MXene loaded two-dimensional branched PdNi nanosheet heterojunction material, and preparation method and application thereof
By preparing two-dimensional branched PdNi nanosheet heterojunction materials in situ on MXene, the problems of cumbersome preparation methods and poor catalytic performance in the prior art are solved, and efficient and uniform electrocatalytic performance is improved.
Patent Information
- Application Number
- CN202310290254.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-23
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2043-03-23
AI Technical Summary
Existing methods for preparing composite heterostructure electrocatalysts are cumbersome, have poor loading stability and uniformity, and the catalyst morphology cannot be adjusted, resulting in poor catalytic performance.
Two-dimensional branched PdNi nanosheets were synthesized on MXene using an in-situ reduction method. The nanosheets were then linked by electrostatic adsorption and electron transfer to form chemical bonds, resulting in a heterojunction material with controllable morphology and uniform distribution of MXene-supported two-dimensional branched PdNi nanosheets.
It improves the stability and electrocatalytic performance of the catalyst, provides more active sites and electronic pathways, improves the metal-support interaction, simplifies the preparation process, and improves the uniformity and robustness of the product.
Smart Images
Figure CN116516387B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalytic water electrolysis for hydrogen production technology, specifically relating to an MXene-supported two-dimensional branched PdNi nanosheet heterojunction material, its preparation method, and its application. Background Technology
[0002] Energy is the material foundation upon which human society depends for survival and development. With global development and population growth, energy demand is increasing, projected to reach 30 terawatts by 2050. Statistics show that 79.5% of consumed energy comes from carbon-based fossil fuels (oil, coal, and natural gas, etc.), causing significant environmental damage and contributing to the greenhouse effect. Therefore, changing the energy structure and increasing the proportion of renewable energy has become a consensus for sustainable development. Hydrogen (H2) is particularly valuable due to its extremely high energy density (120 MJ / kg⁻¹). -1 ~140MJkg -1 Its significant advantages, such as ease of storage and transportation, zero carbon emissions during use, and abundant sources, have made it one of the most promising energy materials to replace fossil fuels, attracting widespread attention.
[0003] The preparation of composite MXene-based two-dimensional material heterostructure electrocatalysts by loading two-dimensional metal alloy catalysts onto two-dimensional MXene supports is a simple method commonly used to improve catalytic performance and stability. Due to the good mutual support and coupling between the different two-dimensional materials, and the triggering of a series of interactions between the metal and the support, MXene-based two-dimensional heterostructure materials can minimize the reduction in catalytic stability caused by self-stacking and rapid oxidation during the reaction. Furthermore, this structure facilitates rapid electron transfer within the catalyst, increasing catalytic reaction kinetics.
[0004] Currently, the construction of composite heterogeneous electrocatalysts mostly employs methods such as self-assembly and vacuum filtration (C.Cui,R.Cheng,H.Zhang,C.Zhang,Y.Ma,C.Shi,B.Fan,H.Wang,X.Wang;G.Xu,R.Si,J.Liu,L.Zhang,X.Gong,R.Gao,B.Liu,J.Zhang.Adv.Funct.Mater.2020,30,2000693;P.Zhang,R.Wang,T.Xiao,Z.Chang,Z.Fang,Z.Zhu,C.Xu,L.Wang,J.Cheng.Energy.Technol.2020,8,2000306). These methods typically involve first synthesizing a metal catalyst and then further loading it onto a support. This process is not only cumbersome and energy-intensive, but also fails to guarantee the robustness and uniformity of the loading. Current literature describes metal catalysts obtained on MXene via in-situ reduction, typically as spherical nanoparticles with untunable morphology. Compared to spherical nanoparticles, two-dimensional branched structures generally possess a higher specific surface area, exposing more active sites and exhibiting superior catalytic performance.
