Preparation method and application of carbon-based high-entropy alloy catalyst

Abstract

A method for preparing a carbon-based high-entropy alloy catalyst and its application, relating to a method for preparing a high-entropy alloy catalyst and its application. The present invention aims to solve the technical problems of metal leakage, poor cycle performance and complicated preparation process in existing high-entropy alloy catalysts. The carbon-based high-entropy alloy prepared by the present invention is used to activate PMS to degrade organic pollutants. The present invention uses simple equipment such as an oil bath pot to successfully load high-entropy alloy nanoparticles on the surface of a carbon-based material through one-pot reduction combined with high-temperature annealing. HEAs have very excellent catalytic performance and stability, and the preparation process is simple, providing an advanced oxidation catalyst with excellent performance, which has great application prospects in treating actual organic polluted wastewater. While solving the problem of wastewater pollution, it also opens up new ideas for the preparation and research of carbon-based supported catalysis, and is a very promising alternative for the preparation of advanced oxidation catalysts.

Description

Technical Field

[0001] The present invention relates to a preparation method of a high entropy alloy catalyst and application thereof. Background Art

[0002] High-entropy alloys (HEAs) are composed of five or more metallic elements, each randomly occupying a lattice site. Their highly disordered atomic arrangement, resulting in excellent mechanical properties, corrosion resistance, and thermal stability, has attracted widespread attention. As a new type of material, HEAs exhibit significant catalytic potential. However, their practical application in the degradation of organic pollutants still faces numerous challenges, such as metal leakage and poor cycling performance. Therefore, the development of low-cost, long-life, acid- and alkali-resistant catalyst materials is urgently needed. Extensive research has shown that compared to bulk materials or nanoparticles themselves, nanoparticles supported on a scaffold can significantly increase the specific surface area and surface energy. Supported HEAs hold broad application prospects in the catalytic degradation of organic pollutants.

[0003] Currently reported methods for preparing high-entropy alloy (HEA) catalysts are becoming increasingly diverse. Common, extremely high-temperature methods, such as arc melting and laser cladding, are unsuitable for preparing supported HEA particles due to the rapid growth and aggregation of nanoparticles. Although multimetallic nanoparticles can be produced under relatively mild conditions, including magnetron sputtering, electrodeposition, and polymer lithography, these methods struggle to uniformly immobilize HEA on supports. Exploring effective methods for immobilizing HEA on supports is crucial for promoting the industrial application of supported HEA in the catalytic degradation of organic pollutants, providing a valuable platform for catalyst design and mechanistic understanding of support-metal interactions. Therefore, designing a carbon-based HEA catalyst is of great practical significance for exploring green and environmentally friendly methods for preparing high-performance HEA catalysts and for their practical application in promoting organic degradation. Summary of the Invention

[0004] The present invention aims to solve the technical problems of metal leakage, poor cycle performance and complicated preparation process of existing high entropy alloy catalysts, and provides a preparation method and application of carbon-based high entropy alloy catalysts.

[0005] The preparation method of the carbon-based high entropy alloy catalyst of the present invention is carried out according to the following steps:

[0006] 1. Adding ferric acetylacetonate, cobalt acetylacetonate, copper acetylacetonate and nickel acetylacetonate to oleylamine, then adding di(acetylacetonate)palladium, then adding reducing agent 2,3,4,5,6-pentahydroxyhexanal and molybdenum hexacarbonyl and surfactant hexadecyltrimethylammonium chloride, stirring for 10 to 15 minutes, and then ultrasonicating at 50 to 55 degrees Celsius for 30 to 35 minutes;

[0007] The molar amounts of the di(acetylacetonate)palladium, ferric acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, and nickel acetylacetonate are equal, and the volume ratio of the molar amount of the di(acetylacetonate)palladium to oleylamine is (0.02 mmol to 0.03 mmol):1 L;

[0008] The mass ratio of molybdenum hexacarbonyl to 2,3,4,5,6-pentahydroxyhexanal is 1:(1.8-2);

[0009] The mass ratio of the bis(acetylacetonate)palladium to molybdenum hexacarbonyl is 1:(4-4.5);

[0010] The mass ratio of molybdenum hexacarbonyl to hexadecyltrimethylammonium chloride is 1:(1.5-2);

[0011] 2. The product of step 1 is placed in an oil bath at 220°C to 230°C and stirred for reaction for 2h to 2.5h. After the reaction is completed, the solution is removed from the oil bath and naturally cooled to room temperature. The cooled product is then centrifuged using a mixture of anhydrous ethanol and cyclohexane as a washing liquid to retain the solid portion, which is the colloid. The product is then washed with a mixture of anhydrous ethanol and cyclohexane until no surfactant is present in the solution. The high entropy alloy particles are obtained by centrifugation.

