Method for constructing ni-ldh film by oxygen non-thermal plasma and electrocatalytic oxygen evolution application thereof
By treating nickel-containing precursor films with oxygen nonthermal plasma, Ni-LDH thin film electrodes were directly constructed, solving the problem of structural collapse of Ni-LDH materials under high-temperature treatment. This enabled the preparation of stable and efficient Ni-LDH thin film electrodes at room temperature, improving electrocatalytic performance and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING INST OF TECH
- Filing Date
- 2026-04-17
- Publication Date
- 2026-07-24
AI Technical Summary
Existing methods for preparing Ni-LDH materials suffer from problems such as particle agglomeration, impurity introduction, insufficient crystallinity, and structural collapse caused by high-temperature treatment, making it difficult to provide stable and efficient OER electrode materials in industrial water electrolysis for hydrogen production.
Ni-LDH thin film electrodes were directly constructed by treating nickel-containing precursor films with oxygen nonthermal plasma at room temperature, avoiding high-temperature annealing and subsequent activation steps, and maintaining the integrity of the layered structure.
Ni-LDH films with porous lamellar morphology can be directly obtained at room temperature, which improves the electrocatalytic oxygen evolution reaction performance. They exhibit excellent electrocatalytic activity and stability, low overpotential, and small Tafel slope, making them suitable for large-area uniform film formation.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalytic materials and functional thin film preparation technology, specifically relating to a Ni-LDH thin film electrode that is in-situ constructed and its structural stability is simultaneously regulated by oxygen nonthermal plasma and its application in alkaline oxygen evolution reaction. Background Technology
[0002] The oxygen evolution reaction (OER) is a key anodic reaction in the electrolysis of water to produce hydrogen. Its multi-step electron transfer process is complex and kineticly slow, typically requiring highly efficient catalysts to reduce overpotential and increase the reaction rate. Ni-layered double hydroxide (Ni-LDH) materials are considered promising non-precious metal OER catalysts due to their low cost, suitability for alkaline water electrolysis and anion exchange membrane (AEM) systems, and the fact that their layered / nanostructure facilitates the exposure of active sites. Furthermore, LDH materials themselves possess a large specific surface area, strong ion exchange capacity, and porous structure, making them suitable for electrocatalysis applications.
[0003] Currently, the main methods for preparing Ni-LDH materials include co-precipitation, hydrothermal methods, mechanical synthesis, and electrochemical deposition. However, these methods generally suffer from the following problems: First, some methods are prone to particle agglomeration, impurity introduction, and insufficient crystallinity. Second, some methods are complex to operate, costly, and often more suitable for preparing powders rather than directly forming film electrodes. Although the sol-gel method can directly obtain film layers and has advantages such as adjustable composition, high uniformity, strong substrate applicability, and suitability for large-area film formation, the high-temperature treatment of thermal annealing can easily cause the layered structure to shrink or even collapse, requiring complex subsequent steps to re-obtain the LDH structure.
[0004] Furthermore, existing technologies typically require high-temperature annealing (>300 °C) and subsequent hydrothermal activation steps, resulting in complex processes, high energy consumption, and difficulties in maintaining the layered structure due to high-temperature treatment, thus affecting the electrocatalytic performance of the material. However, stable and efficient OER electrode materials are required in industrial water electrolysis for hydrogen production, a requirement that current technologies cannot meet. Therefore, there is an urgent need to develop a method for directly constructing Ni-LDH thin-film electrodes with a complete layered structure under low-temperature conditions.
[0005] Based on this, the present invention provides a method for in-situ construction of Ni-LDH thin film electrodes induced by oxygen nonthermal plasma. This method utilizes oxygen nonthermal plasma to treat nickel-containing precursor films at room temperature, directly converting them into Ni-LDH thin film electrodes with a layered double hydroxide structure, without the need for high-temperature annealing and subsequent activation steps. The present invention features a simple process, low energy consumption, and can directly obtain Ni-LDH thin films with porous lamellar morphology and open mass transfer channels, which is beneficial for improving the performance of the electrocatalytic oxygen evolution reaction. Summary of the Invention
[0006] In view of this, the purpose of this invention is to provide a method for in-situ construction of Ni-LDH thin film electrodes induced by oxygen nonthermal plasma and its application in alkaline oxygen evolution reaction. The method is simple, energy-efficient, and can directly obtain Ni-LDH thin film electrodes with a complete layered structure at room temperature.
[0007] To achieve the above objectives, the technical solution of the present invention is as follows.
