A method for preparing a composite electrocatalyst composed of Ni3Se2 and CoFe-based metal-organic frameworks and its application in the electrocatalytic oxygen evolution reaction.
The preparation of CF-MOF@Ni3Se2 electrocatalysts by combining CoFe-based MOF with Ni3Se2 has solved the problems of low conductivity and low utilization of active sites, achieving OER performance with low overpotential and high current density, which has important prospects for scientific research and industrial application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANKAI UNIV
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-31
AI Technical Summary
Existing CoFe-based MOF materials suffer from low conductivity and low utilization of active sites in the electrocatalytic oxygen evolution reaction, leading to increased overpotential. Furthermore, when combined with Ni3Se2, the interface is prone to desorption or physical stacking, hindering electron transport.
A CF-MOF@Ni3Se2 electrocatalyst was prepared by combining CoFe-based MOF with Ni3Se2. The electron transport efficiency and active site utilization were improved by utilizing the electronic interaction and synergistic catalytic mechanism between the two.
It significantly reduced the overpotential of the oxygen evolution reaction (OER) and improved the OER performance of the catalyst in alkaline media, exhibiting excellent electrocatalytic activity and stability.
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Figure CN122484841A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nanomaterial preparation and new energy electrochemical technology, specifically involving a method for preparing a Ni3Se2 and CoFe-based metal-organic framework composite electrocatalyst and its application in the electrocatalytic oxygen evolution reaction. Background Technology
[0002] Hydrogen energy, as an ideal green energy source with high energy density, combustion products consisting only of water, and no carbon emissions, is considered a core carrier for future energy structure transformation. Among numerous hydrogen production technologies, electrochemical water splitting is regarded as one of the most promising approaches to achieving large-scale industrial hydrogen production due to its simple process, high product purity, and ability to be coupled with intermittent renewable energy sources such as wind and solar power.
[0003] The electrochemical water splitting process consists of two half-reactions: the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. The anode OER is a complex process involving four-electron-proton coupling transfer, accompanied by the formation and transformation of multiple adsorption intermediates (such as *OH, *O, and *OOH). Compared to the two-electron transfer-based HER, the reaction kinetics of OER are extremely slow, requiring a large overpotential to drive the reaction in actual electrolysis. This not only significantly increases energy consumption but also severely limits the overall energy conversion efficiency of the water electrolysis device. Therefore, developing OER electrocatalysts with low overpotential, high current density, and long-term stability is crucial for promoting the industrialization of hydrogen energy.
[0004] Metal-organic frameworks (MOFs) are porous materials assembled from metal nodes and organic ligands, and are considered promising OER catalysts due to their unique structural advantages. CoFe-based MOFs, in particular, exhibit excellent intrinsic catalytic activity due to the synergistic electronic effect between Co and Fe metal nodes. Furthermore, MOFs possess ultra-high specific surface area, long-range ordered pore structure, and atomically dispersed metal active centers. This porous structure greatly promotes electrolyte wetting and rapid mass transfer and release of gaseous products, avoiding the shielding effect of bubble accumulation on the electrode surface. However, the inherent low conductivity of MOFs is a major drawback, severely hindering electron transport within the catalyst layer, resulting in low utilization of active sites and a sharp increase in overpotential under high current. To improve the conductivity and catalytic activity of MOFs, conventional methods include adding carbon-based conductive agents such as carbon black and graphene. While this improves conductivity, carbon materials themselves have low catalytic activity for OER, and due to large density differences, the distribution of active materials is prone to unevenness.