[0005] Therefore, there is an urgent need for a composite heterostructure electrocatalyst that is simple to operate under, has high catalytic activity, and exhibits better loading strength and long-term stability. Summary of the Invention
[0006] To address the shortcomings of existing technologies and the urgent need for hydrogen energy, this invention provides an MXene-supported two-dimensional branched PdNi nanosheet heterojunction material, its preparation method, and its applications. Specifically, it is a TBA-V2CT material after intercalation and exfoliation treatment. x As a conductive substrate, branched PdNi nanosheets were synthesized on its surface by in-situ reduction. This MXene-supported two-dimensional branched PdNi nanosheet heterojunction material exhibits excellent hydrogen evolution catalytic activity and stability.
[0007] This invention is achieved through the following technical solution:
[0008] The first objective of this invention is to provide a method for preparing an MXene-supported two-dimensional branched PdNi nanosheet heterojunction material, comprising the following steps:
[0009] (1) V2CT x The powder was dispersed in tetrabutylammonium hydroxide, and the solid phase was separated by solid-liquid separation. Water was added to prepare thin-film TBA-V2CT. x Aqueous solution;
[0010] (2) Disperse the aqueous solutions of palladium salt and nickel salt in a surfactant and mix them evenly. Add the thinly sliced TBA-V2CT obtained in step (1). x The aqueous solutions are mixed thoroughly to obtain a mixed solution.
[0011] (3) The mixed solution obtained in step (2) is mixed and reacted with a reducing agent, and the solid phase is separated by solid-liquid separation. The obtained solid phase is the MXene-supported two-dimensional branched PdNi nanosheet heterojunction material; wherein, the material is supported on TBA-V2CT x The PdNi above is an ultrathin two-dimensional branched nanosheet with controllable morphology.
[0012] In one embodiment of the present invention, in step (1), the thinned TBA-V2CT x The thickness is 0.3nm-1nm.
[0013] In one embodiment of the present invention, in step (2), the palladium salt is selected from chloropalladium acid.
[0014] In one embodiment of the present invention, in step (2), the nickel salt is selected from nickel chloride.
[0015] In one embodiment of the present invention, in step (2), the surfactant is selected from docosyltrimethylammonium chloride.
[0016] In one embodiment of the present invention, in step (3), the reducing agent is selected from ascorbic acid.
[0017] In one embodiment of the present invention, in step (3), the conditions for the mixing reaction are: 15℃~60℃ for 6h~10h.
[0018] The second objective of this invention is to provide an MXene-supported two-dimensional branched PdNi nanosheet heterojunction material prepared by the aforementioned preparation method.
[0019] In one embodiment of the present invention, the molar ratio of palladium to nickel in the MXene-supported two-dimensional branched PdNi nanosheet heterojunction material is 3:7 to 8:2.
[0020] The third objective of this invention is to provide the application of the MXene-supported two-dimensional branched PdNi nanosheet heterojunction material in electrocatalytic water electrolysis for hydrogen production.
[0021] The in-situ reduction loading method adopted in this invention first generates electrostatic adsorption and electron transfer on the surface of the conductive substrate. After being reduced to a metal alloy with the reducing agent, there is a chemical bond connection between the metal and the support. This not only further improves the electronic structure, making the catalyst more stable, but also makes the distribution more uniform and the strength higher.
[0022] The beneficial effects of this invention are:
[0023] (1) This invention provides an MXene-supported two-dimensional branched PdNi nanosheet heterojunction material, its preparation method, and its application. The ultrathin two-dimensional branched PdNi alloy has advantages such as controllable morphology, uniform distribution, multi-dendritic structure, and ultrathin structure, which can provide more defects and electronic pathways and expose a larger specific surface area. Therefore, it has superior electrocatalytic performance.
