Metal-based two-dimensional / two-dimensional heterojunction catalyst and preparation method thereof
Through the use of electrochemical in situ reduction methods in the metal -based two -dimensional/two -dimensional alien catalyst, it solves the problem that the existing technology is difficult to prepare a metal catalyst with a clean surface and a highly exposed activity center. Preparation and excellent catalytic performance.
Patent Information
- Application Number
- CN202310936763.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-27
- Publication Date
- 2025-01-28
AI Technical Summary
It is difficult to prepare metal catalysts with clean surfaces and highly exposed active centers, which affect their catalytic activity and stability.
The metal-based two-dimensional/two-dimensional heterogeneous knot catalyst is used to uniformly dispersed the two-dimensional carrier and metal salt solution, and stirred light at room temperature. Layer thickness metal thin layer structure.
The prepared catalysts have excellent catalytic activity and stability, and are suitable for electrocatalytic, photocatalytic and organic synthesis and other fields.
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Figure CN119368212A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of metal catalysts, and in particular to a metal-based two-dimensional / two-dimensional heterojunction catalyst and a preparation method thereof. Background Art
[0002] Precious metal catalysts have been widely used in photocatalysis, electrocatalysis and organic synthesis due to their excellent catalytic activity. Nevertheless, given the scarcity and high cost of precious metals, it is necessary to optimize the atomic utilization of precious metals for efficient catalysis in the pursuit of sustainable energy in society. As a link between single atoms and nanoparticles, two-dimensional metals show a significant surface area to volume ratio and unsaturated metal atoms, and ultrathin nanostructures with rich sites can maximize the utilization of atoms.
[0003] Since two-dimensional metals have extremely large surface energy, it is thermodynamically unfavorable for metal atoms to spontaneously form two-dimensional structures. The existing technology is to add various organic ligands to reduce the surface energy of the metal, so that the metal nucleates along a specific crystal plane to obtain highly protected two-dimensional nanosheets, but the organic ligands on the metal surface are difficult to remove, thus affecting the catalytic activity; or to use specific carrier gaps or chemical bonding between the carrier and the metal to anchor specific metals, but the active center of the catalyst obtained by this method may be highly covered and cannot be fully exposed, thereby affecting the catalytic activity, and only specific carriers and specific metals can be selected, which is not universal in the expansion of catalysts, which seriously affects the activity and stability of the catalytic reaction and its application in various industrial fields. Summary of the invention
[0004] In view of this, an embodiment of the present invention provides a metal-based two-dimensional / two-dimensional heterojunction catalyst and a preparation method thereof to solve the technical problem that it is difficult to prepare a catalyst with a clean surface and highly exposed active centers.
[0005] To achieve the above-mentioned purpose, according to one aspect of an embodiment of the present invention, a metal-based two-dimensional / two-dimensional heterojunction catalyst is provided, wherein the catalyst is a metal / two-dimensional carrier composite material having a two-dimensional morphology structure; wherein the mass percentage of the metal is 0.01-20wt.%, and the thickness of the metal is 2-5 atomic layers.
[0006] Optionally, the metal is selected from one or more of the following: platinum, ruthenium, rhodium, iridium, palladium, gold, silver, and osmium.
[0007] Optionally, the two-dimensional carrier is selected from at least one of the following: graphene carbon material, nitrogen-doped carbon material, boron-doped carbon material, phosphorus-doped carbon material, sulfur-doped carbon material.
[0008] In addition, according to another aspect of an embodiment of the present invention, a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst is provided, comprising:
[0009] The two-dimensional support is uniformly dispersed in a metal salt solution and stirred at room temperature in the dark to obtain a product;
[0010] washing and drying the product to obtain a catalyst precursor;
[0011] The catalyst precursor is coated on a carbon fiber cloth to obtain a working electrode;
[0012] The working electrode is reduced by an electrochemical in-situ reduction method, thereby preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst.
[0013] Optionally, the metal salt solution is a single metal salt solution or a multi-metal salt solution.
[0014] Optionally, the single metal salt solution is a single metal chloride solution, and the multi-metal salt solution is a multi-metal chloride solution.
[0015] Optionally, the single metal chloride solution is selected from the following: chloroplatinic acid solution, ruthenium trichloride hydrate solution, rhodium trichloride hydrate solution, chloroiridic acid solution, palladium dichloride solution, chloroauric acid solution, silver acetate solution, osmium trichloride solution.
