Fe-cr-ni ternary alloy nanocrystalline particle, preparation method and application

Abstract

The application discloses a Fe-Cr-Ni ternary alloy nanocrystalline particle, a preparation method and application, and belongs to the field of nanocrystalline metal material preparation, and comprises the following steps: FeCl2.4H2O, CrCl3.6H2O and NiCl2.6H2O are dissolved into an ethanol solution in a certain proportion; the obtained solution is dispersed onto carbon nanotube paper and dried at a certain temperature; under the protection of argon, Fe 2+ , Cr 3+ and Ni 2+ on the carbon nanotube paper are reduced into Fe-Cr-Ni ternary alloy nanoparticles by using a pulse laser. Through the above three steps, the carbon nanotube paper electrode loaded with the Fe-Cr-Ni ternary alloy nanoparticles is obtained, the electrode is subjected to constant potential polarization at different points, and is used for anode OER in the water splitting process in an alkaline solution. The preparation method is simple in operation, low in cost, and overcomes the complicated process of electrode loading catalyst in a traditional electrocatalysis process, and can be used as a catalyst for OER in the electrocatalytic water splitting process to improve the catalytic effect.

Description

Technical Field

[0001] This invention belongs to the field of nanocrystalline metal material preparation, and relates to Fe-Cr-Ni ternary alloy nanocrystalline particles, preparation method and application, specifically the application of Fe-Cr-Ni ternary alloy nanocrystalline particles in water electrolysis for oxygen production. Background Technology

[0002] Water electrolysis is a key process in the search for sustainable and clean energy solutions. It involves two half-reactions that electrochemically break down water (H2O) into oxygen (O2) and hydrogen (H2): the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). This process holds great promise for various energy conversion and storage technologies, such as water electrolyzers, fuel cells, and photoelectrochemical cells. The OER is particularly important because it is more kinetically challenging in water splitting. Compared to HER, the OER requires higher energy input and catalytic efficiency. Therefore, improving the efficiency of the OER is crucial for the overall efficiency of water splitting. To enhance the kinetics of the OER, researchers have employed catalysts. These catalysts are typically metal oxides, such as ruthenium (Ru), iridium (Ir), nickel (Ni), cobalt (Co), and manganese (Mn) oxides. Nevertheless, scientists are continuously exploring new materials to improve the efficiency of the OER and reduce the cost of water splitting technologies. Currently, the most efficient OER catalysts are based on rare and expensive elements such as iridium (Ir) and ruthenium (Ru). However, scaling up these catalysts for large-scale applications may be prohibitively expensive. Therefore, finding a large number of cost-effective catalyst materials to match or surpass the performance of current catalysts remains a challenge. Summary of the Invention

[0003] To address the problems faced by OER catalysts in existing water electrolysis technologies, the present invention aims to provide Fe-Cr-Ni ternary alloy nanocrystalline particles, their preparation method, and their application. The prepared Fe-Cr-Ni ternary alloy nanocrystalline particles are applied to OER catalysts in water electrolysis technology. This invention can effectively solve the drawbacks of traditional OER catalysts in water electrolysis technology and provide a new approach for developing low-cost, high-efficiency catalysts.

[0004] To achieve the above objectives, the first aspect of the present invention provides a method for preparing Fe-Cr-Ni ternary alloy nanocrystalline particles, comprising the following steps:

[0005] FeCl2·4H2O, CrCl3·6H2O and NiCl2·6H2O were each prepared into 50-100mM ethanol solutions. The three solutions were then mixed in a certain volume ratio to obtain a solution of Fe, Cr and Ni in a certain atomic mass ratio.

[0006] The prepared ethanol solutions of FeCl2·4H2O, CrCl3·6H2O, and NiCl2·6H2O were added dropwise to the support using a pipette and then vacuum dried at a certain temperature; during this process, 1 cm 2 40–50 μL of FeCl2·4H2O, CrCl3·6H2O and NiCl2·6H2O ethanol solutions were dispersed on the carrier, and the vacuum drying temperature was 40–55 °C.

[0007] The vacuum-dried support was irradiated with a pulsed laser under argon protection to remove Fe from the support. 2+ Cr 3+ and Ni 2+ It is reduced to Fe-Cr-Ni ternary alloy nanocrystalline particles.

