Carbon-loaded metal nanoparticles as well as preparation method and application thereof
By combining low-temperature environment and ultrasonic cavitation-assisted dispersion with gradient dropwise addition of reducing agent, the problems of agglomeration and energy consumption of carbon-supported metal nanoparticles were solved, and nanoparticles with small particle size and good dispersibility were prepared, which are suitable for electrochemical and catalytic applications.
Patent Information
- Application Number
- CN202511108804.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-08
- Publication Date
- 2025-11-28
AI Technical Summary
Existing methods for preparing carbon-supported metal nanoparticles suffer from problems such as severe particle agglomeration, reliance on surfactants for dispersion, and high energy consumption, resulting in uneven particle size distribution and affecting the conductivity of the material.
Carbon-loaded metal nanoparticles were prepared by using a low-temperature ice-water bath environment, the synergistic effect of ultrasonic cavitation-assisted dispersion and gradient dropwise addition of reducing agent, controlling the reaction temperature at -5 to 10℃, the ultrasonic power at 50 to 200 W, and the dropwise addition rate of reducing agent solution at 0.1 to 2 mL/min.
This technology enables the production of carbon-supported metal nanoparticles with small particle size, uniform size distribution, and good dispersibility, thereby reducing energy consumption and dependence on high-concentration stabilizers. These nanoparticles are suitable for electrochemistry, catalysis, and drug delivery.
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Figure CN121035237A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of nanomaterial preparation, and particularly relates to a carbon-loaded metal nanoparticle, a preparation method and application thereof. BACKGROUND
[0002] The carbon-loaded metal nanoparticle plays an important role in electrochemical energy conversion and storage and in the field of catalysis, and can realize a high level of activity-stability balance in electrochemical energy conversion and storage, and is suitable for the preparation of high-performance electrocatalysts and electrodes. In the related art, by controlling the synthesis parameters, the structure, composition and size of carbon and metal particles can be easily designed, so as to optimize the performance of the electrocatalyst. In addition, the carbon nanotube-loaded metal nanoparticle composite material exhibits unique performance in electricity, magnetism and optics. For example, the carbon nanotube / silver nanoparticle composite material has a significant inhibitory effect on a plurality of bacteria; the confinement design of carbon-loaded platinum can improve the stability of intermetallic compound nanoparticles while maintaining the high catalytic activity of the intermetallic compound nanoparticles for PEMFCs; the carbon nanotube / silver nanoparticle composite material has a significant antibacterial effect on Escherichia coli, Bacillus megaterium, Bacillus subtilis and Micrococcus tetragenus.
[0003] In the related art, the preparation of the carbon-loaded metal nanoparticle usually adopts a high-temperature reduction method (such as a hydrothermal method) or a chemical deposition method, and has the following defects: (1) serious particle agglomeration: metal particles are prone to Ostwald ripening under a high-temperature environment, resulting in uneven particle size distribution; (2) dispersion depends on a surfactant: a large amount of organic surfactant (such as PVP, CTAB) needs to be added, which is difficult to purify and affects the conductivity of the material; (3) high energy consumption of the process: the high-temperature reaction equipment is complex and has significant energy consumption (the reaction temperature needs to be maintained at 80-120 DEG C). However, the metal nanoparticles are prepared by using a separate low-temperature method (such as glucose-assisted low-temperature synthesis of silver micro-nanoparticles), a separate ultrasonic method (such as preparation of silver ultrafine particles) or a traditional dropwise addition method (such as preparation of a nano-silver sol by a double injection method), but the dispersion effect or the reaction speed is still limited. SUMMARY
[0004] In view of the above prior art, at least one of the technical problems is solved, and the present application provides a carbon-loaded metal nanoparticle, a preparation method and application thereof. The preparation method realizes the preparation of the carbon-loaded metal nanoparticle with high dispersion and low stabilizer dosage without high temperature through the synergistic effect of an ice-water bath low-temperature environment, ultrasonic cavitation assisted dispersion and gradient dropwise addition control. The carbon-loaded metal nanoparticle obtained by the present application has small particle size and uniform size distribution, and has good dispersion, and the carbon-loaded metal nanoparticle is applied in electrochemistry, catalysis or drug delivery.
[0005] According to a first aspect of the present application, a preparation method of a carbon-loaded metal nanoparticle is provided, and the method comprises the following steps:
[0006] ultrasonic dispersion is performed on the mixture A obtained by mixing the metal salt solution, the stabilizer and the nano-carbon solution; wherein the reaction temperature is -5-10°C, and the ultrasonic power is 50-200W;
[0007] The carbon-metal nanoparticle is obtained by adding the reducing agent solution to the ultrasonic dispersed mixture A at a speed of 0.1-2mL / min at 0-5°C, and then separated and dried.