[0016] Optionally, the multi-metal chloride solution is selected from at least two of the following: chloroplatinic acid solution, ruthenium trichloride hydrate solution, rhodium trichloride hydrate solution, chloroiridic acid solution, palladium dichloride solution, chloroauric acid solution, silver acetate solution, osmium trichloride solution.
[0017] Optionally, the concentration of the metal salt solution is 0.01-50 mM.
[0018] Optionally, the two-dimensional carrier is selected from at least one of the following: graphene carbon material, nitrogen-doped carbon material, boron-doped carbon material, phosphorus-doped carbon material, sulfur-doped carbon material.
[0019] One embodiment of the above invention has the following advantages or beneficial effects: the preparation method of the metal-based two-dimensional / two-dimensional heterojunction catalyst provided in the embodiment of the present invention has the advantage of simple process, and the prepared catalyst has excellent catalytic activity and stability, and can be applied to electrocatalysis, photocatalysis, organic synthesis and other fields.
[0020] The further effects of the above-mentioned non-conventional optional manner will be described below in conjunction with the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:
[0022] Figure 1 is a transmission electron microscope image of the catalyst precursor in Example 1;
[0023] Figure 2 It is a linear sweep voltammetry curve diagram of multiple consecutive times in Example 1;
[0024] Figure 3 A transmission electron microscope image of the platinum-based two-dimensional / two-dimensional heterojunction catalyst in Example 1 and a corresponding absorption intensity curve;
[0025] Figure 4 is an X-ray diffraction spectrum of the platinum-based two-dimensional / two-dimensional heterojunction catalyst and its precursor in Example 1;
[0026] Figure 5 The linear scanning voltammetry curve of the platinum-based two-dimensional / two-dimensional heterojunction catalyst electrode stabilized after continuous linear voltammetry scanning in Example 1 and the linear scanning voltammetry curves of the electrodes of Comparative Example 2 and Comparative Example 3;
[0027] Figure 6 A graph showing the change in current over time in a 12-hour constant potential stability test of a platinum-based two-dimensional / two-dimensional heterojunction catalyst electrode stabilized after continuous linear voltammetric scanning in Example 1;
[0028] Figure 7 It is a transmission electron microscope image of the platinum-rhodium based two-dimensional / two-dimensional heterojunction catalyst in Example 15 and the corresponding absorption intensity curve. DETAILED DESCRIPTION
[0029] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.
[0030] In order to solve the technical problems existing in the prior art, the embodiments of the present invention provide a metal-based two-dimensional / two-dimensional heterojunction catalyst, which controls the coupling of a two-dimensional single metal or alloy with a two-dimensional carrier by designing a novel heterojunction interface charge induction strategy and using an electrochemical in-situ reduction method. And it is not limited by the type of metal and has universal applicability to different types of metals. The preparation method of the metal-based two-dimensional / two-dimensional heterojunction catalyst is simple, has excellent catalytic activity and stability, and can be applied to the fields of electrocatalysis, photocatalysis and organic synthesis.
[0031] Based on the above inventive concept, an embodiment of the present invention provides a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is a metal / two-dimensional carrier composite material with a two-dimensional morphology structure; wherein the mass percentage of the metal is 0.01-20wt.%, and the thickness of the metal is 2-5 atomic layers.
[0032] Optionally, the metal is selected from one or more of the following: platinum, ruthenium, rhodium, iridium, palladium, gold, silver, osmium. The metal in the metal-supported two-dimensional / two-dimensional heterojunction catalyst presents a two-dimensional thin layer structure, including amorphous clusters and crystalline nanosheets, and the thickness does not exceed five atomic layers, or even does not exceed four atomic layers, and has extremely high universality and is not limited by the type of metal.
[0033] This metal-based two-dimensional / two-dimensional heterojunction catalyst was used for electrocatalytic hydrogen evolution reaction and showed quite superior catalytic activity.
[0034] Optionally, the two-dimensional carrier is selected from at least one of the following: graphene carbon material, nitrogen-doped carbon material, boron-doped carbon material, phosphorus-doped carbon material, sulfur-doped carbon material.
[0035] The embodiment of the present invention further provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, comprising the following steps:
[0036] The two-dimensional support is uniformly dispersed in a metal salt solution and stirred at room temperature in the dark to obtain a product;
[0037] washing and drying the product to obtain a catalyst precursor;
[0038] The catalyst precursor is coated on a carbon fiber cloth to obtain a working electrode;
[0039] The working electrode is reduced by an electrochemical in-situ reduction method, thereby preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst.