[0008] Furthermore, the ternary alloy nanocrystalline particles contain three metallic elements: Fe, Cr, and Ni.

[0009] Furthermore, the preparation process of the ternary alloy nanocrystalline particles uses three compounds, FeCl2·4H2O, CrCl3·6H2O and NiCl2·6H2O, as well as an ethanol solution as solvents.

[0010] Furthermore, the carrier used is carbon nanotube paper.

[0011] Furthermore, the laser parameters used in the preparation of the Fe-Cr-Ni ternary alloy nanocrystalline particles are as follows: laser wavelength 1064nm, laser frequency 900kHz, pulse width 2ns, and energy 0.5~0.8W.

[0012] A second aspect of the present invention provides Fe-Cr-Ni ternary alloy nanocrystalline particles, wherein the Fe-Cr-Ni ternary alloy nanocrystalline particles are prepared by the preparation method described in any of the above aspects and are loaded onto carbon nanotube paper.

[0013] A third aspect of the present invention provides an application of Fe-Cr-Ni ternary alloy nanocrystalline particles as described above in water electrolysis, wherein carbon nanotube paper loaded with the Fe-Cr-Ni ternary alloy nanocrystalline particles is used as an electrode, the electrode is subjected to constant potential polarization, and used for water electrolysis in alkaline solution.

[0014] Furthermore, after the electrode was subjected to constant potential polarization in a 1M KOH solution, it was used for the electrolysis of water in an alkaline solution.

[0015] Furthermore, the potentiostatic polarization potential is 0.1–0.5 V. Ag / AgCl The constant potential time is 3600s.

[0016] Furthermore, the alkaline electrolysis solution used for water electrolysis is a 1M KOH solution.

[0017] Compared with existing technologies, the present invention has the following advantages:

[0018] (1) This invention uses laser thermal reduction to prepare multi-element alloy nanocrystalline particles, which is simple, low-cost, and controllable. The multi-element alloy nanocrystalline particles prepared by laser thermal reduction technology have small size (grain size <10nm). The smaller the grain size, the larger the specific surface area, which can provide a large number of reactive sites for catalysis. This method is universal and can be used to prepare multi-element nanocrystalline particles with different groups and ratios as catalysts for water electrolysis.

[0019] (2) The preparation process of Fe-Cr-Ni ternary alloy nanocrystalline particles is green and environmentally friendly. The entire preparation process only requires three inorganic salts, FeCl2·4H2O, CrCl3·6H2O and NiCl2·6H2O, and high-purity ethanol. No harmful substances or gases are generated during the experiment. This environmentally friendly preparation process helps to reduce the impact on the environment and is in line with the principle of sustainable development.

[0020] (3) Compared to the traditional loading method—using a binder to load the catalyst onto a conductive substrate to prepare the catalyst electrode—Fe-Cr-Ni ternary alloy nanocrystals are grown directly on carbon nanotube paper and, after constant potential polarization, can be directly used for water electrolysis OER. This allows for more efficient utilization of the reactive sites of the oxide nanoparticle catalyst, overcoming the limitation imposed by the loading area of ​​the conductive substrate. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings involved in the embodiments are briefly described below. Obviously, the following drawings only illustrate some embodiments of the present invention. Those skilled in the art can obtain other possible drawings based on these drawings without any creative effort.

[0022] Figure 1 This is a schematic diagram illustrating the process of preparing Fe-Cr-Ni ternary alloy nanocrystalline particles in an embodiment of the present invention.

[0023] Figure 2 Scanning electron microscope (SEM) image of Fe-Cr-Ni ternary alloy nanocrystalline particles prepared for an embodiment of the present invention;

[0024] Figure 3 Transmission electron microscope (TEM) image of Fe-Cr-Ni ternary alloy nanocrystal particles prepared for an embodiment of the present invention;

[0025] Figure 4The size statistical distribution diagram of Fe-Cr-Ni ternary alloy nanocrystalline particles prepared in the embodiments of the present invention;

[0026] Figure 5 Energy dispersive spectroscopy (EDS) of Fe-Cr-Ni ternary alloy nanocrystalline particles prepared for an embodiment of the present invention;

[0027] Figure 6 X-ray diffraction (XRD) pattern of Fe-Cr-Ni ternary alloy nanocrystalline particles prepared for an embodiment of the present invention;

[0028] Figure 7 Potentiodynamic polarization curves of Fe-Cr-Ni ternary alloy nanocrystalline particles prepared according to an embodiment of the present invention;

[0029] Figure 8 Impedance spectra (EIS) of Fe-Cr-Ni ternary alloy nanocrystalline particles prepared for an embodiment of the present invention;

[0030] Figure 9 The OER polarization curve of Fe-Cr-Ni ternary alloy nanocrystal particles prepared by electrolysis of water in 1M KOH solution is shown in the embodiment of this invention.

