size range of the metallic copper particles is 5nm-150nm; and / or The particle size range of the second composite particles is 3μm-10μm.

7. The Co-Cu bimetallic carbon material according to claim 6, wherein The particle size range of the second composite particles is 5μm-8μm.

8. The Co-Cu bimetallic carbon material according to any one of claims 1-3, characterized in that, The inert atmosphere is selected from argon atmosphere and / or nitrogen atmosphere.

9. The application of the Co-Cu bimetallic carbon material according to any one of claims 1-8 in the catalytic degradation of phenolic compounds.

10. The application according to claim 9, characterized in that, The phenolic compound is p-nitrophenol.

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