High-entropy alloy / nitrogen-doped carbon nano catalytic material as well as preparation method and application thereof

Abstract

The invention discloses a high-entropy alloy / nitrogen-doped carbon nano catalytic material and a preparation method and application thereof.The nano catalytic material comprises a high-entropy alloy composed of five non-noble metals including Fe, Co, Ni, Cu and Mn and nitrogen-doped carbon synthesized with the assistance of MOF, the non-noble metal high-entropy alloy serves as a main body material, the nitrogen-doped carbon serves as a carrier material, and the nitrogen-doped carbon serves as a carrier material. A non-noble metal high-entropy alloy is loaded on nitrogen-doped carbon to construct a novel nano catalytic material, and the novel nano catalytic material is used for activating peroxydisulfate to remove antibiotics in a water body. The catalyst has the advantages of excellent chemical stability, good reusability and the like and is a novel nano catalytic material with efficient catalytic performance and environment-friendly characteristics, and the preparation method has the advantages of being simple in operation process, green, environmentally friendly, economical, feasible and the like and can be used for large-scale preparation.

Description

Technical Field

[0001] The present application relates to the technical field of environmental functional nanomaterials, and in particular to a high entropy alloy / nitrogen-doped carbon nanocatalytic material and a preparation method and application thereof. Background Art

[0002] With the rapid development of medicine, animal husbandry and aquaculture, antibiotics are widely used. However, most antibiotics that cannot be metabolized in the body are released into various water bodies through excrement, causing water pollution and posing a serious threat to the ecological environment and human health. Although traditional water treatment methods such as physical adsorption, chemical degradation and biological treatment can remove some antibiotics in water, they usually have problems such as low efficiency, high cost and easy secondary pollution. Therefore, the development of economical, efficient, green and adaptable antibiotic removal technology has become a key environmental issue that needs to be solved urgently.

[0003] In recent years, advanced oxidation processes (AOPs) have become an important technology in the field of water pollution control due to their high efficiency and wide applicability. Among various AOPs, persulfate-based advanced oxidation processes have shown unique advantages in the field of water treatment. Compared with AOPs that mainly rely on hydroxyl radicals, the sulfate radical-driven oxidation process has stronger oxidation ability, longer half-life and wider pH application range. In addition, as an oxidant, persulfate has higher catalytic efficiency, lower cost, better stability and safety than traditional oxidants such as hydrogen peroxide, and is easy to store and transport. More importantly, persulfate can be activated in a variety of ways, including external energy such as ultraviolet rays, homogeneous systems such as transition metal ions, and heterogeneous systems such as metal oxides. Among them, heterogeneous systems provide great flexibility and adaptability for process design and application. At present, the main problem of this technology is the rational design and catalytic activity of the catalyst. Therefore, it is crucial to develop efficient, stable and reusable catalytic materials.

[0004] As a new type of catalytic material, high entropy alloys have shown unique advantages in persulfate activation due to their unique surface electronic structure and physicochemical properties. First, high entropy alloys are composed of multiple metal elements in nearly equimolar proportions. Their unique high entropy structure gives the alloys multiple metal active centers and excellent electron transfer capabilities. They can optimize the electronic structure of metal active sites through synergistic effects and significantly improve the activation efficiency of persulfate. Second, the high chemical stability and corrosion resistance of high entropy alloys ensure that the catalyst operates stably for a long time in a complex environment, avoiding the problem of metal ion migration or catalyst deactivation. Third, the multi-metal elements of high entropy alloys are evenly distributed, providing more active centers, thereby accelerating the efficient transfer of electrons, promoting the decomposition of persulfate to generate stronger oxidizing species (such as sulfate radicals and hydroxyl radicals), and improving the degradation efficiency of pollutants. Despite this, high entropy alloy monomers still have certain disadvantages in the process of persulfate activation. First, the surface energy of nanoscale high entropy alloys is relatively high, and they are easy to agglomerate during the preparation and activation of persulfate, resulting in a large number of active sites being buried. Secondly, although the synergistic effect of multiple metal sites can improve activity, the complex interactions between metals may lead to insufficient activity of some sites, or even produce non-target byproducts, reducing catalytic efficiency and selectivity. The recovery and reuse of complex metal components is difficult, which increases the economic and technical burden in their practical applications.