[0031] Figure 10 The OER polarization curve of Fe-Cr-Ni ternary alloy nanocrystal particles prepared for this invention is shown in the electrolysis of water in 1M KOH solution after constant potential polarization. Detailed Implementation

[0032] The present invention will be described in detail below with reference to the embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make non-essential improvements and adjustments based on the content of the present invention.

[0033] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] This invention provides a method for preparing Fe-Cr-Ni ternary alloy nanocrystalline particles and their application as OER catalysts in water electrolysis technology. This invention can effectively solve the drawbacks of traditional OER catalysts in water electrolysis technology and provide a new approach for developing low-cost, high-efficiency catalysts.

[0035] Specifically, the present invention provides a method for preparing Fe-Cr-Ni ternary alloy nanocrystalline particles, such as... Figure 1 As shown, the Fe-Cr-Ni ternary alloy nanocrystalline particles and their application in water electrolysis for oxygen production include the following steps:

[0036] First, FeCl2·4H2O, CrCl3·6H2O, and NiCl2·6H2O were selected as the alloying elements for Fe-Cr-Ni ternary alloy nanocrystals. High-purity ethanol was used as the solvent, and FeCl2·4H2O, CrCl3·6H2O, and NiCl2·6H2O were each prepared into 100mM ethanol solutions. Then, the three solutions were mixed in a specific volume ratio of 11-n:n:1.

[0037] Secondly, the prepared mixed ethanol solution was added according to a certain amount (1cm). 2 After adding 40-50 μL of the solution onto the carbon nanotube paper, place the carbon nanotube paper in a vacuum drying oven to dry at a temperature of 40-55°C.

[0038] Finally, under the protection of argon gas, the dried carbon nanotube paper was irradiated with a pulsed laser to remove Fe. 2+ Cr 3+ and Ni 2+ The material is reduced to Fe-Cr-Ni ternary alloy nanoparticles. The laser wavelength is 1064 nm, the laser frequency is 900 kHz, the pulse width is 2 ns, and the energy is 0.5–0.8 W.

[0039] The present invention provides a Fe-Cr-Ni ternary alloy nanocrystalline particle, which is prepared by the preparation method described above.

[0040] These nanocrystalline particles have been loaded onto carbon nanotube paper and can be directly used as electrodes for water electrolysis OER in alkaline solutions.

[0041] The present invention also provides an application of the Fe-Cr-Ni ternary alloy nanocrystalline particles described above in water electrolysis, wherein carbon nanotube paper loaded with the Fe-Cr-Ni ternary alloy nanocrystalline particles is used as an electrode.

[0042] To improve the catalytic effect of Fe-Cr-Ni ternary alloy nanocrystals, the electrode was first subjected to constant potential polarization in 1 M KOH solution. During constant potential polarization, oxides of Fe, Cr, and Ni are generated on the surface of the Fe-Cr-Ni ternary alloy. These oxide surfaces typically have many active sites, providing suitable adsorption sites and energy, which is beneficial for the adsorption of oxygen molecules and catalytic reactions.

[0043] Based on the potentiodynamic polarization curves of Fe-Cr-Ni ternary alloy nanocrystalline particles, the potential during the constant potential polarization process can be selected from 0.1 to 0.5 V. Ag / AgCl .

[0044] The electrode, after being polarized at constant potential, was used as the anode to electrolyze water in a 1M KOH solution.

