Method for in-situ preparation of FeNi oxide OER self-supporting electrode by femtosecond laser
The in-situ fabrication of FeNi oxide self-supporting electrodes on nickel foam substrates using femtosecond lasers solves the problems of time-consuming, labor-intensive, and safety hazards associated with traditional fabrication methods. This achieves efficient and low-cost fabrication of self-supporting electrodes, improving catalytic performance and stability.
Patent Information
- Application Number
- CN202511291787.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-10
- Publication Date
- 2025-11-07
AI Technical Summary
In the existing technology, the preparation method of self-supporting electrodes is time-consuming and labor-intensive, and there are safety hazards. It is difficult to prepare them on a large scale using laser methods.
FeNi oxide self-supporting electrodes were fabricated in situ on a nickel foam substrate using a femtosecond laser. A nano-flower-like structure was etched on the nickel foam by laser ablation to form FeNi oxide. Taking advantage of the high energy and high precision of the laser, the oxide was directly loaded onto the nickel foam, avoiding the need for adding stabilizers and high-temperature treatment.
This method enables the efficient preparation of self-supporting electrodes, simplifies the operation process, reduces costs, improves catalytic performance and electrode stability, and enhances the loading capacity of active sites.
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Figure CN120905703A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to a preparation method of a non-conventional self-supporting electrode, in particular to a method for preparing a FeNi oxide OER self-supporting electrode in situ by using a femtosecond laser. BACKGROUND
[0002] At present, compared with a powder electrode, a catalyst can be anchored and dispersed on a carrier, so that more active sites are exposed and loaded, in addition, a suitable 3D structure and porosity result in a large specific surface area, fast charging and mass transfer characteristics, finally, a strong adhesion force and seamless integration between the catalyst and the carrier can prevent the mechanical shedding of an electrocatalyst from the carrier during water decomposition at a large current density. Most of the self-supporting electrodes prepared by a traditional chemical method are prepared by a hydrothermal method, so that a displacement reaction occurs between foamed nickel and iron by applying high temperature and high pressure, so that the foamed nickel grows on the foamed nickel, the method is time-consuming and labor-consuming, and a long period is usually required, and the method has a certain danger.
[0003] In recent years, laser technology has been increasingly improved. The self-supporting electrode prepared by using the foamed nickel as the substrate by the femtosecond laser not only greatly reduces the time compared with the chemical preparation, but also is very simple to operate. Laser-induced irradiation has the advantages of high energy, high precision, fast speed, easy control and low cost, and is an excellent method for rapidly preparing nanomaterials. At the same time, due to the high energy of the laser in an instant, the chemical bonds between molecules can be broken and recombined, so that metal elements and non-metal elements are combined to form a new material with structural defects. Therefore, free Fe3+ is combined with O elements to form Fe oxide and Ni oxide, so that the Fe element can be loaded in the foamed nickel material. However, at present, the self-supporting electrode cannot be prepared on a large scale by the laser method.
[0004] In view of this, the application is provided. SUMMARY
[0005] The application aims to provide a method for preparing a FeNi oxide OER self-supporting electrode in situ by using a femtosecond laser, so as to solve the above technical problems in the prior art.
[0006] The application aims to achieve the above technical problems in the prior art.
[0007] The method for preparing a FeNi oxide OER self-supporting electrode in situ by using a femtosecond laser provided by the application has the characteristics that the method comprises the following steps:
[0008] 1) The foamed nickel material is cleaned in hydrochloric acid and ultrapure water;
[0009] 2) An iron nitrate solution is prepared;
[0010] 3) The nickel foam is immersed in an iron nitrate solution and ablated by laser irradiation to obtain an ablated sample;
[0011] The ablated sample is cleaned by ultrasonic cleaning with pure water and anhydrous ethanol and dried for storage.
[0012] 2. The method of claim 1, wherein in step 1), soaking in hydrochloric acid for 20 minutes is used to completely remove the oxide layer.
[0013] 3. The method of claim 2, wherein in step 2), the concentration of the iron nitrate is 0.15 mol / L.