[0024] (2) Traditionally, pre-synthesized nanocatalysts are loaded onto MXene using electrostatic self-assembly or coating methods, resulting in uneven distribution of the nanoalloys. Furthermore, nanoalloys obtained through in-situ reduction in MXene are typically spherical nanoparticles with untunable morphology. The present invention employs in-situ reduction to load two-dimensional PdNi nanosheets onto an MXene support, allowing for controllable and tunable morphology, and ensuring uniform PdNi distribution on the MXene. Due to the strong electron transfer interaction between the nanoalloy and the conductive substrate, the loading is more robust, improving not only the electronic structure of the catalyst metal and the conductive substrate but also more easily triggering strong metal-support interactions, thus enhancing electrocatalytic performance.
[0025] (3) The formula of this invention is simple, the experimental conditions are mild, the product yield is high and uniform, and it can be produced on a large scale. Attached Figure Description
[0026] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:
[0027] Figure 1 It is the Pd6Ni4 / TBA-V2CT in Embodiment 1 of this invention. x Characterization diagrams of composite heterostructure hydrogen evolution electrocatalysts; among which, Figure 1 -a and Figure 1 -b are all Pd6Ni4 / TBA-V2CT x TEM image; Figure 1 -c is Pd6Ni4 / TBA-V2CT x AFM diagram; Figure 1 -d is Figure 1 A graph showing the height versus distance of the selected area in -c;
[0028] Figure 2 This is a high-resolution TEM image of Pd6Ni4 / TBA-V2CTx in Embodiment 1 of the present invention;
[0029] Figure 3 It is the Pd6Ni4 / TBA-V2CT in Embodiment 1 of this invention. xEnergy-dispersive X-ray spectroscopy (EDS);
[0030] Figure 4 The PdNi / TBA-V2CT prepared by adding palladium and nickel precursors in various proportions in Examples 2-4 of this invention. x TEM images; among them, Figure 4 -a represents the PdNi / TBA-V2CT in Embodiment 2 of this invention. x TEM image; Figure 4 -b PdNi / TBA-V2CT in Embodiment 3 of the present invention x TEM image; Figure 4 -c represents the PdNi / TBA-V2CT in Embodiment 4 of this invention. x TEM image;
[0031] Figure 5 These are TEM images of PdNi prepared by adding palladium and nickel precursors in proportions of those found in Comparative Examples 1-3 of this invention; wherein, Figure 5 -a is a TEM image of PdNi in Comparative Example 1 of this invention; Figure 5 -b TEM image of PdNi in Comparative Example 2 of this invention; Figure 5 -c is the TEM image of PdNi in Comparative Example 3 of this invention;
[0032] Figure 6 It is the Pd6Ni4 / TBA-V2CT in performance test 1. x Test curves of Pd6Ni4 and commercial Pd / C electrocatalysts; among which, Figure 6 -a is Pd6Ni4 / TBA-V2CT x LSV curves of Pd6Ni4 and commercial Pd / C electrocatalysts; Figure 6 -b is Pd6Ni4 / TBA-V2CT x Tafel slope curves of Pd6Ni4 and commercial Pd / C electrocatalysts;
[0033] Figure 7 It is the Pd6Ni4 / TBA-V2CT in performance test 2. x Pd3Ni7 / TBA-V2CT x Pd5Ni5 / TBA-V2CT x With Pd8Ni2 / TBA-V2CT x Test curves of electrocatalysts; among which, Figure 7 -a is Pd6Ni4 / TBA-V2CT x Pd3Ni7 / TBA-V2CT x Pd5Ni5 / TBA-V2CT x With Pd8Ni2 / TBA-V2CTx LSV curve of electrocatalyst; Figure 7 -b is Pd6Ni4 / TBA-V2CT x Pd3Ni7 / TBA-V2CT x Pd5Ni5 / TBA-V2CT x With Pd8Ni2 / TBA-V2CT x Tafel slope curve of electrocatalyst;
[0034] Figure 8 These are the test curves for the Pd3Ni7, Pd6Ni4, and Pd8Ni2 electrocatalysts in performance test 3; among them, Figure 8 -a represents the LSV curves of Pd3Ni7, Pd6Ni4, and Pd8Ni2; Figure 8 -b represents the Tafel slope curves of the Pd3Ni7, Pd6Ni4, and Pd8Ni2 electrocatalysts. Detailed Implementation
[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.
