A FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material and its preparation method

Abstract

The present invention discloses a FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material and a preparation method thereof. The material has a chemical formula of (Fe a Co b Ni c B d ) 100‑ x Pt x , where 25≤a, b, c≤30, 10≤d≤25, and 0≤x≤5. The preparation method comprises the following steps: preparing the ingredients according to the molar percentage of each atom and smelting the master alloy, preparing a high-entropy amorphous alloy strip by melt quenching, and then subjecting the catalytic material to electrochemical dealloying treatment. The present invention can be used as a bifunctional catalytic material for complete water splitting in an alkaline electrolyte and exhibits excellent hydrogen evolution reaction activity across the entire pH range. The method of the present invention can in situ generate nanoporous and defect-rich nanocrystalline structures, exposing abundant active sites to enhance catalytic performance. The method is self-supporting, low-cost, and highly stable, allowing for mass production.

Description

Technical Field

[0001] The present invention relates to a water electrolysis catalytic material and a preparation method thereof, and in particular to a FeCoNiBPt high-entropy amorphous alloy water electrolysis catalytic material and a preparation method thereof. Background Art

[0002] In recent years, "green hydrogen" production technologies, represented by water electrolysis, have become a focus of global technological competition. However, the high energy consumption required for actual production has become a bottleneck restricting the large-scale development of this technology. Precious metals such as Pt, IrO2, and RuO2 have been widely reported as catalysts for the cathode hydrogen evolution reaction (HER) and the anode oxygen evolution reaction (OER), respectively. However, their high cost and low reserves limit their widespread application. Therefore, the development of low-cost, highly stable, and efficient catalytic materials is of great significance for promoting the development of the hydrogen energy sector.

[0003] Transition metal elements such as Fe, Co, and Ni exhibit high catalytic activity due to their incompletely filled 3d orbitals and have been widely studied as HER or OER catalytic materials. In addition, the lattice distortion effect of high-entropy alloys promotes the generation of a large number of defects, which serve as catalytic active centers; the "cocktail" effect utilizes the interaction between elements to regulate the electronic structure, promoting catalytic activity and selectivity; the high entropy effect and hysteresis diffusion effect can delay element leaching and improve catalytic stability. The atomic arrangement of amorphous alloys is long-range disordered and short-range ordered, and is in a thermodynamically metastable state. They also contain a high concentration of coordinatively unsaturated sites, which can reduce the reaction energy barrier as a catalytic material. Therefore, combining the advantages of both to design high-entropy amorphous alloys provides a new approach to designing catalytic materials.

[0004] Patent CN 112725818 A discloses a porous high-entropy alloy self-supporting water electrolysis catalytic material. Using Ni powder, Co powder, Cr powder, Fe powder, Al powder, and W powder (molar ratio of 30:30:10:10:18:2) as raw materials, a eutectic high-entropy alloy is smelted and then cut, polished, and dealloyed to obtain a self-supporting electrode. However, each electrode needs to be cut and polished individually, which is time-consuming and labor-intensive, and the post-dealloying treatment takes a long time and is inefficient. Patent CN 113549946 A discloses a FeCoNiMnRu high-entropy alloy / carbon nanofiber HER catalytic material for use in the entire pH range. This material is prepared using a metal salt solution and nanofibers using electrospinning and high-temperature calcination techniques. This method is complex, energy-intensive, requires a large amount of precious metal, and has limited neutral HER performance.

[0005] In terms of preparation methods, bulk alloy electrodes have low production efficiency and a small number of surface exposed active sites, while powder electrodes are complex to prepare and cannot be self-supporting. Summary of the Invention

[0006] Purpose of the invention: The purpose of the present invention is to provide a surface defect-rich FeCoNiBPt high-entropy amorphous alloy water electrolysis catalytic material with low cost, high stability, high catalytic activity, and scalable production;

[0007] The second object of the present invention is to provide a method for preparing the above-mentioned FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material.