[0005] Loading high entropy alloy nanoparticles on the surface of nitrogen-doped carbon materials to construct new nanocatalytic materials will hopefully solve the problems faced by high entropy alloy monomers. First, the metal organic framework-derived nitrogen-doped carbon has a unique high specific surface area and porous structure to provide uniformly dispersed support for high entropy alloy particles, prevent agglomeration and expose more active sites. Secondly, the excellent electronic conductivity of nitrogen-doped carbon promotes efficient electron transfer, accelerates the activation of persulfate, and thus improves the catalytic efficiency. In addition, nitrogen doping can enhance the synergistic effect of the carrier material and the high entropy alloy, thereby improving the activity of the catalyst. However, there are still some difficulties in constructing this nanocomposite material. First, the preparation method of high entropy alloy is relatively complicated, and it is also very challenging to successfully load high entropy alloy on nitrogen-doped carbon; secondly, the mass ratio of high entropy alloy to nitrogen-doped carbon in high entropy alloy / nitrogen-doped carbon nanocatalytic materials has a great influence on the performance of the nanomaterial. Therefore, it is of great significance to load high entropy alloy on the surface of nitrogen-doped carbon nanomaterials to form a new type of nanocomposite material to study its properties. Summary of the invention

[0006] Based on this, the technical problem to be solved in this application is to overcome the shortcomings of the prior art, develop a high-entropy alloy / nitrogen-doped carbon nanocatalytic material with high peroxydisulfate activation efficiency, excellent catalytic performance and strong stability, and provide a method that is simple to operate, green and environmentally friendly, and can be used for large-scale preparation of nanocatalysts.

[0007] The technical solution adopted by the present application to solve its technical problem is: a high entropy alloy / nitrogen-doped carbon nanocatalytic material, which includes a high entropy alloy composed of five non-precious metals Fe, Co, Ni, Cu and Mn and nitrogen-doped carbon, and the high entropy alloy is loaded on the nitrogen-doped carbon.

[0008] In some embodiments, the mass ratio of the high entropy alloy to the nitrogen-doped carbon in the high entropy alloy / nitrogen-doped carbon nanocatalytic material is 1:1 or 2:1 or 4:1.

[0009] On the other hand, the present application provides a method for preparing the above-mentioned high entropy alloy / nitrogen-doped carbon nanocatalytic material, comprising the following steps: S1. Zeolitic imidazolate framework material-8 (ZIF-8) was prepared by coprecipitation method using 2-methylimidazole and zinc acetate dihydrate as precursors; S2. calcining ZIF-8 once to obtain nitrogen-doped carbon; S3. Ferric chloride hexahydrate, cobalt chloride hexahydrate, nickel chloride hexahydrate, cupric chloride dihydrate and manganese chloride tetrahydrate are adsorbed on the surface of nitrogen-doped carbon and a high entropy alloy / nitrogen-doped carbon novel nanocatalytic material is obtained by a secondary calcination method.

[0010] Based on the above preparation method, in some embodiments, the specific process of step S1 is as follows: 2-methylimidazole is dissolved in ultrapure water and ultrasonically formed into a uniform solution, recorded as liquid A; zinc acetate dihydrate is dissolved in ultrapure water and magnetically stirred to form a uniform solution, recorded as liquid B; then liquid A is added to liquid B and stirred vigorously, the obtained white solution is allowed to stand for aging, and then the aged ZIF-8 solution is centrifuged and washed several times, and ZIF-8 is obtained after drying.

[0011] Based on the above preparation method, in some embodiments, in step S1: the mass of the 2-methylimidazole is 1.12 g, the volume of the ultrapure water is 5 mL, the mass of the zinc acetate dihydrate is 0.3 g, the ultrasonic time is 10 min, the magnetic stirring time is 3 min, the vigorous stirring time is 10 s, the washing number is 3-5 times of alternating washing with water and ethanol, the drying is vacuum drying, the drying temperature is 60°C, and the drying time is 12-24 h.

[0012] Based on the above preparation method, in some embodiments, the process of step S2 is as follows: the ZIF-8 obtained in step S1 is placed in a tube furnace for calcination, and after the reaction is completed, the obtained black powder is washed and dried to obtain nitrogen-doped carbon.

