Cobalt-nickel sulfide composite nitrogen-doped carbon nanotube and preparation method and application thereof
By preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes, the problem of uneven doping of metal elements in the prior art is solved, the conductivity and catalytic activity of the material are improved, and it is suitable for a variety of high-performance applications.
Patent Information
- Application Number
- CN202411709606.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-03-11
AI Technical Summary
In the prior art, when preparing metal composite carbon nanotube materials, it is difficult to achieve uniform doping and precise control of metal elements, affecting material performance.
The preparation method of cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes is adopted, and cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes are formed by mixing carbon sources, nitrogen-containing organics, cobalt-salts, and nickel salts, and carbonized under a protective atmosphere, and calcined in a sulfur-containing gas.
It realizes uniform doping and precise control of metal elements, improves the conductivity and catalytic activity of the material, and is suitable for applications such as electrochemical catalysis, analysis and detection, and flexible electronic devices.
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Figure CN119591173A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of carbon nanotubes, and in particular to a cobalt-nickel sulfide composite nitrogen-doped carbon nanotube and a preparation method and application thereof. Background Art
[0002] Metal composite carbon nanotube materials can improve the conductivity and specific surface area of composite materials by efficiently loading metal particles with carbon nanotube materials with high specific surface area. In the field of electrochemical catalysis, the rich active sites and excellent conductivity of metal composite carbon nanotube materials can accelerate the rate of electrochemical reactions and promote the reactions in the preset direction. In the field of analytical detection, highly sensitive detection of trace substances can be achieved, and when applied to electronic devices, the performance and service life of the devices can be improved.
[0003] At present, the methods for preparing carbon nanotubes in the field of materials science mainly include chemical vapor deposition and arc discharge. Chemical vapor deposition is a method in which a gaseous precursor is decomposed and deposited on the surface of a substrate to form carbon nanotubes through a chemical reaction in a gaseous environment, while arc discharge is a method in which an arc is generated between two graphite electrodes under a high voltage, and the high temperature environment generated causes carbon atoms to rearrange and combine into carbon nanotubes.
[0004] However, chemical vapor deposition and arc discharge methods have many limitations in the preparation of metal composite carbon nanotube materials. They not only rely on complex equipment, but also cannot achieve uniform doping and precise control of metal elements. The doping amount, doping position and doping uniformity of metal elements in metal composite carbon nanotube materials have a crucial impact on their performance. Therefore, it is urgent to provide a solution to improve the above problems. Summary of the invention
[0005] The purpose of the present invention is to provide a cobalt-nickel sulfide composite nitrogen-doped carbon nanotube and a preparation method and application thereof.
[0006] In a first aspect, the present invention provides a method for preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes, comprising: mixing a carbon source, a nitrogen-containing organic matter, a cobalt salt and a nickel salt, and then carbonizing the mixture under a protective atmosphere to obtain an intermediate; and calcining the intermediate in a sulfur-containing gas to obtain cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes.
[0007] Optionally, the mass ratio of the carbon source to the nitrogen element in the nitrogen-containing organic matter is 1:(0.2-5), preferably 10:3.
[0008] Optionally, the mass ratio of the carbon source to the cobalt element in the cobalt salt is (20-200):1, preferably 75:1.
[0009] Optionally, the mass ratio of the carbon source to the nickel element in the nickel salt is (20-200):1, preferably 75:1.
[0010] Optionally, the carbon source includes one of lignin, chitosan and glucose.
[0011] Optionally, the nitrogen-containing organic matter includes one of melamine, urea, and 1,2,4-triazole.
[0012] Optionally, the cobalt salt includes one of cobalt nitrate, cobalt chloride and cobalt sulfate.
[0013] Optionally, the nickel salt includes one of nickel nitrate, nickel sulfate and nickel chloride.
[0014] Optionally, after mixing the carbon source, the nitrogen-containing organic matter, the cobalt salt and the nickel salt, carbonization is carried out under a protective atmosphere at 700° C.-1000° C.
[0015] Optionally, after mixing the carbon source, nitrogen-containing organic matter, cobalt salt and nickel salt, carbonization treatment is carried out under a protective atmosphere for 1 h to 5 h.
[0016] Optionally, after mixing the carbon source, nitrogen-containing organic matter, cobalt salt and nickel salt, the mixture is heated at a rate of 2° C. / min-10° C. / min under a protective atmosphere and then carbonized at the same temperature.
[0017] Optionally, after mixing the carbon source, nitrogen-containing organic matter, cobalt salt and nickel salt, the protective atmosphere includes one of argon and helium.
