A palladium / ruthenium / two-dimensional monolayer titanium carbide molybdenum nanosheet / three-dimensional nickel foam composite electrode, a preparation method and application thereof

Abstract

This invention discloses a palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode, its preparation method, and its application. Belonging to the field of electrochemical materials technology, it addresses the problem of the lack of high-efficiency, high-degradation, and economical electrode materials in existing technologies, which limits the development of electrocatalytic degradation of antibiotics. The palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode of this invention comprises, from the inside out, a nickel foam matrix, a two-dimensional monolayer titanium carbide macene nanosheet intermediate layer, a ruthenium intermediate layer, and a palladium layer. Using the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode as the working electrode, tetracycline-containing wastewater is degraded by electrochemical oxidation. It can efficiently degrade tetracycline in wastewater without causing secondary pollution to water bodies, thus achieving the goal of low-cost environmental protection and water conservation.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical materials technology, specifically relating to a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode, its preparation method, and its application. Background Technology

[0002] For decades, antibiotics have been widely used in human production and daily life. Tetracycline, as a broad-spectrum antibiotic, has been detected in many rivers, soils, and other natural environments due to its overuse and large-scale discharge. Since only a small portion of tetracycline is effective in the body during medical and aquaculture processes, approximately one-third to three-quarters of tetracycline is released into the environment through human or animal urine and feces. Tetracycline antibiotics are amphoteric substances, and their hydrochloride salts are relatively stable, meaning they require a long time to degrade in the environment. Therefore, once tetracycline antibiotics enter the environment, they cause serious impacts, posing a threat to ecosystems and public health and safety. Therefore, effectively removing tetracycline from the water cycle is essential.

[0003] In the prior art, patent application number 201811559130.3 provides a method for degrading tetracycline in water. However, this method requires the addition of peroxide to the wastewater, which not only poses certain risks but also increases costs, hindering its widespread application. Electrocatalytic oxidation, among all advanced oxidation methods, has attracted increasing attention due to its high removal efficiency for recalcitrant pollutants, good controllability, and lack of secondary pollution. Electrode materials, as a major influencing factor in the electrocatalytic process, play a crucial role in degradation performance. However, the lack of high-efficiency, economical electrode materials with high degradation rates in the existing technology limits the development of electrocatalytic degradation of antibiotics. Summary of the Invention

[0004] The technical problem to be solved by this invention is:

[0005] The lack of electrode materials with high degradation rates, high efficiency, and economical costs in existing technologies limits the development of electrocatalytic degradation of antibiotics.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] This invention provides a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode, wherein the composite electrode comprises, from the inside out, a nickel foam matrix, a two-dimensional monolayer titanium carbide micene nanosheet intermediate layer, a ruthenium intermediate layer and a palladium layer.

[0008] Furthermore, the titanium carbide micene nanosheets have a single-layer structure.

[0009] Furthermore, the loading of two-dimensional titanium carbide micene in the composite electrode is 1–5 mg / cm³. 2 The ruthenium loading is 0.01–0.1 mg / cm³. 2 The palladium loading is 0.10–0.20 mg / cm³. 2

[0010] Furthermore, it includes the following steps:

[0011] I. Preparation of Two-Dimensional Monolayer Titanium Carbide MacKenzyl Nanosheets: Titanium carbide MacKenzyl nanosheets were prepared using MAX phase titanium aluminum carbide powder as raw material via an etching method. Specifically, titanium aluminum carbide powder was slowly added to an etching solution in multiple portions and stirred. Subsequently, the precipitate was repeatedly washed with deionized water and centrifuged. Finally, the precipitate was added to deionized water, sonicated in an ice bath, and the supernatant was collected to obtain a two-dimensional monolayer titanium carbide MacKenzyl nanosheet dispersion. The etching solution was a lithium fluoride / hydrochloric acid mixture.

[0012] II. Preparation of the intermediate layer of deposited carbon material: The nickel foam was ultrasonically pretreated with hydrochloric acid solution, ethanol and deionized water in sequence to remove the surface oxide layer, and then dried in a vacuum oven; the nickel foam electrode was immersed in a certain concentration of monolayer macene nanosheet dispersion by the impregnation method to obtain a two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode.