[0012] The volume ratio of anhydrous ethanol to cyclohexane in the two mixtures of anhydrous ethanol and cyclohexane recorded in step 2 is 6:1;

[0013] 3. The high entropy alloy particles obtained in step 2 are added to cyclohexane for dispersion, and then the carbon material precursor is added, ultrasonic loading is carried out for 30min to 35min, and then anhydrous ethanol is added for centrifugal separation. The retained solid part is moved into a vacuum drying oven for drying, and then 2,3,4,5,6-pentahydroxyhexanal is added and fully ground and moved into a tube furnace. Annealing is carried out under protective gas for 2h to 2.5h. After the end, it is immediately removed from the tube furnace and naturally cooled to room temperature to obtain a carbon-based high entropy alloy;

[0014] The carbon material precursor is obtained by calcining urea at 550° C. to 600° C. in a muffle furnace for 2 h to 2.5 h;

[0015] The mass ratio of the di(acetylacetonate)palladium described in step 1 to the carbon material precursor described in step 3 is 1:(65-70);

[0016] The mass ratio of 2,3,4,5,6-pentahydroxyhexanal to the carbon material precursor described in step 3 is 1:(1-1.2);

[0017] The annealing temperature is 800°C to 850°C.

[0018] The carbon-based high entropy alloy prepared by the present invention is used to activate PMS to degrade organic pollutants.

[0019] The present invention uses simple equipment such as an oil bath pot to successfully load high-entropy alloy nanoparticles on the surface of a carbon-based material (HEAs) through one-pot reduction combined with high-temperature annealing. After testing, HEAs have very excellent catalytic performance and stability, and the preparation process is simple, providing a high-performance advanced oxidation catalyst with great application prospects in treating actual organic polluted wastewater. While solving the wastewater pollution environment, it has opened up new ideas for the preparation and research of carbon-based supported catalysis, and is a very promising alternative for the preparation of advanced oxidation catalysts. Compared with pure carbon-based support materials (NG), the present invention greatly improves the performance of PMS after activating high-entropy alloy particles after loading. This is due to the fact that the catalyst electronic structure is changed after the high-entropy alloy loading, the internal resistance is reduced and the conductivity is enhanced, the electron transfer ability of HEAs is improved, and the electron transfer of organic pollutants (phenol) to the catalyst surface is accelerated, so that HEAs presents extremely high degradation ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the first XRD pattern;

[0021] Figure 2 is the second XRD pattern;

[0022] Figure 3 Transmission electron micrograph of HEAs prepared in Experiment 1;

[0023] Figure 4 This is a dark field transmission electron microscope image with spherical aberration;

[0024] Figure 5 is the EDS-Mapping diagram;

[0025] Figure 6 is the X-ray absorption fine structure spectrum of Cu;

[0026] Figure 7 is the EXAFS Fourier transform diagram of Cu;

[0027] Figure 8 is the EXAFS wavelet transform of Cu;

[0028] Figure 9 is the X-ray absorption fine structure spectrum of Ni;

[0029] Figure 10 is the EXAFS Fourier transform diagram of Ni;

[0030] Figure 11 is the EXAFS wavelet transform image of Ni;

[0031] Figure 12 This is a comparison chart of degradation performance in Test 2;

[0032] Figure 13 This is the degradation rate graph of the PMS-added group in Experiment 2;

[0033] Figure 14 This is a comparison chart of the degradation performance of Test 3;

[0034] Figure 15 is the degradation rate graph of experiment three;

[0035] Figure 16 This is the degradation data of phenol degradation by HEAs activated PMS with different anions in experiment 4;

[0036] Figure 17 This is the degradation data of phenol degradation by NG activated PMS with different anions in experiment 4;

[0037] Figure 18 This is the performance diagram of phenol degradation by HEAs and NG activated PMS at different pH in experiment five. DETAILED DESCRIPTION