[0008] Technical solution: The FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material of the present invention has a chemical formula of (Fe a Co b Ni c B d ) 100-x Pt x , where 25≤a,b,c≤30, 10≤d≤25, 0≤x≤5.

[0009] The preparation method of the above-mentioned FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material comprises the following steps:

[0010] (1) Weigh Fe, Co, Ni, B, and Pt particles according to the atomic ratio of each element;

[0011] (2) placing the weighed granular raw materials into a quartz crucible and performing vacuum induction melting under argon protection to obtain a FeCoNiBPt master alloy ingot with uniform composition;

[0012] (3) crushing the master alloy ingot, performing vacuum induction melting, remelting the alloy ingot under argon protection, ejecting and rapidly cooling to obtain alloy strips;

[0013] (4) The alloy strips are subjected to electrochemical dealloying treatment, and after washing and drying, FeCoNiBPt high entropy amorphous alloy strips are obtained.

[0014] Wherein, in step (2), the B particles are placed on the bottom layer to prevent splashing.

[0015] Wherein, in step (2), the induced current is 15-20A and the smelting time is 20-30min.

[0016] Wherein, in step (3), the speed of the copper roller when preparing the alloy strip is 30-50 ms -1 , alloy systems with low amorphous glass forming ability must produce amorphous strips at higher rotation speeds.

[0017] Among them, in step (3), the jet pressure difference when preparing the alloy strip is 0.03-0.04MPa, which is adjusted according to the quality and fluidity of the melt to ensure that the air pressure can push the melt to be ejected.

[0018] Wherein, in step (4), the electrolyte used in the electrochemical dealloying process is an acidic solution; preferably at least one of H2SO4, HNO3 or HCl; the concentration of the electrolyte is preferably 0.1-1M. + The acidity and oxidizing properties of the solution dissolve metal elements. If the solution concentration is too low, the dealloying time will be too long and the efficiency will be low; if the concentration is too high, the dealloying rate will be too fast and the dealloying process will be difficult to control.

[0019] Among them, in step (4), the electrochemical dealloying adopts a constant potential test method, and the applied voltage is selected in the active dissolution zone of the corrosion polarization curve, which is conducive to the dissolution of metal elements rather than passivation, such as -0.1-0.5V (vs.Ref); the duration is 0-1800s, specifically adjusted according to the acid concentration and the applied voltage, to find the optimal dealloying conditions so that the strip increases the specific surface area while still maintaining self-support without breaking.

[0020] Principle of the Invention: Transition metals Fe, Co, and Ni possess high catalytic activity due to their incompletely filled 3d orbitals. Non-metallic B enhances the alloy's amorphous formation and catalytic stability, and small B atoms tend to reside in interstitial locations, promoting lattice distortion. Pt enhances intrinsic catalytic activity, with its addition preferably at 3 at.% to reduce costs. Electrochemical dealloying creates a nanoporous structure, increasing the electrochemical specific surface area and the number of active sites. Optimizing the alloy's surface composition exposes more Pt coordination sites. Controlling the dealloying voltage and time allows for in-situ precipitation of nanocrystals on the surface through elemental rearrangement. Due to the atomic size differences of the metal elements and interstitial doping of B, the resulting nanocrystals exhibit significant defects such as lattice distortion and stacking faults. DFT calculations demonstrate that these defects significantly promote the catalytic reaction. In summary, Pt microalloying and dealloying create defect-rich Pt nanocrystals on the surface of the ribbons, enhancing their catalytic performance in water electrolysis.