[0008] A method for in-situ fabrication of Ni-LDH thin film electrodes induced by oxygen nonthermal plasma, the method comprising the following steps: Ethanolamine and acetylacetone were mixed with propionic acid, followed by the addition of a nickel source. A nickel-containing precursor solution was prepared under heating and stirring conditions. The nickel-containing precursor solution was aged, centrifuged, and the supernatant was used as a film-forming sol. The film-forming sol was spin-coated onto the substrate surface and air-dried to obtain a precursor film. The precursor film was placed in a microwave non-thermal plasma under an oxygen atmosphere to treat it, so that the precursor film was converted into a Ni-LDH thin film electrode in situ at room temperature.
[0009] Preferably, the nickel source is a common nickel-containing chemical, including one or more nickel acetate, nickel nitrate, etc.
[0010] Preferably, the molar ratio of ethanolamine to nickel source is 0.5:1 to 5:1.
[0011] Preferably, the molar ratio of acetylacetone to nickel source is 0:1 to 2:1.
[0012] Preferably, the nickel concentration in the nickel-containing precursor solution is 0.1~10 mol / L.
[0013] Preferably, the heating and stirring temperature is 40~100 ℃, and the stirring speed is 200~2000 rpm / min.
[0014] Preferably, the aging time is 12 to 72 hours.
[0015] Preferably, the centrifugation speed is 500~5000 rpm / min, the centrifugation time is 2~10 min, and the supernatant is used as the film-forming sol.
[0016] Preferably, the spin coating conditions are 2000~6000 rpm and 10~60 s.
[0017] Preferably, the precursor film thickness is 50~500 nm.
[0018] Preferably, before the microwave nonthermal plasma treatment, the reaction chamber is first evacuated to 500~1200 mTorr, then oxygen is introduced to 10~70 Torr, and the treatment is carried out at a power of 300~1500 W.
[0019] Preferably, the non-thermal plasma treatment time is 3~12 h, and the sample temperature during the treatment process does not exceed 50℃.
[0020] Preferably, the substrate is a conductive substrate or a characterizing substrate, including one or more of nickel substrates, silicon wafers, KBr wafers, carbon paper, titanium wafers, and stainless steel wafers. Beneficial effects
[0021] Compared with the prior art, the present invention has at least the following advantages: (1) This invention provides a method for in-situ construction of Ni-LDH thin film electrodes induced by oxygen nonthermal plasma, which can directly obtain Ni-LDH thin films with layered double hydroxide structures at room temperature without high-temperature annealing and subsequent hydrothermal activation steps, thus simplifying the process and reducing energy consumption.
[0022] (2) The thin film obtained by the present invention has a layered double hydroxide structure of interlayer anions and water molecules, which is different from the general dense nickel oxide thin film and is beneficial to improving electrocatalytic activity.
[0023] (3) The Ni-LDH film obtained in this invention exhibits excellent electrocatalytic activity and stability in alkaline oxygen evolution reaction, with an overpotential of less than 350 mV and a Tafel slope of less than 80 mV / dec at a current density of 10 mA / cm².
[0024] (4) The process parameters of the present invention are adjustable, applicable to different substrates, and can achieve large-area uniform film formation, which has good prospects for industrial application. Attached Figure Description
[0025] Figure 1 The images show the XRD crystal structures of the Ni-LDH films prepared in different embodiments.
[0026] Figure 2 The images show the FTIR infrared absorption spectra of the Ni-LDH films prepared in different embodiments. Detailed Implementation
[0027] The following detailed description, in conjunction with embodiments, illustrates a method for constructing Ni-LDH thin films using oxygen-nonthermal plasma induction and its application in electrocatalytic oxygen evolution. However, these descriptions should not be construed as limiting the scope of protection of this invention. Clearly, the described embodiments are only a portion of the embodiments of this invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the scope of protection of this invention.
