A method for synthesizing amorphous PdP hollow nanoparticles
Amorphous PdP hollow nanoparticles were prepared by doping carbon, nitrogen and phosphorus with non-metallic elements, which solved the synthesis problem of amorphous hollow platinum group metal materials in the existing technology, achieved the improvement of electrocatalytic performance and simplified the preparation process.
Patent Information
- Application Number
- CN202411886603.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2044-12-20
AI Technical Summary
Existing technologies mainly focus on hollow platinum group metal-based materials in conventional crystalline phases, and lack controllable synthesis methods to prepare amorphous hollow platinum group metal-based intermetallic nanomaterials, which limits their application potential in the field of electrocatalysis.
The method of doping carbon, nitrogen and phosphorus with non-metallic elements is adopted to prepare cubic Pd nanoparticles, cubic PdCN nanoparticles and amorphous PdP hollow nanoparticles, including using reagents such as polyvinylpyrrolidone, L-ascorbic acid, potassium bromide, sodium chloropalladate, oleylamine and trioctylphosphine, and controlling the reaction temperature and cleaning process to synthesize amorphous PdP hollow nanoparticles.
Amorphous PdP hollow nanoparticles of uniform size were successfully prepared, providing more active sites and a large surface area, thereby improving the efficiency of the electrocatalytic reaction. The preparation process was simplified by using commercially available reagents and laboratory equipment.
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Figure CN119683581B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of nano material synthesis and application, and in particular relates to a method for synthesizing amorphous PdP hollow nanoparticles. Background Art
[0002] Since the phase engineering strategy of nanomaterials was proposed, this strategy has played an important role in adjusting the structure and properties of nanomaterials, greatly broadening the application range of various nanomaterials in different fields. In particular, amorphous nanomaterials, whose long-range disordered atomic arrangement exhibits superior performance than crystalline materials in many fields such as optics, magnetism, electricity and catalysis. In addition to the disorder of atomic arrangement, abundant surface defects and good corrosion resistance, the metastable state and dangling bonds generated by the amorphous structure can provide more active sites, making amorphous materials excellent electrocatalyst candidates and widely studied. It is well known that in the field of electrochemistry, crystalline materials based on platinum group metals are generally considered to be the most effective catalysts. Therefore, people have invested huge efforts in the synthesis of amorphous structured materials based on platinum group metals.
[0003] In addition, morphology control of nanomaterials is also an important means to develop advanced catalysts, especially hollow structures. Since the emergence of fullerenes and carbon nanotubes, hollow structured micro-nanomaterials have attracted much attention due to their unique structural features, such as large surface area and well-defined void space. These features can expose more active sites, increase the contact area between the catalyst and the electrolyte, and shorten the mass / charge transport length, thereby facilitating electrocatalytic reactions. However, current research mainly focuses on hollow platinum group metal-based materials with conventional crystalline phases. In view of this, exploring a controllable synthesis method to prepare amorphous hollow platinum group metal-based intermetallic nanomaterials has extremely important academic significance and application value. To this end, the present invention proposes a method for synthesizing amorphous PdP hollow nanoparticles. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for synthesizing amorphous PdP hollow nanoparticles, aiming to solve the problems raised in the above background technology.
[0005] To achieve the above object, the present invention provides the following technical solutions:
[0006] A method for synthesizing amorphous PdP hollow nanoparticles comprises the following steps:
[0007] Step 1, preparing cubic Pd nanoparticles: adding polyvinyl pyrrolidone, L-ascorbic acid, and potassium bromide to deionized water, preheating in an oil bath, and rapidly injecting sodium chloropalladate solution to react. The resulting solution is centrifuged and washed to obtain cubic Pd nanoparticles, which are then dried for later use;
[0008] Step 2, preparing cubic PdCN nanoparticles: dissolving cubic Pd nanoparticles in a dimethyl sulfoxide solution, transferring the solution to a reactor for reaction, centrifuging and washing the resulting solution to obtain cubic PdCN nanoparticles, and drying and storing the resulting solution;
[0009] Step 3, preparing amorphous PdP hollow nanoparticles: mixing cubic PdCN nanoparticles with oleylamine solution, adding trioctylphosphine and heating, centrifuging and washing the resulting solution to obtain amorphous PdP hollow nanoparticles.
[0010] Furthermore, the specific process of step 1 is as follows:
[0011] 1.05 g of polyvinyl pyrrolidone, 0.6 g of L-ascorbic acid, and 6 g of potassium bromide were added to 80 mL of deionized water, preheated to 85°C in an oil bath for 10 min, and 30 mL of 0.065 mol / L sodium chloropalladate solution was rapidly injected. The mixture was reacted at 85°C for 3 h. The mixture was centrifuged and washed 2 to 3 times with deionized water, ethanol, and acetone to obtain cubic Pd nanoparticles, which were then dried for later use.