[0005] In contrast, transition metal selenium compounds (such as Ni3Se2) exhibit near-metallic conductivity due to their smaller band gap and stronger metallic properties. More importantly, Ni3Se2 itself is also a relatively active OER catalyst with resistance to oxidation and corrosion. If highly active CoFe-based MOFs can be effectively combined with highly conductive Ni3Se2 to construct a composite catalyst possessing both fast electron transport channels and abundant active sites, it is expected to overcome the performance bottlenecks of existing MOF-based catalysts, possessing significant scientific research value and promising industrial application prospects. However, the large differences in crystal structure and surface energy between MOFs and Ni3Se2 easily lead to interfacial desorption or physical stacking, resulting in hindered electron transport. Therefore, the composite method needs to be optimized to improve charge transfer efficiency. Summary of the Invention
[0006] To address the shortcomings and deficiencies of existing technologies, this invention synthesizes a highly active alkaline OER electrocatalyst CF-MOF@Ni3Se2 by combining CoFe-based MOF with Ni3Se2.
[0007] The primary objective of this invention is to provide a highly active alkaline OER electrocatalyst CF-MOF@Ni3Se2 synthesized by combining CoFe-based MOF with Ni3Se2.
[0008] The CoFe-based MOF is a cobalt-nickel-based metal-organic framework, which forms a layered pillar MOF structure by cobalt and iron atoms coordinating with terephthalic acid (BDC) organic ligands.
[0009] The Ni3Se2 is obtained by selenization of Ni(OH)2.
[0010] The second objective of this invention is to provide a method for preparing a composite electrocatalyst containing both CoFe-based MOF and Ni3Se2 components, comprising the following steps:
[0011] 1) Synthesis of Ni(OH)2:
[0012] Nickel salt, urea and ammonium fluoride were dissolved in deionized water. The solution and nickel foam were then transferred to a reaction vessel and reacted under certain conditions. The mixture was then cooled to room temperature, rinsed with deionized water and ethanol in sequence, and then dried in a vacuum oven at 60 °C to obtain Ni(OH)2.
[0013] 2) Synthesis of Ni3Se2:
[0014] Sodium selenite was dissolved in 15 mL of deionized water, and hydrazine hydrate was added dropwise to the solution. Then, the above solution and Ni(OH)2 were transferred to a reaction vessel. After reacting under certain conditions, the mixture was cooled to room temperature, rinsed with deionized water and ethanol in sequence, and then dried in a vacuum oven at 60 °C to obtain Ni3Se2.
[0015] 3) Synthesis of CF-MOF@Ni3Se2:
[0016] Iron salt, cobalt salt, and terephthalic acid were dissolved in a mixed solvent containing DMF, ethanol, and deionized water. The solution and Ni3Se2 were then transferred to a reaction vessel and reacted under certain conditions. After cooling to room temperature, the mixture was washed sequentially with DMF, deionized water, and ethanol, and then dried in a vacuum oven at 60 °C to obtain CF-MOF@Ni3Se2.
[0017] Preferably, in step 1) of the present invention, the nickel salt is nickel nitrate hexahydrate, the amount of nickel nitrate hexahydrate is 0.262 mg and 0.9 mmol, the amount of urea is 0.270 mg and 4.5 mmol, the amount of ammonium fluoride is 0.083 mg and 2.2 mmol, the amount of deionized water is 18 mL, and the reaction conditions are 120 °C for 12 hours.
[0018] Preferably, in step 2) of the present invention, the amount of sodium selenite is 0.1 g and 0.58 mmol, the amount of deionized water is 15 mL, the amount of hydrazine hydrate added is 1 mL, and the reaction conditions are 120 °C for 12 hours.
[0019] Preferably, in step 3) of the present invention, the iron salt is ferric chloride hexahydrate, the cobalt salt is cobalt chloride hexahydrate, the amount of ferric chloride hexahydrate is 0.136 mg and 0.5 mmol, the amount of cobalt chloride hexahydrate is 0.118 mg and 0.5 mmol, and the amount of terephthalic acid is 0.250 mg and 1.5 mmol; the amount of DMF in the mixed solvent is 15 mL, the amount of ethanol is 0.9 mL, and the amount of deionized water is 0.9 mL; the reaction conditions are 130 °C for 12 hours.