[0021] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects: (1) By adjusting the non-metallic B content, the alloy's amorphous forming ability and catalytic stability are improved; by microalloying the highly intrinsically active Pt element, the electrolytic water catalytic activity of the alloy strip is significantly improved; (2) By Pt microalloying and electrochemical dealloying treatment, a nanoporous structure is formed on the strip surface and defect-rich nanocrystals are precipitated in situ. The synergistic effect of the abundant active sites, high intrinsic catalytic activity and lattice defects significantly reduces the overpotential of the electrocatalytic reaction, thus achieving the preparation of low-cost, high-stability, high-efficiency and high-entropy amorphous alloy catalytic materials. (3) The alloy can be used as a dual-functional electrolytic water catalytic material for HER and OER under alkaline conditions, and can be used as a HER electrolytic water catalytic material in the entire pH range. (4) The alloy preparation technology is mature and reliable, with low preparation cost, and the dealloying process is simple and time-consuming, making it suitable for industrial large-scale production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 (FeCoNiB 0.75 ) 100-x Pt x XRD pattern of high entropy amorphous alloy ribbon;

[0023] Figure 2 (FeCoNiB 0.75 ) 97 SEM image of Pt3 high entropy amorphous alloy strip;

[0024] Figure 3 For the original (FeCoNiB 0.75 ) 97 TEM image of Pt3 high entropy amorphous alloy strip;

[0025] Figure 4 After dealloying for 150s in Example 5 (FeCoNiB 0.75 ) 97 TEM image of Pt3 high entropy amorphous alloy strip;

[0026] Figure 5 (FeCoNiB 0.75 ) 100-x Pt x Linear sweep voltammetry curve of high entropy amorphous alloy strip in 1MKOH electrolyte for OER;

[0027] Figure 6 (FeCoNiB 0.75 ) 100-x Pt x HER linear sweep voltammetry curve of high entropy amorphous alloy strip in 1MKOH electrolyte;

[0028] Figure 7 (FeCoNiB 0.75 ) 100-x Pt x HER linear sweep voltammetry curve of high entropy amorphous alloy strip in 1MPBS electrolyte;

[0029] Figure 8 (FeCoNiB 0.75 ) 100-x Pt x HER linear sweep voltammetry curve of high entropy amorphous alloy strip in 0.5M H2SO4 electrolyte;

[0030] Figure 9 (FeCoNiB prepared in Example 5 0.75 ) 97 Linear sweep voltammetry curve of Pt3 high entropy amorphous alloy strip in 1M KOH electrolyte after complete water splitting after dealloying for 150s;

[0031] Figure 10 (FeCoNiB prepared in Example 5 0.75 ) 97 OER and HER chronovoltage curves of Pt3 high-entropy amorphous alloy strips under alkaline conditions after dealloying for 150s. DETAILED DESCRIPTION

[0032] The present invention is described in further detail below.

[0033] Example 1

[0034] (1) Preparation of Fe atomic percentage 30 Co 30 Ni 30 B 10 The preparation process of high entropy amorphous alloy strips is as follows:

[0035] (i) High-purity Fe, Co, Ni, and B particles were weighed and mixed according to atomic percentage. The B element was placed at the bottom of the crucible to prevent splashing. Vacuum induction melting was performed under argon protection with an induction current of 15 A for 30 min to ensure uniform composition of Fe. 30 Co 30 Ni 30 B 10 Master alloy ingot;

[0036] (ii) Using a melt quenching method, the master alloy ingot prepared in step (i) was crushed, placed in a quartz tube, and placed in a vacuum induction melting furnace. The alloy ingot was remelted under argon protection, with the jet pressure difference set to 0.04 MPa and the copper roller speed set to 50 m s. -1 The melt was ejected and rapidly cooled to obtain an alloy strip with an average width of about 1.2 mm and a thickness of about 30 μm.

[0037] (2) The Fe 30 Co 30 Ni 30 B 10 The high entropy amorphous alloy strips are dealloyed, and the processing process is as follows:

[0038] (i) Dealloying voltage selection: Polarization curves of the original alloy strips were measured in a three-electrode system using a 1M HNO3 solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The polarization curves of the alloy strips were measured in this system, and a voltage was selected from the active dissolution region of the polarization curve for constant-potential dealloying.

[0039] (ii) Dealloying: A constant potential test method was used with a 1 M HNO₃ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The applied voltage was adjusted to -0.1–0.5 V (vs. Ref) and the duration was 0–600 s.