[0040] Optionally, the preparation method may include the following steps:
[0041] The two-dimensional carrier is uniformly dispersed in a metal salt solution and stirred at room temperature in the dark for 12 hours to obtain a product;
[0042] washing and drying the product to obtain a catalyst precursor;
[0043] 2 mg of catalyst precursor was placed in a small sample tube, and then 0.6 mL of ultrapure water, 1.2 mL of anhydrous ethanol and 0.2 mL of 10 wt.% nafion aqueous dispersion were added, and an ink-like dispersion was formed by ultrasonication. 0.1 mL of the ink-like dispersion was dropped on a 1.0 cm x 1.0 cm carbon fiber cloth, and dried naturally to obtain a working electrode;
[0044] The working electrode was placed in an electrolytic cell containing 0.5M sulfuric acid aqueous solution and electrochemical reduction was performed using linear sweep voltammetry. During multiple continuous scans, the current density output by the working electrode gradually increased until it reached a stable state, and the catalyst precursor on the electrode underwent structural reconstruction and eventually formed a stable metal-based 2D / 2D heterojunction catalyst.
[0045] The embodiment of the present invention designs a new electrochemical in-situ reduction strategy, which utilizes the rectifying interface charge induction to prepare metal-based two-dimensional / two-dimensional heterojunction catalysts. By selecting a suitable two-dimensional carrier, the metal atoms are adsorbed on the two-dimensional carrier, and then in the process of the in-situ electrochemical reduction reaction, the pre-adsorbed metal atoms are diffused and nucleated along the surface of the two-dimensional carrier under the drive of the current. As the reduction reaction proceeds, the metal atoms gradually become a metal phase structure until a stable state is reached. It is precisely because of the interface rectification effect between the metal and the carrier that the prepared catalyst presents an ultra-thin two-dimensional metal sheet or cluster structure with a thickness of 2-5 metal atomic layers. Moreover, the preparation method is not limited by the type of metal, and is universal for different types of metals. It can prepare a variety of metal-based two-dimensional / two-dimensional heterojunction catalysts including platinum, ruthenium, rhodium, iridium, and osmium.
[0046] Optionally, the metal salt solution is a single metal salt solution or a multi-metal salt solution.
[0047] Optionally, the monometallic salt solution is a monometallic chloride solution, and the polymetallic salt solution is a polymetallic chloride solution, which is helpful to adsorb metal atoms on a two-dimensional carrier. For example, one or more of platinum tetrachloride solution, chloroplatinic acid solution, ruthenium trichloride solution, ruthenium trichloride hydrate solution, rhodium trichloride solution, rhodium trichloride hydrate solution, iridium trichloride solution, chloroiridic acid solution, palladium dichloride solution, sodium chloropalladate solution, gold trichloride solution, chloroauric acid solution, silver acetate solution, silver nitrate solution, osmium trichloride solution, osmium trichloride hydrate solution, and the like.
[0048] Optionally, the single metal chloride solution is selected from the following: chloroplatinic acid solution, ruthenium trichloride hydrate solution, rhodium trichloride hydrate solution, chloroiridic acid solution, palladium dichloride solution, chloroauric acid solution, silver acetate solution, osmium trichloride solution.
[0049] Optionally, the multi-metal chloride solution is selected from at least two of the following: chloroplatinic acid solution, ruthenium trichloride hydrate solution, rhodium trichloride hydrate solution, chloroiridic acid solution, palladium dichloride solution, chloroauric acid solution, silver acetate solution, osmium trichloride solution.
[0050] Optionally, the concentration of the metal salt solution is 0.01-50 mM. For example, the concentration of the metal salt solution is 0.02 mM, 0.08 mM, 0.15 mM, 1.70 mM, 5.0 mM, 9.0 mM, 15.0 mM, 22.0 mM, 37.0 mM, 46.0 mM or 48.8 mM, etc. In these embodiments, it is helpful to adsorb metal atoms on the two-dimensional carrier, so that the prepared catalyst has excellent catalytic activity and stability.
[0051] Optionally, the two-dimensional carrier is selected from at least one of the following: graphene carbon material, nitrogen-doped carbon material, boron-doped carbon material, phosphorus-doped carbon material, sulfur-doped carbon material, and these two-dimensional carriers can efficiently adsorb metal atoms.