[0013] III. Preparation of the ruthenium intermediate layer: A constant current deposition method was used with a two-dimensional monolayer titanium carbide Mackene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed in parallel, and a sodium sulfate / ruthenium chloride mixture was used as the electrodeposition solution to perform electrodeposition, thus obtaining the ruthenium / two-dimensional monolayer titanium carbide Mackene nanosheet / three-dimensional nickel foam composite electrode.

[0014] IV. Preparation of the palladium layer: A ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode was prepared by constant current deposition method with a ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed parallel to each other, and a sodium sulfate / palladium chloride mixture was used as the electrodeposition solution for electrodeposition to obtain the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode.

[0015] Furthermore, the etching solution in step one is composed of 1 to 5 parts by mass of LiF and 40 parts by mass of HCl solution with a concentration of 5 mol / L to 9 mol / L.

[0016] Furthermore, the concentration of the monolayer Mackenzie nanosheet dispersion in step two is 1–15 mg / mL.

[0017] Furthermore, in step three, the distance between the cathode and the anode is 10mm to 40mm, and electrodeposition is performed for 10min to 30min at a current of 1mA to 10mA; the sodium sulfate / ruthenium chloride mixture is prepared by mixing equal volumes of sodium sulfate solution with a concentration of 0.1mol / L to 1mol / L and ruthenium chloride solution with a concentration of 0.01mmol / L to 0.1mmol / L.

[0018] Furthermore, in step four, the distance between the cathode and the anode is 10mm to 40mm, and electrodeposition is performed for 10min to 30min at a current of 1mA to 10mA; the sodium sulfate / palladium chloride mixture is prepared by mixing equal volumes of sodium sulfate solution with a concentration of 0.1mol / L to 1mol / L and palladium chloride solution with a concentration of 0.01mmol / L to 0.1mmol / L.

[0019] Furthermore, using a palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode as the working electrode, tetracycline wastewater containing electrolytes was degraded by electrochemical oxidation.

[0020] Furthermore, the specific process of the electrochemical oxidation method for degrading tetracycline wastewater containing electrolytes is as follows: using a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode, at a current density of 1 mA / cm²... 2 ~6mA / cm 2 Electrolysis was performed on an aqueous solution of tetracycline containing an electrolyte, wherein the concentration of sodium chloride electrolyte in the tetracycline aqueous solution was 0.3 mol / L to 0.5 mol / L.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The loading of two-dimensional titanium carbide micene in the composite electrode is 1–5 mg / cm³. 2 The loading of ruthenium in the interlayer is 0.01–0.1 mg / cm³. 2 The palladium loading in the palladium intermediate layer is 0.10–0.20 mg / cm³. 2 Palladium / ruthenium can be uniformly dispersed on the conductive intermediate layer of titanium carbide macene and efficiently degrade tetracycline in wastewater under voltage without causing secondary pollution to water bodies, thus achieving the goal of protecting the environment and saving water resources at low cost.

[0023] Second, the composite electrode of the present invention, when used with an inert anode, achieves a degradation rate of over 90% for tetracycline hydrochloride within one hour.

[0024] Third, compared with multilayer structures, the two-dimensional monolayer titanium carbide macene nanosheets of the composite electrode of the present invention have more active sites and a larger specific surface area, which is conducive to the uniform dispersion of palladium / ruthenium, prevents their aggregation, and adjusts the interface of the catalytic electrode to expose active sites and regulate the electronic state of the catalyst to improve intrinsic activity, thereby promoting the electrocatalytic degradation of tetracycline hydrochloride molecules.

[0025] Fourth, the composite electrode of the present invention has broad applicability under different temperatures and different pH levels. Attached Figure Description

[0026] Figure 1 The XPS spectrum of the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode in the embodiments of the present invention;

[0027] Figure 2 The images shown are scanning electron microscope (SEM) images of the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheets / three-dimensional nickel foam composite electrode in the embodiments of the present invention; wherein Figures (a)-(d) are, respectively, SEM images of the nickel foam substrate, the two-dimensional monolayer titanium carbide macene nanosheets / three-dimensional nickel foam composite electrode, the ruthenium / two-dimensional monolayer titanium carbide macene nanosheets / three-dimensional nickel foam composite electrode, and the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheets / three-dimensional nickel foam composite electrode at 50,000x magnification;

[0028] Figure 3 The XRD spectra of the two-dimensional monolayer titanium carbide micene nanosheets and the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheets / three-dimensional nickel foam composite electrodes in the embodiments of the present invention are shown.