[0040] (iii) Washing and drying: The washing medium is deionized water and anhydrous ethanol, and the washing times are 3 times. After natural drying at room temperature, the nanoporous Fe 30 Co 30 Ni 30 B 10 Alloy strip catalytic material.

[0041] (3) The Fe 30 Co 30 Ni 30 B 10 The high entropy amorphous alloy ribbons were characterized by XRD structural analysis. The results showed that when the rotation speed was low, Ni3Fe crystals were easily precipitated in the ribbons, so the rotation speed needed to be increased to obtain amorphous alloy ribbons.

[0042] (4) The Fe 30 Co 30 Ni 30 B 10 Electrochemical performance tests of high-entropy amorphous alloy strips showed that the catalytic performance of the original alloy strips was not high, but the performance was greatly improved after dealloying, with a current density of 10 mA cm -2 The OER overpotential can be optimized to 260 mV.

[0043] Example 2

[0044] (1) Preparation of Fe atomic percentage 25 Co 25 Ni 25 B 25 The preparation process of high entropy amorphous alloy strips is as follows:

[0045] (i) High-purity Fe, Co, Ni, and B particles were weighed and mixed according to atomic percentage. The B element was placed at the bottom of the crucible to prevent splashing. Vacuum induction melting was performed under argon protection with an induction current of 15 A for 30 min to ensure uniform composition of Fe.25 Co 25 Ni 25 B 25 Master alloy ingot;

[0046] (ii) Using a melt quenching method, the master alloy ingot prepared in step (i) was crushed, placed in a quartz tube, and placed in a vacuum induction melting furnace. The alloy ingot was remelted under argon protection, with the jet pressure difference set to 0.03 MPa and the copper roller speed set to 30 m s. -1 The melt was ejected and rapidly cooled to obtain an alloy strip with an average width of about 1.2 mm and a thickness of about 30 μm.

[0047] (2) The Fe 25 Co 25 Ni 25 B 25 The high entropy amorphous alloy strips are dealloyed, and the processing process is as follows:

[0048] (i) Dealloying voltage selection: Polarization curves of the original alloy strips were measured in a three-electrode system using a 1M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, an Ag / AgCl electrode, and a graphite carbon rod, respectively. The polarization curves of the alloy strips were measured in this system, and a voltage was selected from the active dissolution region of the polarization curve for constant-potential dealloying.

[0049] (ii) Dealloying: A constant potential test method was used with a 1 M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The applied voltage was adjusted to 0.01 V (vs. Ref) and the duration was 0–200 s.

[0050] (iii) Washing and drying: The washing medium is deionized water and anhydrous ethanol, and the washing times are 3 times. After natural drying at room temperature, the nanoporous Fe 25 Co 25 Ni 25 B 25 Alloy strip catalytic material.

[0051] (3) The Fe 25 Co 25 Ni 25 B 25 The electrochemical performance of the high-entropy amorphous alloy strips was tested. The results showed that the electrocatalytic performance was greatly improved after dealloying, with a current density of 10 mA cm -2 The OER overpotential can be optimized to 250 mV.

[0052] Example 3

[0053] (1) Preparation of Fe atomic percentage26.67 Co 26.67 Ni 26.67 B 19.99 High entropy amorphous alloy strip, hereinafter referred to as FeCoNiB according to the atomic ratio 0.75 , its preparation process is as follows:

[0054] (i) High-purity Fe, Co, Ni, and B particles were weighed and mixed according to atomic percentage. The B element was placed at the bottom of the crucible to prevent splashing. Vacuum induction melting was performed under argon protection with an induction current of 20 A for 20 min to ensure uniform composition of FeCoNiB. 0.75 Master alloy ingot;

[0055] (ii) Using a melt quenching method, the master alloy ingot prepared in step (i) was crushed, placed in a quartz tube, and placed in a vacuum induction melting furnace. The alloy ingot was remelted under argon protection, with the jet pressure difference set to 0.03 MPa and the copper roller speed set to 50 m s. -1 The melt was ejected and rapidly cooled to obtain an alloy strip with an average width of about 1.2 mm and a thickness of about 30 μm.

