A doped carbon material, a method for preparing the same and use thereof

Abstract

The application provides a doped carbon material and a preparation method and application thereof, and belongs to the technical field of carbon materials. The preparation method of the doped carbon material comprises the following steps: S1, a compound containing a doping element is dissolved in a solvent to form a doping element precursor solution; an organic carbon layer is coated on a substrate, and then the prepared doping element precursor solution is coated on the organic carbon layer to obtain a composite precursor; S2, the composite precursor obtained in the step S1 is calcined at 200-300 DEG C for 1-30 min in an oxygen-containing atmosphere; and S3, the product after calcination in the step S2 is calcined at a temperature of greater than or equal to 300 DEG C for 3-10 h in a hydrogen atmosphere, so that the doped carbon material is obtained. The whole process is simple in preparation, low in processing temperature, high in doping amount and uniform, effectively reduces energy consumption, and improves the preparation efficiency.

Description

Technical Field

[0001] This invention relates to the field of carbon materials technology, and in particular to a doped carbon material, its preparation method, and its application. Background Technology

[0002] Carbon materials, including porous carbon, graphene oxide, carbon nanotubes, and carbon fibers, are widely used in catalysis, especially heteroatom-doped carbon-based materials. Through the synergistic effects of carbon atoms and heteroatoms, as well as among heteroatoms, they play a crucial role in increasing the interaction between the catalytic center and the reactants, reducing the activation energy of the reaction, and improving the utilization rate of the catalytic center atoms. Therefore, doped carbon materials have been a hot research area in recent years. Currently, doped carbon materials are generally prepared by directly blending carbon material precursors with heteroatom-containing compounds and then performing high-temperature carbonization. This preparation method is simple and readily available, but it also has several drawbacks: first, high temperatures are required for carbonization, generally above 500℃, to completely carbonize the carbon material precursor into carbon material; second, the doping efficiency is not high, as many metal elements easily detach and aggregate on the carbon material; and third, when multiple heteroatoms are required for doping, the preparation process is complex, requiring multiple carbonizations and blendings, resulting in a long preparation cycle and complex carbon precursor pretreatment processes.

[0003] Therefore, there is an urgent need to develop a carbon material with a simple preparation process and high doping capacity. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing doped carbon materials, such as complex preparation processes and low doping levels, by providing a carbon material with a simple preparation process and high doping levels.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a carbon-doped material, comprising the following steps: S1: Dissolve the compound containing the doped element in a solvent to form a doped element precursor solution; coat an organic carbon layer on the substrate, and then coat the prepared doped element precursor solution on the organic carbon layer to obtain a composite precursor. S2: Calcine the composite precursor obtained in step S1 at 200~300℃ for 1~30min in an oxygen-containing atmosphere; S3: The product after calcination in step S2 is calcined in a hydrogen atmosphere at a temperature of 300°C or higher for 3 to 10 hours to obtain the doped carbon material.

[0006] As an embodiment of the present invention, the organic carbon layer is a liquid oil, and the liquid oil includes at least one of peanut oil, rapeseed oil, and soybean oil.

[0007] As an embodiment of the present invention, the doping element includes at least one element selected from platinum, palladium, iron, nickel, copper, cobalt, rhodium, rhenium, nitrogen, sulfur, and phosphorus.

[0008] As an embodiment of the present invention, the compound containing the doped element includes at least one compound selected from the following: nitrate, chloride, perchlorate, sulfate, phosphate, and acetate of platinum, palladium, iron, nickel, copper, cobalt, rhodium, or rhenium.

[0009] As an embodiment of the present invention, the solvent mentioned in step S1 includes at least one of liquid oil, water, ethanol, propanol, tetrahydrofuran, dimethyl sulfoxide, ethylene glycol, and acetic acid.

[0010] As an embodiment of the present invention, the concentration of the compound containing the doped element in the precursor solution is 0.1~100 mmol / L.

[0011] As an embodiment of the present invention, the mass ratio of carbon element in the organic carbon layer to dopant element in the compound containing dopant element is 100:(0.35~5).