[0038] Specific embodiment 1: This embodiment is a method for preparing a carbon-based high entropy alloy catalyst, which is specifically carried out according to the following steps:

[0039] 1. Adding ferric acetylacetonate, cobalt acetylacetonate, copper acetylacetonate and nickel acetylacetonate to oleylamine, then adding di(acetylacetonate)palladium, then adding reducing agent 2,3,4,5,6-pentahydroxyhexanal and molybdenum hexacarbonyl and surfactant hexadecyltrimethylammonium chloride, stirring for 10 to 15 minutes, and then ultrasonicating at 50 to 55 degrees Celsius for 30 to 35 minutes;

[0040] The molar amounts of the di(acetylacetonate)palladium, ferric acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, and nickel acetylacetonate are equal, and the volume ratio of the molar amount of the di(acetylacetonate)palladium to oleylamine is (0.02 mmol to 0.03 mmol):1 L;

[0041] The mass ratio of molybdenum hexacarbonyl to 2,3,4,5,6-pentahydroxyhexanal is 1:(1.8-2);

[0042] The mass ratio of the bis(acetylacetonate)palladium to molybdenum hexacarbonyl is 1:(4-4.5);

[0043] The mass ratio of molybdenum hexacarbonyl to hexadecyltrimethylammonium chloride is 1:(1.5-2);

[0044] 2. The product of step 1 is placed in an oil bath at 220°C to 230°C and stirred for reaction for 2h to 2.5h. After the reaction is completed, the solution is removed from the oil bath and naturally cooled to room temperature. The cooled product is then centrifuged using a mixture of anhydrous ethanol and cyclohexane as a washing liquid to retain the solid portion, which is the colloid. The product is then washed with a mixture of anhydrous ethanol and cyclohexane until no surfactant is present in the solution. The high entropy alloy particles are obtained by centrifugation.

[0045] The volume ratio of anhydrous ethanol to cyclohexane in the two mixtures of anhydrous ethanol and cyclohexane recorded in step 2 is 6:1;

[0046] 3. The high entropy alloy particles obtained in step 2 are added to cyclohexane for dispersion, and then the carbon material precursor is added, ultrasonic loading is carried out for 30min to 35min, and then anhydrous ethanol is added for centrifugal separation. The retained solid part is moved into a vacuum drying oven for drying, and then 2,3,4,5,6-pentahydroxyhexanal is added and fully ground and moved into a tube furnace. Annealing is carried out under protective gas for 2h to 2.5h. After the end, it is immediately removed from the tube furnace and naturally cooled to room temperature to obtain a carbon-based high entropy alloy;

[0047] The carbon material precursor is obtained by calcining urea at 550° C. to 600° C. in a muffle furnace for 2 h to 2.5 h;

[0048] The mass ratio of the di(acetylacetonate)palladium described in step 1 to the carbon material precursor described in step 3 is 1:(65-70);

[0049] The mass ratio of 2,3,4,5,6-pentahydroxyhexanal to the carbon material precursor described in step 3 is 1:(1-1.2);

[0050] The annealing temperature is 800°C to 850°C.

[0051] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the volume ratio of the molar amount of bis(acetylacetonate)palladium to oleylamine in step 1 is 0.025 mmol:1 L. Other aspects are the same as specific embodiment 1.

[0052] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that: in step 1, ultrasonication is performed at 50° C. for 30 minutes. Other aspects are the same as specific embodiment 1 or 2.

[0053] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that in step 2, the product of step 1 is placed in a 220° C. oil bath and stirred for 2 hours. Other aspects are the same as specific embodiments 1 to 3.

[0054] Specific embodiment 5: This embodiment differs from specific embodiment 4 in that the carbon material precursor described in step 3 is obtained by calcining urea at 550° C. for 2 h in a muffle furnace. Other aspects are the same as specific embodiment 4.

[0055] Specific embodiment 6: This embodiment differs from specific embodiment 5 in that the carbon material precursor described in step 3 is obtained by calcining urea at 550°C for 2 hours in a muffle furnace with a heating rate of 10°C / min. Other aspects are the same as specific embodiment 5.

[0056] Specific embodiment 7: This embodiment differs from specific embodiment 6 in that the annealing temperature in step 3 is 800° C. The rest is the same as specific embodiment 6.