[0028] Unless otherwise specified, all raw materials used in the embodiments of the present invention are commercially available or obtainable by those skilled in the art; unless otherwise specified, all methods used in the embodiments of the present invention are methods mastered by those skilled in the art. Example 1
[0029] A method for constructing Ni-LDH thin films induced by oxygen nonthermal plasma, comprising the following specific steps: Step 1: Prepare a nickel-containing precursor solution by mixing 15 mL of propionic acid with 0.3 mL of ethanolamine and stirring magnetically for 5 minutes. Then add 2.49 g of nickel acetate tetrahydrate and stir in an oil bath at 60 °C for 2 hours to obtain a light green clear sol. Step 2: Let the sol stand for 24 hours, centrifuge at 5000 rpm for 5 minutes, and take the supernatant for later use; Step 3: Clean the high-purity nickel sheet sequentially with acetone, ethanol, deionized water, 1 mol / L hydrochloric acid, deionized water, and ethanol using ultrasonic cleaning for 5 minutes, then dry it and clean it with argon plasma (750 W, 3 Torr, 7 minutes). Step 4: Spin coat the sol at 4000 rpm for 30 seconds, and let it dry and cure at room temperature for 12 hours to obtain a precursor film with a thickness of about 200 nm. Step 5: The precursor film is treated in microwave non-thermal plasma. First, the reaction chamber is evacuated to 700 mTorr, then oxygen is introduced to 50 Torr, and the film is treated at 750 W power for 6 hours (sample temperature ≤35 ℃) to obtain Ni-LDH thin film electrode. Step 6: The obtained Ni-LDH thin film electrode was subjected to electrochemical testing in 1M KOH electrolyte. The results showed that the overpotential was 342 mV at a current density of 10 mA / cm², and 435 mV at a current density of 100 mA / cm². The Tafel slope was 76.3 mV / dec, and the current only decreased by 35.1% after 50 hours at an overpotential of 500 mV. Example 2
[0030] A method for constructing Ni-LDH thin films induced by oxygen nonthermal plasma, comprising the following specific steps: Step 1: Prepare a nickel-containing precursor solution by mixing 15 mL of propionic acid with 0.3 mL of ethanolamine and stirring magnetically for 5 minutes. Then add 2.49 g of nickel acetate tetrahydrate and stir in an oil bath at 60 °C for 2 hours to obtain a light green clear sol. Step 2: Let the sol stand for 24 hours, centrifuge at 5000 rpm for 5 minutes, and take the supernatant for later use; Step 3: Clean the high-purity nickel sheet sequentially with acetone, ethanol, deionized water, 1 mol / L hydrochloric acid, deionized water, and ethanol using ultrasonic cleaning for 5 minutes, then dry it and clean it with argon plasma (750 W, 3 Torr, 7 minutes). Step 4: Spin coat the sol at 4000 rpm for 30 seconds, and let it dry and cure at room temperature for 12 hours to obtain a precursor film with a thickness of about 200 nm. Step 5: The precursor film is treated in microwave non-thermal plasma. First, the reaction chamber is evacuated to 700 mTorr, then oxygen is introduced to 50 Torr, and the film is treated at 750 W power for 9 hours (sample temperature ≤35 ℃) to obtain Ni-LDH thin film electrode. Step 6: The obtained Ni-LDH thin film electrode was subjected to electrochemical testing in 1M KOH electrolyte. The results showed that the overpotential was 335 mV at a current density of 10 mA / cm² and 430 mV at a current density of 100 mA / cm². The Tafel slope was 75.2 mV / dec. At an overpotential of 500 mV, the current only decreased by 33.2% after 50 hours. Example 3
[0031] A method for constructing Ni-LDH thin films induced by oxygen nonthermal plasma, comprising the following specific steps: Step 1: Prepare a nickel-containing precursor solution by mixing 15 mL of propionic acid with 0.3 mL of ethanolamine and 0.5 mL of acetylacetone, stirring magnetically for 5 minutes, adding 2.49 g of nickel acetate tetrahydrate, and stirring in an oil bath at 60 °C for 2 hours to obtain a light green clear sol. Step 2: Let the sol stand for 24 hours, centrifuge at 5000 rpm for 5 minutes, and take the supernatant for later use; Step 3: Clean the high-purity nickel sheet sequentially with acetone, ethanol, deionized water, 1 mol / L hydrochloric acid, deionized water, and ethanol using ultrasonic cleaning for 5 minutes, then dry it and clean it with argon plasma (750 W, 3 Torr, 7 minutes). Step 4: Spin coat the sol at 4000 rpm for 30 seconds, and let it dry and cure at room temperature for 12 hours to obtain a precursor film with a thickness of about 200 nm. Step 5: The precursor film is treated in microwave non-thermal plasma. First, the reaction chamber is evacuated to 700 mTorr, then oxygen is introduced to 50 Torr, and the film is treated at 750 W power for 9 hours (sample temperature ≤35 ℃) to obtain Ni-LDH thin film electrode. Step 6: The obtained Ni-LDH thin film electrode was subjected to electrochemical testing in 1M KOH electrolyte. The results showed that the overpotential was 320 mV at a current density of 10 mA / cm², and 389 mV at a current density of 100 mA / cm². The Tafel slope was 74 mV / dec. At an overpotential of 500 mV, the current only decreased by 32.7% after 50 hours. Example 4
