A method for producing a carbon-coated copper-based sulfide

Abstract

The application provides a preparation method of carbon-coated copper-based sulfide, and specifically comprises the following steps: S1, CuCl2.2H2O, Na2S.9H2O and NaCl are mixed and then fully ground, and then a core is obtained after sequentially performing calcination treatment, washing treatment and drying treatment; S2, glucose is dissolved in deionized water, then hydrochloric acid is added to obtain a mixture and perform stirring, then the core obtained in step S1 is added to sequentially perform ultrasonic treatment and hydrothermal treatment, then cooling to room temperature and sequentially performing centrifugation, washing and drying treatment, and finally performing calcination treatment to obtain the carbon-coated copper-based sulfide. Compared with the prior art, the application uses glucose as a carbon source by a solvothermal method to form a uniform carbon shell to wrap the copper-based sulfide core, the carbon layer can not only provide a physical barrier to prevent direct exposure of the internal material to a harsh environment, but also can adjust the electron transport path, thereby improving the overall catalytic stability and durability, meanwhile, the carbon-coated structure can optimize the charge transfer kinetics and possibly introduce new active sites, further improving the catalytic efficiency, and the application uses glucose as a cheap and universally available raw material, combined with a relatively simple solvothermal synthesis method, so that the catalyst is easy to mass-produce and commercialize.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electrocatalysis, and particularly relates to a preparation method of carbon layer coated copper-based sulfide. BACKGROUND

[0002] Electrocatalysis is a technology that accelerates the rate of chemical reactions by applying an external electric potential, which plays a key role in energy conversion and storage, such as water electrolysis for hydrogen production, fuel cells, and carbon dioxide reduction processes. As a clean, efficient and sustainable method, electrocatalysis not only helps to reduce dependence on fossil fuels, but also significantly reduces carbon emissions, which is of great significance for promoting a green energy economy.

[0003] In recent years, transition metal sulfides (TMS) have attracted widespread attention in the field of electrocatalysis due to their unique electronic structure and physical and chemical properties. They exhibit excellent catalytic activity, especially in oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR). In addition, TMS materials have the advantages of high cost-effectiveness, abundance and environmental friendliness, making them potential substitutes for noble metal-based catalysts.

[0004] Although TMS materials perform well under laboratory conditions, they face many challenges in practical applications. The main problems include: insufficient stability: TMS is prone to corrosion or oxidation under long-term operation or extreme working conditions such as high temperature, high pressure or strong acid and alkali environment, leading to rapid decline in catalytic performance. Active sites are easily deactivated: the active sites on the surface of the catalyst may lose activity due to the coverage of adsorbed substances, affecting the catalytic efficiency. Complexity of large-scale production: maintaining consistent high performance and low-cost production from laboratory to industrial scale is still a challenge. SUMMARY

[0005] The purpose of the present application is to provide a preparation method of carbon layer coated copper-based sulfide, which uses inexpensive glucose as a carbon source and is coated by a solvothermal method, which can effectively improve the stability of transition metal-based catalysts and has broad application prospects.

[0006] The present application provides a preparation method of carbon layer coated copper-based sulfide, which specifically comprises the following steps:

[0007] S1, CuCl2.2H2O, Na2S.9H2O and NaCl are mixed and then ground thoroughly, followed by calcination treatment, washing treatment and drying treatment to obtain a core;

[0008] S2, dissolving glucose in deionized water, then adding hydrochloric acid and stirring, then adding the core obtained in step S1, and then sequentially performing ultrasonic treatment and hydrothermal treatment, and then cooling to room temperature and sequentially performing centrifugation, washing and drying treatment, and finally performing calcination treatment to obtain a carbon layer coated copper-based sulfide.

[0009] Compared with the prior art, the application uses glucose as a carbon source by a solvothermal method to form a uniform carbon shell wrapped around a copper-based sulfide core. This layer of carbon not only provides a physical barrier to prevent direct exposure of the internal material to harsh environments, but also adjusts the electron transport path, thereby improving the overall catalytic stability and durability. At the same time, the carbon-coated structure can optimize the charge transfer kinetics and possibly introduce new active sites, further improving catalytic efficiency. Moreover, the application uses glucose, a cheap and universally available raw material, combined with a relatively simple solvothermal synthesis method, making the catalyst easy to mass-produce and commercialize.