[0057] Specific embodiment eight: This embodiment differs from specific embodiment seven in that the shielding gas in step three is argon. Other aspects are the same as specific embodiment seven.

[0058] Specific embodiment 9: This embodiment differs from specific embodiment 8 in that the drying temperature in step 3 is 60° C. and the drying time is 12 hours. Other aspects are the same as specific embodiment 8.

[0059] Specific embodiment ten: This embodiment is the application of the carbon-based high entropy alloy prepared in specific embodiment one, specifically using it to activate PMS to degrade organic pollutants.

[0060] The present invention is verified by the following test:

[0061] Experiment 1: This experiment is a method for preparing a carbon-based high entropy alloy catalyst, which is specifically carried out according to the following steps:

[0062] 1. Add ferric acetylacetonate (8.8 mg), cobalt acetylacetonate (8.9 mg), copper acetylacetonate (6.5 mg) and nickel acetylacetonate (6.4 mg) to 10 mL of oleylamine, then add di(acetylacetonate)palladium (7.6 mg), the reducing agent 2,3,4,5,6-pentahydroxyhexanal (60 mg) and molybdenum hexacarbonyl (33 mg) and the surfactant hexadecyltrimethylammonium chloride (50 mg), stir for 10 min, and then ultrasonicate at 50°C for 30 min;

[0063] 2. The oleylamine mixed solution of step 1 was placed in an oil bath at 220°C and stirred for 2 hours. After the reaction, the solution was removed from the oil bath and naturally cooled to room temperature. A mixture of 30 mL of anhydrous ethanol and 5 mL of cyclohexane was used as a washing solution to centrifuge the colloidal product. The solution was then washed with anhydrous ethanol and cyclohexane until no surfactant was present in the solution. High entropy alloy particles were obtained by centrifugation.

[0064] 3. The high entropy alloy particles prepared in step 2 were dispersed with 10 mL of cyclohexane and then 500 mg of carbon material precursor was added and ultrasonically loaded for 30 min. 30 mL of anhydrous ethanol was added and centrifuged. The mixture was moved into a vacuum drying oven and dried at 60 ° C for 12 h. 500 mg of 2,3,4,5,6-pentahydroxyhexanal was added and ground thoroughly. The mixture was moved into a tube furnace and annealed at 800 ° C for 2 h under Ar gas protection. After the annealing, it was immediately removed and cooled to room temperature to obtain a carbon-based high entropy alloy HEAs.

[0065] The carbon material precursor is obtained by calcining urea at 550° C. for 2 h in a muffle furnace with a heating rate of 10° C. / min.

[0066] Comparative example: Synthesis of carbon-nitrogen material NG without high entropy alloy, the specific process is as follows: the carbon material precursor is obtained by calcining urea at 550°C in a muffle furnace for 2h, and the heating rate is 10°C / min; 500mg of 2,3,4,5,6-pentahydroxyhexanal is added to 500mg of the carbon material precursor and ground thoroughly, moved into a tubular furnace and annealed at 800°C under Ar gas protection for 2h, and then cooled to room temperature to obtain the carbon-nitrogen material NG without high entropy alloy.

[0067] Figure 1 is the first XRD pattern, the upper curve is the HEAs prepared in experiment 1; Figure 2 The second XRD pattern is shown in Figure 1. The upper curve is the HEAs prepared in Experiment 1. Figure 1 and Figure 2 It can be seen that after annealing, the CuPdFeCoNi high entropy alloy (HEAs) loaded on the surface of the carbon-based support still maintains the fcc structure of the CuPd alloy. The diffraction peak shifts to a higher angle, confirming that metal elements with smaller atomic radius are incorporated into the lattice, and no diffraction peaks related to metal oxide species appear, indicating that Fe, Co, and Ni metals do not form separate elements or metal oxides after being incorporated into the CuPd alloy lattice.

[0068] Figure 3 Transmission electron micrograph of HEAs prepared in Experiment 1. Figure 4 This is a dark field transmission electron microscope image with spherical aberration. It can be seen that the CuPdFeCoNi high entropy alloy is evenly dispersed on the surface of the carbon-based material without element segregation or the formation of a core-shell structure. Figure 4 The spherical aberration electron microscope shows that its lattice spacing is 0.217nm, which corresponds exactly to the 111 crystal plane of CuPd alloy. At the same time, according to the EDS-Mapping diagram ( Figure 5 ) found that the elements were evenly distributed, confirming that each element was fully mixed in the HEAs to form a high-entropy structure.