[0056] (2) FeCoNiB prepared above 0.75 The high entropy amorphous alloy strips are dealloyed, and the processing process is as follows:

[0057] (i) Dealloying voltage selection: Polarization curves of the original alloy strips were measured in a three-electrode system using a 0.1 M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The polarization curves of the alloy strips were measured in this system, and a voltage was selected from the active dissolution region of the polarization curve for constant-potential dealloying.

[0058] (ii) Dealloying: A constant potential test method was used with a 0.1 M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The applied voltage was adjusted to -0.1–0.5 V (vs. Ref) and the duration was 0–1800 s.

[0059] (iii) Washing and drying: The washing medium is deionized water and anhydrous ethanol, and the washing times are 3 times. After natural drying at room temperature, nanoporous FeCoNiB is obtained. 0.75 Alloy strip catalytic material.

[0060] (3) FeCoNiB prepared above 0.75 The high entropy amorphous alloy strips were characterized by XRD structural analysis, and the results showed that the alloy strips presented a completely amorphous structure.

[0061] (4) The electrochemical performance of the alloy strips prepared and dealloyed as described above was tested. The results showed that dealloying could significantly improve the electrocatalytic performance of the original strips. The optimized current density was 10 mA cm -2 The OER overpotential is about 250 mV.

[0062] Example 4

[0063] (1) Preparation of FeCoNiB 0.75 The preparation process of high entropy amorphous alloy strips is as follows:

[0064] (i) High-purity Fe, Co, Ni, and B particles were weighed and mixed according to atomic percentage. The B element was placed at the bottom of the crucible to prevent splashing. Vacuum induction melting was performed under argon protection with an induction current of 20 A for 20 min to ensure uniform composition of FeCoNiB. 0.75 Master alloy ingot;

[0065] (ii) Using a melt quenching method, the master alloy ingot prepared in step (i) was crushed, placed in a quartz tube, and placed in a vacuum induction melting furnace. The alloy ingot was remelted under argon protection, with the jet pressure difference set to 0.03 MPa and the copper roller speed set to 30 m s. -1 The melt was ejected and rapidly cooled to obtain an alloy strip with an average width of about 1.2 mm and a thickness of about 35 μm.

[0066] (2) FeCoNiB prepared above 0.75 The high entropy amorphous alloy strips are dealloyed, and the processing process is as follows:

[0067] (i) Dealloying voltage selection: Polarization curves of the original alloy strips were measured in a three-electrode system using a 1M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, an Ag / AgCl electrode, and a graphite carbon rod, respectively. The polarization curves of the alloy strips were measured in this system, and a voltage was selected from the active dissolution region of the polarization curve for constant-potential dealloying.

[0068] (ii) Dealloying: A constant potential test method was used with a 1 M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The applied voltage was adjusted to -0.1–0.5 V (vs. Ref) for a duration of 0–200 s.

[0069] (iii) Washing and drying: The washing medium is deionized water and anhydrous ethanol, and the washing times are 3 times. After natural drying at room temperature, nanoporous FeCoNiB is obtained. 0.75 Alloy strip catalytic material.

[0070] (3) FeCoNiB prepared above0.75 The high entropy amorphous alloy strips were characterized by XRD structural analysis. The results showed that the alloy strips presented a completely amorphous structure, indicating that the alloy composition can form amorphous structures in a wide range of rotation speeds.

[0071] (4) The electrochemical performance of the alloy strips prepared and dealloyed as described above was tested. The results showed that dealloying could significantly improve the electrocatalytic performance of the original strips. The current density was 10 mA cm -2 The OER overpotential is about 260 mV.