[0012] As an embodiment of the present invention, the coating method described in step S1 includes smearing, spraying, or immersion.

[0013] As an embodiment of the present invention, the substrate includes iron sheet, nickel foam, molecular sieve, foam ceramic or copper foam.

[0014] In a second aspect, the present invention provides a carbon-doped material prepared by the preparation method described in the first aspect of the present invention.

[0015] As an embodiment of the present invention, in the doped carbon material, the doping amount of the doping element is greater than or equal to 0.35 wt%.

[0016] A third aspect of the present invention provides the application of the carbon-doped material described in the second aspect of the present invention, wherein the carbon-doped material is applied in at least one field of industrial catalysis, adsorption separation, and water purification.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes a method of localized combustion at a lower temperature followed by reduction calcination at a higher temperature, enabling experimental carbonization at a lower ambient temperature. This simplifies the entire preparation process, reduces processing temperature, and achieves high and uniform doping levels, effectively lowering energy consumption and improving preparation efficiency, thus demonstrating promising prospects for industrial application. Furthermore, the doped carbon material of this invention can support not only metallic elements but also non-metallic elements such as nitrogen, sulfur, and phosphorus, exhibiting excellent loading stability. Detailed Implementation

[0018] To better illustrate the purpose, technical solution, and advantages of this invention, specific embodiments will be used to further describe the invention below. However, these embodiments do not limit the invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in this invention are conventional reagents, methods, and equipment in this technical field. Unless otherwise specified, all reagents and materials used in this invention are commercially available.

[0019] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0020] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0021] Unless otherwise specified, all reagents or instruments used in this invention are commercially available products.

[0022] In a first aspect, embodiments of the present invention provide a method for preparing a carbon-doped material, comprising the following steps: S1: Dissolve the compound containing the doped element in a solvent to form a doped element precursor solution; coat an organic carbon layer on the substrate, and then coat the prepared doped element precursor solution on the organic carbon layer to obtain a composite precursor. S2: Calcine the composite precursor obtained in step S1 at 200~300℃ for 1~30min in an oxygen-containing atmosphere; S3: The product after calcination in step S2 is calcined in a hydrogen atmosphere at a temperature of 300°C or higher for 3 to 10 hours to obtain the doped carbon material.

[0023] This invention utilizes a method of localized combustion at a lower temperature followed by reduction calcination at a higher temperature, enabling experimental carbonization at a lower ambient temperature. This simplifies the entire preparation process, reduces processing temperature, and achieves high and uniform doping levels, effectively lowering energy consumption and improving preparation efficiency, thus demonstrating promising prospects for industrial application. Furthermore, the doped carbon material of this invention can support not only metallic elements but also non-metallic elements such as nitrogen, sulfur, and phosphorus, exhibiting excellent loading stability.

[0024] In some embodiments of the present invention, the oxygen-containing atmosphere described in step S2 may be an atmosphere formed by air or pure oxygen.

[0025] In some embodiments of the present invention, the calcination temperature in step S3 is 300~400°C. Although the carbon reduction effect is better as the temperature increases, excessively high temperatures will increase energy consumption. Therefore, it is sufficient to keep it within the above-mentioned suitable range.

[0026] In some embodiments of the present invention, the organic carbon layer is a liquid oil, which may be edible oil or animal oil, and more specifically includes, but is not limited to, at least one of peanut oil, rapeseed oil, and soybean oil.

[0027] In some embodiments of the present invention, the doping element includes at least one element selected from platinum, palladium, iron, nickel, copper, cobalt, rhodium, rhenium, nitrogen, sulfur, and phosphorus. The doped carbon material of the present invention can not only support metallic elements, but also non-metallic elements such as nitrogen, sulfur, and phosphorus, and all exhibit high doping levels and loading stability.