[0069] In order to further verify that the nanoparticles on the surface of HEAs exist in the form of alloy, the HEAs prepared in Experiment 1 were characterized by X-ray fine structure absorption spectra using a synchrotron radiation source. Figure 6 is the X-ray absorption fine structure spectrum of Cu, Figure 7 is the EXAFS Fourier transform diagram of Cu, Figure 8 is the EXAFS wavelet transform of Cu, Figure 9 is the X-ray absorption fine structure spectrum of Ni, Figure 10 is the EXAFS Fourier transform diagram of Ni, Figure 11 The EXAFS wavelet transform of Ni is shown. Comparison of the Cu element on the HEAs surface with standards such as Cufoil, CuPc, and CuO reveals that Cu forms Cu-M coordination bonds with other metals on the HEAs surface, and also forms Cu-N coordination bonds with nitrogen on the carbon-based surface. This confirms that the high-entropy alloy particles are mixed and stably loaded on the carbon-based material surface in a high-entropy metal disordered state. Furthermore, the X-ray fine structure absorption spectrum of Ni also exhibits the same Ni-M metal coordination bonds, while the Ni-N bonds are relatively weak. This further confirms the aforementioned XRD and electron microscopy results, indicating that the Ni element is primarily incorporated into the CuPd alloy lattice, successfully loading the CuPdFeCoNi high-entropy alloy on the carbon-based material surface.

[0070] Experiment 2: Comparison of the performance of HEAs and NG in activating PMS to degrade phenol. In order to evaluate the performance of the HEAs catalyst prepared in Experiment 1 in activating peroxide to degrade organic pollutants, a carbon-based material NG (prepared in the comparative example) without high entropy alloy loading was used as a performance comparison sample. Phenol was selected as the target pollutant. The degradation performance of HEAs and NG was tested by activating PMS. The specific test steps and results are as follows:

[0071] 5 mg of HEAs and NG were weighed and added to 50 mL of a 0.1 mM phenol solution. After uniform dispersion on a magnetic stirrer, PMS was added to a 0.25 mM concentration of PMS in the solution system. The magnetic stirrer was rotated at 600 rpm. A timer was started simultaneously. Samples were taken at time intervals during the degradation process. The concentration of phenol in the solution at each time point was measured using an ultra-high performance liquid chromatograph, and the degradation rate of phenol at each time point was calculated. The sampling times were 1, 2, 4, 7, 10, 15, 20, 28, 45, and 60 minutes, respectively. As a control group, HEAs and NG were subjected to experiments without PMS.

[0072] Figure 12 This is a comparison chart of the degradation performance of Test 2. Figure 13This is the degradation rate diagram of the PMS group in Experiment 2. It can be seen from the figure that without the addition of PMS, HEAs and NG have only a weak adsorption effect on phenol; under the condition of adding PMS, HEAs and NG have a significant degradation effect on phenol, and HEAs greatly improves the degradation rate of phenol, reaching more than 7 times that of NG. This is attributed to the CuPdFeCoNi high-entropy alloy particles loaded on its surface, which may greatly promote the activation efficiency of PMS.

[0073] Experiment 3: Comparison of the performance of HEAs and corresponding metal ion activated PMS in degrading phenol:

[0074] Since some metal ions can also activate PMS to degrade pollutants, in order to verify the difference in degradation performance between metal ions and HEAs, Co 2+ and Cu 2+ 、Pd 2+ 、Fe 3+ 、Co 2+ 、Ni 2+ The degradation experiments were compared with mixed ions of five metals. The metal content loaded on the surface of HEAs was used as a reference, and 5 times, 10 times, 20 times, and 40 times the Co 2+ The degradation of 0.1 mM phenol was carried out by activating PMS with 5, 10, and 20 times mixed ions. After the metal ions were evenly dispersed in the phenol solution by a magnetic stirrer, PMS was added. The concentration of PMS in the solution system was 0.25 mM. The timer was started at the same time. Samples were taken at the time during the degradation process. The concentration of phenol in the solution at each time point was measured by ultra-high performance liquid chromatography, and the degradation rate of phenol at each time point was calculated. The sampling time was 1, 2, 4, 7, 10, 15, 20, 28, 45, and 60 (units are min). Co 2+ The concentrations were 5 times (2.5 mg / L), 10 times (5 mg / L), 20 times (10 mg / L), and 40 times (20 mg / L), respectively. The concentrations of the mixed ions were Cu, Pd, Fe, Co, and Ni, and the corresponding concentrations of the five metal ions were added. The speed of the magnetic stirrer was 600 rpm.