[0014] 4. The method of claim 3, wherein in step 3), the laser parameters are 800 nm, 1.55 eV, and 1 kHz, and the sample is obtained by ablation for 20 minutes.
[0015] 5. The method of any one of claims 1-4, wherein the obtained sample is matched with the characteristic peaks of the iron oxide standard card JCPDS No. 84-0311, and powder X-ray diffraction is performed to determine the phase of the sample.
[0016] 6. The method of claim 5, wherein the SEM results of the obtained sample show that the morphology is nanoflower-shaped, and the size is 190-210 nm.
[0017] Compared with the prior art, the method for in-situ preparation of FeNi oxide OER self-supporting electrode provided by the application utilizes femtosecond laser micro-nano processing, can controllably change the surface structure of the material, endows the material with specific physical properties, and brings excellent structural defects. The method uses foamed nickel as a substrate, ablates the metal foamed nickel in an iron nitrate solution to prepare a self-supporting electrode with foamed nickel as a substrate, does not need to add any other stabilizer and carrier during the reaction process, does not need high temperature and other various gases, and has the advantages of high efficiency, simple operation, and low price of raw materials. Moreover, the method directly uses foamed nickel as a substrate without other adhesives, and has great application prospects in the field of catalysts. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 The figure shows the schematic diagram of the embodiment of the application before (left) and after (right) femtosecond laser etching.
[0019] Figure 2 EDS pattern of the ablated nickel foam in the Fe(NO3)3 solution of the embodiment of the present application;
[0020] Figure 3 XRD pattern of the ablated nickel foam in the Fe(NO3)3 solution of the embodiment of the present application;
[0021] Figure 4 XPS pattern of the ablated nickel foam in the Fe(NO3)3 solution of the embodiment of the present application;
[0022] Figure 5 Schematic diagram of the electrochemical performance comparison of the ablated nickel foam in the Fe(NO3)3 solution and air of the embodiment of the present application. DETAILED DESCRIPTION
[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application, which do not constitute a limitation on the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.
[0024] Firstly, the terms possibly used in the present text are explained as follows:
[0025] The terms “include”, “contain”, “have”, “possess” or other similar semantic descriptions should be interpreted as non-exclusive inclusion.
[0026] The contents not described in detail in the embodiments of the present application belong to the prior art known to those skilled in the art. If the specific conditions are not indicated in the embodiments of the present application, the conventional conditions or the conditions suggested by the manufacturer are adopted. If the reagents or instruments used in the embodiments of the present application are not indicated by the manufacturer, they are all conventional products that can be purchased in the market.
[0027] The method for in-situ preparation of FeNi oxide OER self-supporting electrode by femtosecond laser of the present application comprises the following steps:
[0028] 1) The nickel foam material is cleaned in hydrochloric acid and ultrapure water;
[0029] 2) The ferric nitrate solution is configured;
[0030] 3) The nickel foam is immersed in the ferric nitrate solution and ablated by laser irradiation to obtain the ablated product sample;
[0031] And the ablated sample is ultrasonically cleaned with pure water and anhydrous ethanol, and dried and stored.
[0032] In step 1), the immersion in hydrochloric acid is 20 min, which is used for completely removing the oxide layer.
[0033] In step 2), the concentration of ferric nitrate is prepared to be 0.15 mol / L.
[0034] In step 3), the laser parameters are 800nm, 1.55eV, and 1kHz; the sample is obtained by ablation for 20 minutes.
[0035] The obtained sample was matched with the characteristic peaks of the iron oxide standard card JCPDS No. 84-0311, and powder X-ray diffraction was performed to determine the sample phase.
[0036] The obtained sample SEM results showed that the morphology was nanoflower-like, with a size of 190 nm to 210 nm.
[0037] In summary, the method for in-situ fabrication of FeNi oxide OER self-supporting electrodes using femtosecond lasers in this invention utilizes the high frequency and low energy characteristics of femtosecond lasers. By intentionally controlling the laser velocity, different morphological structures are etched onto a nickel foam substrate. Simultaneously, the laser's properties allow iron ions from ferric nitrate to be tightly loaded onto the nickel foam, thereby forming the FeNi oxide self-supporting electrode. Because the process requires no additional stabilizers or other carriers, and does not require high temperatures or various gases, this method is highly efficient, simple to operate, and uses inexpensive raw materials.