[0013] Based on the above preparation method, in some embodiments, in step S2: the mass of the ZIF-8 is 2 g, the tubular furnace calcination conditions are a calcination temperature of 1000°C, a heating rate of 2°C / min, an Ar environment, and a calcination time of 2 h. The cleaning is performed by alternating water and ethanol for 3-5 times, the drying is performed by vacuum drying, the drying temperature is 60°C, and the drying time is 12-24 h.

[0014] Based on the above preparation method, in some embodiments, the specific process of step S3 is as follows: dispersing nitrogen-doped carbon in an ethanol solution, adding ethanol solutions of ferric chloride hexahydrate, cobalt chloride hexahydrate, nickel chloride hexahydrate, cupric chloride dihydrate and manganese chloride tetrahydrate to the ethanol solution of nitrogen-doped carbon, stirring magnetically to form a black solution, and then placing the black solid obtained by rotary evaporation in a tubular furnace for secondary calcination. After the reaction is completed, the obtained black powder is washed and dried to obtain a high entropy alloy / nitrogen-doped carbon nanocatalytic material.

[0015] Based on the above preparation method, in some embodiments, in the step S3: the mass of the nitrogen-doped carbon is 50 mg, the ethanol solution is 44 mL, the concentration of the ferric chloride hexahydrate ethanol solution is 1 mg / mL, the added volume is 1.1 mL, the concentration of the cobalt chloride hexahydrate ethanol solution is 25 mg / mL, the added volume is 247 μL, the concentration of the nickel chloride hexahydrate ethanol solution is 25 mg / mL, the added volume is 247 μL, the concentration of the cupric chloride dihydrate ethanol solution is 25 mg / mL, the added volume is 140 μL, the concentration of the manganese chloride tetrahydrate ethanol solution is 25 mg / mL, the added volume is 205 μL, the magnetic stirring time is 24 h, the rotary evaporation temperature is 40°C, the tubular furnace calcination conditions are that the calcination temperature is 1000°C, the heating rate is 10°C / min, the calcination atmosphere is Ar environment, and the calcination time is 1 h, the washing is performed by washing with water and ethanol alternately for 3-5 times, the drying is performed by vacuum drying, the drying temperature is 60° C., and the drying time is 12-24 h.

[0016] In some embodiments, the high entropy alloy / nitrogen-doped carbon nanocatalytic material is used to activate peroxodisulfate to remove antibiotics in water.

[0017] The beneficial effects of this application are: 1. This application constructs a new type of high entropy alloy / nitrogen-doped carbon nanocatalytic material, which is mainly composed of two new types of nanomaterials: non-precious metal high entropy alloy and nitrogen-doped carbon. The non-precious metal high entropy alloy is the main material, and the nitrogen-doped carbon material is the carrier material. The high entropy alloy is loaded on the nitrogen-doped surface to form a new type of nanocatalytic material. Non-precious metal high entropy alloys have the advantages of stable structure, corrosion resistance, and strong electron transmission ability. In addition, the high entropy alloy is composed of five transition metals and has low cost. Therefore, the photocatalytic material has the characteristics of both green environmental protection and economic efficiency, and has broad application prospects.

[0018] 2. In the high entropy alloy / nitrogen-doped carbon nanocatalytic material of the present application, the nitrogen-doped carbon is a new type of carbon material derived from MOF, and its high specific surface area and rich pore structure can promote the adsorption of metal ions, which is beneficial to the subsequent synthesis of high entropy alloys. At the same time, nitrogen doping introduces additional electronic structures, which enhances the conductivity and catalytic activity of carbon materials. In addition, nitrogen doping can enhance the adhesion of high entropy alloy nanoparticles of carbon materials. Nitrogen-doped carbon nanomaterials also have excellent chemical stability and thermal stability, providing a stable working environment for composite catalysts.

[0019] 3. In the high entropy alloy / nitrogen-doped carbon nanocatalytic material of the present application, the prepared high entropy alloy is composed of a variety of metal elements, and the synergistic effect between different metal centers also plays a vital role in enhancing the catalytic performance of the catalyst. In addition, the prepared high entropy alloy is composed of five transition metals, Fe, Co, Ni, Cu and Mn. These transition metal raw materials are relatively cheap and abundant in resources. Compared with the traditional catalytic materials that rely on precious metals such as Pt and Pd, their cost is significantly reduced, and they have stronger economic adaptability. As a carrier, nitrogen-doped carbon material not only provides abundant surface active sites, but also optimizes the electron density of these sites through the electronic effect of nitrogen atoms. These sites have a promoting effect on the loading of high entropy alloy nanoparticles, improve the surface activity of high entropy alloy catalysts, and thus enhance the efficiency of catalytic reactions.