[0012] Furthermore, the specific process of step 2 is as follows:
[0013] 0.03 g of cubic Pd nanoparticles were weighed and dissolved in 60 mL of dimethyl sulfoxide solution, transferred to a reactor, reacted at 180° C. for 2 h, centrifuged and washed 2 to 3 times with deionized water and ethanol to obtain cubic PdCN nanoparticles, and dried at 40° C. for storage.
[0014] Furthermore, the specific process of step 3 is as follows:
[0015] 21 mg of cubic PdCN nanoparticles were weighed and mixed with 77 mL of oleylamine solution. After adding 7 mL of trioctylphosphine, the mixture was heated at 220°C for 10 min, centrifuged and washed with ethanol and toluene 2 to 3 times to obtain amorphous PdP hollow nanoparticles.
[0016] Furthermore, in step 1, during the first cleaning, acetone is used to separate the sample from the reaction solution, and the volume ratio of acetone to the reaction solution is 3:1; in the subsequent cleaning process, a mixture of deionized water, ethanol and acetone is used, and the volume ratio of deionized water, ethanol and acetone is 1:1:10.
[0017] Furthermore, in step 2, the number of cleaning times is 3 times, and the volume ratio of deionized water and ethanol used in the cleaning process is 1:5.
[0018] Furthermore, in step 3, the number of cleanings is 3 times, and the volume ratio of ethanol to toluene used in the cleaning process is 1:1.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] 1. The present invention successfully uses non-metallic elements to dope carbon, nitrogen and phosphorus for the first time to prepare amorphous PdP hollow nanoparticles with uniform size.
[0021] 2. The reagents used in the present invention can all be purchased on the market and do not require further processing. The preparation method is simple and the required equipment are all basic laboratory equipment, without the need for expensive equipment and instruments. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 These are the X-ray diffraction (XRD) patterns of the cubic Pd nanoparticles, cubic PdCN nanoparticles, and amorphous PdP hollow nanoparticles obtained in Example 1; (a) is the XRD pattern of the cubic Pd nanoparticles; (b) is the XRD pattern of the cubic PdCN nanoparticles; and (c) is the XRD pattern of the amorphous PdP hollow nanoparticles.
[0023] Figure 2 1 and 2 are transmission electron microscope (TEM) images of the amorphous PdP hollow nanoparticles prepared in Example 1; (a) is a TEM image at a 50 nm scale; (b) is a TEM image at a 10 nm scale.
[0024] Figure 3 3 is a scanning electron microscope image of the amorphous PdP hollow nanoparticles obtained in Example 1.
[0025] Figure 4 These are the X-ray diffraction (XRD) patterns of the cubic Pd nanoparticles, cubic PdCN nanoparticles, and mixed nanoparticles obtained in Example 2; (a) is the XRD pattern of the cubic Pd nanoparticles; (b) is the XRD pattern of the cubic PdCN nanoparticles; and (c) is the XRD pattern of the mixed nanoparticles.
[0026] Figure 5 These are transmission electron microscope (TEM) images of the amorphous PdP hollow nanoparticles obtained in Example 2; (a) is a TEM image at a 50 nm scale; and (b) is a TEM image at a 10 nm scale.
[0027] Figure 6 3 is a scanning electron microscope image of the amorphous PdP hollow nanoparticles prepared in Example 2. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. Unless otherwise specified, all reagents used are commercially available products and are not required to be further purified.
[0029] The specific implementation of the present invention is described in detail below with reference to specific embodiments.
[0030] Example 1: Synthesis of amorphous PdP hollow nanoparticles;
[0031] A method for synthesizing amorphous PdP hollow nanoparticles comprises the following steps:
[0032] 1) 1.05 g of polyvinylpyrrolidone, 0.6 g of L-ascorbic acid, and 6 g of potassium bromide were added to 80 mL of deionized water and preheated to 85°C in an oil bath for approximately 10 min. 30 mL of a 0.065 mol / L sodium chloropalladate solution was rapidly injected and reacted at 85°C for 3 h. The resulting solution was centrifuged and washed with deionized water, ethanol, and acetone to obtain cubic Pd nanoparticles, which were then dried for later use.
[0033] The cleaning times were 3 times. During the first cleaning, acetone was used to separate the sample from the reaction liquid, and the volume ratio of acetone to the reaction liquid was 3:1. In the subsequent cleaning process, a mixture of deionized water, ethanol and acetone was used, and the volume ratio of deionized water, ethanol and acetone was 1:1:10.
[0034] 2) Weigh 0.03 g of cubic Pd nanoparticles and dissolve them in 60 mL of dimethyl sulfoxide solution. The mixture is transferred to a reactor and reacted at 180°C for 2 h. The resulting solution is centrifuged and washed three times with deionized water and ethanol to obtain cubic PdCN nanoparticles, which are then dried at 40°C for storage.