[0045] Example 1

[0046] 1. Preparation of Fe-Cr-Ni ternary alloy nanocrystalline particles

[0047] First, 100 mM ethanol solutions of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O were prepared separately. The prepared ethanol solutions of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O were mixed in a volume ratio of 8.5:2.5:1 and then pipette-added dropwise onto carbon nanotube paper, which was then vacuum-dried at a certain temperature. During this process, 1 cm... 2 A mixed solution of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O in ethanol was dispersed on carbon nanotube paper, and the paper was vacuum-dried at 40°C. The vacuum-dried carbon nanotube paper was then irradiated with a pulsed laser under argon protection to remove the FeCl₂·4H₂O from the carbon nanotube paper. 2+ Cr 3+ and Ni 2+ The carbon nanotube paper was reduced to Fe-Cr-Ni ternary alloy nanocrystalline particles. The laser parameters for this process were: laser wavelength 1064 nm, laser frequency 900 kHz, pulse width 2 ns, and energy 0.5 W. The carbon nanotube paper loaded with Fe-Cr-Ni ternary alloy nanocrystalline particles was then sequentially immersed in ethanol and deionized water for 5 min to remove impurities from its surface. After the final ethanol cleaning, the paper was vacuum dried.

[0048] Figure 2 The image shown is a scanning electron microscope (SEM) image of the Fe-Cr-Ni ternary alloy nanocrystals prepared in this embodiment. Figure 3 The image shows a transmission electron microscope (TEM) image of the Fe-Cr-Ni ternary alloy nanocrystals prepared in this embodiment, revealing a distinct crystal structure. Figure 4 The image shows a statistical chart of the nanocrystalline particle size of ternary alloys, with an average grain size of approximately 9 nm. Figure 5 The image shows the energy spectrum of ternary alloy nanocrystalline particles, indicating that the ternary alloy contains three elements: Fe, Cr, and Ni. Figure 6 The XRD results of the ternary alloy nanocrystalline particles indicate that the ternary alloy has a crystalline structure. Figure 7 The potentiodynamic polarization curves of the ternary alloy nanocrystalline particles FeCr18Ni9 prepared in this embodiment in 1M KOH solution are shown.

[0049] (2) Catalysis of Fe-Cr-Ni ternary alloy nanocrystal particles

[0050] The prepared Fe-Cr-Ni ternary alloy nanocrystals were used as electrodes to electrolyze water in a 1M KOH solution.

[0051] Appendix Figure 8 The image shows the Nyquist plot of the Fe-Cr-Ni ternary alloy nanocrystalline particles prepared in this example in 1M KOH solution. The results indicate that the charge transfer resistance of these nanocrystalline particles in 1M KOH solution is 16 Ω·cm. 2 , Figure 9 The polarization diagram of the Fe-Cr-Ni ternary alloy nanocrystals prepared in this example in 1M KOH solution shows an oxygen evolution overpotential of 270 mV @ 10 mA·cm. -1 .

[0052] Example 2

[0053] 1. Preparation of Fe-Cr-Ni ternary alloy nanocrystalline particles

[0054] First, 100 mM ethanol solutions of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O were prepared separately. The prepared ethanol solutions of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O were mixed in a volume ratio of 8.5:2.5:1 and then pipette-added dropwise onto carbon nanotube paper, which was then vacuum-dried at a certain temperature. During this process, 1 cm... 2 A mixed solution of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O in ethanol was dispersed on carbon nanotube paper, and the paper was vacuum-dried at 40°C. The vacuum-dried carbon nanotube paper was then irradiated with a pulsed laser under argon protection to remove the FeCl₂·4H₂O from the carbon nanotube paper. 2+ Cr 3+ and Ni 2+ The carbon nanotube paper was reduced to Fe-Cr-Ni ternary alloy nanocrystalline particles. The laser parameters for this process were: laser wavelength 1064 nm, laser frequency 900 kHz, pulse width 2 ns, and energy 0.5 W. The carbon nanotube paper loaded with Fe-Cr-Ni ternary alloy nanocrystalline particles was then sequentially immersed in ethanol and a precipitate solution for 5 min to remove impurities from its surface. The final step involved vacuum drying after ethanol washing.

[0055] (2) Catalysis of Fe-Cr-Ni ternary alloy nanocrystal particles

[0056] The prepared Fe-Cr-Ni ternary alloy nanocrystals were used as electrodes. First, potentiostatic polarization was performed in 1M KOH solution for 3600 s at a constant potential of 0.5 V vs. Ag / AgCl. After potentiostatic polarization, OER (Oil Emission Reduction) tests were conducted in 1M KOH solution.