[0020] 4. In the high entropy alloy / nitrogen-doped carbon nanocatalytic material of the present application, the prepared high entropy alloy nanoparticles are relatively small in size, so they have a higher surface energy. However, high surface energy easily leads to serious agglomeration of high entropy alloy nanoparticles, thereby significantly reducing their specific surface area and covering a large number of active sites. By loading the high entropy alloy on the surface of the nitrogen-doped carbon material, the nitrogen-doped carbon can be used as a supporting carrier to disperse the high entropy alloy, which can effectively inhibit the agglomeration of the high entropy alloy, thereby significantly increasing the exposure of the active sites. The exposure of a large number of active sites provides more reaction sites for the catalytic reaction, thereby significantly improving the catalytic performance of the new nanocatalytic material.

[0021] 5. The present application proposes a simple method for preparing a new type of nanocatalytic material. This method uses a high entropy alloy as the main material and nitrogen-doped carbon as the carrier material. A new type of high entropy alloy / nitrogen-doped carbon nanocomposite material with excellent Fenton-like performance can be prepared by a simple two-step calcination method. Compared with traditional preparation technology, this method does not require complex equipment and the process operation is simple. At the same time, the obtained material has good dispersibility and significantly exposes active sites. In the field of preparation of environmental functional nanomaterials, the preparation method provided in this application shows broad application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a scanning transmission electron micrograph of the new high entropy alloy / nitrogen-doped carbon nanocatalytic material in Example 2 of the present application.

[0024] Figure 2 This is the X-ray diffraction pattern of the new high entropy alloy / nitrogen-doped carbon nanocatalytic material in Example 2 of the present application.

[0025] Figure 3 This is the Raman spectrum of the new high entropy alloy / nitrogen-doped carbon nanocatalytic material in Example 2 of the present application.

[0026] Figure 4 This is a performance diagram of tetracycline degradation by the new high entropy alloy / nitrogen-doped carbon nanocatalytic materials in different ratios in Examples 1-3 of the present application. DETAILED DESCRIPTION

[0027] The present application is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present application is not limited thereby.

[0028] The materials and instruments used in the following examples are all commercially available.

[0029] A new type of high entropy alloy / nitrogen-doped carbon nanocatalytic material and a preparation method thereof. The nanocatalytic material comprises a high entropy alloy and nitrogen-doped carbon, wherein the high entropy alloy is used as a main material and the nitrogen-doped carbon is a carrier material. The high entropy alloy and the nitrogen-doped carbon are composited to prepare the new type of nanocatalytic material.

[0030] Example 1: A high entropy alloy / nitrogen-doped carbon nanocatalytic material includes a high entropy alloy and nitrogen-doped carbon, wherein the high entropy alloy is the main material and the nitrogen-doped carbon is the carrier material. The high entropy alloy and the nitrogen-doped carbon are compounded to form a new type of nanocatalytic material.

[0031] In this embodiment, the mass ratio of high entropy alloy to nitrogen-doped carbon in the high entropy alloy / nitrogen-doped carbon nanocatalytic material is 1:1.

[0032] A method for preparing the nitrogen-doped carbon-supported non-precious metal high-entropy alloy catalytic material of the present embodiment comprises the following steps: (1) Accurately weigh 1.12 g of 2-methylimidazole and dissolve it in 5 mL of ultrapure water and ultrasonicate to form a uniform solution, which is recorded as solution A. Accurately weigh 0.3 g of zinc acetate dihydrate and dissolve it in 5 mL of ultrapure water, which is recorded as solution B. Solution A is added to solution B and stirred vigorously. The resulting white solution is allowed to stand for 24 h. The aged ZIF-8 solution is then washed by centrifugation with water and anhydrous ethanol for 3-5 times, and then dried under vacuum at 60°C for 12 h to obtain ZIF-8.

