Preparation method of copper-based high-entropy alloy Fenton-like catalyst based on controllable electrodeposition

Abstract

The present invention discloses a method for preparing a copper-based high-entropy alloy Fenton-like catalyst based on a controllable electrodeposition method. The method first prepares electrodes, with a pure copper electrode selected as the cathode and a graphite electrode selected as the anode. An electrolyte solution of copper sulfate / ferrous sulfate / cobalt sulfate / nickel sulfate / zinc sulfate / manganese sulfate is then prepared, to which a complexing agent and a hydrogen evolution inhibitor are added. A negative ion exchange membrane is then pretreated. An electrodeposition apparatus is fabricated using the cathode and anode. A power supply voltage is set to initiate a reaction, and copper-based high-entropy micro-nano alloy powder is deposited on the cathode electrode. Finally, the catalyst powder is collected. The copper-based high-entropy micro-nano alloy Fenton-like catalyst prepared by the present invention exhibits a multi-level dendritic structure with a large specific surface area. The active components are evenly distributed within or on the catalyst surface, facilitating reaction with PMS or complexation with pollutants, thereby enhancing reaction activity.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment, and in particular relates to a method for preparing a copper-based high-entropy alloy Fenton-type catalyst based on a controllable electrodeposition method. Background Art

[0002] Nowadays, the scarcity of freshwater resources and the increasingly serious environmental pollution are increasingly attracting people's attention. Antibiotic contamination in wastewater that has adverse effects on human health must be reduced to an acceptable level. So far, humans have developed various wastewater treatment technologies, such as filtration processes, biodegradation, and advanced oxidation processes. Advanced oxidation technology achieves the oxidation effect of organic pollutants through strongly oxidizing free radicals and has a very broad application prospect. However, the current Fenton oxidation technology still has some unavoidable shortcomings, such as: low hydrogen peroxide utilization rate, narrow applicable pH range of the reaction system, and poor catalyst reusability resulting in increased costs. Therefore, the development of an efficient heterogeneous Fenton-like catalyst material that is inexpensive, easy to obtain, reusable, and has high catalytic performance over a wide pH range has important application value in the field of water treatment. Summary of the Invention

[0003] To overcome the shortcomings of the existing technology, the present invention provides a method for preparing a copper-based high-entropy alloy Fenton-like catalyst based on a controllable electrodeposition method. The method first prepares electrodes, selecting a pure copper electrode as the cathode and a graphite electrode as the anode. An electrolyte solution of copper sulfate / ferrous sulfate / cobalt sulfate / nickel sulfate / zinc sulfate / manganese sulfate is then prepared, to which a complexing agent and a hydrogen evolution inhibitor are added. A negative ion exchange membrane is then pretreated. An electrodeposition apparatus is fabricated using the cathode and anode. A power supply voltage is set to initiate a reaction, and copper-based high-entropy micro-nano alloy powder is deposited on the cathode electrode. Finally, the catalyst powder is collected. The copper-based high-entropy micro-nano alloy Fenton-like catalyst prepared by the present invention exhibits a multi-level dendritic structure with a large specific surface area. The active components are evenly distributed within or on the catalyst surface, facilitating reaction with PMS or complexation with pollutants, thereby enhancing reaction activity.

[0004] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0005] Step 1: Prepare electrodes;

[0006] Cathode: Choose a pure copper electrode as the cathode. Polish it with sandpaper of different specifications to remove the metal burrs on the electrode surface. Then soak the electrode in 1mol / L hydrochloric acid + 0.1mol / L dilute sulfuric acid solution to remove the oxide layer on the metal surface. Finally, clean it with anhydrous ethanol.

[0007] Anode: Choose a graphite electrode as the anode. Soak the graphite electrode in a 30% HNO3 solution, then rinse it with a KOH-ethanol solution until it is neutral. Use an ultrasonic cleaner with deionized water as the cleaning solution, then soak it in deionized water, remove it, and dry it for later use.