[0052] Optionally, the two-dimensional carrier is uniformly dispersed in water to obtain an aqueous dispersion of the two-dimensional carrier, comprising: uniformly dispersing the two-dimensional carrier in water by ultrasonic stirring to obtain an aqueous dispersion of the two-dimensional carrier. Ultrasonic stirring helps to uniformly disperse the two-dimensional carrier in water, so that the metal atoms are quickly adsorbed on the two-dimensional carrier.
[0053] Therefore, the preparation method of the metal-based two-dimensional / two-dimensional heterojunction catalyst provided in the embodiment of the present invention has the advantage of simple process, and the prepared catalyst has excellent catalytic activity and stability, and can be applied to fields such as electrocatalysis, photocatalysis and organic synthesis.
[0054] In order to help understand the solutions of the present invention, several specific technical solutions are given below for detailed description.
[0055] Example 1
[0056] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is prepared according to the following steps:
[0057] The two-dimensional nitrogen-doped carbon material is uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 20.0mM, and stirred in the dark at room temperature for 12 hours. The product is washed and dried to obtain a catalyst precursor. 2mg of the catalyst precursor is placed in a small sample tube, and then 0.6mL of ultrapure water, 1.2mL of anhydrous ethanol and 0.2mL of 10wt.% nafion aqueous dispersion are added. The ink-like dispersion is formed by ultrasonication, and 0.1mL of the ink-like dispersion is dropped on a 1.0cm x 1.0cm carbon fiber cloth, and the working electrode is naturally dried to obtain the working electrode. The working electrode is placed in an electrolytic cell containing a 0.5M sulfuric acid aqueous solution, and electrochemical reduction is performed using linear sweep voltammetry. In multiple continuous scans, the current density output by the working electrode gradually increases until it reaches a stable state, and the catalyst precursor on the electrode undergoes structural reconstruction and eventually forms a stable platinum-based two-dimensional / two-dimensional heterojunction catalyst.
[0058] Example 2
[0059] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that: the two-dimensional graphene carbon material is uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 20.0 mM.
[0060] Example 3
[0061] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that: the two-dimensional boron-doped carbon material is uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 20.0 mM.
[0062] Example 4
[0063] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that: the two-dimensional phosphorus-doped carbon material is uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 20.0 mM.
[0064] Example 5
[0065] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 0.01 mM.
[0066] Example 6
[0067] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 50.0 mM.
[0068] Example 7
[0069] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a ruthenium trichloride hydrate solution with a ruthenium concentration of 20.0 mM.
[0070] Example 8
[0071] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a rhodium trichloride hydrate solution with a rhodium concentration of 20.0 mM.
[0072] Example 9
[0073] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a chloroiridic acid solution with an iridium concentration of 20.0 mM.
[0074] Example 10
[0075] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a palladium dichloride solution with a palladium concentration of 10.0 mM.
[0076] Embodiment 11
[0077] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a chloroauric acid solution with a gold concentration of 0.01 mM.
[0078] Example 12
[0079] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a silver acetate solution with a silver concentration of 10.0 mM.
[0080] Example 13
[0081] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in an osmium trichloride solution with an osmium concentration of 20.0 mM.
[0082] Embodiment 14
[0083] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional boron-doped carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid and rhodium trichloride with a total metal concentration of 20.0 mM (wherein the concentration ratio of platinum to rhodium is 9:1).
[0084] Embodiment 15
[0085] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid and rhodium trichloride with a total metal concentration of 20.0 mM (wherein the concentration ratio of platinum to rhodium is 1:1).
[0086] Example 16
[0087] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional sulfur-doped carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid and rhodium trichloride with a total metal concentration of 10.0 mM (wherein the concentration ratio of platinum to rhodium is 1:9).
[0088] Embodiment 17
[0089] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which is different from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid and chloroiridic acid with a total metal concentration of 20.0 mM (wherein the concentration ratio of platinum to iridium is 1:1).
[0090] Embodiment 18
[0091] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which differs from the preparation method of Example 1 in that the two-dimensional graphene carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid and ruthenium trichloride with a total metal concentration of 20.0 mM (wherein the concentration ratio of platinum to ruthenium is 1:1).
[0092] Embodiment 19
[0093] This embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which differs from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a mixed solution of ruthenium trichloride and rhodium trichloride with a total metal concentration of 20.0 mM (wherein the concentration ratio of ruthenium to rhodium is 1:1).