[0010] In a possible implementation, in step S1, the mass ratio of CuCl2.2H2O to Na2S.9H2O is 1:1, and the mass ratio of CuCl2.2H2O to NaCl is 1:10.

[0011] Compared with the prior art, the application uses CuCl2.2H2O and Na2S.9H2O in a mass ratio of 1:1. This ratio ensures that the stoichiometric ratio between the two reactants is close to ideal, allowing copper ions (Cu2+) and sulfur ions (S2-) to react as completely as possible to form the target product, copper-based sulfide. Such a ratio helps to obtain high-purity, uniformly distributed sulfide particles, which are crucial for catalytic activity. At the same time, an appropriate ratio of CuCl2.2H2O to Na2S.9H2O can effectively control the growth rate and morphology of the crystals. Excess of either can lead to the formation of by-products or uncontrolled crystal growth, affecting the physical properties and catalytic performance of the final material. Maintaining a 1:1 ratio helps to obtain nanoscale structures with appropriate size and good dispersion, which is particularly advantageous for improving catalytic efficiency.

[0012] The addition of an appropriate amount of NaCl can serve several purposes: 1. Inhibition of agglomeration: The presence of NaCl can prevent agglomeration between copper-based sulfide particles to some extent, promoting more uniform dispersion; 2. Adjusting the reaction environment: NaCl can change the ionic strength of the solution, thereby affecting the reaction kinetics, making the reaction more gentle and easy to control; 3. Template effect: In some cases, NaCl crystals can act as temporary templates during synthesis, helping to form sulfide particles of specific shapes.

[0013] In a possible implementation, in step S1, the parameters of the calcination treatment are as follows: the temperature is 60℃, and the time is 30min.

[0014] Compared with the prior art, the advantages of the present application using the above calcination parameters are that: at a lower temperature (such as 60℃), the structural damage or component volatilization caused by high temperature can be avoided, which is very important for maintaining the original structure and composition of copper-based sulfides. Especially when the target is to prepare nanoscale materials, too high temperature can cause particle agglomeration or excessive crystal growth, thereby affecting the catalytic performance of the final product.

[0015] In one possible implementation, in the step S1, the washing treatment respectively uses deionized water and ethanol, and the drying treatment is at a temperature of 40℃.

[0016] Compared with the prior art, the present application first uses deionized water to wash, which can effectively remove inorganic salts and other water-soluble impurities generated during the reaction process, ensuring the purity of the sample, and then uses ethanol to wash, which helps to further remove the residual water and organic impurities on the surface, while reducing the water content in the subsequent drying process. And 40℃ is a relatively low temperature, which can effectively remove the residual water and ethanol without damaging the material structure. This is very important for maintaining the original morphology and composition of copper-based sulfides, especially when the material is nanoscale, too high temperature can cause particle agglomeration or excessive crystal growth.

[0017] In one possible implementation, in the step S2, the concentration of glucose in the mixture is 0.006-0.03g / ml, and the concentration of hydrochloric acid is 0.0005-0.003%.

[0018] Compared with the prior art, the present application sets the concentration of glucose between 0.006-0.03g / ml, which helps to ensure sufficient carbon source supply, but not too much to cause balling phenomenon. Such concentration can promote the carbon layer to uniformly coat on the surface of copper-based sulfides, rather than forming independent carbon balls. Proper carbon coating not only protects the internal active substances from corrosion, but also provides additional conductive paths to enhance catalytic performance, and glucose as a carbon source provides sufficient raw materials to build a carbon shell of moderate thickness. With the increase of the amount of carbon source added, the thickness of the carbon layer gradually increases, but at the above concentration, the carbon layer will not be too thick to affect the exposure of the active sites of the internal copper-based sulfides. A carbon layer of appropriate thickness can protect the internal structure while maintaining good catalytic activity.