[0008] Step 2: Prepare copper sulfate / ferrous sulfate / cobalt sulfate / nickel sulfate / zinc sulfate / manganese sulfate electrolyte, and add complexing agent and hydrogen evolution inhibitor; 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ 、Mn 2+ The total ion concentration remains unchanged at 0.5-1.0 mol / L, and the element Cu 2+ The ratio of Fe is 20-40%, 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ 、Mn 2+ The atomic ratio is 5% to 20%;

[0009] Step 3: Anion exchange membrane pretreatment;

[0010] The negative ion exchange membrane is immersed in 80°C hydrogen peroxide with a mass fraction of 5%, and then immersed in deionized water; then immersed in 5% dilute sulfuric acid at 80°C to fully activate it, and then transferred to deionized water for immersion; before preparing the material, the pretreated negative ion exchange membrane is immersed in the electrolyte in step 2 for 0.5 to 2 hours;

[0011] Step 4: Using the cathode and anode prepared in step 1 to make an electrodeposition device;

[0012] The electrodeposition device is composed of an electrode cathode, an anode, a negative ion exchange membrane and a transparent quartz reaction tank base. The electrodeposition device is filled with electrolyte. The positive pole of the power supply is connected to the electrode anode, and the negative pole of the power supply is connected to the electrode cathode. The negative ion exchange membrane is immersed in the electrolyte.

[0013] Step 5: Set the initial power supply voltage to 20V and react for 10 seconds; then reduce it to 0.5 times the initial voltage and react for another 10 seconds, and the copper-based high-entropy micro-nano alloy powder is deposited on the electrode cathode;

[0014] Step 6: Collecting catalyst powder;

[0015] The cathode was rinsed with anhydrous ethanol, and the rinse liquid containing the catalyst powder was collected. The catalyst was separated using a centrifuge, and finally washed with deionized water and ethanol three times, and dried at 65°C in a vacuum oven for 6 h.

[0016] Preferably, the specific method for making the cathode and anode in step 1 is as follows:

[0017] Cathode: A pure copper electrode with a length of 100 mm and a width of 50 mm was selected as the cathode. It was polished with 400, 800, and 1200 grit sandpaper in sequence to remove metal burrs on the electrode surface. The electrode was immersed in a 1 mol / L hydrochloric acid + 0.1 mol / L dilute sulfuric acid solution for 30 minutes to remove the oxide layer on the metal surface. Finally, it was cleaned with anhydrous ethanol.

[0018] Anode: A graphite electrode with a length of 100 mm and a width of 50 mm was selected as the anode. The graphite electrode was soaked in a 30% HNO3 solution for 30 min, and then cleaned with a 0.1 mol / L KOH-ethanol solution until neutral. The electrode was ultrasonically cleaned with deionized water in an ultrasonic cleaning machine for 10 to 20 minutes, and then soaked in deionized water for 1 h, taken out and dried for later use.

[0019] Preferably, the complexing agent includes one or two of sodium hexametapolyphosphate, citric acid, and sodium lauryl sulfate, with a total concentration of 10g to 80g / L; the hydrogen evolution inhibitor is one or more of ethanol, ethylene glycol, and glycerol, with a total concentration of 10 to 50ml / L.

[0020] Preferably, in step 3, the sample is immersed in hydrogen peroxide for 1 hour, then immersed in deionized water for half an hour; and then immersed in 5% dilute sulfuric acid at 80° C. for half an hour.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. Advantages of controllable electrochemical reduction method: The copper-based high-entropy micro-nano alloy Fenton catalyst has a multi-level dendritic structure with a large specific surface area, and the active components are evenly distributed in or on the catalyst surface, which is conducive to reaction with PMS or complexation with pollutants, thereby improving reaction activity.

[0023] 2. Catalytic performance of transition metals such as Fe, Co, Mn, Ni, and Zn: Transition metals such as Fe, Co, Mn, Ni, and Zn have multiple redox states and have good catalytic performance for PMS in a wide pH range;

[0024] 3. Synergistic effect of Fe, Co, Mn, Ni, Zn and Cu: Cu and transition metals such as Fe, Co, Mn, Ni, and Zn will form a weak galvanic cell, which can react with PMS faster than single Cu to produce active oxygen species free radicals, thereby degrading pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a diagram of the electrodeposition device of the present invention.