[0029] Figure 4 The image shows the fluorescence spectrum of the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode in a coumarin solution in an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram illustrating the mechanism of action of the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode in this embodiment of the invention. Detailed Implementation

[0031] Specific implementation scheme one: A palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode, wherein the composite electrode comprises, from the inside to the outside, a nickel foam matrix, a two-dimensional monolayer titanium carbide micene nanosheet intermediate layer, a ruthenium intermediate layer and a palladium layer.

[0032] Specific Implementation Scheme Two: The titanium carbide-micron nanosheets are a single-layer structure, rather than the traditional accordion shape. All other aspects of this scheme are the same as Specific Implementation Scheme One.

[0033] Specific implementation scheme three: The loading of two-dimensional titanium carbide micene in the composite electrode is 1-5 mg / cm³. 2 The ruthenium loading is 0.01–0.1 mg / cm³. 2 The palladium loading is 0.10–0.20 mg / cm³. 2 This implementation plan is otherwise the same as Implementation Plan Two.

[0034] Specific Implementation Scheme Four: The preparation method of the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode includes the following steps:

[0035] I. Preparation of Two-Dimensional Monolayer Titanium Carbide MacKenzyl Nanosheets: Titanium carbide MacKenzyl nanosheets were prepared using MAX phase titanium aluminum carbide powder as raw material via an etching method. Specifically, titanium aluminum carbide powder was slowly added to an etching solution in multiple portions and stirred. Subsequently, the precipitate was repeatedly washed with deionized water and centrifuged. Finally, the precipitate was added to deionized water, sonicated in an ice bath, and the supernatant was collected to obtain a two-dimensional monolayer titanium carbide MacKenzyl nanosheet dispersion. The etching solution was a lithium fluoride / hydrochloric acid mixture.

[0036] II. Preparation of the intermediate layer of deposited carbon material: The nickel foam was ultrasonically pretreated with hydrochloric acid solution, ethanol and deionized water in sequence to remove the surface oxide layer, and then dried in a vacuum oven; the nickel foam electrode was immersed in a certain concentration of monolayer macene nanosheet dispersion by the impregnation method to obtain a two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode.

[0037] III. Preparation of the ruthenium intermediate layer: A constant current deposition method was used with a two-dimensional monolayer titanium carbide Mackene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed in parallel, and a sodium sulfate / ruthenium chloride mixture was used as the electrodeposition solution to perform electrodeposition, thus obtaining the ruthenium / two-dimensional monolayer titanium carbide Mackene nanosheet / three-dimensional nickel foam composite electrode.

[0038] IV. Preparation of the palladium layer: A ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode was prepared by constant current deposition method with a ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed parallel to each other, and a sodium sulfate / palladium chloride mixture was used as the electrodeposition solution for electrodeposition to obtain the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode.

[0039] Specific Implementation Scheme Five: The etching solution mentioned in Step One is composed of 1 to 5 parts by mass of LiF and 40 parts by mass of HCl solution with a concentration of 5 mol / L to 9 mol / L. All other aspects of this implementation scheme are the same as those in Specific Implementation Scheme Four.

[0040] Specific Implementation Scheme Six: The concentration of the monolayer micene nanosheet dispersion described in Step Two is 1–15 mg / mL. All other aspects of this implementation scheme are the same as in Specific Implementation Scheme Four.

[0041] Specific Implementation Scheme Seven: In step three, the distance between the cathode and anode is 10mm to 40mm, and electrodeposition is performed for 10min to 30min at a current of 1mA to 10mA. The sodium sulfate / ruthenium chloride mixture is prepared by mixing equal volumes of sodium sulfate solution with a concentration of 0.1mol / L to 1mol / L and ruthenium chloride solution with a concentration of 0.01mmol / L to 0.1mmol / L. All other aspects of this implementation scheme are the same as in Specific Implementation Scheme Four.

[0042] Specific Implementation Scheme Eight: In step four, the distance between the cathode and anode is 10mm to 40mm, and electrodeposition is performed for 10min to 30min at a current of 1mA to 10mA. The sodium sulfate / palladium chloride mixture is prepared by mixing equal volumes of sodium sulfate solution with a concentration of 0.1mol / L to 1mol / L and palladium chloride solution with a concentration of 0.01mmol / L to 0.1mmol / L. All other aspects of this implementation scheme are the same as in Specific Implementation Scheme Four.