[0019] At the same time, the present application sets the concentration of hydrochloric acid to be 0.0005-0.003%, as the acid concentration increases, the ability of glucose to automatically form balls also increases. Therefore, maintaining a low acid concentration can effectively inhibit the self-assembly of glucose into balls, thereby avoiding unnecessary byproduct formation. This can ensure that the main product is a coated rather than a dispersed carbon ball, improving the consistency and controllability of the material.

[0020] In a possible implementation, the ultrasonic treatment in step S2 is performed for 30 minutes.

[0021] Compared with the prior art, the present application uses ultrasonic treatment to generate strong mechanical vibration and cavitation effect, effectively breaking up the agglomerated particles, and making the copper-based sulfide and glucose and other components more uniformly dispersed in the solution, which is crucial for forming a uniform carbon coating layer, because any unevenness can lead to a decline in catalytic performance. Ultrasonic waves can significantly accelerate the collision frequency between molecules, thereby promoting contact between reactants and reaction rate. In particular during the solvothermal synthesis process, ultrasonic treatment helps to accelerate the decomposition and carbonization process of glucose, enabling the carbon layer to be uniformly deposited on the surface of copper-based sulfide in a shorter time.

[0022] In a possible implementation, the hydrothermal treatment in step S2 is performed at a temperature of 170-210℃ for 2-10 hours.

[0023] Through the inventor's experimental verification, it is found that effective carbon layer coating cannot be performed at 150℃. Therefore, the temperature of the hydrothermal treatment is set to be in the range of 170-210℃, which ensures sufficient heat to start and accelerate the carbonization process. This temperature range not only activates the decomposition and carbonization reaction of glucose, but also promotes the uniform deposition of the carbon layer on the surface of copper-based sulfide. As the temperature increases, the carbon layer coating speed becomes faster and faster, which means that at a higher temperature of 170-210℃, efficient carbon coating can be achieved in a shorter time, thereby shortening the production cycle and improving the yield. At the same time, a higher temperature helps to form a more compact and stable carbon layer structure, enhancing the stability and catalytic performance of the material.

[0024] In addition, at a fixed temperature, by adjusting the hydrothermal time (2-10 hours), the hydrothermal treatment can generate coated materials with a hexagonal nanosheet structure. This unique morphology not only provides a larger specific surface area, increasing the number of active sites, but also improves the electron transport path, further enhancing the catalytic efficiency. Therefore, setting the hydrothermal time can accurately control the thickness of the carbon coating layer. Shorter time is suitable for preparing thin layer coated materials, while longer time allows the formation of a thicker carbon layer.

[0025] In a possible implementation, the washing in step S2 uses deionized water and ethanol, respectively.

[0026] Compared with the prior art, the use of deionized water can first effectively remove inorganic salts and other water-soluble impurities generated during the reaction process, ensuring the purity of the sample, and then using ethanol for further cleaning can help to remove the residual water and other organic impurities on the surface, such as unreacted glucose or by-products. As a non-polar solvent, ethanol can help disperse nanoparticles, preventing them from agglomerating due to interaction, thereby ensuring the uniformity and stability of the final product. Good dispersibility is crucial for maintaining high activity and long life of the catalyst.

[0027] In one possible implementation, the parameters of the drying treatment in step S2 are as follows: the temperature is 40°C, and the time is 12 hours.

[0028] Compared with the prior art, 40°C is a relatively low temperature that can effectively remove residual moisture and ethanol without damaging the material structure, which is very important for maintaining the original morphology and composition of the copper-based sulfide and its carbon coating, especially when the material is at the nanoscale, as excessive temperature can cause particle agglomeration or excessive crystal growth; and the longer drying time of 12 hours ensures that the sample can be fully dried, effectively removing all moisture inside and on the surface, even for more complex structures or larger sample quantities. This helps to avoid subsequent problems caused by residual moisture, such as unstable material performance or chemical changes during storage.