[0033] (2) The ZIF-8 obtained in step S1 was placed in a tube furnace, heated to 1000°C at a heating rate of 2°C / min in an Ar atmosphere, and calcined at 1000°C for 2 h. After the reaction was completed, the obtained black powder was washed with water and anhydrous ethanol for 3-5 times, and vacuum dried at 60°C for 12 h to obtain nitrogen-doped carbon.

[0034] (3) Accurately weigh 25 mg of nitrogen-doped carbon and ultrasonically disperse it in 44 mL of ethanol solution, then add 1.1 mL of ferric chloride hexahydrate ethanol solution (1 mg / mL), 247 μL of cobalt chloride hexahydrate ethanol solution (25 mg / mL), 247 μL of nickel chloride hexahydrate ethanol solution (25 mg / mL), 140 μL of cupric chloride dihydrate ethanol solution (25 mg / mL) and 205 μL of manganese chloride tetrahydrate (25 mg / mL) in sequence, and stir magnetically for 24 h to form a black solution, which is then rotary evaporated at 40 °C to obtain a black solid. The black solid is placed in a tube furnace, heated to 1000 °C at a heating rate of 10 °C / min in an Ar atmosphere, and calcined at 1000 °C for 1 h. After the reaction is completed, the obtained black powder is washed 3-5 times with water and anhydrous ethanol, and vacuum dried at 60 °C for 12 h to obtain a high entropy alloy / nitrogen-doped carbon nanocatalytic material.

[0035] In the high entropy alloy / nitrogen-doped carbon nanocatalytic material prepared in this embodiment, the mass ratio of high entropy alloy to nitrogen-doped carbon is 1:1.

[0036] Example 2: A high entropy alloy / nitrogen-doped carbon nanocatalytic material includes a high entropy alloy and nitrogen-doped carbon, wherein the high entropy alloy is the main material and the nitrogen-doped carbon is the carrier material. The high entropy alloy and the nitrogen-doped carbon are compounded to form a new type of nanocatalytic material.

[0037] In this embodiment, the mass ratio of high entropy alloy to nitrogen-doped carbon in the high entropy alloy / nitrogen-doped carbon nanocatalytic material is 1:2.

[0038] A method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material of the present embodiment comprises the following steps: (1) Accurately weigh 1.12 g of 2-methylimidazole and dissolve it in 5 mL of ultrapure water and ultrasonically form a uniform solution, which is recorded as liquid A; accurately weigh 0.3 g of zinc acetate dihydrate and dissolve it in 5 mL of ultrapure water, which is recorded as liquid B; add liquid A to liquid B and stir vigorously, and let the resulting white solution stand for 24 h, then wash the aged ZIF-8 solution with water and anhydrous ethanol by centrifugation for 3-5 times, and vacuum dry it at 60°C for 12 h to obtain ZIF-8. (2) Place the ZIF-8 obtained in step S1 in a tube furnace, heat it to 1000°C at a heating rate of 2°C / min in an Ar atmosphere, and calcine it at 1000°C for 2 h. After the reaction is completed, the heating rate is 2 °C / min to obtain a black powder. The obtained black powder is filtered and washed 3-5 times with water and anhydrous ethanol. The solid obtained after washing is placed in a vacuum drying oven and dried at 60 °C for 12 h to obtain nitrogen-doped carbon. Nitrogen-doped carbon can be obtained by vacuum drying at 60 °C for 12 h.

[0039] (3) Accurately weigh 50 mg of nitrogen-doped carbon and ultrasonically disperse it in 44 mL of ethanol solution, then add 1.1 mL of ferric chloride hexahydrate ethanol solution (1 mg / mL), 247 μL of cobalt chloride hexahydrate ethanol solution (25 mg / mL), 247 μL of nickel chloride hexahydrate ethanol solution (25 mg / mL), 140 μL of cupric chloride dihydrate ethanol solution (25 mg / mL) and 205 μL of manganese chloride tetrahydrate (25 mg / mL) in sequence, and stir magnetically for 24 h to form a black solution, which is then rotary evaporated at 40 °C to obtain a black solid. The black solid is placed in a tube furnace, heated to 1000 °C at a heating rate of 10 °C / min in an Ar atmosphere, and calcined at 1000 °C for 1 h. After the reaction is completed, the obtained black powder is washed 3-5 times with water and anhydrous ethanol, and vacuum dried at 60 °C for 12 h to obtain a high entropy alloy / nitrogen-doped carbon nanocatalytic material.

