Method for synthesizing amorphous PdP hollow nanoparticles

Abstract

The invention is applicable to the technical field of synthesis and application of nano materials, and provides a method for synthesizing amorphous PdP hollow nanoparticles, which comprises the following steps: adding polyvinylpyrrolidone, L-ascorbic acid and potassium bromide into deionized water, preheating in an oil bath pan, injecting a sodium chloropalladate solution for reaction, filtering, washing, and drying to obtain the amorphous PdP hollow nanoparticles. Centrifuging and cleaning to obtain cubic Pd nano-particles; dissolving the cubic Pd nano-particles in a dimethyl sulfoxide solution, reacting in a reaction kettle, centrifuging and cleaning to obtain cubic PdCN nano-particles; and mixing the cubic PdCN nanoparticles with an oleylamine solution, adding trioctylphosphine, heating, centrifuging and cleaning to obtain the amorphous PdP hollow nanoparticles. According to the invention, the amorphous PdP hollow nanoparticles with uniform size are prepared for the first time. The used reagents can be purchased in the market and do not need to be further treated; the preparation method is simple, required equipment is basic laboratory equipment, and expensive equipment and instruments are not needed.

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 nano particles. 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 an excellent candidate for electrocatalysts 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 a lot of energy in the synthesis research of amorphous structure materials based on platinum group metals.

[0003] In addition, the 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 clear 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, which is beneficial to the electrocatalytic reaction. 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 hollow platinum group metal-based intermetallic nanomaterials with amorphous phases has extremely important academic significance and application value. For this reason, 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, quickly injecting sodium chloropalladate solution to react, centrifuging and washing the resulting solution to obtain cubic Pd nanoparticles, drying and setting aside;

[0008] Step 2, preparing cubic PdCN nanoparticles: dissolving cubic Pd nanoparticles in a dimethyl sulfoxide solution, transferring the cubic Pd nanoparticles to a reactor for reaction, centrifuging and washing the resulting solution to obtain cubic PdCN nanoparticles, and drying and storing the resulting cubic PdCN nanoparticles;

[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 quickly injected. The mixture was reacted at 85° C. for 3 h, and centrifuged and washed 2 to 3 times with deionized water, ethanol and acetone to obtain cubic Pd nanoparticles, which were 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 2 to 3 times with ethanol and toluene 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 cleaning times is 3 times, and the volume ratio of ethanol and 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 be purchased on the market and do not require further processing. The preparation method is simple and the required equipment is 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; wherein (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 is a transmission electron microscope (TEM) image of the amorphous PdP hollow nanoparticles prepared in Example 1; wherein (a) is a TEM image at a 50 nm scale; and (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; wherein (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 scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Unless otherwise specified, the reagents used are all commercially available products and do not need to be further purified for use.

[0029] The specific implementation of the present invention is described in detail below in conjunction with 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) Add 1.05 g of polyvinyl pyrrolidone, 0.6 g of L-ascorbic acid and 6 g of potassium bromide to 80 mL of deionized water, preheat in an oil bath to 85° C. for about 10 min, quickly inject 30 mL of 0.065 mol / L sodium chloropalladate solution, react at 85° C. for 3 h, centrifuge and wash the resulting solution with deionized water, ethanol and acetone to obtain cubic Pd nanoparticles, which are dried for later use.

[0033] Among them, the number of cleaning times is 3 times. In the first cleaning, acetone is used to separate the sample from the reaction liquid, and the volume ratio of acetone to the reaction liquid 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.

[0034] 2) Weigh 0.03 g of cubic Pd nanoparticles and dissolve them in 60 mL of dimethyl sulfoxide solution, transfer them to a reactor, and react 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 cleaning times were 3 times, 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, add 7 mL of trioctylphosphine, heat the mixture at 220° C. for 10 min, centrifuge and wash the resulting solution with ethanol and toluene three times to obtain a product.

[0037] The cleaning times were 3 times, 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 example is as follows Figure 1 As shown, transmission electron microscopy and element distribution photos are shown in Figure 2, SEM and element distribution photos are shown in Figure 3 The XRD spectrum shows that the product is amorphous PdP hollow nanoparticles, and the diffraction intensity is weak, indicating that its crystallinity is weak. Transmission electron microscopy and element distribution pictures and scanning electron microscopy and element distribution pictures show that the synthesized nanoparticles have uniform size, and Pd and P elements are evenly distributed in the nanoparticles, indicating that amorphous PdP hollow nanoparticles are successfully synthesized in this example.

[0039] Example 2: Synthesizing 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, heat the mixture at 210° C. for 10 min, centrifuge the resulting solution with ethanol and toluene, wash the sample three times, and obtain the product.

[0044] The cleaning times were 3 times, 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 example is as follows Figure 4 As shown, 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 the 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 modifications and improvements can be made without departing from the concept of the present invention. These should also be regarded as the protection scope 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: adding polyvinyl pyrrolidone, L-ascorbic acid and potassium bromide to deionized water, preheating in an oil bath, quickly injecting sodium chloropalladate solution to react, centrifuging and washing the resulting solution to obtain cubic Pd nanoparticles, drying and setting aside; Step 2, preparing cubic PdCN nanoparticles: dissolving cubic Pd nanoparticles in a dimethyl sulfoxide solution, transferring the cubic Pd nanoparticles to a reactor for reaction, centrifuging and washing the resulting solution to obtain cubic PdCN nanoparticles, and drying and storing the resulting cubic PdCN nanoparticles; 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.

2. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 1, characterized in that: The specific process of step 1 is as follows: 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 quickly injected. The mixture was reacted at 85° C. for 3 h, and centrifuged and washed 2 to 3 times with deionized water, ethanol and acetone to obtain cubic Pd nanoparticles, which were dried for later use.

3. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 1, characterized in that: The specific process of step 2 is as follows: 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.

4. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 1, characterized in that: The specific process of step 3 is as follows: 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.

5. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 2, characterized in that: 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.

6. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 3, characterized in that: In step 2, the cleaning times are 3 times, and the volume ratio of deionized water and ethanol used in the cleaning process is 1:

5.

7. The method for synthesizing amorphous PdP hollow nanoparticles according to claim 4, characterized in that: In the step 3, the washing times are 3 times, and the volume ratio of ethanol and toluene used in the washing process is 1:1.

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