[0036] Example 1
[0037] This embodiment provides an MXene-supported two-dimensional branched PdNi nanosheet heterostructure material (PdNi / TBA-V2CT). x The preparation method of ) is as follows:
[0038] 1) Add 0.2g MXene (V2CT) x The powder (purchased from Shandong Xiyan New Materials Co., Ltd.) was uniformly dispersed in 20 mL of a 25% tetrabutylammonium hydroxide aqueous solution (TBAOH) intercalating agent. The solution was shaken at a constant speed at 20°C for 3 hours. After washing three times by centrifugation with ultrapure water, ultrapure water was added to prepare a 1M TBA-V2CT solution. x The aqueous solution was centrifuged at 6000 r / min.
[0039] 2) Disperse 600 μL of 0.01 mol / L palladium chloroacetic acid and 400 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly. Add the 1 MtBA-V2CT solution prepared above. x Mix 1 mL of the aqueous solution thoroughly to obtain a mixed solution.
[0040] 3) Place the mixed solution from step 2) in a constant temperature water bath at 25°C, add 1 mL of 0.1 mol / L ascorbic acid (AA) as a reducing agent, mix thoroughly, and continue the reaction in the 25°C water bath for 8 hours. After the reaction is complete, wash the mixed solution four times with ultrapure water by centrifugation, and then freeze-dry it into powder to obtain Pd6Ni4 / TBA-V2CT. x The powder (MXene-supported two-dimensional branched PdNi nanosheet heterojunction material) was centrifuged at 10,000 r / min, pre-cooled in a freeze dryer for 3 hours, and then freeze-dried for 30 hours.
[0041] The Pd6Ni4 / TBA-V2CT obtained in this embodiment x TEM images of composite heterostructure hydrogen evolution electrocatalysts are shown below. Figure 1 -a and Figure 1 As shown in -b, Pd6Ni4 two-dimensional nanodendritic wafers are uniformly loaded onto the conductive substrate TBA-V2CT. x Above, the lateral length of Pd6Ni4 is approximately 35 nm, and the resulting Pd6Ni4 / TBA-V2CT x AFM images as Figure 1 As shown in -c, TBA-V2CT x The thickness is approximately 0.5 nm, with a thickness distribution range of 0.3 nm to 1 nm. The average thickness of the Pd6Ni4 nanosheets is approximately 3.25 nm, classifying them as ultrathin two-dimensional materials.
[0042] The high-resolution TEM image of Pd6Ni4 / TBA-V2CTx obtained in this embodiment is as follows: Figure 2 As shown, two lattice fringes of Pd (111) and (112) can be distinguished on the surface of the Pd6Ni4 two-dimensional dendritic wafer, with interplanar spacings of 0.208 nm and 0.186 nm, respectively. These are slightly smaller than the interplanar spacings of pure Pd (111) and (112), which is attributed to the introduction of Ni with a smaller lattice, which causes the interplanar spacing of the alloy to decrease. This confirms the formation of the PdNi alloy. The conductive substrate TBA-V2CT x A lattice pattern can be distinguished on the surface, with a lattice spacing of 0.123 nm.
[0043] The Pd6Ni4 / TBA-V2CT obtained in this embodiment x Energy dispersive X-ray spectroscopy (EDS) such as Figure 3 As shown, elemental mapping confirms that Pd and Ni are uniformly dispersed in each two-dimensional nanodendritic, and that V, C, and O elements in the conductive matrix are uniformly distributed throughout the entire conductive matrix TBA-V2CT. x middle.