[0035] The number of cleaning times was 3, and the volume ratio of deionized water and ethanol used in the cleaning process was 1:5.
[0036] 3) Weigh 21 mg of cubic PdCN nanoparticles and mix with 77 mL of oleylamine solution. After adding 7 mL of trioctylphosphine, the mixture is heated at 220° C. for 10 min. The resulting solution is centrifuged and washed three times with ethanol and toluene to obtain the product.
[0037] The number of cleaning times was 3, and the volume ratio of ethanol and toluene used in the cleaning process was 1:1.
[0038] The XRD pattern of the sample prepared in this embodiment is as follows Figure 1 Transmission electron microscopy and element distribution photos are shown in Figure 2, SEM and element distribution photos are shown in Figure 3 The XRD pattern indicates that the product is amorphous PdP hollow nanoparticles, with weak diffraction intensity, indicating weak crystallinity. Transmission electron microscopy and element distribution images, as well as scanning electron microscopy and element distribution photos, show that the synthesized nanoparticles are uniform in size, and the Pd and P elements are evenly distributed within the nanoparticles, indicating that amorphous PdP hollow nanoparticles were successfully synthesized in this example.
[0039] Example 2: Synthesis of amorphous PdP hollow nanoparticles by changing the reaction temperature;
[0040] A method for synthesizing amorphous PdP hollow nanoparticles by changing the reaction temperature comprises the following steps:
[0041] 1) is the same as step 1) in Example 1.
[0042] 2) is the same as step 2) in Example 1.
[0043] 3) Weigh 21 mg of cubic PdCN nanoparticles and mix with 77 mL of oleylamine solution. Add 7 mL of trioctylphosphine and heat the mixture at 210° C. for 10 min. Centrifuge the resulting solution and wash with ethanol and toluene three times to obtain the product.
[0044] The number of cleaning times was 3, and the volume ratio of ethanol and toluene used in the cleaning process was 1:1.
[0045] The XRD pattern of the sample prepared in this embodiment is as follows Figure 4 Transmission electron microscopy and element distribution photos are shown in Figure 5 , SEM and element distribution photos are shown in Figure 6 . The XRD spectrum of the mixed sample shows that the diffraction intensity of the synthesized nanoparticles is weaker than that of PdCN, indicating that its crystallinity is weaker. Transmission electron microscopy and element distribution images and scanning electron microscopy and element distribution photos show that the synthesized nanoparticles are a mixture of amorphous PdP hollow nanoparticles and crystalline PdCN@amorphous PdP core-shell nanoparticles with uniform size, and Pd and P elements are evenly distributed in the nanoparticles. This shows that this example successfully synthesized a mixture of amorphous PdP hollow nanoparticles and crystalline PdCN@amorphous PdP core-shell nanoparticles.
[0046] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention. These should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.
Claims
1. A method for synthesizing amorphous PdP hollow nanoparticles, characterized in that: The following steps are involved: Step 1, preparing cubic Pd nanoparticles: 1.05g of polyvinyl pyrrolidone, 0.6g of L-ascorbic acid and 6g of potassium bromide were added to 80mL of deionized water, preheated to 85°C in an oil bath for 10min, and 30mL of 0.065mol / L sodium chloropalladate solution was quickly injected. The mixture was reacted at 85°C for 3h, and centrifuged and washed 2-3 times with deionized water, ethanol and acetone to obtain cubic Pd nanoparticles, which were dried and set aside. During the first washing, acetone was used to separate the sample from the reaction solution, and the volume ratio of acetone to the reaction solution was 3:
1. In the subsequent washing process, a mixture of deionized water, ethanol and acetone was used, and the volume ratio of deionized water, ethanol and acetone was 1:1:
10. Step 2, preparing cubic PdCN nanoparticles: weighing 0.03 g of cubic Pd nanoparticles and dissolving them in 60 mL of dimethyl sulfoxide solution, transferring the mixture to a reactor, reacting at 180° C. for 2 h, centrifuging and washing 2-3 times with deionized water and ethanol to obtain cubic PdCN nanoparticles, and drying and storing at 40° C.; Step 3. Preparation of amorphous PdP hollow nanoparticles: 21 mg of cubic PdCN nanoparticles were weighed and mixed with 77 mL of oleylamine solution. After adding 7 mL of trioctylphosphine, the mixture was heated at 220° C. for 10 min, centrifuged and washed 2 to 3 times with ethanol and toluene to obtain amorphous PdP hollow nanoparticles.
2. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 1, characterized in that: In step 2, the washing times are 3 times, and the volume ratio of deionized water and ethanol used in the washing process is 1:
5.
3. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 1, characterized in that: In step 3, the washing times are 3 times, and the volume ratio of ethanol and toluene used in the washing process is 1:1.