[0040] In the high entropy alloy / nitrogen-doped carbon nanocatalytic material prepared in this embodiment, the mass ratio of high entropy alloy to nitrogen-doped carbon is 1:2.

[0041] Figure 1 This is a scanning electron microscope image of the high entropy alloy / nitrogen-doped carbon nanocatalyst material in Example 2 of the present application. Figure 1It can be seen that nitrogen-doped carbon is also octahedral, with some small nanoparticles attached to its surface. These nanoparticles are non-precious metal high entropy alloys.

[0042] Figure 2 This is the X-ray diffraction pattern of the high entropy alloy / nitrogen-doped carbon nanocatalyst material in Example 2 of the present application. Figure 2 It can be seen that the nanocatalytic material contains diffraction peaks of both high entropy alloy and nitrogen-doped carbon.

[0043] Figure 3 This is the Raman spectrum of the high entropy alloy / nitrogen-doped carbon nanocatalyst material in Example 2 of the present application. The gray dotted lines represent the D band and the G band, respectively. The D band is related to the defects or disordered structure in the material, and the G band reflects the crystallinity and graphitization degree of the material. D / I G Used to quantify the defect density of a material. Figure 3 It can be seen that the ratio of the D band to the G band of the high entropy alloy / nitrogen-doped carbon nanocatalyst is larger than that of the nitrogen-doped carbon nanocatalyst, indicating that there are more defects in the high entropy alloy / nitrogen-doped carbon nanocatalyst.

[0044] The above can prove that high entropy alloy / nitrogen-doped carbon nanocatalytic materials have been successfully prepared.

[0045] Example 3: A high entropy alloy / nitrogen-doped carbon nanocatalytic material includes a high entropy alloy and nitrogen-doped carbon, wherein the high entropy alloy is the main material and the nitrogen-doped carbon is the carrier material. The high entropy alloy and the nitrogen-doped carbon are compounded to form a new type of nanocatalytic material.

[0046] In this embodiment, the mass ratio of high entropy alloy to nitrogen-doped carbon in the high entropy alloy / nitrogen-doped carbon nanocatalytic material is 1:4.

[0047] A method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material of the present embodiment comprises the following steps: (1) Accurately weigh 1.12 g of 2-methylimidazole and dissolve it in 5 mL of ultrapure water and ultrasonicate to form a uniform solution, which is recorded as solution A. Accurately weigh 0.3 g of zinc acetate dihydrate and dissolve it in 5 mL of ultrapure water, which is recorded as solution B. Solution A is added to solution B and stirred vigorously. The resulting white solution is allowed to stand for 24 h. The aged ZIF-8 solution is then washed by centrifugation with water and anhydrous ethanol for 3-5 times, and then dried under vacuum at 60°C for 12 h to obtain ZIF-8.

[0048] (2) The ZIF-8 obtained in step S1 is placed in a tube furnace, heated to 1000°C at a heating rate of 2°C / min in an Ar atmosphere, and calcined at 1000°C for 2 hours. After the reaction is completed, the heating rate is 2°C / min to obtain a black powder, the obtained black powder is filtered and washed 3-5 times with water and anhydrous ethanol, and the solid obtained after washing is placed in a vacuum drying oven, and dried at 60°C for 12 hours to obtain nitrogen-doped carbon.

[0049] (3) Accurately weigh 100 mg of nitrogen-doped carbon and ultrasonically disperse it in 44 mL of ethanol solution, then add 1.1 mL of 1 mg / mL ferric chloride hexahydrate ethanol solution, 247 μL of 25 mg / mL cobalt chloride hexahydrate ethanol solution, 247 μL of 25 mg / mL nickel chloride hexahydrate ethanol solution, 140 μL of 25 mg / mL copper chloride dihydrate ethanol solution and 205 μL of 25 mg / mL manganese chloride tetrahydrate, stir magnetically for 24 h to form a black solution, and then evaporate it at 40 °C to obtain a black solid. The black solid was placed in a tube furnace, heated to 1000 °C at a heating rate of 10 °C / min in an Ar atmosphere, and calcined at 1000 °C for 1 h. After the reaction was completed, the obtained black powder was washed 3-5 times with water and anhydrous ethanol, and vacuum dried at 60 °C for 12 h to obtain a high entropy alloy / nitrogen-doped carbon nanocatalytic material.