[0020] A third objective of this invention is to provide the use of the electrocatalyst described in the first objective as an anode material in the oxygen evolution reaction in an alkaline electrolyte system. The composite electrocatalyst prepared by the method of this invention has excellent oxygen evolution activity and exhibits a low oxygen evolution overpotential in an alkaline electrolyte.
[0021] The fourth objective of this invention is to provide a method for alkaline water electrolysis, wherein the method uses the electrocatalyst provided by this invention as the anode oxygen evolution catalyst. The electrolyte is 1 M KOH.
[0022] Advantages of this invention:
[0023] This invention discloses a highly active alkaline OER electrocatalyst (CF-MOF@Ni3Se2) and its preparation method. The catalyst is based on a composite of a CoFe-based metal-organic framework (MOF) and Ni3Se2. This catalyst significantly lowers the reaction energy barrier by utilizing the electronic interactions and synergistic catalytic mechanism between the two phases, exhibiting excellent OER performance in alkaline media. This work lays the technical foundation for the development of novel, highly efficient non-noble metal OER catalysts. Attached Figure Description
[0024] Figure 1 The X-ray powder diffraction patterns of Ni3Se2, CF-MOF, and CF-MOF@Ni3Se2 in Example 1 are shown.
[0025] Figure 2 The images shown are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of Ni3Se2 from Example 1.
[0026] Figure 3 The images shown are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of the CF-MOF in Example 1.
[0027] Figure 4 The images shown are scanning electron microscope (SEM) and transmission electron microscope (TEM) images of CF-MOF@Ni3Se2 in Example 1.
[0028] Figure 5 The OER polarization curves of Ni(OH)2, Ni3Se2, CF-MOF and CF-MOF@Ni3Se2 in 1 M KOH are shown in Example 1. Detailed Implementation
[0029] The present invention will be further described below with reference to specific embodiments.
[0030] This invention provides a method for preparing an alkaline OER electrocatalyst that combines CoFe-based MOF and Ni3Se2. The method involves dissolving nickel salt, urea, and ammonium fluoride in deionized water, and then reacting the above solution with nickel foam in a reactor to obtain Ni(OH)2. Subsequently, sodium selenite is dissolved in deionized water, and hydrazine hydrate is added. The above solution and Ni(OH)2 are then reacted in a reactor to obtain Ni3Se2. Finally, cobalt salt and iron salt are dissolved in a mixed solution of N,N-dimethylformamide (DMF), ethanol, and deionized water. The above solution and Ni3Se2 are then reacted in a reactor to obtain CF-MOF@Ni3Se2.
[0031] In an embodiment of the present invention, the nickel salt is selected from nickel nitrate hexahydrate.
[0032] In an embodiment of the present invention, the cobalt salt is selected from cobalt chloride hexahydrate.
[0033] In an embodiment of the present invention, the iron salt is selected from ferric chloride hexahydrate.
[0034] In an embodiment of the present invention, the reaction temperature for synthesizing Ni(OH)2 is 120 °C and the reaction time is 12 h.
[0035] In an embodiment of the present invention, the reaction temperature for synthesizing Ni3Se2 is 120 °C and the reaction time is 12 h.
[0036] In an embodiment of the present invention, the reaction temperature for synthesizing CF-MOF@Ni3Se2 is 130 °C and the reaction time is 12 h.
[0037] In an embodiment of the present invention, the volume of the reaction vessel is 25 mL.
[0038] Example 1
[0039] The preparation method of a highly active alkaline OER electrocatalyst (CF-MOF@Ni3Se2) synthesized by combining CoFe-based MOF with Ni3Se2 includes the following steps:
[0040] 1) Nickel foam pretreatment:
[0041] Cut the nickel foam into 1 × 3 cm pieces. 2 Then, it was placed in 1 M HCl, deionized water, and anhydrous ethanol in sequence and sonicated for 20 minutes, followed by drying in a 60 ℃ vacuum oven.