[0028] In some embodiments of the present invention, the compound containing the doped element includes at least one compound selected from the group consisting of nitrates, chlorides, perchlorates, sulfates, phosphates, and acetates corresponding to platinum, palladium, iron, nickel, copper, cobalt, rhodium, or rhenium. More specifically, the compound containing the doped element includes, but is not limited to, at least one selected from the group consisting of palladium nitrate, platinum perchlorate, and ferric chloride.

[0029] In some embodiments of the present invention, the solvent mentioned in step S1 includes at least one of liquid oil, water, ethanol, propanol, tetrahydrofuran, dimethyl sulfoxide, ethylene glycol, and acetic acid, as long as it can dissolve the compound containing the dopant element.

[0030] In some embodiments of the present invention, the concentration of the compound containing the dopant element in the dopant precursor solution is 0.1~100 mmol / L.

[0031] In some embodiments of the present invention, the mass ratio of carbon in the organic carbon layer to dopant in the compound containing dopant is 100:(0.35~5). The preparation method of the present invention can stably and uniformly dope carbon materials with a high content of dopant elements, thereby enhancing the application value of doped carbon materials.

[0032] In some embodiments of the present invention, the coating method described in step S1 may be smearing, spraying, or dipping.

[0033] In some embodiments of the present invention, the substrate may be selected from high-temperature resistant metal or non-metal materials. Exemplarily, the substrate includes, but is not limited to, iron sheets, nickel foam, molecular sieves, ceramic foam, or copper foam. The preparation process of the present invention involves loading an organic carbon source onto the surface of the substrate and calcining it together with the substrate, thus bonding it in situ to the substrate surface. No other binding agents are required, and this process does not affect the performance of the doped carbon material.

[0034] In some preferred embodiments of the present invention, the substrate is selected from foamed nickel, molecular sieve, foamed ceramic or foamed copper with a porous structure. The substrate with a porous structure can load more doping elements.

[0035] In a second aspect of the present invention, an embodiment provides a carbon-doped material prepared by the preparation method described in the first aspect of the present invention.

[0036] In some embodiments of the present invention, the doping amount of the doping element in the doped carbon material is greater than or equal to 0.35 wt%.

[0037] A third aspect of the present invention provides the application of the carbon-doped material described in the second aspect of the present invention, wherein the carbon-doped material is applied in at least one field of industrial catalysis, adsorption separation, and water purification.

[0038] The following are specific embodiments of the present invention.

[0039] Example 1 This embodiment provides a carbon-doped material, prepared according to a method including the following steps: S1: Dissolve palladium nitrate dihydrate in water to prepare a 0.1 mmol / L solution; impregnate the substrate nickel foam in peanut oil for 10 min, and then further impregnate the nickel foam in the solvent of palladium nitrate dihydrate for 10 min to obtain the composite precursor; S2: Transfer the composite precursor obtained in step S1 to a high-temperature furnace and calcine it in air at 200°C for 30 min. S3: Introduce hydrogen gas until it completely replaces the air in the furnace, raise the temperature to 300°C, and calcine for 3 hours to obtain the doped carbon material.

[0040] Example 2 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the concentration of palladium nitrate dihydrate in the palladium nitrate dihydrate solution in step S1 is 10 mmol / L.

[0041] Example 3 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the concentration of palladium nitrate dihydrate in the palladium nitrate dihydrate solution in step S1 is 20 mmol / L.

[0042] Example 4 This embodiment provides a carbon-doped material, prepared according to the method of Example 1. The difference from Example 1 is that the concentration of palladium dihydrate in the palladium dihydrate solution in step S1 is 50 mmol / L.

[0043] Example 5 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the concentration of palladium nitrate dihydrate in the palladium nitrate dihydrate solution in step S1 is 100 mmol / L.

[0044] Example 6 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S2 is 250°C and the calcination time is 20 min.

[0045] Example 7 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S2 is 300°C and the calcination time is 10 min.

[0046] Example 8 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S3 is 350°C and the calcination time is 8 hours.

[0047] Example 9 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S3 is 400°C and the calcination time is 6 hours.

[0048] Example 10 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S3 is 450°C and the calcination time is 3 hours.