[0057] Example 3

[0058] 1. Preparation of Fe-Cr-Ni ternary alloy nanocrystalline particles

[0059] First, 100 mM ethanol solutions of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O were prepared separately. The prepared ethanol solutions of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O were mixed in a volume ratio of 6:5:1 and then added dropwise onto carbon nanotube paper using a pipette, followed by vacuum drying at a specific temperature. During this process, 1 cm... 2 A mixed solution of FeCl₂·4H₂O, CrCl₃·6H₂O, and NiCl₂·6H₂O in ethanol was dispersed on carbon nanotube paper, and the paper was vacuum-dried at 40°C. The vacuum-dried carbon nanotube paper was then irradiated with a pulsed laser under argon protection to remove the FeCl₂·4H₂O from the carbon nanotube paper. 2+ Cr 3+ and Ni 2+ The carbon nanotube paper was reduced to Fe-Cr-Ni ternary alloy nanocrystalline particles. The laser parameters for this process were: laser wavelength 1064 nm, laser frequency 900 kHz, pulse width 2 ns, and energy 0.5 W. The carbon nanotube paper loaded with Fe-Cr-Ni ternary alloy nanocrystalline particles was then sequentially immersed in ethanol and a precipitate solution for 5 min to remove impurities from its surface. The final step involved vacuum drying after ethanol washing.

[0060] Figure 7 The potentiodynamic polarization curves of the ternary alloy nanocrystalline particles FeCr36Ni9 prepared in this embodiment in 1M KOH solution are shown.

[0061] (2) Catalysis of Fe-Cr-Ni ternary alloy nanocrystal particles.

[0062] The prepared Fe-Cr-Ni ternary alloy nanocrystals were used as electrodes. First, potentiostatic polarization was performed in 1M KOH solution for 3600 s at a constant potential of 0.5 V vs. Ag / AgCl. After potentiostatic polarization, OER (Oil Emission Reduction) tests were conducted in 1M KOH solution.

[0063] Figure 10The polarization results of the Fe-Cr-Ni ternary alloy nanocrystalline particles prepared in this example after being subjected to different constant potential polarizations are shown. The results indicate that the oxygen evolution overpotential of the nanocrystalline particles after constant potential polarization at 0V, 0.1V, 0.2V, and 0.4V is 277mV@10mA·cm. -1 250mV@10mA·cm -1 230mV@10mA·cm -1 230mV@10mA·cm -1 .

[0064] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and these forms are all within the protection scope of the present invention.

Claims

1. A method for preparing Fe-Cr-Ni ternary alloy nanocrystalline particles, characterized in that, Includes the following steps: Step 1: Prepare ethanol solutions of FeCl2·4H2O, CrCl3·6H2O and NiCl2·6H2O respectively; mix the three ethanol solutions in a certain volume ratio to obtain a mixed solution; Step 2: drop the mixed solution on the carbon nanotube paper and vacuum dry; wherein, 40~50 μL of the mixed solution is dispersed on 1 cm 2 of the carbon nanotube paper, and the temperature of vacuum drying is 40~55 ℃; Step 3: Irradiate the vacuum-dried carbon nanotube paper with a pulsed laser under argon protection to prepare Fe-Cr-Ni ternary alloy nanocrystalline particles on the carbon nanotube paper; wherein the pulsed laser parameters are: laser wavelength 1064 nm, laser frequency 900 kHz, pulse width 2 ns, and energy 0.5~0.8 W.

2. A Fe-Cr-Ni ternary alloy nanocrystalline particle, characterized in that, The Fe-Cr-Ni ternary alloy nanocrystalline particles were prepared using the preparation method described in claim 1 and loaded onto carbon nanotube paper.

3. The application of Fe-Cr-Ni ternary alloy nanocrystalline particles according to claim 2 in water electrolysis, characterized in that, Carbon nanotube paper loaded with the Fe-Cr-Ni ternary alloy nanocrystal particles was used as an electrode, and the electrode was subjected to constant potential polarization and used for the electrolysis of water in an alkaline electrolytic solution.

4. The application according to claim 3, characterized in that, The electrode was subjected to constant potential polarization in a 1 M KOH solution.

5. The application according to claim 3, characterized in that, The potential for constant potential polarization is 0.1~0.5 V. Ag / AgCl The constant potential polarization time is 3600 s.

6. The application according to claim 3, characterized in that, The alkaline electrolysis solution for the electrolyzed water is a 1 M KOH solution.

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