[0032] A method for constructing Ni-LDH thin films induced by oxygen nonthermal plasma, comprising the following specific steps: Step 1: Prepare a nickel-containing precursor solution by mixing 15 mL of propionic acid with 0.3 mL of ethanolamine and 0.5 mL of acetylacetone, stirring magnetically for 5 minutes, adding 2.91 g of nickel nitrate, and stirring in an oil bath at 60 °C for 2 hours to obtain a light green clear sol. Step 2: Let the sol stand for 24 hours, centrifuge at 5000 rpm for 5 minutes, and take the supernatant for later use; Step 3: Clean the high-purity nickel sheet sequentially with acetone, ethanol, deionized water, 1 mol / L hydrochloric acid, deionized water, and ethanol using ultrasonic cleaning for 5 minutes, then dry it and clean it with argon plasma (750 W, 3 Torr, 7 minutes). Step 4: Spin coat the sol at 4000 rpm for 30 seconds, and let it dry and cure at room temperature for 12 hours to obtain a precursor film with a thickness of about 200 nm. Step 5: The precursor film is treated in microwave non-thermal plasma. First, the reaction chamber is evacuated to 700 mTorr, then oxygen is introduced to 50 Torr, and the film is treated at 750 W power for 9 hours (sample temperature ≤35 ℃) to obtain Ni-LDH thin film electrode. Step 6: The obtained Ni-LDH thin film electrode was subjected to electrochemical testing in 1M KOH electrolyte. The results showed that the overpotential was 311 mV at a current density of 10 mA / cm², and 394 mV at a current density of 100 mA / cm². The Tafel slope was 79.2 mV / dec, and the current only decreased by 28.4% after 500 mV overpotential for 50 hours.
[0033] In this invention, the prepared Ni-LDH thin film electrode exhibited a layered characteristic peak at 12.6 ° (interlayer spacing 6.3-8.9 Å) by XRD characterization, confirming the Ni-LDH structure; FTIR characterization showed an 833 cm⁻¹ peak.-1 (interlayer CO3) 2- ), 1632 cm -1 Characteristic absorption peaks, such as those indicating interlayer water, were observed. These characterization results collectively confirm that the present invention successfully prepared a Ni-LDH thin film electrode with a complete layered structure.
[0034] In summary, the invention includes, but is not limited to, the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.
Claims
1. A method for preparing a Ni-LDH thin film electrode, characterized in that: The method steps include: A nickel-containing precursor film-forming solution is prepared and loaded onto the substrate surface to form a precursor layer; subsequently, the precursor layer is subjected to non-thermal plasma treatment in an oxygen-containing atmosphere to convert the precursor layer into a Ni-LDH thin film electrode in situ.
2. The method for preparing a Ni-LDH thin film electrode as described in claim 1, characterized in that: The nickel source is one or more of nickel acetate and nickel nitrate.
3. The method for preparing a Ni-LDH thin film electrode as described in claim 1, characterized in that: The nickel-containing precursor film-forming solution is prepared by mixing a nickel source with a complexing agent and a solvent.
4. The preparation method according to any one of claims 1 to 3, characterized in that: The precursor layer is formed on the substrate surface by spin coating, spraying, dip coating, blade coating, printing, or a combination thereof.
5. The preparation method according to any one of claims 1 to 4, characterized in that: The non-thermal plasma is microwave plasma, dielectric barrier discharge plasma, radio frequency plasma, glow discharge plasma, or a combination thereof; the oxygen-containing atmosphere includes oxygen, air, or an oxygen-containing mixture.
6. The preparation method according to any one of claims 1 to 5, characterized in that: The substrate is a conductive substrate or a characterizing substrate, including one or more of nickel substrates, silicon wafers, KBr wafers, carbon paper, titanium wafers, and stainless steel wafers.
7. A Ni-LDH thin film electrode, characterized in that: The Ni-LDH thin film electrode is prepared by the preparation method according to any one of claims 1 to 6, and the thin film has a layered double hydroxide structure containing Ni. 2+ and Ni 3+ It has a mixed valence state and contains interlayer anions and water molecules.
8. The application of the Ni-LDH thin film electrode as described in claim 7 in the alkaline oxygen evolution reaction, characterized in that, In 1.0 M KOH electrolyte, 10 mA / cm 2 The overpotential at current density is less than 350 mV, the Tafel slope is less than 80 mV / dec, and the current decay is less than 35% after continuous operation for 50 hours at an overpotential of 500 mV.