[0075] Figure 14 This is a comparison chart of the degradation performance of Experiment 3. Figure 15 This is the degradation rate diagram of experiment 3. It can be seen from the figure that Co 2+ The degradation performance of mixed ions increased with the increase of concentration, but the degradation rate increased gradually with the increase of concentration of Co. 2+ The degradation rate of mixed ions with a concentration of 20 times is still much lower than that of HEAs, which once again verifies that the CuPdFeCoNi high-entropy alloy particles loaded on the surface of HEAs greatly promote the performance of metal-activated PMS through the high-entropy disordering of the alloy, making it have extremely high degradation performance higher than that of metal ions.

[0076] Experiment 4: Effect of different anions on the degradation of phenol by HEAs and NG activated PMS: Cl - 、SO4 2- 、NO3 - 、HCO3 - 、H2PO3 - Phenol solutions with 5 mM and 10 mM ion concentrations and phenol solutions with 5 mg / L and 10 mg / L humic acid (HA) concentrations, each with a phenol concentration of 0.1 mM, were prepared. 5 mg of HEAs and NG, respectively, were added to 50 mL of the phenol solution and uniformly dispersed on a magnetic stirrer. PMS was then added to a PMS concentration of 0.25 mM. A timer was simultaneously started, and samples were taken at intervals during the degradation process. The phenol concentration in the solution at each time point was measured using ultra-high performance liquid chromatography, and the degradation rate of phenol at each time point was calculated. The sampling intervals were 1, 2, 4, 7, 10, 15, 20, 28, 45, and 60 minutes, and the magnetic stirrer speed was 600 rpm.

[0077] Figure 16 This is the degradation data of phenol degradation by HEAs activated PMS with different anions in experiment 4. Figure 17 The degradation data of phenol degradation by NG activated PMS with different anions in experiment 4 are shown. - 、SO4 2- 、NO3 - 、HCO3 - 、H2PO3 - Under the influence of HA, HEAs did not show a significant decrease in degradation rate and still maintained excellent degradation performance. However, the degradation performance of NG without high entropy alloy nanoparticles on the surface was significantly affected and interfered. - The most obvious effect was observed, with a significant decrease in the degradation rate. This suggests that HEAs loaded with CuPdFeCoNi high-entropy alloy particles are more resistant to interference and less susceptible to anionic interference. In practical applications, their degradation performance remains relatively stable across various water bodies.

[0078] Experiment 5: Effect of Different pH Values ​​on the Phenol Degradation Performance of HEAs and NG-Activated PMS: Solutions with initial pH values ​​of 1, 3, 5, and 9, and an acid buffer solution with a pH of 7.8, each containing 0.1 mM phenol, were prepared. 5 mg of each HEAs and NG were weighed and added to 50 mL of the phenol solution. After uniform dispersion on a magnetic stirrer, PMS was added to a concentration of 0.25 mM. A timer was started, and samples were taken at intervals during the degradation process. The phenol concentration in the solution at each time point was measured by ultra-high performance liquid chromatography, and the phenol degradation rate at each time point was calculated. The sampling intervals were 1, 2, 4, 7, 10, 15, 20, 28, 45, and 60 minutes (unit: min), and the magnetic stirrer was operated at 600 rpm.

[0079] Figure 18 The following graph shows the performance of HEAs and NG-activated PMS in phenol degradation at different pH values ​​in Experiment 5. The figure shows that HEAs maintained relatively stable degradation rates in solutions with initial pH values ​​of 1, 3, 5, and 9, as well as in an acid buffer solution with a pH of 7.8. Only at pH 1 did the degradation rate of HEAs decrease somewhat. However, compared to the significant degradation performance drop observed with NG, HEAs still demonstrated their exceptional acid and alkali resistance. The slight decrease at pH 1 is likely due to a change in the form of PMS in the solution, which weakened the degradation performance. This further demonstrates the excellent anti-interference ability of HEAs in the degradation of organic pollutants by activated PMS. In practical applications, HEAs can maintain stable degradation efficiency in water bodies with varying pH values ​​in diverse and complex environments.