[0038] To more clearly demonstrate the technical solution and its effects provided by the present invention, the embodiments of the present invention will be described in detail below with reference to specific examples.
[0039] Example 1
[0040] like Figure 1 As shown:
[0041] To extend this invention, a method for fabricating self-supporting electrodes based on nickel foam substrates using laser technology is presented, showing a comparison before (left) and after (right) femtosecond laser etching.
[0042] Specifically, it includes:
[0043] First, nickel foam was placed in a ferric nitrate solution and ablated for 20 minutes using an 800 nm, 1.55 eV, 1000 Hz femtosecond laser at a speed of 4.67 mm / s. The sample was then ultrasonically cleaned and dried to obtain a FeNi oxide self-supporting electrode based on nickel foam.
[0044] like Figure 2 The image shown is an EDS diagram of ablated nickel foam in ferric nitrate.
[0045] In order to determine whether the surface morphology structure of the foamed nickel is changed obviously under the action of femtosecond laser and whether the iron oxide is grown in situ in the foamed nickel. It is determined by SEM test that the foamed nickel is etched out of different morphology by femtosecond laser, the surface structure is changed obviously, and the obvious nano flower structure appears. This structure can load more active sites due to the increase of the specific surface area of the material, so as to achieve the purpose of enhancing the catalytic performance.
[0046] As shown in Figure 3 , it is the XRD diagram of the ablated foamed nickel in Fe(NO3)3 solution
[0047] Through the XRD analysis of the ablated foamed nickel in the iron nitrate solution, it is confirmed that compared with the original foamed nickel, in addition to the characteristic peak of nickel, the characteristic peaks of iron oxide and nickel oxide appear after ablation in the Fe(NO3)3 solution. It can be determined that the oxide is grown in situ in the foamed nickel material after laser ablation. This structure can greatly enhance the catalytic performance of the material.
[0048] At the same time, the original foamed nickel and the treated foamed nickel are subjected to XPS test:
[0049] Figure 4 It is the XPS diagram of the ablated foamed nickel in Fe(NO3)3 solution;
[0050] As shown in Figure 4 , it can be known that the original foamed nickel has been partially oxidized in the air. There is a peak of 0-valent Ni at 854eV, and the other four peaks are respectively the two characteristic peaks of Ni 2p3 / 2 and Ni 2p1 / 2 of 0-valent Ni oxidized to +2-valent, accompanied by two satellite peaks, as shown in Figure 4 . By observing the Ni 2p peak of the foamed nickel material treated by laser, the characteristic peak of 0-valent nickel has completely disappeared, only the Ni 2p3 / 2 peak at 856eV and the Ni 2p1 / 2 peak at 872.9 remain.
[0051] As shown in Figure 4 , from the Fe 2p spectrum, two characteristic peaks of Fe3+ 2p3 / 2 (712.8eV) and Fe3+ 2p1 / 2 (723.4eV) are presented. Figure 4 As shown in , from the O 1s spectrum, one oxygen vacancy peak and one metal oxide peak can be observed, which is due to the instantaneous energy of laser, which can break and recombine chemical bonds, and then promote the recombination of nickel iron elements and oxygen to form oxides.