[0043] Specific Implementation Scheme Nine: Using a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode as the working electrode, electrochemical oxidation is used to degrade tetracycline wastewater containing electrolytes. All other aspects of this implementation scheme are the same as Specific Implementation Scheme Four.

[0044] Specific Implementation Scheme Ten: The specific process of the electrochemical oxidation method for degrading tetracycline wastewater containing electrolytes is as follows: using a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode, at a current density of 1 mA / cm²... 2 ~6mA / cm 2 Electrolysis is performed on an aqueous solution of tetracycline containing an electrolyte, wherein the concentration of sodium chloride electrolyte in the tetracycline aqueous solution is 0.3 mol / L to 0.5 mol / L. All other aspects of this implementation scheme are the same as those in specific implementation scheme nine.

[0045] Example 1:

[0046] The following experiments were conducted to verify the effectiveness of the present invention.

[0047] A method for preparing a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode, which is completed according to the following steps:

[0048] I. Preparation of two-dimensional monolayer titanium carbide macene nanosheets: Titanium carbide macene was prepared by etching using MAX phase titanium aluminum carbide powder as raw material. Specifically, titanium aluminum carbide powder was slowly added to the etching solution in multiple portions and stirred. Subsequently, the precipitate was repeatedly washed with deionized water and centrifuged. Finally, the precipitate was added to deionized water, sonicated in an ice bath, and the supernatant was collected to obtain a two-dimensional monolayer titanium carbide macene nanosheet dispersion. The etching solution was prepared by mixing 2g of lithium fluoride and 40mL of 9mol / L hydrochloric acid solution.

[0049] II. Preparation of the intermediate layer of deposited carbon material: The nickel foam was pretreated by ultrasonic treatment with hydrochloric acid solution, ethanol and deionized water in sequence to remove the surface oxide layer, and then dried in a vacuum oven; the nickel foam electrode was immersed in a 10 mg / mL monolayer macene nanosheet dispersion by impregnation method to obtain a two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode; the monolayer macene nanosheet dispersion was obtained by freeze-drying the macene dispersion of unknown concentration obtained in step one, grinding it into powder using an agate mortar to obtain two-dimensional monolayer titanium carbide macene nanosheet powder, weighing the monolayer macene nanosheet powder and adding deionized water, and ultrasonicating in an ice bath for 30 min to mix it evenly to obtain a monolayer macene nanosheet dispersion with a concentration of 10 mg / mL.

[0050] III. Preparation of the ruthenium intermediate layer: A constant current deposition method was used with a two-dimensional monolayer titanium carbide-micron nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed parallel to each other with a distance of 20 mm between them. Electrodeposition was performed using a sodium sulfate / ruthenium chloride mixture as the electrodeposition solution at a current of 5 mA for 30 min to obtain the ruthenium / two-dimensional monolayer titanium carbide-micron nanosheet / three-dimensional nickel foam composite electrode. The sodium sulfate / ruthenium chloride mixture was prepared by mixing equal volumes of a 0.5 mol / L sodium sulfate solution and a 0.01 mmol / L ruthenium chloride solution at a concentration of 1 mA to 10 mA.

[0051] IV. Preparation of the Palladium Layer: A ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode was used as the cathode and a platinum sheet as the anode, with the cathode and anode placed parallel to each other and a distance of 20 mm between them. Electrodeposition was performed using a sodium sulfate / palladium chloride mixture as the electrodeposition solution at a current of 5 mA for 10 min to obtain the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode. The sodium sulfate / palladium chloride mixture was prepared by mixing equal volumes of a 0.5 mol / L sodium sulfate solution and a 0.025 mmol / L palladium chloride solution.

[0052] Example 2: The preparation process is the same as in Example 1, except that the concentration of the monolayer micene nanosheet dispersion in step two is 1 mg / L.

[0053] Example 3: The preparation process is the same as in Example 1, except that the concentration of the monolayer micene nanosheet dispersion in step two is 2 mg / L.

[0054] Example 4: The preparation process is the same as in Example 1, except that the concentration of the monolayer micene nanosheet dispersion in step two is 5 mg / L.

