Self-assembled iridium nanoflower and preparation method thereof
By synthesizing self-assembled iridium nanoflowers in a one-pot method, the problem of large overpotential in the process of hydrogen production by electrolysis of water was solved, and low-cost and efficient preparation of uniform nanoflower-shaped catalysts was achieved, which improved the activity and stability of the electrode material and is suitable as a template for other nanomaterials.
Patent Information
- Application Number
- CN202211661037.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-23
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2042-12-23
AI Technical Summary
In the existing process of hydrogen production by water electrolysis, the overpotential of the oxygen evolution reaction at the anode is large and the overpotential of the cathode is also high, resulting in a scarcity of electrode materials, hindering the commercialization of hydrogen production by water electrolysis. In addition, the size and morphology of the catalyst affect its activity and stability.
Self-assembled iridium nanoflowers were synthesized in a one-pot method under mild conditions using iridium trichloride hydrate as a precursor, polyvinylpyrrolidone as a surfactant, and formic acid as a reducing agent and surface directing agent. Self-assembled iridium nanoflowers with uniform size and morphology were prepared using N-methylpyrrolidone as a solvent.
A simple and low-cost preparation process was achieved, and uniformly dispersed self-assembled nanoflower-like products were obtained, which improved the catalytic performance and stability and can be used as templates for other alloy nanomaterials with self-assembled nanoflower structures.
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Figure CN115815617B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of nanocatalytic materials, and particularly relates to a self-assembled iridium nanoflower and a preparation method thereof. Background Art
[0002] Energy is an integral part of scientific and technological development. Hydrogen has attracted the attention of researchers due to its high calorific value, pollution-free nature, and widespread availability. Among traditional hydrogen production methods, water electrolysis is considered a promising approach because it completely eliminates dependence on fossil fuels and can be easily integrated with other renewable energy conversion systems. However, current water electrolysis hydrogen production faces a challenge: the oxygen evolution reaction (OER) at the anode exhibits excessively high overpotentials, while the cathode overpotential needs to be reduced. Electrode materials that can operate stably and maintain activity at these high overpotentials are extremely scarce, hindering the commercialization of water electrolysis hydrogen production. Iridium-based materials have relatively excellent hydrogen adsorption free energies, theoretically allowing for low overpotentials. They also maintain strong stability even at the high OER overpotentials. Therefore, they are currently considered one of the best electrode materials for the OER. As one of the most chemically stable elements, the development of iridium-based materials for the HER also holds promise for achieving long-term stable operation. Furthermore, in current research, the size, dimensions, and morphology of the catalyst electrode material itself influence the ultimate activity and stability. Self-assembled nanomaterials have unique structural advantages, such as anisotropy, excellent structural stability, and strong anti-dissolution ability. Self-assembled nanomaterials can also be used as substrates for modification or used in different systems to enhance catalytic performance and stability. Summary of the Invention
[0003] The purpose of the present invention is to provide a self-assembled iridium nanoflower and a preparation method thereof.
[0004] In order to achieve the above object, the present invention adopts the following technical solutions:
[0005] A method for preparing self-assembled iridium nanoflowers is characterized in that it comprises the following steps:
[0006] Step 1, adding 4-20 mg of iridium trichloride hydrate and 10-30 mg of polyvinyl pyrrolidone to 3-9 mL of organic solvent in sequence, stirring evenly with a magnetic stirrer, and then ultrasonicating for 20-50 minutes to obtain a homogeneous solution;
[0007] Step 2: quickly add 1-4 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution;
[0008] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform a hydrothermal reaction in an oven preheated to 80-120° C. for 7-9 hours;
[0009] Step 4: After the reaction is completed, the oven is sealed and cooled to room temperature in the oven, and then the obtained product is centrifuged and washed to obtain self-assembled iridium nanoflowers.
[0010] Furthermore, the solvent is N-methylpyrrolidone, N-vinylpyrrolidone or N-ethylpyrrolidone.
[0011] Furthermore, the centrifugal washing in step 4 is performed by centrifugation at 12000 rpm using acetone for three times, with each centrifugation time being 10 minutes.
[0012] The principle of the present invention is: using iridium trichloride hydrate as a precursor, polyvinyl pyrrolidone as a surfactant, formic acid as a reducing agent and surface directing agent, and N-methylpyrrolidone as a solvent (N-vinylpyrrolidone or N-ethylpyrrolidone can also be used as a solvent, but the repeatability is best when N-methylpyrrolidone is used as a solvent), self-assembled iridium nanoflowers with uniform size and morphology can be synthesized through a one-pot method under relatively mild conditions.
[0013] The beneficial effects of the present invention are embodied in:
[0014] 1. The present invention adopts a one-pot method to prepare self-assembled iridium nanoflowers, which has simple process, low cost and high yield;
[0015] 2. The product prepared by the present invention presents a uniformly dispersed self-assembled nanoflower shape with consistent size;
[0016] 3. The self-assembled iridium nanoflower structure prepared by the present invention can be used as a template to synthesize other alloy nanomaterials with self-assembled nanoflower structures. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 and Figure 2 This is the FESEM image of the self-assembled iridium nanoflower obtained in Example 1, where Figure 1 and Figure 2 Corresponding to different magnifications.
[0018] Figure 3 and Figure 4 This is a TEM image of the self-assembled iridium nanoflower obtained in Example 1, wherein Figure 3 and Figure 4 Corresponding to different magnifications.
[0019] Figure 5 This is the X-ray energy spectrum EDS data of the self-assembled iridium nanoflowers obtained in Example 1. DETAILED DESCRIPTION
[0020] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.
[0021] Example 1
[0022] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0023] Step 1: To 6 mL of N-methylpyrrolidone, 12 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred evenly by magnetic stirring, and ultrasonicated for 40 minutes to obtain a homogeneous solution.