[0050] In the high entropy alloy / nitrogen-doped carbon nanocatalytic material prepared in this embodiment, the mass ratio of high entropy alloy to nitrogen-doped carbon is 1:4.

[0051] The effects of different high entropy alloy / nitrogen-doped carbon nanocatalytic materials prepared in Examples 1-3 on the degradation efficiency of tetracycline were studied.

[0052] Accurately weigh 10 mg of nitrogen-doped carbon, 1:1, 1:2, 1:4 high entropy alloy / nitrogen-doped carbon new nanocatalytic materials, and add them to 100 mL of a 10 mg / L tetracycline solution. Under dark conditions, the mixed suspension was stirred on a magnetic stirrer for 30 min to allow tetracycline to reach adsorption-desorption equilibrium on different catalyst surfaces. Then, the mixed solution that reached adsorption equilibrium was added with peroxydisulfate for a Fenton-like reaction. 1.5 mL of the solution was sampled with an organic filter every 5 min, and the total sampling time was 30 min. After the experiment, the concentration of tetracycline in the solution was tested using a high performance liquid chromatograph, and the degradation efficiency of tetracycline was calculated. The experimental results are shown in the figure. Figure 4 shown.

[0053] Figure 4This is a performance diagram of the degradation of tetracycline by potassium persulfate, nitrogen-doped carbon, and 1:1, 1:2, and 1:4 high entropy alloy / nitrogen-doped carbon novel nanocatalytic materials prepared in Examples 1-3 of the present application. Figure 4 In the data, -30 minutes to 0 minutes is the adsorption stage of the material, because the adsorption is 30 minutes, and the subsequent reaction is also 30 minutes. If the data is not represented by breakpoints (" / / "), the data of the subsequent reaction stage is not prominent enough and cannot be effectively compared. However, the use of " / / " will not affect the adsorption data, nor will it affect the subsequent reaction data, and has no effect on the overall experimental results. Figure 4 It can be seen that the degradation of tetracycline by potassium persulfate alone is negligible, and the degradation performance of nitrogen-doped carbon monomer on tetracycline is relatively poor, with only x% of tetracycline being degraded within 30 min. However, the degradation performance of high entropy alloy / nitrogen-doped carbon nanocatalyst material on tetracycline is much higher than that of nitrogen-doped carbon monomer, and the catalytic performance gradually increases with the increase of the mass of high entropy alloy in the nanocatalyst material. The 1:2 high entropy alloy / nitrogen-doped carbon nanocatalyst material shows the best degradation performance on tetracycline, and about 91% of tetracycline can be degraded. The increase in the performance of the composite material is because nitrogen-doped carbon can be used as a carrier of high entropy alloy to disperse the nano-scale high entropy alloy, avoid its agglomeration, and then expose more active sites for catalytic reaction. In addition, after the high entropy alloy and nitrogen-doped carbon are combined, the multiple active centers and excellent electron transfer ability of the high entropy alloy help to improve the catalytic performance of the composite material. However, when the content of high entropy alloy in the composite material continues to increase, the catalytic performance will decrease. This is because the excessive high entropy alloy will not be evenly dispersed on the nitrogen-doped carbon carrier, which will cause some active sites to be buried, thereby reducing the overall catalytic performance. Therefore, the 1:2 high entropy alloy / nitrogen-doped carbon new nanocatalytic material has the best degradation effect on tetracycline.

[0054] In summary, it is only the preferred embodiment of the present application, and it is not intended to limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present application by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment of equivalent changes without departing from the spirit and technical solution of the present application. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solution of the present application, still fall within the scope of protection of the technical solution of the present application.

Claims

1. A high entropy alloy / nitrogen-doped carbon nanocatalytic material, characterized in that: The high entropy alloy / nitrogen-doped carbon nanocatalytic material comprises a high entropy alloy composed of five non-noble metals, Fe, Co, Ni, Cu and Mn, and nitrogen-doped carbon, wherein the high entropy alloy is loaded on the nitrogen-doped carbon.

2. The high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 1, characterized in that: The mass ratio of the high entropy alloy to the nitrogen-doped carbon in the high entropy alloy / nitrogen-doped carbon nanocatalytic material is 1:1 or 2:1 or 4:

1.