[0029] In one possible implementation, the parameters of the calcination treatment in step S2 are as follows: the temperature is 700°C, the time is 2 hours, and the atmosphere is argon.

[0030] Compared with the prior art, the present application adopts the above-mentioned calcination treatment parameters, wherein 700°C is a relatively high temperature that can provide sufficient energy to drive the phase transition process inside the material, making the copper-based sulfide more completely converted into the target phase state, and at the same time, high temperature helps to improve the crystallinity of the material, forming a more regular and stable crystal structure, which has a significant improvement on the catalytic performance; and the calcination time of 2 hours is long enough to ensure that all necessary physical and chemical changes are completed, and not too long to cause excessive sintering or structural damage to the material. Such a time setting can improve production efficiency and reduce energy consumption on the premise of ensuring quality. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 are respectively the sem and tem images of the copper-based sulfide prepared in example 1;

[0032] Figure 2 are respectively the sem and tem images of the copper-based sulfide prepared in example 2;

[0033] Figure 3SEM and TEM images of copper-based sulfide prepared in Example 3, respectively;

[0034] Figure 4 SEM and TEM images of copper-based sulfide prepared in Example 4, respectively;

[0035] Figure 5 SEM and TEM images of copper-based sulfide prepared in Example 5, respectively;

[0036] Figure 6 SEM and TEM images of copper-based sulfide prepared in Example 6, respectively;

[0037] Figure 7 SEM and TEM images of copper-based sulfide prepared in Example 7, respectively;

[0038] Figure 8 SEM and TEM images of copper-based sulfide prepared in Example 8, respectively;

[0039] Figure 9 SEM and TEM images of copper-based sulfide prepared in Example 9, respectively;

[0040] Figure 10 SEM and TEM images of copper-based sulfide prepared in Example 10, respectively;

[0041] Figure 11 SEM and TEM images of copper-based sulfide prepared in Example 11, respectively;

[0042] Figure 12 SEM and TEM images of copper-based sulfide prepared in Example 12, respectively;

[0043] Figure 13 SEM and TEM images of copper-based sulfide prepared in Example 13, respectively;

[0044] Figure 14 SEM and TEM images of copper-based sulfide prepared in Example 14, respectively;

[0045] Figure 15 Test results of oxygen evolution reaction performance of copper-based sulfide prepared in Example 3. DETAILED DESCRIPTION

[0046] In order to make the above objectives, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation method and typical parameters of the present application, and are not used to limit the parameter range described in the present application, and the reasonable changes derived therefrom are still within the protection scope of the claims of the present application.

[0047] It should be noted that the endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0048] Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In some instances, terms having a conventional meaning are defined herein for clarification or ease of reference, and such definitions should not be construed as indicating a significant difference from conventional understanding in the art. The technical methods described or referenced herein are generally well understood by those skilled in the art and employed by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents, and instruments shall be performed according to the manufacturer's instructions and parameters.

[0049] The technical effects of the present invention will be described below with reference to specific embodiments.

[0050] Example 1

[0051] This embodiment provides a carbon-coated copper-based sulfide, which is prepared by the following method:

[0052] S1, Add 200mg CuC l2 .2H2O, 200mg Na2S.9H2O and 2g NaCl were mixed and ground thoroughly, and calcined in a muffle furnace at 60℃ for 30min. Then, the mixture was washed with deionized water and ethanol, and dried in a vacuum drying oven at 40℃ to obtain the core.

[0053] S2. Dissolve 0.5g of glucose in 30mL of deionized water, then add 15μL of hydrochloric acid and stir for 20min. Next, add 35mg of calcined copper-based sulfide and sonicate for 30min to ensure uniform dispersion of the solid in the solution. Hydrothermally heat at 150℃ for 10h. After cooling to room temperature, wash by centrifugation with water and ethanol, dry in a vacuum drying oven at 40℃ for 12h, and calcine at 700℃ for 2h under an Ar atmosphere to obtain the copper-based sulfide.

