Preparation method and application of ferronickel phosphide coated nickel telluride nanorod material

Abstract

The invention discloses a preparation method and application of a nickel telluride nanorod material coated with ferronickel phosphide. The preparation method comprises the following steps: firstly, growing a ferro-nickel metal organic framework material MOF-74 (Ni, Fe) on the surface of a nickel telluride nanorod array in situ through a solvothermal method; then, the MOF-74 (Ni, Fe) is converted into nickel iron phosphide (NiFeP) particles in situ by utilizing a vapor deposition technology, so that a core-shell heterostructure (NiTe / NiFeP / NF) is formed. A built-in electric field effect is generated by a rich interface between NiTe and NiFeP, so that excellent chlorine corrosion resistance and rich contactable active sites are considered, and high activity and super durability required by direct seawater electrolysis are realized. When the prepared nickel telluride nanorod array material coated with the ferronickel phosphide particles is used for seawater electrolysis oxygen evolution reaction, the electrocatalyst shows excellent catalytic activity (low overpotential) and excellent long-term electrolysis stability.

Description

Technical Field

[0001] This invention belongs to the field of new energy material synthesis and electrochemical technology, specifically relating to a method for preparing nickel iron phosphide coated nickel telluride nanorods and their applications. Background Technology

[0002] The production of green hydrogen through water electrolysis using renewable energy has attracted widespread attention. Seawater electrolysis, as a sustainable technology, can simultaneously alleviate freshwater shortages and the energy crisis. However, seawater contains high concentrations (approximately 0.5 mol / L) of chloride ions (Cl). - This significantly reduces the performance of electrocatalysts, posing a serious challenge to the oxygen evolution reaction (OER) at the anode. The root cause lies in Cl... - The active sites of catalysts can be poisoned through surface adsorption or coordination, which can severely reduce the durability of materials and thus greatly restrict the practical application of this technology.

[0003] To alleviate Cl - Corrosion caused by this process is primarily addressed by adding a surface protective layer to the catalyst's outer surface, including solid-phase protective coatings (such as CeO2, MnO). x , Cr(OH)3, Cr2O3) or Cl - Repulsive oxygen anions (such as PO4) 3- SO4 2- 、NO3 - and CO3 2- (etc.). However, these methods still have significant limitations in terms of activity or stability: dense protective coatings may block active sites due to physical coverage, reducing OER activity; oxygen anions are rapidly lost under industrial-grade high current densities due to vigorous bubble formation and electrolyte scouring. Therefore, the activity and resistance to Cl- in catalysts currently used in the electrocatalytic seawater electrochemical oxygen release reaction are crucial. - Its corrosion resistance is limited. For example, in patent document CN202210986687.5, a CeO2@NiFe-LDH / NF core-shell structure catalyst was constructed by electrodepositing a dense layer of CeO2 nanoparticles on the surface of NiFe-LDH. However, this dense CeO2 coating significantly hinders the mass transfer process and shields some active sites, resulting in a corrosion resistance of 100 mA cm⁻¹ in 1M KOH seawater. -2 The required overpotential for this current density is relatively high (~300mV). For example, in patent document CN202510085889.6, CO3 is used. 2- Anion-modified CoMoO4 / Co3O4 heterojunctions were used as oxygen evolution catalysts. However, CO3... 2- Anion modification of Cl - The repulsive effect is limited, resulting in the material's resistance to Cl in 1M KOH seawater. -Insufficient corrosion resistance, at 100mA cm -2 Stability can only be maintained for about 30 hours at current density. In summary, the design possesses excellent resistance to Cl... - Electrocatalysts with strong corrosion resistance, high intrinsic activity, and ultra-long-term stability to meet the stringent requirements of industrial-scale seawater electrolysis have become a key challenge that urgently needs to be overcome in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing nickel iron phosphide coated nickel telluride nanorods and their application, so as to solve the problem of poor stability of existing electrolyzed seawater mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a method for preparing nickel iron phosphide-coated nickel telluride nanorods, characterized by comprising the following steps:

[0006] S1. 2,5-Dihydroxyterephthalic acid, nickel metal salt, iron metal salt, N,N-dimethylformamide and nickel telluride nanorod array are mixed in a beaker and stirred at room temperature to obtain a mixed solution. The solution is then placed in the lining of a reaction vessel and heated. After the reaction vessel cools and stands, the foamed nickel is removed, washed with ethanol and vacuum dried to obtain NiTe / MOF-74(Ni,Fe) / NF material.