[0049] Example 11 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the organic carbon source in step S1 is replaced with soybean oil instead of peanut oil.

[0050] Example 12 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the organic carbon source in step S1 is replaced by animal oil (edible lard purchased from Shuanghui Company), and the animal oil is heated into a liquid state before use.

[0051] Example 13 This embodiment provides a carbon-doped material, prepared according to the method of Example 1. The difference from Example 1 is that the compound of the doping element in step S1 is replaced with nickel acetate, and the substrate is replaced with copper foam.

[0052] Example 14 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the compound of the doping element in step S1 is replaced with platinum perchlorate.

[0053] Example 15 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the compound of the dopant element in step S1 is replaced with ferric chloride.

[0054] Example 16 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the compound of the dopant element in step S1 is replaced with copper sulfate.

[0055] Example 17 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the substrate in step S1 is replaced with an iron sheet.

[0056] Comparative Example 1 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S2 is 150°C and the calcination time is 1 hour.

[0057] Comparative Example 2 This embodiment provides a doped carbon material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S2 is 350°C and the calcination time is 10 min.

[0058] Comparative Example 3 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the calcination temperature in step S3 is 250°C and the calcination time is 12h.

[0059] Comparative Example 4 This embodiment provides a carbon-doped material, prepared according to the method of Example 1, except that the atmosphere in step S2 is replaced with a hydrogen atmosphere.

[0060] Comparative Example 5 This embodiment provides a carbon-doped material, which is prepared according to the method of Example 1. The difference from Example 1 is that the atmosphere in step S2 is replaced with a nitrogen atmosphere.

[0061] Comparative Example 6 This embodiment provides a carbon-doped material, prepared according to the method of Example 1. The difference from Example 1 is that the steps in steps S1 and S2 are slightly different, specifically: S1: The substrate nickel foam is immersed in peanut oil for 10 minutes to obtain a carbon-supported precursor. Then the carbon-supported precursor is transferred to a high-temperature furnace and calcined in air at 200°C for 15 minutes. S2: Immerse the calcined product from step S1 in an aqueous solution of palladium nitrate dihydrate with a concentration of 0.1 mmol / L for 10 min, and then transfer it to a high-temperature furnace for calcination at 200°C in air for 15 min. S3: Same as Example 1.

[0062] Performance testing The doped carbon materials prepared in the above embodiments and comparative examples were used as test samples, and their performance was tested. The specific test methods and test results are as follows: 1. Elemental Doping Analysis The content of the corresponding elements was obtained by EDX energy dispersive spectroscopy analysis. The formula for calculating the loading and / or doping content of the elements is as follows: Carbon loading = M C / M 基 ; Dopant loading (%) = M 掺 / M 基 ×100%; Doping amount (%) = (Doping element loading / Carbon loading) × 100%; Among them, M C This indicates the mass content of carbon in the sample being tested; M 基 This indicates the mass content of the element in the substrate of the sample to be tested; M 掺 This indicates the mass content of the corresponding dopant element in the sample being tested; The specific test results are shown in Table 1; 2. Load stability The sample to be tested was placed in water and sonicated for 30 minutes. The mass ratio before and after sonication was used as an indicator. The closer the ratio was to 1, the better the stability of the loaded material. The specific test results are shown in Table 1. 3. Temperature resistance test The sample to be tested was placed at 200℃ for 12 hours. The ratio of the mass after the test to the mass before the test was calculated. The closer the ratio is to 1, the better the temperature resistance and the more stable the doping. The specific test results are shown in Table 1. 4. Solvent resistance test The sample to be tested was immersed in acetone solution for 12 hours. The ratio of the mass after the test to the mass before the test was calculated. The closer the ratio is to 1, the better the solvent resistance. The specific test results are shown in Table 1.

[0063] Table 1 The results above show that: This invention utilizes a method of localized combustion at a lower temperature followed by reduction calcination at a higher temperature, enabling experimental carbonization at a lower ambient temperature. This simplifies the entire preparation process, reduces processing temperature, and achieves high and uniform doping levels, effectively lowering energy consumption and improving preparation efficiency, thus demonstrating promising prospects for industrial application. Furthermore, the doped carbon material of this invention can support not only metallic elements but also non-metallic elements such as nitrogen, sulfur, and phosphorus, exhibiting excellent loading stability.