[0055] Example 5: The preparation process is the same as in Example 1, except that the concentration of the single-layer micene nanosheet dispersion in step two is 15 mg / L.

[0056] Example 6: Using the palladium / ruthenium / two-dimensional monolayer titanium carbide MacKenzyl nanosheet / three-dimensional nickel foam composite electrode obtained in Example 1 as the working electrode, an electrochemical oxidation method was used to degrade tetracycline hydrochloride wastewater containing electrolytes. The specific operation is as follows: using the palladium / ruthenium / two-dimensional monolayer titanium carbide MacKenzyl nanosheet / three-dimensional nickel foam composite electrode obtained in Example 1 as the cathode, and a platinum sheet as the anode, at a current density of 1 mA / cm²... 2 3mA / cm 2 and 6mA / cm 2 Electrochemical oxidation of tetracycline hydrochloride aqueous solution containing sodium chloride electrolyte was carried out under pH 4 conditions for 60 min. The initial concentration of tetracycline hydrochloride aqueous solution was 20 mg / L, and the concentration of sodium chloride electrolyte was 0.3 mol / L.

[0057] Comparative Example 1: This comparative example differs from Example 6 in that the composite electrode prepared in Example 2 is used as the working electrode. Everything else is the same as in Example 6.

[0058] Comparative Example 2: This comparative example differs from Example 6 in that the composite electrode prepared in Example 3 is used as the working electrode. Everything else is the same as in Example 6.

[0059] Comparative Example 3: This comparative example differs from Example 6 in that the composite electrode prepared in Example 4 is used as the working electrode. Everything else is the same as in Example 6.

[0060] Comparative Example 4: This comparative example differs from Example 6 in that the composite electrode prepared in Example 5 is used as the working electrode. Everything else is the same as in Example 6.

[0061] The degradation rate of tetracycline hydrochloride in Examples 6, Comparative Examples 1, 2, 3, and 4 was calculated using ultraviolet spectrophotometry. The degradation efficiency was calculated by subtracting the initial absorbance of the solution before degradation from the absorbance of the tetracycline hydrochloride aqueous solution after degradation and then dividing by the initial absorbance. The specific results are shown in Table 1.

[0062] Table 1

[0063]

[0064]

[0065] Example 7: Using the palladium / ruthenium / two-dimensional monolayer titanium carbide Mackenene nanosheet / three-dimensional nickel foam composite electrode obtained in Example 1 as the working electrode, at a current density of 6 mA / cm²... 2 Electrolysis was then performed on an aqueous solution of tetracycline hydrochloride containing 0.5 mol / L sodium chloride electrolyte. Everything else was the same as in Example 6.

[0066] Comparative Example 5: This comparative example differs from Example 7 in that it uses an aqueous solution of tetracycline hydrochloride containing 0.1 mol / L sodium chloride electrolyte for electrolysis. Everything else is the same as in Example 7.

[0067] Comparative Example 6: This comparative example differs from Example 7 in that it uses an aqueous solution of tetracycline hydrochloride containing 0.2 mol / L sodium chloride electrolyte for electrolysis. Everything else is the same as in Example 7.

[0068] Comparative Example 7: This comparative example differs from Example 7 in that it uses an aqueous solution of tetracycline hydrochloride containing 0.3 mol / L sodium chloride electrolyte for electrolysis. Everything else is the same as in Example 7.

[0069] Comparative Example 8: This comparative example differs from Example 7 in that it uses an aqueous solution of tetracycline hydrochloride containing 0.4 mol / L sodium chloride electrolyte for electrolysis. Everything else is the same as in Example 7.

[0070] The degradation rates of tetracycline hydrochloride in Example 7, Comparative Example 5, Comparative Example 6, Comparative Example 7 and Comparative Example 8 were calculated, and the results are shown in Table 2.

[0071] Table 2

[0072]

[0073] As can be seen from the results in Table 2, the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode of the present invention can achieve a degradation rate of more than 90% for tetracycline hydrochloride aqueous solution in a short time (60 min), and can have a high degradation rate for tetracycline wastewater.

[0074] like Figure 1 As shown, the full-scan XPS measurement spectrum indicates that Ni, Ti, C, Ru, Pd and O elements coexist on the composite electrode sample, demonstrating that the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode has been successfully fabricated.