[0007] S2. The NiTe / MOF-74(Ni,Fe) / NF material obtained in step S1 and sodium hypophosphite are separately packed into two quartz boats and then placed in a tube furnace for heating. After cooling, NiTe / NiFeP / NF is obtained.

[0008] In one specific embodiment, the nickel metal salt in step S1 is one of nickel sulfate, nickel nitrate, and nickel acetate, and the iron metal salt is one of ferric sulfate, ferric nitrate, and ferric acetate.

[0009] In one specific embodiment, the molar ratio of nickel metal salt to iron metal salt in step S1 is 0.3 to 3:1.

[0010] In one specific embodiment, the heating temperature in step S1 is 100-140°C, and the heating time is 12-36 hours.

[0011] In one specific embodiment, the heating temperature in step S2 is 300-350°C, and the heating time is 1-3 hours.

[0012] The present invention also provides a nickel iron phosphide coated nickel telluride nanorod material, wherein the nickel iron phosphide coated nickel telluride nanorod material is prepared by the aforementioned preparation method of nickel iron phosphide coated nickel telluride nanorod material.

[0013] The present invention also provides an application of nickel iron phosphide coated nickel telluride nanorod material, which is used in the electrolysis of seawater.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] Unlike traditional protective layer strategies, this invention proposes a reverse design that loads catalyst particles onto NiTe nanorods, effectively avoiding the shielding effect of traditional coatings on active sites. Furthermore, it utilizes the built-in electric field formed at the NiTe / NiFeP heterojunction interface to achieve Cl-resistance. - Corrosion resistance was achieved, resulting in ultra-low overpotential and long-term stability in alkaline real seawater.

[0016] The catalyst prepared by this invention features uniform morphology and enrichment of active components in the outer layer. Its well-defined nanorod structure directly provides fully exposed active sites and efficient mass transfer channels. The abundant interface between NiTe and NiFeP generates a built-in electric field effect, enabling it to also exhibit excellent resistance to Cl. - Corrosion resistance and catalytic activity.

[0017] The electrocatalytic material of this invention achieves superior oxygen evolution performance in alkaline real seawater and significantly improves its operational stability under high current density.

[0018] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The present invention will now be described in further detail. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 These are the X-ray diffraction (XRD) patterns of the 1#NiTe / NiFeP / NF material prepared in Example 1 of the present invention and the 3#NiTe / NiFeP / NF material prepared in Example 3.

[0021] Figure 2 This is a scanning electron microscope (SEM) image of the 1#NiTe / NiFeP / NF prepared in Example 1;

[0022] Figure 3 This is a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) image of the 1#NiTe / NiFeP / NF prepared in Example 1;

[0023] Figure 4This is the energy-dispersive X-ray spectroscopy (EDS) elemental mapping diagram of 1#NiTe / NiFeP / NF prepared in Example 1;

[0024] Figure 5 This is a linear sweep voltammetry curve of the 1#NiTe / NiFeP / NF prepared in Example 1;

[0025] Figure 6 This is a stability test diagram of 1#NiTe / NiFeP / NF prepared in Example 1. Detailed Implementation

[0026] The embodiments of the present invention will be described in detail below. The specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0027] Example 1

[0028] 0.4 mmol of 2,5-dihydroxyterephthalic acid, 0.5 mmol of Ni(NO3)2·6H2O, and 1 mmol of Fe(NO3)3·9H2O were dissolved in 50 mL of N,N-dimethylformamide and stirred at room temperature for 30 minutes to obtain a mixed solution. The resulting mixed solution and NiTe / NF were then added to a 100 mL autoclave and heated at 120 °C for 24 hours. After the autoclave cooled to room temperature, it was washed three times with ethanol and then vacuum dried at 60 °C for 12 hours to obtain NiTe / MOF-74(Ni,Fe) / NF. The NiTe / MOF-74(Ni,Fe) / NF material and 1 g of sodium hypophosphite were placed in two ceramic boats and placed in a tube furnace for phosphating at 300 °C for 2 hours to finally obtain #1 NiTe / NiFeP / NF.