[0026] Figure 2 This is the XRD pattern of copper-based high-entropy micro-nano alloy.

[0027] Figure 3 This is the morphology of commercially available copper powder alloy.

[0028] Figure 4 The ratio of Fe, Co, Mn, Ni and Zn sources is 5-10%, and the obtained Cu 40 M x(5＜x≤10) Morphology of copper-based high-entropy micro-nano alloys.

[0029] Figure 5 The ratio of Fe, Co, Mn, Ni and Zn sources is 10-15%, and the obtained Cu 30 M x(10＜x≤15) Morphology of copper-based high-entropy micro-nano alloys.

[0030] Figure 6 The ratio of Fe, Co, Mn, Ni and Zn sources is 15-20%, and the obtained Cu 20 M x(15＜x≤20) Morphology of copper-based high-entropy micro-nano alloys.

[0031] Figure 7 Degradation performance of pure copper and different copper-based high-entropy micro-nano alloys at pH 4.

[0032] Figure 8 Degradation performance of pure copper and different copper-based high-entropy micro-nano alloys at pH 6.

[0033] Figure 9 Degradation performance of pure copper and different copper-based high-entropy micro-nano alloys at pH 9.

[0034] In the figure, 1-electrode cathode, 2-electrode anode, 3-electrolyte, 4-negative ion exchange membrane, 5-negative power supply electrode, 6-positive power supply electrode. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings and examples.

[0036] A method for preparing a copper-based high-entropy alloy Fenton-like catalyst based on a controllable electrodeposition method comprises the following steps:

[0037] 1. Prepare the electrodes.

[0038] Cathode: A pure copper electrode with a length of 100 mm and a width of 50 mm was selected as the cathode. It was polished with 400, 800, and 1200 grit sandpaper in sequence to remove the metal burrs on the electrode surface as much as possible. The electrode was soaked in a 1 mol / L hydrochloric acid + 0.1 mol / L dilute sulfuric acid solution for 30 minutes to remove the oxide layer on the metal surface. Finally, it was cleaned with anhydrous ethanol.

[0039] Anode: A graphite electrode with a length of 100 mm and a width of 50 mm was selected as the anode. The graphite electrode was soaked in a 30% HNO3 solution for 30 min, and then cleaned with a KOH-ethanol solution (0.1 mol / L) until neutral. Ultrasonic cleaning was performed in an ultrasonic cleaner for 10 to 20 minutes (the cleaning solution was deionized water), and then soaked in deionized water for 1 h, and then taken out to dry for use.

[0040] 2. Prepare copper sulfate / ferrous sulfate / cobalt sulfate / nickel sulfate / zinc sulfate / manganese sulfate electrolyte, and add complexing agent and hydrogen evolution inhibitor. 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ 、Mn 2+ The total ion concentration remains unchanged at 0.5-1.0 mol / L, of which the main element Cu 2+ The ratio of Fe is 20-40%, 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ 、Mn 2+ The atomic ratio is 5% to 20%. The complexing agent includes one or two of sodium hexametapolyphosphate, citric acid, and sodium lauryl sulfate, with a total concentration of 10g to 80g / L. The hydrogen evolution inhibitor is one or more of ethanol, ethylene glycol, and glycerol, with a total concentration of 10 to 50ml / L.

[0041] 3. Pretreatment of the Negative Ion Exchange Membrane: Soak a commercially available negative ion exchange membrane in 5% hydrogen peroxide at 80°C for 1 hour, then in deionized water for half an hour. Then, soak in 5% dilute sulfuric acid at 80°C for half an hour. After fully activating the membrane, transfer it to deionized water for soaking. Before preparing the material, soak the pretreated negative ion exchange membrane in the electrolyte solution from step 2 for 0.5-2 hours.