[0094] Embodiment 20
[0095] The present embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which differs from the preparation method of Example 1 in that the two-dimensional graphene carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid, chloroiridic acid and osmium trichloride with a total metal concentration of 20.0 mM (wherein the concentration ratio of platinum, iridium and osmium is 1:1:1).
[0096] Embodiment 21
[0097] The present embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which differs from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a mixed solution of ruthenium trichloride, rhodium trichloride and chloroiridic acid with a total metal concentration of 20.0 mM (wherein the concentration ratio of ruthenium, rhodium and iridium is 1:1:1).
[0098] Embodiment 22
[0099] The present embodiment provides a method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, which differs from the preparation method of Example 1 in that the two-dimensional nitrogen-doped carbon material is uniformly dispersed in a mixed solution of chloroplatinic acid, osmium trichloride, ruthenium trichloride, rhodium trichloride and chloroiridic acid with a total metal concentration of 20.0 mM (wherein the concentration ratio of platinum, osmium, ruthenium, rhodium and iridium is 1:1:1:1:1).
[0100] Comparative Example 1: Preparation of platinum nanoparticle heterojunction catalyst
[0101] The two-dimensional nitrogen-doped carbon material was uniformly dispersed in a chloroplatinic acid solution with a platinum concentration of 20.0 mM, and stirred at room temperature in the dark for 12 hours. The product was washed and dried to obtain a catalyst precursor. The catalyst precursor was placed in a tube furnace, heated to 750°C at a rate of 5°C / min in a 5% H2 / Ar atmosphere, calcined for 2 hours, and naturally cooled to room temperature to obtain a platinum nanoparticle heterojunction catalyst.
[0102] Comparative Example 2: Preparation of platinum nanoparticle nitrogen-carbon material working electrode
[0103] 2 mg of the platinum nanoparticle nitrogen-carbon material prepared in Comparative Example 1 was put into a small sample tube, and then 0.6 mL of ultrapure water, 1.2 mL of anhydrous ethanol and 0.2 mL of a 10% nafion aqueous solution were added, and an ink-like dispersion was formed by ultrasound. 0.1 mL of the ink-like dispersion was dropped on a 1.0 cm x 1.0 cm carbon fiber cloth, and the workpiece was naturally dried to obtain a platinum nanoparticle nitrogen-carbon material working electrode. The performance of hydrogen production by electrolysis of water was tested in a 0.5 M sulfuric acid aqueous solution, and the performance was compared with that in Example 1.
[0104] Comparative Example 3: Preparation of Commercial Platinum-Carbon Material Working Electrode
[0105] 2 mg of commercial platinum carbon with a mass fraction of 40 wt.% of platinum was put into a small sample tube, and then 0.6 mL of ultrapure water, 1.2 mL of anhydrous ethanol and 0.2 mL of a 10% nafion aqueous solution were added, and an ink-like dispersion was formed by ultrasonication. 0.1 mL of the ink-like dispersion was dropped on a 1.0 cm x 1.0 cm carbon fiber cloth, and dried naturally to obtain a commercial platinum carbon material working electrode, and the performance of hydrogen production by electrolysis of water was tested in a 0.5 M sulfuric acid aqueous solution, and the performance was compared with that of Example 1. Comparative Example 3 uses commercial platinum carbon, which is currently widely studied, to prepare an electrode.
[0106] The following is a structural analysis of the single metal platinum-based two-dimensional / two-dimensional heterojunction catalyst obtained in Example 1 and a bimetallic platinum-rhodium-based two-dimensional / two-dimensional heterojunction catalyst obtained in Example 15, as well as water electrolysis hydrogen evolution reaction testing and performance evaluation.
[0107] Figure 1 This is a transmission electron microscope image of the catalyst precursor in Example 1. The bright spots in the image are all platinum ion precursors.
[0108] Figure 2 It is a linear scanning voltammetry curve diagram of multiple consecutive times in Example 1. In the consecutive scanning, the current density output by the working electrode gradually increases until it becomes stable.
[0109] Figure 3 The transmission electron microscope image and the corresponding absorption intensity curve of the platinum-based two-dimensional / two-dimensional heterojunction catalyst in Example 1. It can be seen from the absorption intensity curve that, taking the absorption intensity of one atom as one atomic layer as the benchmark, the absorption intensity of the obtained nanosheet is 2-5 times the absorption intensity of the single atomic platinum marked with a circle, so it can be concluded that its thickness is 2-5 atomic layers.