[0018] Optionally, when the intermediate is calcined in a sulfur-containing gas: the sulfur-containing gas comprises an inert carrier and sulfur vapor, and the concentration of the sulfur vapor in the sulfur-containing gas is 0.1 mmol / L-100 mmol / L, preferably 10 mmol / L.
[0019] Optionally, when the intermediate is calcined in a sulfur-containing gas: the intermediate is calcined in a sulfur-containing gas of 0.1 sccm-200 sccm, preferably 10 sccm.
[0020] Optionally, when the intermediate is calcined in a sulfur-containing gas: the intermediate is calcined in the sulfur-containing gas at 300°C-550°C, preferably 350°C.
[0021] Optionally, when the intermediate is calcined in a sulfur-containing gas: the intermediate is heated in the sulfur-containing gas at a rate of 1° C. / min-15° C. / min, preferably 5° C. / min.
[0022] Optionally, when the intermediate is calcined in a sulfur-containing gas: the intermediate is calcined in the sulfur-containing gas for 0.1 h to 10 h, preferably 1 h.
[0023] In a second aspect, the present invention also provides a cobalt-nickel sulfide composite nitrogen-doped carbon nanotube prepared by any of the above optional preparation methods, wherein the carbon nanotube comprises a nitrogen-doped carbon nanotube matrix and cobalt-nickel sulfide nanoparticles composited on both sides of the nitrogen-doped carbon nanotube matrix.
[0024] Optionally, the length of the carbon nanotubes is 1 μm-20 mm, preferably 1 μm-100 μm.
[0025] Optionally, the carbon nanotube has a diameter of 10 nm-500 nm, preferably 50 nm-90 nm.
[0026] Optionally, the aspect ratio of the carbon nanotube is 10 2 -10 6 , preferably 10 3 .
[0027] Optionally, the size of the cobalt nickel sulfide nanoparticles supported on the carbon nanotubes is 1 nm-300 nm, preferably 10 nm-90 nm.
[0028] Optionally, the loading amount of the cobalt nickel sulfide nanoparticles on the carbon nanotubes is 2%-30%, preferably 8%.
[0029] In a third aspect, the present invention also provides an application of cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared by any of the above optional preparation methods, wherein the application includes electrochemical catalysis, analytical detection, and flexible electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 A flowchart of a method for preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes provided by the present invention;
[0031] Figure 2 The SEM images of the intermediate (cobalt-nickel composite nitrogen-doped carbon nanotube) prepared in Example 1 of the present invention at different scales;
[0032] Figure 3 This is a SEM image of the cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared in Example 1 of the present invention;
[0033] Figure 4 The SEM images of the intermediate (cobalt-nickel composite nitrogen-doped carbon nanotube) prepared in Example 2 of the present invention at different scales;
[0034] Figure 5 The HAADF-STEM, TEM, EDS and element distribution characterization diagrams of the cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared in Example 1 of the present invention;
[0035] Figure 6 The XRD and XPS characterization diagrams of the cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared in Example 1 of the present invention;
[0036] Figure 7 This is a performance curve of electrocatalytic oxygen reduction of the cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared in Example 1 of the present invention. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.
[0038] See also Figure 1 The present invention provides a method for preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes, comprising the following steps:
[0039] S1, mixing a carbon source, a nitrogen-containing organic matter, a cobalt salt and a nickel salt to prepare a mixture;
[0040] S2, carbonizing the mixture under a protective atmosphere to obtain an intermediate;
[0041] S3. calcining the intermediate in a sulfur-containing gas to obtain cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes.
[0042] In fact, pre-blending the carbon source, nitrogen-containing organic matter, cobalt salt and nickel salt in step S1 is beneficial to improving the mixing uniformity of carbon, nitrogen, cobalt and nickel elements, and then the carbon source can be carbonized into carbon nanotubes after carbonization in step S2, and can improve the doping uniformity of nitrogen elements on carbon nanotubes and the loading uniformity of cobalt and nickel.
[0043] In some embodiments, the mass ratio of the carbon source used in step S1 to the nitrogen element in the nitrogen-containing organic matter is 1:(0.2-5). In fact, by adjusting the mass ratio of the carbon source to the nitrogen element, the doping amount of the nitrogen element in the obtained nitrogen-doped carbon nanotubes can be adjusted. Specifically, the mass ratio of the carbon source to the nitrogen element is preferably 10:3.