[0064] In step S2 of Comparative Example 1, the calcination temperature in air atmosphere is relatively low (lower than 200°C of the present invention). As a result, when the temperature is too low, the carbon precursor is not completely carbonized, causing its load stability, temperature resistance, solvent resistance and metal element loading to decrease significantly.

[0065] In Comparative Example 2, S2 was calcined at a higher temperature in air (higher than the 300°C of this invention). Some of the loaded carbon material would oxidize in the air environment, resulting in a low load of carbon material, which affected the loading efficiency and reduced the loading stability to some extent.

[0066] The calcination temperature in S3 of Comparative Example 3 is relatively low (lower than the 300°C of the present invention), resulting in some dopants not being reduced, causing a decrease in their doping amount and affecting their subsequent performance.

[0067] In Comparative Examples 4 and 5, the calcination atmosphere in step S2 was replaced with an oxygen-free atmosphere. The carbon precursor was not activated, which resulted in a significant decrease in the content of doped elements when the reduction calcination was carried out at a lower temperature in step S3, and the stability of the prepared doped carbon material also deteriorated significantly.

[0068] Comparative Example 6 involves calcining the carbon precursor first, followed by loading dopant elements and calcining again. This also results in a significant reduction in the dopant content after reduction calcination at a lower temperature in step S3, and a significant deterioration in the stability of the prepared doped carbon material.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a carbon-doped material, characterized in that, Includes the following steps: S1: Dissolve the compound containing the doped element in a solvent to form a doped element precursor solution; coat an organic carbon layer on the substrate, and then coat the prepared doped element precursor solution on the organic carbon layer to obtain a composite precursor. S2: Calcine the composite precursor obtained in step S1 at 200~300℃ for 1~30min in an oxygen-containing atmosphere; S3: The product after calcination in step S2 is calcined in a hydrogen atmosphere at a temperature of 300°C or higher for 3 to 10 hours to obtain the doped carbon material.

2. The method for preparing the doped carbon material according to claim 1, characterized in that, The organic carbon layer is a liquid oil, which includes at least one of peanut oil, rapeseed oil, and soybean oil.

3. The method for preparing the doped carbon material according to claim 1, characterized in that, The doping element includes at least one element selected from platinum, palladium, iron, nickel, copper, cobalt, rhodium, rhenium, nitrogen, sulfur, and phosphorus.

4. The method for preparing the doped carbon material according to claim 1, characterized in that, The doped compound includes at least one compound selected from the following: nitrate, chloride, perchlorate, sulfate, phosphate, and acetate of platinum, palladium, iron, nickel, copper, cobalt, rhodium, or rhenium.

5. The method for preparing doped carbon material according to claim 1, characterized in that, The solvent mentioned in step S1 includes at least one of liquid oil, water, ethanol, propanol, tetrahydrofuran, dimethyl sulfoxide, ethylene glycol, and acetic acid.

6. The method for preparing the doped carbon material according to claim 1, characterized in that, The concentration of the compound containing the doped element in the precursor solution is 0.1~100 mmol / L.

7. The method for preparing the doped carbon material according to claim 1, characterized in that, The mass ratio of carbon in the organic carbon layer to dopant in the compound containing dopant is 100:(0.35~5).

8. The method for preparing the doped carbon material according to claim 1, characterized in that, The substrate includes iron sheet, nickel foam, molecular sieve, foam ceramic or copper foam.

9. A carbon-doped material, characterized in that, The doped carbon material is prepared by any one of the preparation methods according to claims 1 to 9, wherein the doping amount of the doping element is greater than or equal to 0.35 wt%.

10. The application of the carbon-doped material according to claim 9, characterized in that, The doped carbon material is used in at least one of the following fields: industrial catalysis, adsorption separation, and water purification.

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