[0110] Figure 4 : This is the X-ray diffraction spectrum of the platinum-based two-dimensional / two-dimensional heterojunction catalyst and its precursor in Example 1. It can be seen that after electrochemical reduction, a new peak appears at 39.7°, which corresponds to the 111 characteristic crystal plane of metallic platinum.
[0111] Figure 5 The linear scanning voltammetry curve of the platinum-based two-dimensional / two-dimensional heterojunction catalyst electrode stabilized after continuous linear voltammetry scanning in Example 1 and the linear scanning voltammetry curves of the electrodes of Comparative Examples 2 and 3. It can be seen that the platinum-based two-dimensional / two-dimensional heterojunction catalyst prepared in Example 1 exhibits excellent electrocatalytic hydrogen evolution performance, and its performance is significantly better than that of platinum nanoparticle nitrogen-carbon materials and commercial platinum-carbon catalysts.
[0112] Figure 6The current variation over time of the platinum-based two-dimensional / two-dimensional heterojunction catalyst electrode stabilized after continuous linear voltammetric scanning in Example 1 in a constant potential stability test within 12 hours is shown. It can be seen that after a long period of hydrogen evolution reaction at a high current density, the current of the platinum-based two-dimensional / two-dimensional heterojunction catalyst has no obvious attenuation compared to the initial current, indicating its excellent stability for hydrogen evolution in water electrolysis.
[0113] Figure 7 The transmission electron microscope image and the corresponding absorption intensity curve of the platinum-rhodium based two-dimensional / two-dimensional heterojunction catalyst in Example 15. From the absorption intensity curve, it can be seen that the absorption intensity of the obtained platinum-rhodium particles is 2-5 times the absorption intensity of the single atom marked with a circle, so it can be concluded that its thickness is 2-5 atomic layers.
[0114] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A metal-based two-dimensional / two-dimensional heterojunction catalyst, characterized in that: The catalyst is a metal / two-dimensional carrier composite material with a two-dimensional morphology structure; wherein the mass percentage of the metal is 0.01-20wt.%, and the thickness of the metal is 2-5 atomic layers.
2. The metal-based two-dimensional / two-dimensional heterojunction catalyst according to claim 1, characterized in that: The metal is selected from one or more of the following: platinum, ruthenium, rhodium, iridium, palladium, gold, silver, and osmium.
3. The metal-based two-dimensional / two-dimensional heterojunction catalyst according to claim 1 or 2, characterized in that: The two-dimensional carrier is selected from at least one of the following: graphene carbon material, nitrogen-doped carbon material, boron-doped carbon material, phosphorus-doped carbon material, and sulfur-doped carbon material.
4. A method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst, characterized in that: include: The two-dimensional support is uniformly dispersed in a metal salt solution and stirred at room temperature in the dark to obtain a product; washing and drying the product to obtain a catalyst precursor; The catalyst precursor is coated on a carbon fiber cloth to obtain a working electrode; The working electrode is reduced by an electrochemical in-situ reduction method, thereby preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst.
5. The method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst according to claim 4, characterized in that: The metal salt solution is a single metal salt solution or a multi-metal salt solution.
6. The method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst according to claim 5, characterized in that: The single metal salt solution is a single metal chloride solution, and the multi-metal salt solution is a multi-metal chloride solution.
7. The method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst according to claim 6, characterized in that: The single metal chloride solution is selected from the following: chloroplatinic acid solution, ruthenium trichloride hydrate solution, rhodium trichloride hydrate solution, chloroiridic acid solution, palladium dichloride solution, chloroauric acid solution, silver acetate solution, osmium trichloride solution.
8. The method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst according to claim 6, characterized in that: The multi-metal chloride solution is selected from at least two of the following: chloroplatinic acid solution, ruthenium trichloride hydrate solution, rhodium trichloride hydrate solution, chloroiridic acid solution, palladium dichloride solution, chloroauric acid solution, silver acetate solution, and osmium trichloride solution.
9. The method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst according to any one of claims 4 to 8, characterized in that: The concentration of the metal salt solution is 0.01-50 mM.
10. The method for preparing a metal-based two-dimensional / two-dimensional heterojunction catalyst according to any one of claims 4 to 9, characterized in that: The two-dimensional carrier is selected from at least one of the following: graphene carbon material, nitrogen-doped carbon material, boron-doped carbon material, phosphorus-doped carbon material, and sulfur-doped carbon material.