[0044] In some embodiments, the mass ratio of the carbon source used in step S1 to the cobalt element in the cobalt salt is (20-200):1, and the mass ratio of the carbon source used to the nickel element in the nickel salt is (20-200):1. In fact, by adjusting the mass ratio of the carbon source, the cobalt element, and the nickel element, the loading amount of cobalt and nickel in the nitrogen-doped carbon nanotubes can be adjusted. Specifically, the mass ratio of the carbon source, the cobalt element, and the nickel element is preferably 75:1:1.
[0045] In some embodiments, the carbon source used in step S1 includes lignin, chitosan and glucose. In fact, by using relatively common and inexpensive biomass materials, some biomass waste materials can be recycled, which can effectively reduce production costs and facilitate large-scale industrial production.
[0046] In some embodiments, the nitrogen-containing organic matter used in step S1 includes one of melamine, urea, and 1,2,4-triazole. In fact, the nitrogen-containing organic matter is mixed with the carbon source and carbonized during a high-temperature carbonization process and then carbonized with the carbon source to form carbon nanotubes, and nitrogen is doped into the carbon nanotubes.
[0047] In some embodiments, the cobalt salt used in step S1 is an inorganic cobalt salt, specifically including one of cobalt nitrate, cobalt chloride and cobalt sulfate, and the nickel salt used is an inorganic nickel salt, specifically including one of nickel nitrate, nickel sulfate and nickel chloride.
[0048] In some embodiments, in step S2, the mixture is carbonized in a protective atmosphere at 700°C-1000°C for 1h-5h, so that the carbon source and the nitrogen-containing organic matter therein are fully carbonized and form carbon nanotubes, and the cobalt salt and the nickel salt can also be sintered on the carbon nanotubes to form a load structure. Specifically, the mixture is heated to 700°C-1000°C in a protective atmosphere at a rate of 2°C / min-10°C / min and then carbonized at a temperature of 700°C-1000°C. In fact, the protective atmosphere used includes one of argon and helium.
[0049] In fact, in step S3, the intermediate is calcined in a sulfur-containing gas, which is conducive to converting the cobalt salt and nickel salt supported on the nitrogen-doped carbon nanotubes into sulfide forms. Specifically, the sulfur-containing gas used includes an inert carrier and sulfur vapor, and the inert carrier can play a certain role of dilution and environmental gas, and the concentration of sulfur vapor in the sulfur-containing gas is 0.1mmol / L-100mmol / L, so that the intermediate can be fully sulfurized. Preferably, the concentration of sulfur vapor is 10mmol / L.
[0050] In some embodiments, in step S3, the intermediate is calcined in a sulfur-containing gas of 0.1 sccm-200 sccm. In fact, sccm is a volume flow unit. By controlling the flow rate of the sulfur-containing gas, the uniformity and degree of sulfurization of the intermediate can be controlled. Specifically, the flow rate of the sulfur-containing gas is preferably 10 sccm.
[0051] In some embodiments, in step S3, the intermediate is calcined at 300-550°C in a sulfur-containing gas for 0.1h-10h. In addition, the intermediate can be heated at a rate of 1°C / min-15°C / min in the sulfur-containing gas. Specifically, it is preferred to heat the intermediate to 350°C at a rate of 5°C / min, calcine for 1h, and then cool to obtain cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes.
[0052] In fact, the present invention also provides a cobalt-nickel sulfide composite nitrogen-doped carbon nanotube prepared by any of the above optional preparation methods, including a nitrogen-doped carbon nanotube matrix and cobalt-nickel sulfide nanoparticles composited on both sides of the nitrogen-doped carbon nanotube matrix.
[0053] Specifically, the length of the cobalt-nickel sulfide composite nitrogen-doped carbon nanotube is 1 μm-20 mm, preferably 1 μm-100 μm; the diameter of the carbon nanotube is 10 nm-500 nm, preferably 50 nm-90 nm; the aspect ratio of the carbon nanotube is 10 2 -10 6 , preferably 10 3 .
[0054] Specifically, the size of the cobalt nickel sulfide nanoparticles loaded on the cobalt nickel sulfide composite nitrogen-doped carbon nanotubes is 1nm-300nm, preferably 10nm-90nm, and the loading amount of the cobalt nickel sulfide nanoparticles is 2%-30%, preferably 8%.
[0055] The present invention also provides an application of the cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared by any of the above optional preparation methods, including electrochemical catalysis, analytical detection, and flexible electronic devices.