[0008] In some embodiments, the metal in the metal salt solution comprises platinum, gold, silver, copper or palladium.
[0009] In some embodiments, the metal salt solution has a concentration of 0.1-5wt%, and comprises a chloroauric acid solution, a chloroplatinic acid solution, a silver nitrate solution, a silver acetate solution, a chloropalladic acid solution, gold acetate, palladium acetate, platinum nitrate, copper nitrate or copper sulfate.
[0010] In some embodiments, the stabilizer has a concentration of 0.1-5wt%, and is used to complex metal ions to enhance the cleaning effect, and comprises a sodium citrate solution, a sodium gluconate solution or an ethylenediaminetetraacetic acid sodium salt solution.
[0011] In some embodiments, the nano-carbon solution has a carbon content of 0.1wt%-10wt%, and the nano-carbon comprises nano-carbon black or graphene.
[0012] The volume ratio of the metal salt solution, the stabilizer and the nano-carbon solution is 1:1:(10-90).
[0013] In some embodiments, the reducing agent solution comprises a 0.05-0.5M sodium borohydride solution, lithium aluminum hydride, sodium cyanoborohydride or sodium triacetoxyborohydride.
[0014] In some embodiments, the drying process after the separation of the carbon-metal nanoparticle comprises centrifugal collection of the carbon-metal nanoparticle and vacuum drying,
[0015] Or, the reaction system after the completion of the dropwise addition of the reducing agent solution is directly dried by baking or air drying, and the carbon-metal nanoparticle is used after ultrasonic dispersion.
[0016] According to a second aspect of the present application, a carbon-metal nanoparticle is provided, which is obtained by the preparation method described in any of the above embodiments.
[0017] In some embodiments, the carbon-metal nanoparticle has a particle size of less than 20nm, and the metal particles therein are in a single crystal form.
[0018] According to a third aspect of the present application, the carbon-metal nanoparticle described in any of the above embodiments is applied in electrochemical catalysis.
[0019] In some embodiments, the carbon-supported metal nanoparticles are used as cathodes in energy storage batteries and conversion batteries; the energy storage batteries include metal-air batteries, metal-ion batteries, or supercapacitors; and the conversion batteries include microbial fuel cells.
[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0021] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:
[0022] Figure 1 XRD pattern of carbon-supported Au nanoparticles provided in an embodiment of this application;
[0023] Figure 2 TEM-EDS image of carbon-supported Au nanoparticles provided in another embodiment of this application;
[0024] Figure 3 HRTEM image of carbon-supported Au nanoparticles provided in an embodiment of this application;
[0025] Figure 4 TEM image of carbon-supported Au nanoparticles provided in an embodiment of this application;
[0026] Figure 5 This is an H-cell graph showing the electrochemical test of carbon-supported Au nanoparticles for CO2 electrolysis to syngas production, provided in an embodiment of this application.
[0027] Figure 6 This application describes the batch synthesis of carbon-supported Au nanoparticles as provided in one embodiment. Detailed Implementation
[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present application, not all of them, and are not intended to limit the scope of the disclosure of the present application. Furthermore, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion regarding the concepts disclosed in the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort should fall within the scope of protection of the present application.
[0029] The accompanying drawings show structural schematic diagrams according to embodiments disclosed in this application. These drawings are not drawn to scale, and some details have been enlarged and may have been omitted for clarity. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.
[0030] According to the first aspect of this application, a method for preparing carbon-supported metal nanoparticles is provided, comprising the following steps:
[0031] S1: Mixture A, obtained by mixing metal salt solution, stabilizer and nano carbon solution, is subjected to ultrasonic reaction; wherein the reaction temperature is -5-10℃ and the ultrasonic power is 50-200W.
[0032] S2: Add a reducing agent solution at 0-5℃ dropwise to the ultrasonically dispersed mixture A at a rate of 0.1-2 mL / min to obtain carbon-supported metal nanoparticles, which are then separated and dried.
[0033] In step S1, mixture A is obtained by mixing a metal salt solution, a stabilizer, and a nano-carbon solution. The metal in the metal salt solution includes platinum, gold, silver, copper, or palladium. Example metal salt solutions include 0.1-5 wt% solutions of chloroauric acid, chloroplatinic acid, silver nitrate, silver acetate, chloropalladic acid, gold acetate, palladium acetate, platinum nitrate, copper nitrate, or copper sulfate. In other words, the metal salt solution includes 0.1-5 wt% solutions of chloroauric acid, chloroplatinic acid, silver nitrate, silver acetate, chloropalladic acid, gold acetate, palladium acetate, platinum nitrate, copper nitrate, or copper sulfate. For example, the concentrations of the metal salt solutions are 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 5 wt%, etc.