[0029] Example 2

[0030] 0.4 mmol of 2,5-dihydroxyterephthalic acid, 0.5 mmol of Ni(CH3COO)2, and 1 mmol of Fe(OH)(CH3COO)2 were dissolved in 50 mL of N,N-dimethylformamide and stirred at room temperature for 30 minutes to obtain a mixed solution. The resulting mixed solution and NiTe / NF were then added to a 100 mL autoclave and heated at 120 °C for 24 hours. After the autoclave cooled to room temperature, it was washed three times with ethanol and then vacuum dried at 60 °C for 12 hours to obtain NiTe / MOF-74(Ni,Fe) / NF. The NiTe / MOF-74(Ni,Fe) / NF material and 1 g of sodium hypophosphite were placed in two separate ceramic boats and placed in a tube furnace for phosphating at 300 °C for 2 hours to finally obtain #2 NiTe / NiFeP / NF.

[0031] Example 3

[0032] 0.4 mmol of 2,5-dihydroxyterephthalic acid, 0.75 mmol of Ni(NO3)2·6H2O, and 0.75 mmol of Fe(NO3)3·9H2O were dissolved in 50 mL of N,N-dimethylformamide and stirred at room temperature for 30 minutes to obtain a mixed solution. The resulting mixed solution and NiTe / NF were then added to a 100 mL autoclave and heated at 120 °C for 24 hours. After the autoclave cooled to room temperature, it was washed three times with ethanol and then vacuum dried at 60 °C for 12 hours to obtain NiTe / MOF-74(Ni,Fe) / NF. The NiTe / MOF-74(Ni,Fe) / NF material and 1 g of sodium hypophosphite were placed in two separate ceramic boats and placed in a tube furnace for phosphating at 300 °C for 2 hours to finally obtain #3 NiTe / NiFeP / NF.

[0033] Example 4

[0034] 0.4 mmol of 2,5-dihydroxyterephthalic acid and 1.5 mmol of Ni(NO3)2·6H2O were dissolved in 50 mL of N,N-dimethylformamide and stirred at room temperature for 30 minutes to obtain a mixed solution. The resulting mixed solution and NiTe / NF were then added to a 100 mL autoclave and heated at 120 °C for 24 hours. After the autoclave cooled to room temperature, it was washed three times with ethanol and then vacuum dried at 60 °C for 12 hours to obtain NiTe / MOF-74(Ni,Fe) / NF. The NiTe / MOF-74(Ni,Fe) / NF material and 1 g of sodium hypophosphite were placed in two separate ceramic boats and placed in a tube furnace for phosphating at 300 °C for 2 hours to finally obtain NiTe / NiP / NF.

[0035] Example 5

[0036] 0.4 mmol of 2,5-dihydroxyterephthalic acid, 0.5 mmol of Ni(NO3)2·6H2O, and 1 mmol of Fe(NO3)3·9H2O were dissolved in 50 mL of N,N-dimethylformamide and stirred at room temperature for 30 minutes to obtain a mixed solution. The resulting mixed solution and NiTe / NF were then added to a 100 mL autoclave and heated at 130 °C for 12 hours. After the autoclave cooled to room temperature, it was washed three times with ethanol and then vacuum dried at 60 °C for 12 hours to obtain NiTe / MOF-74(Ni,Fe) / NF. The NiTe / MOF-74(Ni,Fe) / NF material and 1 g of sodium hypophosphite were placed in two separate ceramic boats and placed in a tube furnace for phosphating at 300 °C for 2 hours to finally obtain #5 NiTe / NiFeP / NF.

[0037] Example 6

[0038] 0.4 mmol of 2,5-dihydroxyterephthalic acid, 0.5 mmol of Ni(NO3)2·6H2O, and 1 mmol of Fe(NO3)3·9H2O were dissolved in 50 mL of N,N-dimethylformamide and stirred at room temperature for 30 minutes to obtain a mixed solution. The resulting mixed solution and NiTe / NF were then added to a 100 mL autoclave and heated at 120 °C for 24 hours. After the autoclave cooled to room temperature, it was washed three times with ethanol and then vacuum dried at 60 °C for 12 hours to obtain NiTe / MOF-74(Ni,Fe) / NF. The NiTe / MOF-74(Ni,Fe) / NF material and 1 g of sodium hypophosphite were placed in two ceramic boats and placed in a tube furnace for phosphating at 350 °C for 3 hours to finally obtain #6 NiTe / NiFeP / NF.