[0044] Example 2
[0045] This embodiment provides an MXene-supported two-dimensional branched PdNi nanosheet heterostructure material (PdNi / TBA-V2CT). x The preparation method of ) is as follows:
[0046] 1) Add 0.2g MXene (V2CT) x The powder was uniformly dispersed in 20 mL of a 25% tetrabutylammonium hydroxide aqueous solution as an intercalating agent. The solution was shaken at a constant speed at 20°C for 3 hours. Afterward, it was washed three times by centrifugation with ultrapure water. Finally, ultrapure water was added to prepare a 1 M TBA-V2CT solution. x The aqueous solution was centrifuged at 6000 r / min.
[0047] 2) Disperse 300 μL of 0.01 mol / L palladium chloroacetic acid and 700 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly. Then add the 1 MtBA-V2CT solution prepared above. x Mix 1 mL of the aqueous solution thoroughly to obtain a mixed solution.
[0048] 3) Place the mixed solution from step 2) in a constant temperature water bath at 25°C, add 600 μL of 0.1 mol / L ascorbic acid (AA) as a reducing agent, mix thoroughly, and continue the reaction in the 25°C water bath for 8 hours. After the reaction is complete, wash the mixed solution three times with ultrapure water by centrifugation, and then freeze-dry to obtain Pd3Ni7 / TBA-V2CT. x The powder was centrifuged at a speed of 10,000 r / min.
[0049] The Pd3Ni7 / TBA-V2CT obtained in this embodiment x TEM image as Figure 4 As shown in -a, by Figure 4 -a shows that the molar ratio of palladium to nickel precursors is 3:7.
[0050] Example 3
[0051] This embodiment provides an MXene-supported two-dimensional branched PdNi nanosheet heterostructure material (PdNi / TBA-V2CT). x The preparation method of ) is as follows:
[0052] 1) Add 0.2g MXene (V2CT) xThe powder was uniformly dispersed in 20 mL of a 25% tetrabutylammonium hydroxide aqueous solution as an intercalating agent. The solution was shaken at a constant speed at 20°C for 3 hours. Afterward, it was washed three times by centrifugation with ultrapure water. Finally, ultrapure water was added to prepare a 1 M TBA-V2CT solution. x The aqueous solution was centrifuged at 6000 r / min.
[0053] 2) Disperse 500 μL of 0.01 mol / L palladium chloroacetic acid and 500 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly. Then add the 1 MTBA-V2CT solution prepared above. x Mix 1 mL of the aqueous solution thoroughly to obtain a mixed solution.
[0054] 3) Place the mixed solution from step 2) in a constant temperature water bath at 25°C, add 600 μL of 0.1 mol / L ascorbic acid (AA) as a reducing agent, mix thoroughly, and continue the reaction in the 25°C water bath for 8 hours. After the reaction is complete, wash the mixed solution three times with ultrapure water by centrifugation, and then freeze-dry to obtain Pd5Ni5 / TBA-V2CT. x The powder was centrifuged at a speed of 10,000 r / min.
[0055] The Pd5Ni5 / TBA-V2CT obtained in this embodiment x TEM image as Figure 4 -b shows that, by Figure 4 -b shows that the molar ratio of palladium to nickel precursors is 5:5.
[0056] Example 4
[0057] This embodiment provides an MXene-supported two-dimensional branched PdNi nanosheet heterostructure material (PdNi / TBA-V2CT). x The preparation method of ) is as follows:
[0058] 1) Add 0.2g MXene (V2CT) x The powder was uniformly dispersed in 20 mL of a 25% tetrabutylammonium hydroxide aqueous solution as an intercalating agent. The solution was shaken at a constant speed at 20°C for 3 hours. Afterward, it was washed three times by centrifugation with ultrapure water. Finally, ultrapure water was added to prepare a 1 M TBA-V2CT solution. x The aqueous solution was centrifuged at 6000 r / min.
[0059] 2) Disperse 800 μL of 0.01 mol / L palladium chloroacetic acid and 200 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly. Then add the 1 MtBA-V2CT solution prepared above. x Mix 1 mL of the aqueous solution thoroughly to obtain a mixed solution.