[0042] 4. Use the activated pure copper electrode as cathode and the graphite electrode as anode to make an electrodeposition device such as Figure 1 shown.

[0043] 5. Set the power supply voltage to 20V and react for 10 seconds; then reduce it to 0.5 times the initial voltage and react for a further 10 seconds. In this way, the copper-based high-entropy micro-nano alloy powder will be deposited on the cathode.

[0044] 6. Collect the catalyst powder. Rinse the cathode with anhydrous ethanol, collect the rinse solution containing the catalyst powder, separate the catalyst using a centrifuge, and finally rinse with deionized water and ethanol three times, and dry under vacuum at 65°C for 6 hours.

[0045] Example:

[0046] Degradation experiment

[0047] The prepared powder was tested for degradation of tetracycline hydrochloride solution: 100 mL of a 10 ppm tetracycline hydrochloride solution in deionized water was prepared, and the pH was adjusted to 4, 6, and 9 using dilute sulfuric acid and sodium hydroxide solutions. 5 mg of the prepared catalyst was added to the solution, mechanically stirred and dispersed, and then PMS solution was added to achieve a PMS concentration of 1 mmol / L. The temperature was set at 25°C, and the change in pollutant concentration over time after the addition of PMS was measured.

[0048] Table 1 related data and description:

[0049]

[0050] Table 1 shows the energy spectrum results of high-entropy micro-nano alloys prepared in electrolytes with different metal ion ratios. The data in the table show that this high-entropy alloy is primarily copper, and the proportions of the different metals in the sample differ from the concentration ratios in the electrolyte. This is due to the different redox properties of the different metal ions.

[0051] Figure 2 This is the XRD pattern of the copper-based high-entropy micro-nano alloy. It can be seen that the dendrite is still mainly composed of Cu crystal phase.

[0052] Figure 3 The morphology is that of commercially available copper powder alloy, with a size between 3-8 μm.

[0053] Figure 4 The ratio of Fe, Co, Mn, Ni and Zn sources is 5-10%, and the obtained Cu 40 M x(5＜x≤10) The copper-based high-entropy micro-nano alloy morphology is between 3-8μm in size, and the multi-level dendritic structure is conducive to reaction with PMS or complexation with pollutants to improve reaction activity.

[0054] Figure 5 The ratio of Fe, Co, Mn, Ni and Zn sources is 10-15%, and the obtained Cu 30 M x(10＜x≤15) The copper-based high-entropy micro-nano alloy morphology is between 3-8μm in size, and the multi-level dendritic structure is conducive to reaction with PMS or complexation with pollutants to improve reaction activity.

[0055] Figure 6 The ratio of Fe, Co, Mn, Ni and Zn sources is 15-20%, and the obtained Cu 20 M x(15＜x≤20) The copper-based high-entropy micro-nano alloy morphology is between 3-8μm in size, and the multi-level dendritic structure is conducive to reaction with PMS or complexation with pollutants to improve reaction activity.

[0056] Figure 7 、 Figure 8 、 Figure 9 The degradation performance of pure copper and different copper-based high-entropy micro-nano alloys at pH 4, 6, and 9, respectively, is shown. It can be seen that increasing the proportion of Fe, Co, Mn, Ni, and Zn sources significantly improves degradation performance. Although the degradation capacity of the reaction system decreases under alkaline conditions, the copper-based high-entropy micro-nano alloys still have good degradation capabilities for organic pollutants, demonstrating that the copper-based high-entropy micro-nano alloys prepared by this method can treat complex wastewater environments in real-world situations.