[0034] In this embodiment, the concentration of the stabilizer is 0.1-5 wt%, which is used to complex metal ions to enhance the cleaning effect. For example, the stabilizer is a 0.1-5 wt% sodium citrate solution, sodium gluconate solution, or sodium ethylenediaminetetraacetate solution; wherein the sodium ethylenediaminetetraacetate solution includes disodium ethylenediaminetetraacetate solution, trisodium ethylenediaminetetraacetate solution, and tetrasodium ethylenediaminetetraacetate solution.
[0035] The carbon nanoparticle solution contains 0.1 wt% to 10 wt% carbon, where the carbon nanoparticles include carbon black nanoparticles or graphene; the volume ratio of the metal salt solution, stabilizer, and carbon nanoparticle solution is 1:1:(10-90). Examples include a volume ratio of 0.1-5 wt% metal salt solution, 0.1-5 wt% stabilizer, and 0.1-10 wt% carbon nanoparticle solution of 1:1:(10, 20, 30, 40, 50, 60, 70, 80, 90), etc.
[0036] Mixture A, obtained by mixing a metal salt solution, a stabilizer, and a nano-carbon solution, is subjected to an ultrasonic reaction at a temperature of -5 to 10°C and a power of 50 to 200 W. For example, mixture A is placed in an ice-containing ultrasonic bath at a temperature of -5 to 10°C; the ultrasonic bath temperatures are -5°C, 0°C, 2°C, 3°C, 5°C, 6°C, 8°C, 9°C, and 10°C, respectively. Ultrasonic reactions are then initiated, with the power adjusted from 50 to 200 W; for example, the ultrasonic power is 50 W, 80 W, 100 W, 150 W, and 200 W. Low temperature controls the reaction rate, while ultrasonic power acts as a dispersant; generally, higher temperatures and lower viscosity result in better ultrasonic dispersion. This application utilizes the shock waves generated by ultrasonic cavitation and microjets to break up nanoparticle aggregates, achieving spatially uniform dispersion of the carbon support and providing abundant, uniform, and small-particle-size heterogeneous nucleation sites.
[0037] In step S2, the reducing agent solution is pre-cooled to 0-5°C. The reducing agent solution includes 0.05-0.5M sodium borohydride solution, lithium aluminum hydride, sodium cyanoborohydride, or sodium triacetoxyborohydride. The reducing agent is determined according to the stoichiometric ratio of the redox reaction, generally in excess of no more than one fold. The 0-5°C reducing agent solution is added dropwise to the ultrasonically dispersed mixture A at a rate of 0.1-2 mL / min to obtain carbon-supported metal nanoparticles, which are then separated and dried. The dropping rate of mixture A can be 0.1 mL / min, 1 mL / min, 1.5 mL / min, 2 mL / min, etc. A higher drop rate results in more reactants and larger nanomaterial sizes. In this embodiment, the drying process after separation of the carbon-supported metal nanoparticles includes centrifugation to collect the carbon-supported metal nanoparticles and vacuum drying, or directly drying or air-drying the reaction system after the reducing agent solution has been added. When using the carbon-supported metal nanoparticles, ultrasonic dispersion is sufficient.
[0038] In this process, lowering the temperature can slow down the reaction rate, reduce the growth rate of nano-metals, and decrease side reactions. It also helps control the nucleation and growth of nanoparticles, contributing to the formation of regular morphologies. This application, by controlling the dropping rate of the reducing agent, can maintain local concentration equilibrium in the reaction system, reduce agglomeration, slow down the growth rate of nano-metal particles, and obtain nanoparticles with narrower particle size distributions.
[0039] This application represents a multi-dimensional optimization compared to related technologies. This includes balancing reaction kinetics and thermodynamics through low-temperature and dropwise control, while simultaneously addressing the problem of particle agglomeration in traditional methods by incorporating ultrasonic dispersion. Furthermore, low-temperature conditions reduce energy consumption, and ultrasonic dispersion reduces reliance on high-concentration stabilizers, aligning with green chemistry trends. Therefore, through synergistic effects, this application yields carbon-supported metal nanoparticles with small particle size, uniform size distribution, and good dispersibility. This method is simple to operate, requires no complex equipment or high-temperature processes, and enables the mass production of high-quality carbon-supported metal nanoparticles, demonstrating significant commercial potential.
[0040] According to a second aspect of this application, a carbon-supported metal nanoparticle is provided, which is obtained using the preparation method in any of the above embodiments.