[0072] Example 5

[0073] (1) Select FeCoNiB 0.75 Pt microalloying was performed on the base alloy to prepare (FeCoNiB 0.75 ) 100-x Pt x High entropy amorphous alloy strips, where x = 0.3, are prepared as follows:

[0074] (i) High-purity Fe, Co, Ni, B, and Pt particles were weighed and mixed according to atomic percentage. The B element was placed in the bottom layer to prevent splashing, and the Fe, Co, and Ni elements were placed in the upper layer to facilitate induction heating. Vacuum induction melting was performed under argon protection with an induction current of 20 A for 20 min to ensure uniform composition (FeCoNiB 0.75 ) 100-x Pt x Master alloy ingot;

[0075] (ii) Using a melt quenching method, the master alloy ingot prepared in step (i) was crushed, placed in a quartz tube, and placed in a vacuum induction melting furnace. The alloy ingot was remelted under argon protection. The jet pressure difference was set to 0.03 MPa and the copper roller speed was set to 35 m s. -1 The melt is ejected and rapidly cooled to obtain an alloy strip with an average width of about 1 mm and a thickness of about 30 μm.

[0076] Figure 1 (FeCoNiB 0.75 ) 100-x Pt x The XRD pattern of the original alloy strip has a diffuse scattering bun peak near 45°, indicating an amorphous structure.

[0077] (2) The above-prepared (FeCoNiB 0.75 ) 100-x Pt x The alloy strips are dealloyed and the processing process is as follows:

[0078] (i) Dealloying voltage selection: Polarization curves of the original alloy strips were measured in a three-electrode system with a 0.5 M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were the alloy strip, Ag / AgCl electrode, and graphite carbon rod, respectively. The polarization curves of the alloy strips were measured in this system with a voltage range of -0.1-0.5 V (vs. Ref).

[0079] (ii) Dealloying: A potentiostatic test method was used, with a 0.5 M H₂SO₄ solution as the electrolyte. The working electrode, reference electrode, and counter electrode were alloy strips, Ag / AgCl electrodes, and graphite carbon rods, respectively. The dealloying time was fixed at 100 s, and the applied voltage was -0.1-0.5 V (vs. Ref). The optimal dealloying voltage was found to be -0.05 V (vs. Ref). This voltage was then fixed, and the dealloying time was adjusted from 0 to 300 s to explore the optimal dealloying conditions.

[0080] (iii) Washing and drying: The washing medium was deionized water and anhydrous ethanol, and the washing times were 3 times. After natural drying at room temperature, the nanoporous (FeCoNiB 0.75 ) 100-x Pt x Alloy strip catalytic material.

[0081] Figure 1 It can be observed that (FeCoNiB 0.75 ) 97 As the dealloying time of the Pt3 alloy strip increases, the diffuse scattering peak of the XRD pattern shifts to the left, indicating that the average atomic distance increases.

[0082] Figure 2 For different dealloying times (FeCoNiB 0.75 ) 97 SEM images of Pt3 alloy ribbons, where (a) shows the original ribbon surface scan, and (b), (c), (d), (e), and (f) show the scans after dealloying for 10, 50, 100, 150, and 200 seconds, respectively. The original ribbon surface is smooth and flat; after dealloying, a nanoporous structure gradually emerges. After 150 seconds of dealloying, the surface porous structure is uniform and dense, significantly increasing the specific surface area of ​​the alloy and improving catalytic performance.

[0083] Figure 3 For the original (FeCoNiB 0.75 ) 97 TEM images of Pt3 alloy strips, where (a) and (b) are the high-resolution and SAED patterns of the original strips, respectively, indicating that the original alloy strips exhibit an amorphous structure, which is consistent with the XRD results. Figure 4 After dealloying for 150s (FeCoNiB 0.75) 97 TEM images of Pt3 alloy strips, where (a) is a cross-sectional view of the strip after dealloying for 150 seconds. It can be seen that there is a Pt-rich layer of tens of nanometers on the surface of the strip. Further high-resolution observation of the Pt-rich layer reveals that atomic rearrangement leads to the in-situ precipitation of nanocrystals (bd); Figure 4 As shown in (b), there is a step interface between the nanocrystal and the amorphous matrix. Figure 4 (c) Figure 4 (b) In the FFT and IFFT images of the area where the square box is located, it can be observed that there is obvious lattice distortion in the nanocrystal, and there are also stacking fault defects ( Figure 4 (d)), which is mainly due to the size difference of metal atoms and interstitial B atoms. DFT simulation calculations have confirmed that the presence of the above-mentioned Pt-rich nanocrystals, especially defect sites, can put the alloy in a higher energy state, reduce the energy barrier of the catalytic reaction, and at the same time regulate the electronic structure and promote the improvement of catalytic performance.