[0054] Example 2

[0055] This embodiment provides a copper-based sulfide coated with a carbon layer. The only difference from Embodiment 1 is that the hydrothermal treatment temperature in this embodiment is 170°C. Everything else is the same as in Embodiment 1, and will not be repeated here.

[0056] Example 3

[0057] This example provides a carbon layer coated copper-based sulfide, which is different from example 1 only in that the temperature of the hydrothermal treatment in this example is 190°C, and the others are the same as example 1, which will not be repeated here.

[0058] Example 4

[0059] This example provides a carbon layer coated copper-based sulfide, which is different from example 1 only in that the temperature of the hydrothermal treatment in this example is 210°C, and the others are the same as example 1, which will not be repeated here.

[0060] Example 5

[0061] This example provides a carbon layer coated copper-based sulfide, which is different from example 3 only in that the hydrothermal treatment time in this example is 2h, and the others are the same as example 3, which will not be repeated here.

[0062] Example 6

[0063] This example provides a carbon layer coated copper-based sulfide, which is different from example 3 only in that the hydrothermal treatment time in this example is 6h, and the others are the same as example 3, which will not be repeated here.

[0064] Example 7

[0065] This example provides a carbon layer coated copper-based sulfide, which is different from example 3 only in that the hydrothermal treatment time in this example is 14h, and the others are the same as example 3, which will not be repeated here.

[0066] Example 8

[0067] This example provides a carbon layer coated copper-based sulfide, which is different from example 3 only in that the hydrothermal treatment time in this example is 18h, and the others are the same as example 3, which will not be repeated here.

[0068] Example 9

[0069] This example provides a carbon layer coated copper-based sulfide, which is different from example 3 only in that no hydrochloric acid is added in this example, and the others are the same as example 3, which will not be repeated here.

[0070] Example 10

[0071] This example provides a carbon layer coated copper-based sulfide, which is different from example 3 only in that the amount of hydrochloric acid added in this example is 50μL, and the others are the same as example 3, which will not be repeated here.

[0072] Example 11

[0073] The present example provides a carbon layer coated copper-based sulfide, and the difference from example 3 is only that the amount of hydrochloric acid added in the present example is 100 μL, and the others are the same as example 3, which will not be repeated here.

[0074] Example 12

[0075] The present example provides a carbon layer coated copper-based sulfide, and the difference from example 3 is only that the amount of hydrochloric acid added in the present example is 100 μL, and the others are the same as example 3, which will not be repeated here.

[0076] Example 13

[0077] The present example provides a carbon layer coated copper-based sulfide, and the difference from example 3 is only that the amount of hydrochloric acid added in the present example is 100 μL, and the others are the same as example 3, which will not be repeated here.

[0078] Example 14

[0079] The present example provides a carbon layer coated copper-based sulfide, and the difference from example 3 is only that the amount of hydrochloric acid added in the present example is 100 μL, and the others are the same as example 3, which will not be repeated here.

[0080] The inventors respectively tested the performance of the copper-based sulfides prepared in examples 1-14, wherein Figure 1 respectively are the sem and tem images of the copper-based sulfide prepared in example 1, Figure 2 respectively are the sem and tem images of the copper-based sulfide prepared in example 2, Figure 3 respectively are the sem and tem images of the copper-based sulfide prepared in example 3, Figure 4 respectively are the sem and tem images of the copper-based sulfide prepared in example 4, Figure 5 respectively are the sem and tem images of the copper-based sulfide prepared in example 5, Figure 6 respectively are the sem and tem images of the copper-based sulfide prepared in example 6, Figure 7 respectively are the sem and tem images of the copper-based sulfide prepared in example 7, Figure 8 respectively are the sem and tem images of the copper-based sulfide prepared in example 8, Figure 9 respectively are the sem and tem images of the copper-based sulfide prepared in example 9, Figure 10 respectively are the sem and tem images of the copper-based sulfide prepared in example 10, Figure 11 respectively are the sem and tem images of the copper-based sulfide prepared in example 11, Figure 12 respectively are the sem and tem images of the copper-based sulfide prepared in example 12, Figure 13 respectively are the sem and tem images of the copper-based sulfide prepared in example 13,Figure 14 The images shown are SEM and TEM images of the copper-based sulfide prepared in Example 14.