[0060] 3) Place the mixed solution from step 2) in a constant temperature water bath at 25°C, add 600 μL of 0.1 mol / L ascorbic acid (AA) as a reducing agent, mix thoroughly, and continue the reaction in the 25°C water bath for 8 hours. After the reaction is complete, wash the mixed solution three times with ultrapure water by centrifugation, and then freeze-dry to obtain Pd8Ni2 / TBA-V2CT. x The powder was centrifuged at a speed of 10,000 r / min.
[0061] The Pd8Ni2 / TBA-V2CT obtained in this embodiment x TEM image as Figure 4 As shown in -c, by Figure 4 -c shows that the molar ratio of palladium to nickel precursors is 8:2, and the PdNi two-dimensional dendritic nanosheets are uniformly dispersed on the entire conductive matrix, exhibiting a controllable dendration morphology.
[0062] Comparative Example 1
[0063] This comparative example provides a method for preparing a PdNi aqueous solution, the preparation method is as follows:
[0064] 1) Disperse 300 μL of 0.01 mol / L palladium chloride and 700 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly to obtain a mixed solution.
[0065] 2) Place the mixed solution from step 1) in a constant temperature water bath and maintain the temperature at 25℃. Add 1 mL of a reducing agent with a concentration of 0.1 mol / L ascorbic acid (AA), mix well, and continue to react in the constant temperature water bath at 25℃ for 8 hours. After the reaction is completed, use ultrapure water to centrifuge and wash the mixed solution 3 times to obtain a Pd3Ni7 aqueous solution. After freeze-drying, Pd3Ni7 powder is obtained.
[0066] The TEM image of PdNi obtained in this comparative example is as follows: Figure 5 As shown in -a, by Figure 5 -a shows that the molar ratio of palladium to nickel precursors is 3:7.
[0067] Comparative Example 2
[0068] This comparative example provides a method for preparing a PdNi aqueous solution, the preparation method is as follows:
[0069] 1) Disperse 600 μL of 0.01 mol / L palladium chloride and 400 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly to obtain a mixed solution.
[0070] 2) Place the mixed solution from step 1) in a constant temperature water bath and maintain the temperature at 25℃. Add 1 mL of a reducing agent with a concentration of 0.1 mol / L ascorbic acid (AA), mix well, and continue to react in the constant temperature water bath at 25℃ for 8 hours. After the reaction is completed, use ultrapure water to centrifuge and wash the mixed solution 3 times to obtain Pd6Ni4 aqueous solution. After freeze-drying, Pd6Ni4 powder is obtained.
[0071] The TEM image of PdNi obtained in this comparative example is as follows: Figure 5 -b shows that, by Figure 5 -b shows that the molar ratio of palladium to nickel precursors is 6:4.
[0072] Comparative Example 3
[0073] This comparative example provides a method for preparing a PdNi aqueous solution, the preparation method is as follows:
[0074] 1) Disperse 800 μL of 0.01 mol / L palladium chloride and 200 μL of 0.01 mol / L nickel chloride aqueous solution in 10 mL of 0.01 mol / L docosyltrimethylammonium chloride surfactant and mix thoroughly to obtain a mixed solution.
[0075] 2) Place the mixed solution from step 1) in a constant temperature water bath and maintain the temperature at 25℃. Add 1 mL of a reducing agent with a concentration of 0.1 mol / L ascorbic acid (AA), mix well, and continue to react in the constant temperature water bath at 25℃ for 8 hours. After the reaction is completed, use ultrapure water to centrifuge and wash the mixed solution 3 times to obtain a Pd8Ni2 aqueous solution. After freeze-drying, Pd8Ni2 powder is obtained.
[0076] The TEM image of PdNi obtained in this comparative example is as follows: Figure 5 As shown in -c, by Figure 5 -c shows that the molar ratio of palladium to nickel precursors is 8:2.