[0075] like Figure 2 As shown in (a), the surface of the nickel foam substrate is uniform and smooth; Figure 2As shown in (b), black monolayer micene nanosheets are uniformly distributed on the surface of nickel foam. The micene nanosheets were successfully loaded onto the nickel foam surface, providing attachment sites for subsequent loading of metal nanoparticles. After electrodeposition treatment; as Figure 2 As shown in (c), cubic ruthenium nanoparticles are uniformly dispersed on the surface of a two-dimensional monolayer titanium carbide-micron nanosheet / three-dimensional nickel foam composite electrode, and no aggregation is observed, indicating its good dispersibility. Figure 2 As shown in (d), palladium nanoparticles are uniformly embedded on the surface of a two-dimensional monolayer titanium carbide-micron nanosheet. This embedded structure can largely prevent the aggregation of nanoparticles and promote the electro-interaction between the active sites of palladium and ruthenium nanoparticles and the electrolyte, thereby accelerating electron transfer during electrolysis. Figure 2 (d) It can be seen that compared with the nickel foam electrode, its surface roughness is greatly increased, indicating that its specific surface area is increased, which is also beneficial to provide sufficient active sites for the reaction.

[0076] like Figure 3 As shown, diffraction signals appeared at 7.1° and 60.8°, corresponding to the (002) and (110) crystal planes of the titanium carbide macene nanosheets, respectively. No aluminum diffraction peak was observed at 39°, indicating that the etching operation of the aluminum layer within the titanium carbide aluminum MAX phase was successful. For the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheets / three-dimensional nickel foam composite electrode, three sharp diffraction peaks appeared at 44.5°, 51.9°, and 76.5°, corresponding to the (111), (200), and (220) crystal planes of the nickel foam, respectively. However, due to its strong diffraction signal, it was difficult to distinguish the diffraction signal of the two-dimensional monolayer titanium carbide macene nanosheets. Ru... 0.1 Pd 0.9 The (111) and (200) crystal planes indicate that palladium and ruthenium were successfully loaded onto the surface of the nickel foam, and the palladium content was higher than the ruthenium content.

[0077] Example 8: The ·OH generated by the composite electrode of the present invention during the electrochemical oxidation reaction process has a strong oxidizing ability for tetracycline wastewater. Since coumarin can capture ·OH to generate 7-hydroxycoumarin, a fluorescent compound detectable by fluorescence spectroscopy, this example characterizes the chiral ·OH concentration by electrolyzing a coumarin aqueous solution and detecting the fluorescence intensity of 7-hydroxycoumarin in the solution. The specific operation method is as follows: using the palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode prepared in Example 1 as the cathode, and a platinum sheet as the anode, at a current density of 6 mA / cm²... 2 The electrochemical oxidation reaction was carried out for 60 minutes. Figure 4As shown, the fluorescence intensity gradually increases with the extension of degradation time, indicating that ·OH is generated during the DC electrocatalytic degradation process and its concentration gradually accumulates.

[0078] like Figure 5 As shown, the ·OH and H generated during the operation of the composite electrode of the present invention * and ClO - It acts on tetracycline hydrochloride molecules, converting them into smaller molecules. Specifically, tetracycline hydrochloride is oxidized at the anode surface via direct electron transfer. Simultaneously, water forms heterogeneous ·OH groups during anodic oxidation and exists on the anode surface through physical adsorption, thus achieving the oxidative degradation of tetracycline hydrochloride. In addition to the aforementioned water oxidation, indirect oxidation at the anode also involves Cl... - Chlorine radicals are generated directly on the anolyte surface through oxidation. Ru and Pd are both group VIII transition metals, and the electronic structure of group VIII metals, particularly the d orbitals, facilitates the formation of metal-hydrogen bonds. Free hydrogen is chemisorbed in solution, forming relatively stable metal-hydrogen bonds on the surface, which are subsequently promoted by single-electron reduction of the metal-[H+] group. * The generation of ads. Secondly, H * It can be used to reduce tetracycline adsorbed on the electrode surface and intermediates (R) generated during degradation. In addition, due to the hydrogen overflow mechanism, antibiotic molecules near the cathode surface can also be reduced by the overflowing atomic hydrogen, and the resulting reduction products can also be desorbed from the cathode surface and enter the solution.