[0084] Experiment 1: Comparison of catalytic performance of original alloy strips before and after Pt microalloying

[0085] (FeCoNiB before and after Pt microalloying 0.75 ) 100-x Pt x The alloy strips were tested for alkaline OER performance, where x = 0.3. The test process is as follows:

[0086] 1. Obtain FeCoNiB 0.75 With (FeCoNiB 0.75 ) 97 The Pt3 alloy strip was cut into 2 cm lengths and used directly as the working electrode, fixed on the electrode holder. The reference electrode and counter electrode were Hg / HgO electrode and graphite carbon rod, respectively. The electrolyte was 1 M KOH solution.

[0087] 2. The OER performance of the alloy strips was tested in the above three-electrode system using linear sweep voltammetry with a scan rate of 5 mV s -1 .

[0088] Figure 5 Contains FeCoNiB 0.75 With (FeCoNiB 0.75 ) 97 The OER linear sweep voltammetry curve of the original Pt3 alloy strip shows that after microalloying with 3 at.% Pt element, the alkaline OER catalytic performance of the alloy strip is improved. At a current density of 10 mA cm -2 When (FeCoNiB 0.75 ) 97The overpotential of the original Pt3 alloy strip is 338 mV, which is lower than that of FeCoNiB 0.75 The alloy strip has a V of 374 mV, indicating that Pt microalloying helps improve the alkaline OER catalytic performance of the sample. Figure 6-8 The HER performance before and after Pt microalloying is also greatly improved, which is mainly due to the excellent intrinsic HER catalytic activity of Pt element. The specific values ​​of overpotential are shown in Table 1.

[0089] Experiment 2: Dealloying treatment of (FeCoNiB 0.75 ) 97 Effect of Pt3 high entropy amorphous alloy strips on catalytic performance

[0090] (FeCoNiB 0.75 ) 97 The Pt3 alloy strips were dealloyed for different times and their alkaline OER, alkaline HER, neutral HER and acidic HER performance tests were carried out. The reference electrode used under neutral and acidic conditions was Ag / AgCl electrode.

[0091] Figure 5-8 Includes different dealloying times (FeCoNiB 0.75 ) 97 The linear sweep voltammetry curves of the catalytic performance of the Pt3 alloy strips are alkaline OER, alkaline HER, neutral HER and acidic HER. Figure 5-7 It can be seen that when the dealloying time is 150s, the overpotential of the alloy catalytic reaction is the lowest and the catalytic activity is the best. The specific catalytic reaction overpotential values ​​are shown in Table 1. The above results show that the dealloying treatment can significantly improve the alkaline OER, alkaline HER and neutral HER catalytic performance of the sample. Figure 8 It can be seen that the acidic HER catalytic performance of the original strip is greatly improved after Pt microalloying, while dealloying treatment slightly improves its catalytic performance.

[0092] Experiment 3: Nanoporous (FeCoNiB 0.75 ) 97 Study on the alkaline complete water splitting performance of Pt3 high entropy amorphous alloy ribbons

[0093] The above studies show that the nanoporous high-entropy amorphous alloy strips have excellent alkaline OER and HER catalytic activities. Therefore, the alkaline water splitting performance of the alloy material was tested in a two-electrode system. Both the anode and the cathode are nanoporous high-entropy amorphous alloy materials after dealloying treatment.