[0024] Step 2: Rapidly add 2 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0025] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 100° C. for 7 hours.
[0026] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0027] The scanning electron microscope images, transmission electron microscope images and X-ray energy spectrum images of the self-assembled iridium nanoflowers prepared in this embodiment are shown in FIG. Figures 1 to 5 As shown. Figures 1 to 5 It can be seen that the product obtained in this example presents a uniform self-assembled nanoflower structure with consistent size.
[0028] Example 2
[0029] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0030] Step 1: To 3 mL of N-methylpyrrolidone, 12 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred evenly by magnetic stirring, and ultrasonicated for 40 minutes to obtain a homogeneous solution.
[0031] Step 2: Rapidly add 2 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0032] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 120° C. for 7 hours.
[0033] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0034] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0035] Example 3
[0036] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0037] Step 1: To 9 mL of N-methylpyrrolidone, 4 mg of iridium trichloride hydrate and 10 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred evenly by magnetic stirring, and ultrasonicated for 40 min to obtain a homogeneous solution.
[0038] Step 2: Rapidly add 2 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0039] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 90° C. for 7 hours.
[0040] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0041] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0042] Example 4
[0043] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0044] Step 1: To 6 mL of N-methylpyrrolidone, 20 mg of iridium trichloride hydrate and 30 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred evenly by magnetic stirring, and ultrasonicated for 40 minutes to obtain a homogeneous solution.
[0045] Step 2: Rapidly add 2 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0046] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 80° C. for 7 hours.
[0047] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0048] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0049] Example 5
[0050] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0051] Step 1: To 6 mL of N-methylpyrrolidone, 12 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred evenly by magnetic stirring, and ultrasonicated for 40 minutes to obtain a homogeneous solution.
[0052] Step 2: 1 mL of formic acid was quickly added to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0053] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 120° C. for 7 hours.
[0054] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0055] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0056] Example 6
[0057] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0058] Step 1: To 3 mL of N-methylpyrrolidone, 12 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred evenly by magnetic stirring, and ultrasonicated for 40 minutes to obtain a homogeneous solution.
[0059] Step 2: 3 mL of formic acid was quickly added to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0060] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 110° C. for 7 hours.
[0061] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0062] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0063] Example 7
[0064] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0065] Step 1: To 6 mL of N-ethylpyrrolidone, 12 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was magnetically stirred and ultrasonicated for 40 min to obtain a homogeneous solution.
[0066] Step 2: 2 mL of formic acid was quickly added to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0067] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 100° C. for 7 hours.
[0068] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0069] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0070] Example 8
[0071] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0072] Step 1: To 9 mL of N-vinyl pyrrolidone, 12 mg of iridium trichloride hydrate and 20 mg of polyvinyl pyrrolidone were added in sequence, the mixture was stirred magnetically and ultrasonicated for 40 min to obtain a homogeneous solution.
[0073] Step 2: 1 mL of formic acid was quickly added to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0074] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 100° C. for 7 hours.
[0075] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0076] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0077] Example 9
[0078] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0079] Step 1: To 3 mL of N-methylpyrrolidone, 16 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred magnetically and ultrasonicated for 40 min to obtain a homogeneous solution.
[0080] Step 2: Rapidly add 2 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0081] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 120° C. for 7 hours.
[0082] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0083] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0084] Example 10
[0085] In this embodiment, self-assembled iridium nanoflowers were prepared according to the following steps:
[0086] Step 1: To 6 mL of N-methylpyrrolidone, 16 mg of iridium trichloride hydrate and 20 mg of polyvinylpyrrolidone were added in sequence, the mixture was stirred magnetically and ultrasonicated for 40 min to obtain a homogeneous solution.
[0087] Step 2: 4 mL of formic acid was quickly added to the homogeneous solution obtained in step 1 to obtain a precursor solution.
[0088] Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform hydrothermal reaction in an oven preheated to 100° C. for 7 hours.
[0089] Step 4: After the reaction is completed, keep the oven sealed and cool to room temperature in the oven, then use acetone to centrifuge and wash the resulting product three times at 12000 rpm, each centrifugation time is 10 minutes, and self-assembled iridium nanoflowers are obtained.
[0090] Characterization showed that the product obtained in this example had a uniform self-assembled iridium nanoflower structure and was relatively consistent in size.
[0091] The above are merely exemplary embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for preparing self-assembled iridium nanoflowers, characterized in that: The steps include: Step 1, adding 4-20 mg of iridium trichloride hydrate and 10-30 mg of polyvinyl pyrrolidone to 3-9 mL of an organic solvent, stirring the mixture magnetically, and then ultrasonicating the mixture for 20-50 minutes to obtain a homogeneous solution; the solvent is N-methylpyrrolidone, N-vinylpyrrolidone, or N-ethylpyrrolidone; Step 2: quickly add 1-4 mL of formic acid to the homogeneous solution obtained in step 1 to obtain a precursor solution; Step 3: Transfer the precursor solution obtained in step 2 to a polytetrafluoroethylene reactor and perform a hydrothermal reaction in an oven preheated to 80-120° C. for 7-9 hours; Step 4: After the reaction is completed, the oven is sealed and cooled to room temperature in the oven, and then the obtained product is centrifuged and washed to obtain self-assembled iridium nanoflowers.
2. The method for preparing self-assembled iridium nanoflowers according to claim 1, wherein: The centrifugal washing in step 4 is performed by centrifugation at 12000 rpm using acetone for three times, with each centrifugation time being 10 minutes.
3. A self-assembled iridium nanoflower prepared by the preparation method according to any one of claims 1 to 2.
Citation Information
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