Claims

1. A method for preparing a copper-based high-entropy alloy Fenton-type catalyst based on a controllable electrodeposition method, characterized in that: The steps include: Step 1: Prepare electrodes; Cathode: Choose a pure copper electrode as the cathode. Polish it with sandpaper of different specifications to remove the metal burrs on the electrode surface. Then soak the electrode in 1mol / L hydrochloric acid + 0.1mol / L dilute sulfuric acid solution to remove the oxide layer on the metal surface. Finally, clean it with anhydrous ethanol. Anode: A graphite electrode is selected as the anode; soak the graphite electrode in a 30% HNO3 solution, remove it and clean it with a KOH-ethanol solution until it is neutral, use an ultrasonic cleaner with deionized water as the cleaning liquid, then soak it in deionized water and take it out to dry for later use; Step 2: Prepare copper sulfate / ferrous sulfate / cobalt sulfate / nickel sulfate / zinc sulfate / manganese sulfate electrolyte, and add complexing agent and hydrogen evolution inhibitor; 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ 、Mn 2+ The total ion concentration remains unchanged at 0.5-1.0 mol / L, and the element Cu 2+ The ratio of Fe is 20-40%, 2+ 、Co 2+ 、Ni 2+ 、Zn 2+ 、Mn 2+ The atomic ratio is 5% to 20%; The complexing agent includes one or two of sodium hexametapolyphosphate, citric acid, and sodium lauryl sulfate, with a total concentration of 10g to 80g / L; the hydrogen evolution inhibitor is one or more of ethanol, ethylene glycol, and glycerol, with a total concentration of 10 to 50mL / L; Step 3: Anion exchange membrane pretreatment; The negative ion exchange membrane is immersed in 80°C hydrogen peroxide with a mass fraction of 5%, and then immersed in deionized water; then immersed in 5% dilute sulfuric acid at 80°C to fully activate it, and then transferred to deionized water for immersion; before preparing the material, the pretreated negative ion exchange membrane is immersed in the electrolyte in step 2 for 0.5 to 2 hours; Step 4: Using the cathode and anode prepared in step 1 to make an electrodeposition device; The electrodeposition device is composed of an electrode cathode, an anode, a negative ion exchange membrane and a transparent quartz reaction tank base. The electrodeposition device is filled with electrolyte. The positive pole of the power supply is connected to the electrode anode, and the negative pole of the power supply is connected to the electrode cathode. The negative ion exchange membrane is immersed in the electrolyte. Step 5: Set the initial power supply voltage to 20V and react for 10 seconds; then reduce it to 0.5 times the initial voltage and react for another 10 seconds, and the copper-based high-entropy micro-nano alloy powder is deposited on the electrode cathode; Step 6: Collecting catalyst powder; The cathode was rinsed with anhydrous ethanol, and the rinse liquid containing the catalyst powder was collected. The catalyst was separated using a centrifuge, and finally washed with deionized water and ethanol three times, and dried at 65°C in a vacuum oven for 6 h.

2. The method for preparing a copper-based high entropy alloy Fenton-type catalyst based on a controllable electrodeposition method according to claim 1, characterized in that: The specific method for making the cathode and anode in step 1 is as follows: Cathode: A pure copper electrode with a length of 100 mm and a width of 50 mm was selected as the cathode. It was polished with 400, 800, and 1200 grit sandpaper in sequence to remove metal burrs on the electrode surface. The electrode was immersed in a 1 mol / L hydrochloric acid + 0.1 mol / L dilute sulfuric acid solution for 30 minutes to remove the oxide layer on the metal surface. Finally, it was cleaned with anhydrous ethanol. Anode: A graphite electrode with a length of 100 mm and a width of 50 mm was selected as the anode. The graphite electrode was soaked in a 30% HNO3 solution for 30 min, and then cleaned with a 0.1 mol / L KOH-ethanol solution until neutral. The electrode was ultrasonically cleaned with deionized water in an ultrasonic cleaning machine for 10 to 20 minutes, and then soaked in deionized water for 1 h, taken out and dried for later use.

3. The method for preparing a copper-based high-entropy alloy Fenton-type catalyst based on a controllable electrodeposition method according to claim 1, characterized in that: In step 3, the substrate is immersed in hydrogen peroxide for 1 hour, then immersed in deionized water for half an hour; and then immersed in 5% dilute sulfuric acid at 80° C. for half an hour.

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