3. A method for preparing a high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 1 or 2, characterized in that: The following steps are involved: S1. Zeolitic imidazolate framework material-8 (ZIF-8) was prepared by coprecipitation method using 2-methylimidazole and zinc acetate dihydrate as precursors; S2. calcining ZIF-8 once to obtain nitrogen-doped carbon; S3. Ferric chloride hexahydrate, cobalt chloride hexahydrate, nickel chloride hexahydrate, cupric chloride dihydrate and manganese chloride tetrahydrate are adsorbed on the surface of nitrogen-doped carbon and a high entropy alloy / nitrogen-doped carbon novel nanocatalytic material is obtained by a secondary calcination method.

4. The method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 3, characterized in that: The specific process of step S1 is as follows: 2-methylimidazole is dissolved in ultrapure water and ultrasonically formed into a uniform solution, which is recorded as liquid A; zinc acetate dihydrate is dissolved in ultrapure water and magnetically stirred to form a uniform solution, which is recorded as liquid B; then liquid A is added to liquid B and vigorously stirred, the obtained white solution is allowed to stand for aging, and then the aged ZIF-8 solution is centrifuged and washed several times, and ZIF-8 is obtained after drying.

5. The method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 4, characterized in that: In the step S1: the mass of the 2-methylimidazole is 1.12 g, the volume of the ultrapure water is 5 mL, the mass of the zinc acetate dihydrate is 0.3 g, the ultrasonic time is 10 min, the magnetic stirring time is 3 min, the vigorous stirring time is 10 s, the washing number is 3-5 times of alternating washing with water and ethanol, the drying is vacuum drying, the drying temperature is 60° C., and the drying time is 12-24 h.

6. The method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 3, characterized in that: The process of step S2 is as follows: the ZIF-8 obtained in step S1 is placed in a tube furnace for calcination, and after the reaction is completed, the obtained black powder is washed and dried to obtain nitrogen-doped carbon.

7. The method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 6, characterized in that: In the step S2: the mass of the ZIF-8 is 2 g, the tubular furnace calcination conditions are a calcination temperature of 1000°C, a heating rate of 2°C / min, an Ar environment, a calcination time of 2 h, cleaning is performed by alternating water and ethanol for 3-5 times, drying is performed by vacuum drying, the drying temperature is 60°C, and the drying time is 12-24 h.

8. The method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 3, characterized in that: The specific process of step S3 is as follows: dispersing nitrogen-doped carbon in an ethanol solution, adding ethanol solutions of ferric chloride hexahydrate, cobalt chloride hexahydrate, nickel chloride hexahydrate, cupric chloride dihydrate and manganese chloride tetrahydrate to the ethanol solution of nitrogen-doped carbon, stirring magnetically to form a black solution, and then placing the black solid obtained by rotary evaporation in a tubular furnace for secondary calcination. After the reaction is completed, the obtained black powder is washed and dried to obtain a high entropy alloy / nitrogen-doped carbon nanocatalytic material.

9. The method for preparing the high entropy alloy / nitrogen-doped carbon nanocatalytic material according to claim 8, characterized in that: In the step S3, the mass of the nitrogen-doped carbon is 50 mg, the ethanol solution is 44 mL, the concentration of the ferric chloride hexahydrate ethanol solution is 1 mg / mL, the added volume is 1.1 mL, the concentration of the cobalt chloride hexahydrate ethanol solution is 25 mg / mL, the added volume is 247 μL, the concentration of the nickel chloride hexahydrate ethanol solution is 25 mg / mL, the added volume is 247 μL, the concentration of the cupric chloride dihydrate ethanol solution is 25 mg / mL, the added volume is 140 μL, the concentration of the manganese chloride tetrahydrate ethanol solution is 25 mg / mL, the added volume is 205 μL, the magnetic stirring time is 24 h, the rotary evaporation temperature is 40°C, the tubular furnace calcination conditions are that the calcination temperature is 1000°C, the heating rate is 10°C / min, the calcination atmosphere is Ar environment, and the calcination time is 1 h, the washing is performed by washing with water and ethanol alternately for 3-5 times, the drying is performed by vacuum drying, the drying temperature is 60° C., and the drying time is 12-24 h.

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