Claims

1. Application of a carbon-based high entropy alloy catalyst, characterized in that Carbon-based high entropy alloy catalysts are used to activate PMS to degrade organic pollutants; The preparation method of the carbon-based high entropy alloy catalyst is carried out according to the following steps:

1. Add ferric acetylacetonate, cobalt acetylacetonate, copper acetylacetonate and nickel acetylacetonate to oleylamine, then add di(acetylacetonate)palladium, then add reducing agent 2,3,4,5,6-pentahydroxyhexanal and molybdenum hexacarbonyl and surfactant hexadecyltrimethylammonium chloride, stir for 10-15 minutes, and then ultrasonicate at 50-55°C for 30-35 minutes; The molar amounts of the di(acetylacetonate)palladium, ferric acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, and nickel acetylacetonate are equal, and the volume ratio of the molar amount of di(acetylacetonate)palladium to oleylamine is (0.02 mmol to 0.03 mmol):1L; The mass ratio of molybdenum hexacarbonyl to 2,3,4,5,6-pentahydroxyhexanal is 1:(1.8-2); The mass ratio of the bis(acetylacetonate)palladium to molybdenum hexacarbonyl is 1:(4-4.5); The mass ratio of molybdenum hexacarbonyl to hexadecyltrimethylammonium chloride is 1:(1.5-2); 2. The product of step 1 is placed in an oil bath at 220°C to 230°C and stirred for reaction for 2h to 2.5h. After the reaction is completed, the solution is removed from the oil bath and naturally cooled to room temperature. The cooled product is then centrifuged using a mixture of anhydrous ethanol and cyclohexane as a washing liquid to retain the solid portion, which is the colloid. The product is then washed with a mixture of anhydrous ethanol and cyclohexane until no surfactant is present in the solution. The high entropy alloy particles are obtained by centrifugation. The volume ratio of anhydrous ethanol to cyclohexane in the two mixtures of anhydrous ethanol and cyclohexane recorded in step 2 is 6:1; 3. The high entropy alloy particles obtained in step 2 are added to cyclohexane for dispersion, and then the carbon material precursor is added, ultrasonic loading is carried out for 30min~35min, and then anhydrous ethanol is added for centrifugal separation. The retained solid part is moved into a vacuum drying oven for drying, and then 2,3,4,5,6-pentahydroxyhexanal is added and fully ground and moved into a tube furnace. Annealing is carried out under protective gas for 2h~2.5h. After the end, it is immediately removed from the tube furnace and naturally cooled to room temperature to obtain a carbon-based high entropy alloy; The carbon material precursor is obtained by calcining urea at 550° C. to 600° C. for 2 h to 2.5 h in a muffle furnace; The mass ratio of the di(acetylacetonate)palladium described in step 1 to the carbon material precursor described in step 3 is 1:(65-70); The mass ratio of 2,3,4,5,6-pentahydroxyhexanal to the carbon material precursor described in step 3 is 1:(1-1.2); The annealing temperature is 800°C to 850°C.

2. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that The volume ratio of the molar amount of bis(acetylacetonate)palladium to oleylamine in step 1 is 0.025 mmol:1 L.

3. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that In step 1, ultrasonication was performed at 50° C. for 30 min.

4. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that In step 2, the product of step 1 was placed in an oil bath at 220° C. and stirred for reaction for 2 h.

5. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that The carbon material precursor described in step 3 is obtained by calcining urea at 550° C. for 2 h in a muffle furnace.

6. The use of a carbon-based high entropy alloy catalyst according to claim 5, characterized in that The carbon material precursor described in step 3 is obtained by calcining urea at 550° C. for 2 h in a muffle furnace with a heating rate of 10° C. / min.

7. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that The annealing temperature in step 3 is 800°C.

8. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that The protective gas described in step 3 is argon.

9. The use of a carbon-based high entropy alloy catalyst according to claim 1, characterized in that The drying temperature in step 3 is 60° C. and the drying time is 12 h.

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