[0056] Example 1
[0057] This embodiment 1 provides a method for preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes, comprising the following steps:
[0058] S1, 6 g of lignin, 3 g of melamine, 1.8 mL of 0.8 mol / L aqueous cobalt nitrate solution, 1.8 mL of 0.8 mol / L aqueous nickel nitrate solution, and 15 mL of deionized water were stirred and mixed, and then dried in an oven at 60° C. in an air atmosphere for 12 h to obtain a mixture;
[0059] S2, transfer 2g of the mixture into a quartz boat and place it in the furnace of a tube furnace, use argon gas to replace the gas in the tube furnace and control the argon gas flow rate to 50sccm, heat the tube furnace from room temperature to 800°C at a rate of 5°C / min, keep the temperature and calcine for 2h, and then cool to room temperature with the furnace to obtain an intermediate (cobalt-nickel composite nitrogen-doped carbon nanotubes);
[0060] S3. Transfer 50 mg of the intermediate into a quartz boat and place it in the furnace of a tubular furnace. Use argon to replace the gas in the tubular furnace and control the argon flow rate to 50 sccm. Put 1 g of sulfur powder in a ceramic boat and place it upstream of the tubular furnace. Heat the tubular furnace to 400°C at a rate of 10°C / min and keep it warm for 2 hours. Then cool it to room temperature with the furnace, take it out, clean it, and dry it to obtain cobalt-nickel sulfide nitrogen-doped carbon nanotubes.
[0061] Example 2
[0062] This embodiment 2 provides a method for preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes, comprising the following steps:
[0063] S1, 5 g of chitosan, 4 g of urea, 1.8 mL of 0.8 mol / L aqueous cobalt nitrate solution, 1.8 mL of 0.8 mol / L aqueous nickel nitrate solution, and 15 mL of deionized water were stirred and mixed, and then dried in an oven at 60° C. in an air atmosphere for 12 h to obtain a mixture;
[0064] S2, 1.8 g of the mixture was transferred into a quartz boat and placed in the furnace of a tube furnace, the tube furnace was gas-displaced with argon and the argon flow rate was controlled to be 30 sccm, the tube furnace was heated from room temperature to 1000°C at a rate of 5°C / min, the temperature was kept and calcined for 2 h, and the intermediate (cobalt-nickel composite nitrogen-doped carbon nanotubes) was obtained after cooling to room temperature with the furnace;
[0065] S3. 50 mg of the intermediate was transferred into a quartz boat and placed in the furnace of a tube furnace. Argon was used to replace the gas in the tube furnace and the argon flow rate was controlled to be 30 sccm. 1 g of sulfur powder was placed in a ceramic boat and placed in the upstream position of the tube furnace. The tube furnace was heated to 350 °C at a rate of 10 °C / min and kept warm for 2 h. After cooling to room temperature with the furnace, the boat was taken out, cleaned and dried to obtain a cobalt-nickel sulfide nitrogen-doped carbon nanotube structure characterization.
[0066] The intermediate (cobalt-nickel composite nitrogen-doped carbon nanotube) prepared in Example 1 was characterized by scanning electron microscopy at 1 μm and 100 nm scales, and the results were as follows: Figure 2 As shown in a and b in the figure; the cobalt nickel sulfide nitrogen-doped carbon nanotubes prepared in Example 1 were characterized by scanning electron microscopy as shown in Figure 3As shown; the intermediate (cobalt-nickel composite nitrogen-doped carbon nanotube) prepared in Example 2 was characterized by scanning electron microscopy at 1 μm and 100 nm scales, and the results were respectively Figure 4 As shown in a and b in the figure; the cobalt nickel sulfide nitrogen-doped carbon nanotubes prepared in Example 1 were characterized by HAADF-STEM, TEM, EDS and element distribution, and the results were as follows Figure 5 a, b, c, d in the figure; XRD and XPS characterizations were performed on the cobalt nickel sulfide nitrogen-doped carbon nanotubes prepared in Example 1, as shown in FIG. Figure 6 shown.
[0067] from Figure 2 and Figure 4 It can be seen from the figure that the length of the cobalt-nickel composite nitrogen-doped carbon nanotubes prepared in Example 1 reaches the micrometer level and has a good morphology. Figure 3 It can be seen that after the sulfurization treatment, there are nanoparticles on both the inside and outside of the carbon nanotubes, and the diameter of the nanotubes can reach 50-90nm. The distribution of nanoparticles is relatively uniform, and the carbon nanotubes as a whole show a high aspect ratio. Figure 2 and Figure 5 It can be seen from the successful synthesis of cobalt nickel sulfide on the surface of carbon nanotubes. Figure 6 It can be seen that the valence states of each element are combined with the valence states in the components of the related products, which further illustrates that the method provided by the present invention can successfully synthesize cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes.