[0041] In some embodiments, the carbon-supported metal nanoparticles have a particle size of less than 20 nm, and the metal particles therein are in a single-crystal morphology.
[0042] The method of preparing highly dispersible carbon-supported metal nanoparticles by means of low-temperature reaction, controlled addition of reducing agent and ultrasonic dispersion is particularly suitable for the controllable preparation of carbon-supported noble metal (Pt, Au, Ag, Pd) nanoparticles.
[0043] This application, for the first time, combines low-temperature environmental control, ultrasonic dynamic dispersion, and gradient supply of reducing agent, breaking through the contradictory relationship between temperature, dispersibility, and reaction rate in traditional processes, and providing a new paradigm for the preparation of high-precision nanocomposite materials. Therefore, this application achieves the preparation of highly dispersed carbon-loaded metal nanoparticles with small particle size and uniform size distribution by comprehensively utilizing the synergistic effects of a low-temperature ice-water bath environment, ultrasonic cavitation-assisted dispersion, and gradient dropwise control of the reducing agent.
[0044] The application of carbon-supported metal nanoparticles in electrochemical catalysis in any of the above embodiments is proposed according to a third aspect of this application.
[0045] In some embodiments, carbon-supported metal nanoparticles are used as cathodes in energy storage batteries and conversion batteries; energy storage batteries include metal-air batteries, metal-ion batteries, or supercapacitors; conversion batteries include microbial fuel cells.
[0046] To facilitate a further understanding of this application, the solutions described below are further described in conjunction with embodiments. Those skilled in the art will understand that the embodiments described in this application are only some examples, and any other suitable specific embodiments are within the scope of this application.
[0047] Example 1
[0048] This embodiment provides a carbon-supported metal nanoparticle, the preparation method and specific parameters of which are as follows: Mixture A is obtained by mixing 0.5 mL of 2 wt% chloroauric acid solution, 0.5 mL of 0.56 wt% sodium citrate solution, and 20 mL of 1 wt% nano-carbon black solution; Mixture A is placed in an ultrasonic bath containing 60% ice (temperature 5℃), and ultrasonication is performed at 40 kHz (power 100 W). 0.6 mL of 0.1 M NaBH4 solution pre-cooled to 4℃ is added dropwise at 0.1 mL / min to obtain carbon-supported metal nanoparticles. The product is collected by centrifugation and vacuum dried. Figure 6 The method shown can be used to synthesize 5g of carbon-loaded gold nanoparticles by scaling up to the same scale.
[0049] Example 2
[0050] This embodiment provides a carbon-supported metal nanoparticle, which differs from Embodiment 1 in the following ways: the metal salt solution is a chloroplatinic acid solution, the nano carbon solution is graphene, the ultrasonic power is 150W, the reducing agent is 0℃, and the dropping rate is 0.5mL / min, resulting in graphene-supported nano-Pt with a crystal size of only 15nm and uniform distribution and good dispersion.
[0051] Example 3
[0052] This embodiment provides a carbon-supported metal nanoparticle, which differs from Embodiment 1 in the following ways: the metal salt solution is silver nitrate solution, the nano carbon solution is graphene, the ultrasonic power is 200W, the reducing agent is 0℃, and the dropping rate is 0.2mL / min, resulting in graphene-supported silver nanoparticles with a crystal size of only 10nm and uniform distribution and good dispersion.
[0053] Comparative Example 1
[0054] This comparative example differs from Example 1 in the following ways: the ultrasonic temperature was 10°C, the ultrasonic power was 50W, and the NaBH4 solution drop rate was 4mL / min, resulting in carbon-loaded metal particles.
[0055] Comparative Example 2
[0056] This comparative example differs from Example 2 in the following ways: ultrasonic temperature 10°C, ultrasonic power 50W, NaBH4 solution drop acceleration rate 3mL / min, and graphene-supported nano-Pt particles.
[0057] Experimental Example
[0058] The carbon-supported metal nanoparticles obtained in Example 1 were subjected to X-ray diffraction analysis, and the results are as follows: Figure 1 As shown, Figure 1The XRD pattern shows that the full width at half maximum (FWHM) of the XRD peaks of the experimental sample is more than twice as wide as that of the control sample. According to the Scherrer formula, the grain size of the experimental sample can be considered to be more than half smaller than that of the control sample.
[0059] The carbon-supported metal nanoparticles obtained in Example 1 were analyzed by transmission electron microscopy-energy dispersive spectroscopy, and the results are as follows: Figure 2 As shown, TEM-EDS reveals that gold is uniformly loaded on the surface of carbon particles.