[0077] In summary, it can be observed that as the molar ratio of palladium to nickel precursors changes, the unloaded TBA-V2CT...x It is impossible to prepare ultrathin, multi-dendritic, and uniformly dispersed PdNi alloys at present, which shows that the in-situ reduction loading has the significant advantage of controllable morphology.
[0078] Performance Test 1
[0079] Electrochemical performance testing: 0.3 mg of the Pd6Ni4 / TBA-V2CT prepared in Example 1 above was taken respectively. x Pd6Ni4 powder (prepared in Comparative Example 2) and 0.3 mg of commercial Pd / C powder were dispersed in a mixed solution of 400 μL ultrapure water, 560 μL ethanol, and 40 μL NaFion solution, respectively. The mixture was ultrasonically mixed for 30 min to obtain electrocatalyst ink. 30 μL of the electrocatalyst ink was dropped onto the surface of a glassy carbon electrode and dried at room temperature for more than 2 hours. The reference electrode was a calomel electrode, the counter electrode was a carbon rod, and the working electrode was a glassy carbon electrode. The mass of electrocatalyst ink coated on the surface of the glassy carbon electrode per square centimeter was 0.4 mg. The electrocatalytic hydrogen evolution performance was measured using an electrochemical workstation (Shanghai Chenhua, CHI660e).
[0080] The Pd6Ni4 / TBA-V2CT obtained in Example 1 x The LSV curves and Tafel slope curves of Pd6Ni4 obtained in Comparative Example 2 and the commercial Pd / C electrocatalyst are shown below. Figure 6 -a、 Figure 6 As shown in -b, it can be seen that the electrocatalytic performance of Pd6Ni4 / TBA-V2CT is significantly optimized after TBAOH intercalation treatment and in-situ reduction loading. x It exhibits significantly lower overpotentials than Pd6Ni4 and Pd / C, as well as the smallest Tafel slope, at a current density of 10 mA / cm². -2 At that time, the overpotential was only 88mV, and the Tafel slope was only 69.4mV dec -1 This confirms the Pd6Ni4 / TBA-V2CT x Heterogeneous electrocatalysts exhibit excellent electrocatalytic performance.
[0081] Performance Test 2
[0082] Electrochemical performance testing: 0.3 mg of Pd6Ni4 / TBA-V2CT prepared in Examples 1, 2, 3, and 4 above were taken respectively. x Powder, Pd3Ni7 / TBA-V2CT x Powder, Pd5Ni5 / TBA-V2CT x Powder, Pd8Ni2 / TBA-V2CT xThe powder was dispersed in a mixed solution of 400 μL ultrapure water, 560 μL ethanol and 40 μL NaFion solution, and ultrasonically mixed for 30 min to obtain electrocatalyst ink. 30 μL of the electrocatalyst ink was dropped onto the surface of a glassy carbon electrode and dried at room temperature for more than 2 hours. The reference electrode was a calomel electrode, the counter electrode was a carbon rod, and the working electrode was a glassy carbon electrode. The mass of electrocatalyst ink coated on the surface of the glassy carbon electrode per square centimeter was 0.4 mg. The electrocatalytic hydrogen evolution performance was measured using an electrochemical workstation (Shanghai Chenhua, CHI660e).
[0083] The Pd6Ni4 / TBA-V2CT obtained in Examples 1, 2, 3, and 4 x Pd3Ni7 / TBA-V2CT x Pd5Ni5 / TBA-V2CT x and Pd8Ni2 / TBA-V2CT x The LSV curves and Tafel slope curves of the electrocatalyst are shown below. Figure 7 As shown in -a and 7-b, Pd6Ni4 / TBA-V2CT can be found. x It possesses the lowest overpotential and the smallest Tafel slope, making it the most active among the selected electrocatalysts.