[0079] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An application of a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode, characterized in that, Using a palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode as the working electrode, tetracycline wastewater containing electrolytes was degraded by electrochemical oxidation. The composite electrode comprises, from the inside out, a nickel foam matrix, a two-dimensional monolayer titanium carbide micene nanosheet intermediate layer, a ruthenium intermediate layer, and a palladium layer; The electrode was prepared according to the following method: I. Preparation of Two-Dimensional Monolayer Titanium Carbide MacKenzyl Nanosheets: Titanium carbide MacKenzyl nanosheets were prepared using MAX phase titanium aluminum carbide powder as raw material via an etching method. Specifically, titanium aluminum carbide powder was slowly added to an etching solution in multiple portions and stirred. Subsequently, the precipitate was repeatedly washed with deionized water and centrifuged. Finally, the precipitate was added to deionized water, sonicated in an ice bath, and the supernatant was collected to obtain a two-dimensional monolayer titanium carbide MacKenzyl nanosheet dispersion. The etching solution was a lithium fluoride / hydrochloric acid mixture. II. Preparation of the intermediate layer of deposited carbon material: The nickel foam was ultrasonically pretreated with hydrochloric acid solution, ethanol and deionized water in sequence to remove the surface oxide layer, and then dried in a vacuum oven; the nickel foam electrode was immersed in a certain concentration of monolayer macene nanosheet dispersion by the impregnation method to obtain a two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode. III. Preparation of the ruthenium intermediate layer: A constant current deposition method was used with a two-dimensional monolayer titanium carbide Mackene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed in parallel, and a sodium sulfate / ruthenium chloride mixture was used as the electrodeposition solution to perform electrodeposition, thus obtaining the ruthenium / two-dimensional monolayer titanium carbide Mackene nanosheet / three-dimensional nickel foam composite electrode. IV. Preparation of the palladium layer: A ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode was prepared by constant current deposition method with a ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode as the cathode and a platinum sheet as the anode. The cathode and anode were placed parallel to each other, and a sodium sulfate / palladium chloride mixture was used as the electrodeposition solution for electrodeposition to obtain the palladium / ruthenium / two-dimensional monolayer titanium carbide macene nanosheet / three-dimensional nickel foam composite electrode.

2. The application according to claim 1, characterized in that, The specific process of the electrochemical oxidation method for degrading tetracycline wastewater containing electrolytes is as follows: using a palladium / ruthenium / two-dimensional monolayer titanium carbide micene nanosheet / three-dimensional nickel foam composite electrode as the cathode, and a platinum sheet as the anode, at a current density of 1 mA / cm². 2 ~6mA / cm 2 Electrolysis was performed on an aqueous solution of tetracycline containing an electrolyte, wherein the concentration of sodium chloride electrolyte in the tetracycline aqueous solution was 0.3 mol / L to 0.5 mol / L.

3. The application according to claim 2, characterized in that, The loading of two-dimensional titanium carbide micene in the composite electrode is 1~5 mg / cm³. 2 The ruthenium loading is 0.01~0.1 mg / cm³. 2 The palladium loading was 0.10~0.20 mg / cm³. 2 .

4. The application according to claim 3, characterized in that, The etching solution mentioned in step one is composed of 1 to 5 parts by mass of LiF and 40 parts by mass of HCl solution with a concentration of 5 mol / L to 9 mol / L.

5. The application according to claim 4, characterized in that, The concentration of the monolayer Mackenzie nanosheet dispersion in step two is 1~15 mg / mL.

6. The application according to claim 5, characterized in that, In step three, the distance between the cathode and the anode is 10mm~40mm, and electrodeposition is performed for 10min~30min at a current of 1mA~10mA. The sodium sulfate / ruthenium chloride mixture is prepared by mixing equal volumes of sodium sulfate solution with a concentration of 0.1mol / L~1mol / L and ruthenium chloride solution with a concentration of 0.01mmol / L~0.1mmol / L.

7. The application according to claim 6, characterized in that, In step four, the distance between the cathode and the anode is 10mm~40mm, and electrodeposition is performed for 10min~30min at a current of 1mA~10mA. The sodium sulfate / palladium chloride mixture is prepared by mixing equal volumes of sodium sulfate solution with a concentration of 0.1mol / L~1mol / L and palladium chloride solution with a concentration of 0.01mmol / L~0.1mmol / L.

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