[0052] The sample was subjected to electrochemical test, and the OER activity was analyzed in 1M KOH solution. For comparison, we analyzed the OER of the nickel foam material ablated in air and Fe(NO3)3 solution, respectively. It can be seen that the performance of the nickel foam material ablated in the laser is significantly improved as Figure 5 After ablation in air, the overpotential at 10 mA cm⁻² is reduced to 389.4 mV, and the LSV curve shows a rising and then falling trend at 400 mV, which is due to the oxidation peak of nickel itself. The nickel foam material ablated by femtosecond laser in Fe(NO3)3 solution has the best performance, with an overpotential of only 194.4 mV at 10 mA cm⁻², and the Tafel slope is reduced to 86 mV dec⁻¹, which shows the effect of laser ablation on the improvement of electrocatalytic performance. This is because the femtosecond laser changes the structure and morphology of the nickel foam itself, greatly improving its hydrophilicity and air resistance, which is beneficial to the separation of H2 and O2 generated, and the specific surface area of the nickel foam material is increased, adding more active sites, which also helps to improve the electrochemical performance. In addition, under the action of femtosecond laser, oxides are grown in situ on the nickel foam substrate. Due to the electronic coupling between Fe and Ni, the overall water splitting performance is improved. Based on the above research, a high-performance electrocatalytic electrode with OER was successfully ablated. At the same time, we tested the impedance of the nickel foam ablated in air and the nickel foam ablated by laser in Fe(NO3)3 solution, and the results showed that the nickel foam material ablated in Fe(NO3)3 had the lowest charge transfer resistance, indicating that it had good electrode kinetics. Under the condition of stable electrocatalytic current density of 10 mA cm⁻², the electrolysis voltage based on laser ablated nickel foam can basically remain unchanged within 40 h. But it is still relatively stable, which confirms the excellent stability of the nickel foam electrode.
[0053] As shown in Figure 5 , it is a comparison chart of electrochemical performance of nickel foam ablated in iron nitrate solution and air.
[0054] The present application is based on the characteristics of femtosecond laser with high peak power, low heat effect and high power, and can change the surface structure of the material controllably by micro-nano processing of femtosecond laser, so that the material has the desired physical properties, and also can generate rich structural defects. Compared with pure metal elements, the electronic coupling effect between Fe and Ni can significantly improve the performance of water electrolysis. Therefore, the present application ablates the foamed nickel material in the Fe solution by laser, generates oxides, and synchronously changes the surface morphology structure of the foamed nickel, thereby greatly strengthening the catalytic effect of water electrolysis. The self-supporting electrode prepared by this method avoids the coating process and the addition of adhesive and conductive agent, simplifies the electrode manufacturing process and greatly saves the cost, in addition, the substrate material can cause high loading of active material, can provide rich active sites, at the same time, without the addition of adhesive, prevents the catalyst from falling off. This method is simple in operation, green and efficient, and has strong universality, which expands the new application of femtosecond laser preparation technology.
[0055] The above description is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be limited to the protection scope of the claims. The information disclosed in the background section of the present application is only intended to deepen the understanding of the general background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes the prior art known to those skilled in the art.
Claims
1. A method for in-situ preparation of FeNi oxide OER self-supporting electrode by femtosecond laser, characterized in that, The method comprises the steps of: 1) cleaning the foamed nickel material in hydrochloric acid and ultrapure water; 2) preparing an iron nitrate solution; 3) immersing the foamed nickel in the iron nitrate solution and performing laser irradiation ablation to obtain an ablated product sample; and cleaning the ablated sample with pure water and anhydrous ethanol, drying and storing.
2. The method for in-situ fabrication of FeNi oxide OER self-supporting electrode by femtosecond laser according to claim 1, characterized in that, In the step 1), the foamed nickel is immersed in the hydrochloric acid for 20 min to completely remove the oxide layer.
3. The method for in-situ fabrication of FeNi oxide OER self-supporting electrode by femtosecond laser according to claim 2, characterized in that, In the step 2), the concentration of the iron nitrate is 0.15 mol / L.
4. The method for in-situ fabrication of FeNi oxide OER self-supporting electrode by femtosecond laser according to claim 3, characterized in that, In the step 3), the laser parameters are 800 nm, 1.55 eV and 1 kHz; and the sample is obtained by ablation for 20 min.
5. The method for fabricating FeNi oxide OER self-supporting electrode in situ by femtosecond laser according to any one of claims 1-4, characterized in that, The obtained sample is matched with the characteristic peaks of the iron oxide standard card JCPDS No. 84-0311, and powder X-ray diffraction is performed to determine the phase of the sample.
6. The method for in-situ fabrication of FeNi oxide OER self-supporting electrode by femtosecond laser according to claim 5, characterized in that, The SEM result of the obtained sample shows that the morphology is nanoflower-shaped, and the size is 190 nm to 210 nm.