[0042] 2) Synthesis of Ni(OH)2:
[0043] Nickel nitrate hexahydrate (0.262 mg, 0.9 mmol), urea (0.270 mg, 4.5 mmol), and ammonium fluoride (0.083 mg, 2.2 mmol) were dissolved in 18 mL of deionized water. The solution and nickel foam were then transferred to a 25 mL reaction vessel and placed in an oven at 120 °C for 12 hours. After cooling to room temperature, the mixture was washed with deionized water and ethanol, and then dried in a vacuum oven at 60 °C to obtain Ni(OH)2.
[0044] 3) Synthesis of Ni3Se2:
[0045] Sodium selenite (0.1 g, 0.58 mmol) was dissolved in 15 mL of deionized water. 1 mL of hydrazine hydrate was added dropwise to the solution. The solution and Ni(OH)2 were then transferred to a 25 mL reactor and placed in an oven at 120 °C for 12 hours. After cooling to room temperature, the mixture was washed with deionized water and ethanol, and then dried in a vacuum oven at 60 °C to obtain Ni3Se2.
[0046] 4) Synthesis of CF-MOF:
[0047] Ferric chloride hexahydrate (0.136 mg, 0.5 mmol), cobalt chloride hexahydrate (0.118 mg, 0.5 mmol), and terephthalic acid (0.250 mg, 1.5 mmol) were dissolved in a mixed solvent containing DMF (15 mL), ethanol (0.9 mL), and deionized water (0.9 mL). The solution and nickel foam were then transferred to a 25 mL reaction vessel and reacted in an oven at 130 °C for 12 hours. After cooling to room temperature, the mixture was washed sequentially with DMF, deionized water, and ethanol, and then dried in a vacuum oven at 60 °C to obtain CF-MOF.
[0048] 5) Synthesis of CF-MOF@Ni3Se2:
[0049] Ferric chloride hexahydrate (0.136 mg, 0.5 mmol), cobalt chloride hexahydrate (0.118 mg, 0.5 mmol), and terephthalic acid (0.250 mg, 1.5 mmol) were dissolved in a mixed solvent containing DMF (15 mL), ethanol (0.9 mL), and deionized water (0.9 mL). The solution and Ni3Se2 were then transferred to a 25 mL reaction vessel and reacted in an oven at 130 °C for 12 hours. After cooling to room temperature, the mixture was washed sequentially with DMF, deionized water, and ethanol, and then dried in a vacuum oven at 60 °C to obtain CF-MOF.
[0050] Figure 1 The X-ray powder diffraction patterns of Ni3Se2, CF-MOF, and CF-MOF@Ni3Se2 show that the successful composite of Ni3Se2 and CF-MOF was achieved in CF-MOF@Ni3Se2.
[0051] Figure 2 The scanning electron microscope and transmission electron microscope images of Ni3Se2 show that Ni3Se2 has a rough, lamellar structure.
[0052] Figure 3 The scanning and transmission electron microscopy images of CF-MOF show that CF-MOF has a layered stacked structure.
[0053] Figure 4 The scanning electron microscope (SEM) and transmission electron microscope (TEM) images of CF-MOF@Ni3Se2 verify the successful composite of Ni3Se2 and CF-MOF phases.
[0054] Application Example 1
[0055] Application of CF-MOF@Ni3Se2 electrode as anode material in oxygen evolution reaction in alkaline electrolyte:
[0056] The hydrogen evolution performance (OER) of CF-MOF@Ni3Se2 in alkaline electrolyte was tested using a three-electrode system. A platinum sheet was used as the counter electrode, a silver / silver chloride electrode as the reference electrode, and the working electrodes were Ni(OH)2, Ni3Se2, CF-MOF, and CF-MOF@Ni3Se2 obtained in Example 1. The test was conducted in 1 M KOH, and the resulting OER polarization curves are shown below. Figure 5 As shown, CF-MOF@Ni3Se2 exhibits excellent OER performance, reaching 300 mA cm⁻¹. -2 The overpotential required for the current density is only 250 mV, which is significantly better than that of the single-component catalysts Ni(OH)2, Ni3Se2 and CF-MOF.