[0094] Figure 9 (FeCoNiB 0.75 ) 97The linear sweep voltammetric curve of the Pt3 high entropy amorphous alloy strip in 1M KOH electrolyte after dealloying for 150s. As can be seen from the figure, the catalytic material reaches 10mA cm -2 The potential required for the current density of 1.51 V is only 1.51 V, indicating its excellent alkaline overall water splitting catalytic activity.

[0095] Experiment 4: Nanoporous (FeCoNiB 0.75 ) 97 Study on the catalytic stability of Pt3 high entropy amorphous alloy ribbons

[0096] The stability of the alloy catalytic material was tested by chronopotentiometry. Figure 10 (FeCoNiB 0.75 ) 97 Chronovoltaometric curves of the OER and HER reactions of a Pt3 high-entropy amorphous alloy ribbon under alkaline conditions after dealloying for 150 seconds. The figure shows no significant increase in overpotential during the 48-hour OER and HER test, demonstrating the sample's excellent catalytic stability.

[0097] Table 1 below compares the overpotentials of the alloy strip catalytic materials at different dealloying times.

[0098] Table 1 Comparison of overpotentials of alloy strip catalytic materials at different dealloying times

[0099]

Claims

1. A FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material, characterized in that: Calculated by the molar percentage of each atom, its chemical formula is: (Fe a Co b Ni c B d ) 100-x Pt x , where 25≤a, b, c≤30, 10≤d≤25, 0≤x≤5; The preparation method of the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material comprises the following steps: (1) Weigh Fe, Co, Ni, B, and Pt particles according to the atomic ratio of each element; (2) The weighed granular raw materials were placed in a quartz crucible and vacuum induction melting was performed under argon protection to obtain a FeCoNiBPt master alloy ingot with uniform composition; the induction current was 15-20 A and the melting time was 20-30 min; (3) crushing the master alloy ingot, performing vacuum induction melting, remelting the alloy ingot under argon protection, ejecting and rapidly cooling to obtain alloy strips; (4) The alloy strips are subjected to electrochemical dealloying treatment, and after washing and drying, FeCoNiBPt high entropy amorphous alloy strips are obtained; the concentration of the electrolyte used in the electrochemical dealloying process is 0.1-1M; the electrochemical dealloying adopts a constant potential test method, the applied voltage is -0.1-0.5 V, and the duration is 0-1800 s, wherein the duration does not include 0.

2. A method for preparing the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material according to claim 1, characterized in that: The following steps are involved: Weigh Fe, Co, Ni, B, and Pt particles according to the atomic ratio of each element; The weighed granular raw materials were placed in a quartz crucible and vacuum induction melted under argon protection to obtain a FeCoNiBPt master alloy ingot with uniform composition; The master alloy ingot is crushed, vacuum induction melting is performed, the alloy ingot is remelted under argon protection, and the alloy strip is obtained by ejecting and rapid cooling; The alloy strips were electrochemically dealloyed, washed, and dried to produce FeCoNiBPt high-entropy amorphous alloy strips; the concentration of the electrolyte used in the electrochemical dealloying process was 0.1-1 M; the electrochemical dealloying was performed using a constant potential test method with an applied voltage of -0.1-0.5 V and a duration of 0-1800 s, where the duration does not include 0.

3. The preparation method of the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material according to claim 2, characterized in that: In step (2), the B particles are placed at the bottom layer to prevent splashing.

4. The preparation method of the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material according to claim 2, characterized in that: In step (2), the induced current is 15-20 A and the melting time is 20-30 min.

5. The preparation method of the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material according to claim 2, characterized in that: In step (3), the copper roller speed during the preparation of the alloy strip is 30-50 ms -1 .

6. The preparation method of the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material according to claim 2, characterized in that: In step (3), the jet pressure difference during the preparation of the alloy strip is 0.03-0.04 MPa.

7. The preparation method of the FeCoNiBPt high entropy amorphous alloy water electrolysis catalytic material according to claim 2, characterized in that: In step (4), the electrolyte used in the electrochemical dealloying process is at least one of H2SO4, HNO3 or HCl.

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