[0039] Figure 1 These are the XRD patterns of the #1 NiTe / NiFeP / NF material prepared in Example 1 and the #3 NiTe / NiFeP / NF material prepared in Example 3. From... Figure 1 The XRD results show that both materials match the characteristic peaks of NiTe and NiFeP, indicating that this material forms NiTe and NiFeP structures.

[0040] The SEM and HAADF-STEM images of #1 NiTe / NiFeP / NF are shown below. Figure 2 and Figure 3 As shown. From Figure 2 It can be seen that #1 NiTe / NiFeP / NF is a nanorod, and the material has uniform morphology and size; from Figure 3 It can be seen that the diameter of NiTe / NiFeP / NF #1 is 200 nm. And... Figure 4 The EDS elemental mapping diagram confirmed the uniform distribution of Ni, Fe, P, O and C in 1#NiTe / NiFeP / NF and the local enrichment of Te in the structure, proving its core-shell structure.

[0041] Figure 5 The figure shows the linear sweep voltammetry curves of 1# NiTe / NiFeP / NF in 1M KOH & 0.5M NaCl (simulated seawater) and 1M KOH & seawater (real seawater). 1# NiTe / NiFeP / NF exhibits excellent electrochemical performance. 1# NiTe / NiFeP / NF drives a 500 mA cm⁻¹ in electrolytes of 1M KOH & 0.5M NaCl and 1M KOH & seawater. -2 The required overpotentials for the current densities are 217 and 232 mV, respectively. Figure 6In this study, the No. 1 NiTe / NiFeP / NF exhibited excellent electrolytic stability within the range of 100–1000 mA cm⁻¹. -2 It maintains stable performance for over 6800 hours at current densities.

[0042] The nickel iron phosphide coated nickel telluride nanorod material prepared by this invention was applied to seawater electrolysis, achieving better oxygen evolution performance and significantly improving its operational stability under high current density.

[0043] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions and substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing nickel telluride nanorods coated with nickel iron phosphide, characterized in that, The steps include: S1. 2,5-Dihydroxyterephthalic acid, nickel metal salt, iron metal salt, N,N-dimethylformamide and nickel telluride nanorod array are mixed in a beaker and stirred at room temperature to obtain a mixed solution. The solution is then placed in the lining of a reaction vessel and heated. After the reaction vessel cools and stands, the foamed nickel is removed, washed with ethanol and vacuum dried to obtain NiTe / MOF-74(Ni,Fe) / NF material. S2. The NiTe / MOF-74(Ni,Fe) / NF material obtained in step S1 and sodium hypophosphite are separately packed into two quartz boats and then placed in a tube furnace for heating. After cooling, NiTe / NiFeP / NF is obtained.

2. The method for preparing nickel telluride nanorods coated with nickel iron phosphide according to claim 1, characterized in that, The nickel metal salt mentioned in step S1 is one of nickel sulfate, nickel nitrate, and nickel acetate, and the iron metal salt is one of ferric sulfate, ferric nitrate, and ferric acetate.

3. The preparation method of nickel iron phosphide coated nickel telluride nanorod material according to claim 1, characterized in that, The molar ratio of nickel metal salt to iron metal salt in step S1 is 0.3 to 3:

1.

4. The method for preparing nickel telluride nanorods coated with nickel iron phosphide according to claim 1, characterized in that, The heating temperature in step S1 is 100-140°C, and the heating time is 12-36 hours.

5. The method for preparing nickel telluride nanorods coated with nickel iron phosphide according to claim 1, characterized in that, The heating temperature in step S2 is 300-350°C, and the heating time is 1-3 hours.

6. A nickel-iron phosphide-coated nickel telluride nanorod material, characterized in that, The nickel ferrophosphide-coated nickel telluride nanorod material is prepared by the preparation method of nickel ferrophosphide-coated nickel telluride nanorod material according to any one of claims 1 to 5.

7. An application of a nickel ferrophosphide-coated nickel telluride nanorod material, characterized in that, The nickel phosphide-coated nickel telluride nanorod material as described in claim 6 is applied in the electrolysis of seawater.

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