[0057] The above embodiments are merely illustrative examples of the implementation of the present invention and are not intended to limit the present invention in any other way. Any simple modifications, substitutions, equivalent changes and modifications made without departing from the design and construction principles and spirit of the present invention are included within the protection scope of the present invention.
Claims
1. A method for preparing an alkaline OER electrocatalyst composed of CoFe-based MOF and Ni3Se2, comprising the following steps: 1) Synthesis of Ni(OH)2: Nickel salt, urea and ammonium fluoride were dissolved in deionized water. The solution and nickel foam were then transferred to a reaction vessel and reacted under certain conditions. The mixture was then cooled to room temperature, rinsed with deionized water and ethanol in sequence, and then dried in a vacuum oven at 60 °C to obtain Ni(OH)2. 2) Synthesis of Ni3Se2: Sodium selenite was dissolved in 15 mL of deionized water, and hydrazine hydrate was added dropwise to the solution. Then, the above solution and Ni(OH)2 were transferred to a reaction vessel. After reacting under certain conditions, the mixture was cooled to room temperature, rinsed with deionized water and ethanol in sequence, and then dried in a vacuum oven at 60 °C to obtain Ni3Se2. 3) Synthesis of CF-MOF@Ni3Se2: Iron salt, cobalt salt, and terephthalic acid were dissolved in a mixed solvent containing DMF, ethanol, and deionized water. The solution and Ni3Se2 were then transferred to a reaction vessel and reacted under certain conditions. After cooling to room temperature, the mixture was washed sequentially with DMF, deionized water, and ethanol, and then dried in a vacuum oven at 60 °C to obtain CF-MOF@Ni3Se2.
2. The method for preparing the alkaline OER electrocatalyst combining CoFe-based MOF and Ni3Se2 as described in claim 1, characterized in that, In step 1), the nickel salt is nickel nitrate hexahydrate, with the amounts of nickel nitrate hexahydrate being 0.262 mg and 0.9 mmol, urea being 0.270 mg and 4.5 mmol, and ammonium fluoride being 0.083 mg and 2.2 mmol; the amount of deionized water is 18 mL; and the reaction conditions are 120 °C for 12 hours.
3. The method for preparing the alkaline OER electrocatalyst combining CoFe-based MOF and Ni3Se2 as described in claim 1, characterized in that, In step 2), the amount of sodium selenite used is 0.1 g and 0.58 mmol, the amount of deionized water is 15 mL, the amount of hydrazine hydrate added is 1 mL, and the reaction conditions are 120 °C for 12 hours.
4. The method for preparing the alkaline OER electrocatalyst combining CoFe-based MOF and Ni3Se2 as described in claim 1, characterized in that, In step 3), the iron salt is ferric chloride hexahydrate, the cobalt salt is cobalt chloride hexahydrate, the amount of ferric chloride hexahydrate is 0.136 mg and 0.5 mmol, the amount of cobalt chloride hexahydrate is 0.118 mg and 0.5 mmol, and the amount of terephthalic acid is 0.250 mg and 1.5 mmol; the amount of DMF in the mixed solvent is 15 mL, the amount of ethanol is 0.9 mL, and the amount of deionized water is 0.9 mL; the reaction conditions are 130 ℃ for 12 hours.
5. A basic OER electrocatalyst that combines CoFe-based MOF and Ni3Se2, characterized in that: it is The method described in any one of claims 1-4 is used to prepare MOFs formed by cobalt and iron atoms coordinating with organic ligands of terephthalic acid and then combining them with sheet-like Ni3Se2.
6. The application of the alkaline OER electrocatalyst of claim 5, which combines CoFe-based MOF and Ni3Se2, in the electrocatalytic oxygen evolution reaction.
7. A method for alkaline electrolysis of water, characterized in that, The electrocatalyst described in claim 5 is used as the anode oxygen evolution catalyst.