[0081] 3 mg of the copper-based sulfide prepared in Example 3 was added to 300 μL of deionized water, 300 μL of ethanol, and 30 μL of 5% Nafion solution, and sonicated for 30 min to form a suspension. 100 μL of the suspension was then coated onto a 1*1 cm... 2 The oxygen evolution reaction (OER) performance was tested on carbon paper after drying. The OER stability was also tested at a constant potential of 1.6V. The results are as follows: Figure 15 As shown.

[0082] from Figures 1-15 The results show that: 1. Hydrothermal temperature: can control the rate of carbon layer coating. Coating cannot be carried out at 150℃. As the temperature increases, the carbon layer coating speed becomes faster and faster.

[0083] 2. Hydrothermal time: Under constant temperature, hexagonal nanosheets are generated using hydrothermal methods. As the hydrothermal time increases, the thickness of the carbon coating layer gradually increases.

[0084] 3. Acid addition: Without acid, a non-fixed-shape coating material is formed. As the acid concentration increases, the glucose's ability to spontaneously form spheres increases, resulting in carbon spheres instead of a coating material.

[0085] 4. Effect of different carbon source addition amounts: In the absence of glucose, amorphous small particles are formed. As the amount of carbon source added increases, the thickness of the carbon layer also increases.

[0086] 5. Application potential: The presence of a carbon layer can effectively improve the stability of materials and prevent catalyst deactivation.

[0087] As can be seen from the above results, this invention uses glucose as a carbon source through a solvothermal method to form a uniform carbon shell that encapsulates the copper-based sulfide core. This carbon layer not only provides a physical barrier to prevent the internal material from being directly exposed to harsh environments, but also regulates the electron transport path, thereby improving the overall catalytic stability and durability. At the same time, the carbon coating structure can optimize charge transfer kinetics and may introduce new active sites, further improving catalytic efficiency. Moreover, this invention uses glucose, a cheap and widely available raw material, combined with a relatively simple solvothermal synthesis method, making the catalyst easy to produce on a large scale and commercialize.

[0088] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A method for producing a carbon-coated copper-based sulfide, characterized by, The preparation method specifically comprises the following steps: S1, mixing CuCl2·2H2O, Na2S·9H2O and NaCl, then grinding thoroughly, then sequentially performing calcination treatment, washing treatment and drying treatment to obtain a core; S2, dissolving glucose in deionized water, then adding hydrochloric acid to obtain a mixture and stirring, then adding the core obtained in step S1, sequentially performing ultrasonic treatment and hydrothermal treatment, then cooling to room temperature, sequentially performing centrifugation, washing and drying treatment, and finally performing calcination treatment to obtain a carbon-coated copper-based sulfide; In step S1, the mass ratio of CuCl2·2H2O to Na2S·9H2O is 1:1, and the mass ratio of CuCl2·2H2O to NaCl is 1:10; the parameters of the calcination treatment are as follows: the temperature is 60°C, and the time is 30 min; the temperature of the drying treatment is 40°C; In step S2, the concentration of glucose in the mixture is 0.006-0.03 g / ml, and the concentration of hydrochloric acid is 0.0005-0.003%; the parameters of the hydrothermal treatment are as follows: the temperature is 170-210°C, and the time is 2-10 h; the parameters of the calcination treatment are as follows: the temperature is 700°C, the time is 2 h, and the atmosphere is argon.

2. The production method according to claim 1, wherein In the step S1, the washing treatment respectively uses deionized water and ethanol.

3. The production method according to claim 1, wherein In step S2, the time of the ultrasonic treatment is 30 min.

4. The production method according to claim 1, wherein In step S2, the washing respectively uses deionized water and ethanol.

5. The production method according to claim 1, wherein In step S2, the parameters of the drying treatment are as follows: the temperature is 40°C, and the time is 12 h.

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