[0060] The carbon-supported metal nanoparticles obtained in Example 1 were examined using high-resolution transmission electron microscopy, and the results are as follows: Figure 3 As shown, HRTEM characterization reveals that the interplanar spacing is close to that of the (111) plane of gold, confirming that the loaded material is gold, and that there is only one set of diffraction fringes, indicating that it is a single crystal. Combined with... Figure 1 It can be assumed that the thickness of the gold sample in this application is less than half, thus saving the amount of gold used.
[0061] The carbon-supported metal nanoparticles obtained in Example 1 were examined by transmission electron microscopy, and the results are as follows: Figure 4 As shown, the carbon-supported gold nanoparticles have a size of less than 20 nanometers, a uniform size distribution, and good dispersibility.
[0062] The carbon-supported metal nanoparticles obtained in Example 1 were subjected to CO2 electrolysis to produce syngas (H-cell) tests, and the results are as follows: Figure 5 As shown, in the electrolysis experiment in 1M KHCO3, the overpotential of CO2 electrolysis in the experimental sample was much lower than that in Comparative Example 1. The experimental sample had an overpotential of 40 mA / cm². -2 The CO2 electrolysis products at the current density contain 95% CO and 5% H2, while the control sample contains only 35% CO and 65% H2 under the same conditions. The CO Faraday efficiency of the control sample is much lower than that of the experimental sample, which proves that the combination of low temperature environment control, ultrasonic dynamic dispersion and reducing agent gradient supply achieves excellent technical results.
[0063] The graphene Pt particles obtained in Example 2 and Comparative Example 2 were applied in alkaline water electrolysis for hydrogen production. The graphene Pt nanoparticles in Example 2 were used at 1000 mA / cm². 2 The hydrogen evolution overpotential at the current density is only 100 mV; the graphene-supported Pt particles in Comparative Example 2 have an overpotential of 1000 mA / cm². 2 The hydrogen evolution overpotential at the current density is 300mV.
[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0066] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A method for preparing carbon-supported metal nanoparticles, characterized in that, Includes the following steps: Mixture A, obtained by mixing metal salt solution, stabilizer and nano carbon solution, is ultrasonically dispersed. The reaction temperature is -5 to 10℃, and the ultrasonic power is 50 to 200W. A reducing agent solution at 0-5℃ is added dropwise to the ultrasonically dispersed mixture A at a rate of 0.1-2 mL / min to obtain carbon-supported metal nanoparticles, which are then separated and dried.
2. The preparation method according to claim 1, characterized in that, The metal salt solution contains platinum, gold, silver, copper, or palladium. And / or, the concentration of the metal salt solution is 0.1-5 wt%, including chloroauric acid solution, chloroplatinic acid solution, silver nitrate solution, silver acetate solution, chloropalladium acid solution, gold acetate, palladium acetate, platinum nitrate, copper nitrate or copper sulfate.
3. The preparation method according to claim 2, characterized in that, The stabilizer, at a concentration of 0.1-5 wt%, is used to complex metal ions to enhance cleaning performance and includes sodium citrate solution, sodium gluconate solution, or sodium ethylenediaminetetraacetate solution.
4. The preparation method according to claim 2, characterized in that, The carbon content in the nano-carbon solution is 0.1wt%-10wt%, wherein the nano-carbon includes nano-carbon black or graphene; The volume ratio of the metal salt solution, the stabilizer, and the nano carbon solution is 1:1:(10-90).
5. The preparation method according to claim 2, characterized in that, The reducing agent solution includes a 0.05-0.5M sodium borohydride solution, lithium aluminum hydride, sodium cyanoborohydride, or sodium triacetoxyborohydride.
6. The preparation method according to claim 2, characterized in that, The drying process after separation of the carbon-supported metal nanoparticles includes centrifugation to collect the carbon-supported metal nanoparticles and vacuum drying. Alternatively, the reducing agent solution can be added dropwise to the completed reaction system and then dried or air-dried. When using the carbon-supported metal nanoparticles, they can be ultrasonically dispersed.
7. A carbon-supported metal nanoparticle, characterized in that, It is obtained using any of the preparation methods described in claims 1-6.
8. The carbon-supported metal nanoparticles according to claim 7, characterized in that, Its particle size is less than 20nm, and the metal particles in it are in single crystal form.
9. The application of the carbon-supported metal nanoparticles as described in claim 7 or 8 in electrochemical catalysis.
10. The application according to claim 9, characterized in that, The carbon-supported metal nanoparticles are used as cathodes in energy storage batteries and conversion batteries; the energy storage batteries include metal-air batteries, metal-ion batteries, or supercapacitors; the conversion batteries include microbial fuel cells.