[0068] Electrocatalytic Application Performance Characterization
[0069] The electrocatalytic oxygen reduction (ORR) performance of the cobalt nickel sulfide nitrogen-doped carbon nanotubes prepared in Example 1 was investigated. Figure 7 a is the cyclic voltammetry curve (scan rate 50 mV / s) of the cobalt nickel sulfide nitrogen-doped carbon nanotube catalyst prepared in Example 1 in 0.1 mol / L KOH solution saturated with oxygen and argon respectively. An obvious reduction peak can be observed in the oxygen-saturated solution, indicating that it has ORR performance. Figure 7 b is the linear scanning curve at different scanning rates. It can be observed that this material has a higher initial ORR reduction potential and half-wave potential, showing better ORR activity. Figure 7 The KL equation in c shows that an electron transfer reaction occurs on this material. Figure 7 d shows that after 5000 cycles, the ORR half-wave potential of this material changes by only 13 mV, indicating the good ORR stability of this material. Figure 7 The electrocatalytic performance results show that this material has good electrocatalytic performance.
[0070] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.
Claims
1. A method for preparing cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes, characterized in that: include: The intermediate is obtained by mixing a carbon source, a nitrogen-containing organic matter, a cobalt salt and a nickel salt and then carbonizing the mixture under a protective atmosphere; The intermediate is calcined in sulfur-containing gas to obtain cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes.
2. The preparation method according to claim 1, characterized in that: When mixing a carbon source, a nitrogen-containing organic matter, a cobalt salt and a nickel salt: the mass ratio of the carbon source to the nitrogen element in the nitrogen-containing organic matter is 1:(0.2-5), preferably 10:3; and / or the mass ratio of the carbon source to the cobalt element in the cobalt salt is (20-200):1, preferably 75:1; and / or the mass ratio of the carbon source to the nickel element in the nickel salt is (20-200):1, preferably 75:1; and / or the carbon source comprises one of lignin, chitosan and glucose; and / or the nitrogen-containing organic matter comprises one of melamine, urea and 1,2,4-triazole; and / or the cobalt salt comprises one of cobalt nitrate, cobalt chloride and cobalt sulfate; and / or the nickel salt comprises one of nickel nitrate, nickel sulfate and nickel chloride.
3. The preparation method according to claim 1, characterized in that: After mixing the carbon source, nitrogen-containing organic matter, cobalt salt and nickel salt, the steps include: carbonizing under a protective atmosphere at 700°C-1000°C; and / or carbonizing under a protective atmosphere for 1h-5h; and / or heating at a rate of 2°C / min-10°C / min under a protective atmosphere and then carbonizing with insulation; and / or the protective atmosphere includes one of argon and helium.
4. The preparation method according to claim 1, characterized in that: When the intermediate is calcined in a sulfur-containing gas: the sulfur-containing gas includes an inert carrier and sulfur vapor, and the concentration of the sulfur vapor in the sulfur-containing gas is 0.1mmol / L-100mmol / L, preferably 10mmol / L; and / or, the intermediate is calcined in a sulfur-containing gas of 0.1sccm-200sccm, preferably 10sccm; and / or, the intermediate is calcined in the sulfur-containing gas at 300℃-550℃, preferably 350℃; and / or, the intermediate is heated in the sulfur-containing gas at a rate of 1℃ / min-15℃ / min, preferably 5℃ / min; and / or, the intermediate is calcined in the sulfur-containing gas for 0.1h-10h, preferably 1h.
5. A cobalt-nickel sulfide composite nitrogen-doped carbon nanotube obtained by the preparation method according to any one of claims 1 to 4, characterized in that: The carbon nanotubes include a nitrogen-doped carbon nanotube matrix and cobalt-nickel sulfide nanoparticles compounded on both sides of the nitrogen-doped carbon nanotube matrix.
6. The cobalt-nickel sulfide composite nitrogen-doped carbon nanotube according to claim 5, characterized in that: The length of the carbon nanotube is 1 μm-20 mm, preferably 1 μm-100 μm; and / or the diameter of the carbon nanotube is 10 nm-500 nm, preferably 50 nm-90 nm; and / or the aspect ratio of the carbon nanotube is 10 2 -10 6 , preferably 10 3 ; and / or, the size of the cobalt nickel sulfide nanoparticles supported on the carbon nanotubes is 1nm-300nm, preferably 10nm-90nm; and / or, the loading amount of the cobalt nickel sulfide nanoparticles on the carbon nanotubes is 2%-30%, preferably 8%.
7. An application of cobalt-nickel sulfide composite nitrogen-doped carbon nanotubes prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The applications include electrochemical catalysis, analytical detection, and flexible electronic devices.