[0084] Performance Test 3
[0085] Electrochemical performance testing: 0.3 mg of Pd3Ni7 powder, Pd6Ni4 powder, and Pd8Ni2 powder prepared in Comparative Examples 1, 2, and 3 were respectively dispersed in a mixed solution of 400 μL ultrapure water, 560 μL ethanol, and 40 μL NaFion solution. The mixture was ultrasonically mixed for 30 min to obtain electrocatalyst ink. 30 μL of the electrocatalyst ink was dropped onto the surface of a glassy carbon electrode and dried at room temperature for more than 2 hours. The reference electrode was a calomel electrode, the counter electrode was a carbon rod, and the working electrode was a glassy carbon electrode. The mass of electrocatalyst ink coated on the surface of the glassy carbon electrode per square centimeter was 0.4 mg. The electrocatalytic hydrogen evolution performance was measured using an electrochemical workstation (Shanghai Chenhua, CHI660e).
[0086] The LSV curves and Tafel slopes of the Pd3Ni7, Pd6Ni4, and Pd8Ni2 electrocatalysts obtained in Comparative Examples 1, 2, and 3 are as follows: Figure 8 -a、 Figure 8 As shown in -b, it can be found that the best-performing Pd6Ni4 electrocatalyst operates at a current density of 10 mA / cm². -2 At that time, the overpotential was still as high as 130mV, and the Tafel slope was 148.53mV dec. -1The reason stems from the non-dendritic morphology and the unsupported catalyst, thus explaining the relationship between dendritic morphology and in-situ supported reduction and V2CT. x The above can significantly optimize the catalytic activity of electrocatalysts.
[0087] Meanwhile, a comparison with the data from Examples 1, 3, and 4 reveals that for electrocatalysts with the same Pd and Ni ratios, the overpotential and Tafel slope both decrease when loaded onto the MXene substrate via in-situ reduction, resulting in improved electrocatalytic hydrogen evolution activity. This indicates that loading onto the MXene conductive substrate via in-situ reduction is an effective method to improve the activity of electrocatalysts.
[0088] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for preparing an MXene-supported two-dimensional branched PdNi nanosheet heterojunction material, characterized in that, Includes the following steps: (1) V2CT x The powder was dispersed in tetrabutylammonium hydroxide, and the solid phase was separated by solid-liquid separation. Water was added to prepare thin-film TBA-V2CT. x Aqueous solution; (2) Disperse the aqueous solutions of palladium salt and nickel salt in a surfactant and mix them evenly. Add the thinly sliced TBA-V2CT obtained in step (1). x The aqueous solutions are mixed thoroughly to obtain a mixed solution. (3) The mixed solution obtained in step (2) is mixed with a reducing agent and reacted. The solid phase is separated from the liquid phase and the obtained solid phase is the MXene-supported two-dimensional branched PdNi nanosheet heterojunction material. In step (2), the surfactant is selected from docosyltrimethylammonium chloride.
2. The preparation method according to claim 1, characterized in that, In step (1), the thinned TBA-V2CT x The thickness is 0.3 nm - 1 nm.
3. The preparation method according to claim 1, characterized in that, In step (2), the palladium salt is selected from chloropalladium acid.
4. The preparation method according to claim 1, characterized in that, In step (2), the nickel salt is selected from nickel chloride.
5. The preparation method according to claim 1, characterized in that, In step (3), the reducing agent is selected from ascorbic acid.
6. The preparation method according to claim 1, characterized in that, In step (3), the conditions for the mixed reaction are: 15 ℃~60 ℃ for 6 h~10 h.
7. The MXene-supported two-dimensional branched PdNi nanosheet heterojunction material prepared by the preparation method according to any one of claims 1 to 6.
8. The MXene-supported two-dimensional branched PdNi nanosheet heterojunction material according to claim 7, characterized in that, The molar ratio of palladium to nickel in the MXene-supported two-dimensional branched PdNi nanosheet heterojunction material is 3:7~8:
2.
9. The application of the MXene-supported two-dimensional branched PdNi nanosheet heterojunction material according to claim 7 in electrocatalytic water electrolysis for hydrogen production.