Preparation method of cobalt-zinc-based electron inversion perovskite nitride material and its application in photothermal catalytic carbon monoxide oxidation

Abstract

The invention discloses a preparation method of a cobalt-zinc-based electron-inverted perovskite nitride material and its application in photothermal catalytic carbon monoxide oxidation. The method comprises the following steps: S1, adding a cobalt salt and a zinc salt to ethanol, and fully stirring at room temperature to obtain a mixed solution; S2, ultrasonically dispersing the mixed solution, and then transferring it to a vacuum constant-temperature oven for vacuum drying, and after drying, a cobalt-zinc bimetallic precursor of the cobalt-zinc-based electron-inverted perovskite nitride material can be obtained; S3, placing the cobalt-zinc bimetallic precursor material in a tube furnace, performing a nitriding treatment in an ammonia atmosphere with a certain flow rate during a programmed temperature rise process, and then introducing nitrogen during a cooling process and naturally cooling to room temperature to obtain the cobalt-zinc-based electron-inverted perovskite nitride material; the cobalt-zinc-based electron-inverted perovskite nitride material prepared by this method has the advantages of high thermal stability, light absorption capacity covering the entire solar spectrum, and efficient photothermal conversion.

Description

Technical Field

[0001] The present invention belongs to the technical field of photothermal catalytic materials, and specifically relates to a preparation method of a cobalt-zinc-based electron-inverted perovskite nitride material and its application in photothermal catalytic carbon monoxide oxidation. Background Art

[0002] Carbon monoxide (CO) is a colorless, odorless gas whose invisibility makes it a dangerous environmental threat. It primarily originates from incomplete combustion of fossil fuels such as coal, oil, and natural gas, and is also closely linked to transportation and industrial emissions. Whether emitted from vehicle exhaust or factory waste, CO release can negatively impact air quality. Due to its serious health risks, such as headaches, dizziness, and even fatal poisoning, effectively removing CO from the environment has become a global concern.

[0003] Traditional catalytic combustion technology is one of the main methods currently widely used for carbon monoxide removal. This technology relies on precious metal catalysts (such as platinum and palladium) to convert carbon monoxide into carbon dioxide by promoting the reaction of carbon monoxide with oxygen at high temperatures. Catalytic combustion can not only quickly and effectively reduce the concentration of carbon monoxide, but also reduce the emission of other harmful substances to a certain extent. However, despite the relatively high efficiency of catalytic combustion, its application is limited by the scarcity and high cost of precious metal resources. In addition, these catalytic reactions usually need to be carried out under high temperature conditions, which not only increases energy consumption, but may also bring economic burdens, while also affecting environmental friendliness, making it difficult to meet actual usage needs. Summary of the Invention

[0004] To solve the above problems, the present invention proposes a preparation method of a cobalt-zinc-based electron-inverted perovskite nitride material and its application in photothermal catalytic carbon monoxide oxidation. The preparation method of the invention is simple, the raw materials are easily available, the cost is low and the reproducibility is good. The prepared cobalt-zinc-based electron-inverted perovskite nitride material has the advantages of high material thermal stability, light absorption capacity covering the entire solar spectrum and efficient photothermal conversion.

[0005] The present invention adopts the following technical solutions:

[0006] A method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material comprises the following steps:

[0007] S1. Add cobalt salt and zinc salt to ethanol and stir thoroughly at room temperature to obtain a mixed solution;

[0008] S2. Ultrasonic dispersion of the mixed solution is performed, and the mixture is subsequently transferred to a vacuum constant temperature oven for vacuum drying. After drying, a cobalt-zinc bimetallic precursor of a cobalt-zinc-based electron-inverted perovskite nitride material can be obtained;

[0009] S3. Place the cobalt-zinc bimetallic precursor material in a tubular furnace, perform nitridation treatment in an ammonia atmosphere with a certain flow rate during programmed temperature rise, then introduce nitrogen during cooling and naturally cool to room temperature to obtain a cobalt-zinc-based electron inversion perovskite nitride material.

[0010] Preferably, the cobalt salt in step S1 is one or more of cobalt nitrate, cobalt acetate, and cobalt chloride.

[0011] Preferably, the zinc salt in step S1 is one or more of zinc nitrate, zinc acetate, and zinc chloride.

[0012] Preferably, the molar ratio of the cobalt salt to the zinc salt in step S1 is (2-4):1, the amount of ethanol used is 60-100 ml, and the stirring rate is 400-1000 r / min.

[0013] Preferably, the ultrasonic dispersion time in step S2 is 20-60 min, the vacuum drying time is 500-800 min, and the drying temperature is 70-90°C.

[0014] Preferably, in step S3, the purity of ammonia is ≥98%, the purity of nitrogen is ≥98%, the flow rate of ammonia is 10-60 mL / min, and the flow rate of nitrogen is 10-60 mL / min; the nitriding treatment temperature is 550-650° C., and the nitriding treatment time is 6-10 h.

[0015] A cobalt-zinc-based electron-inverted perovskite nitride material is prepared using the method for preparing the cobalt-zinc-based electron-inverted perovskite nitride material; the cobalt-zinc-based electron-inverted perovskite nitride material has a chemical formula of ZnNCo3 and has a cubic crystal phase. In the crystal structure, nitrogen and cobalt are coordinated to form an octahedron, with nitrogen at the center of the octahedron, cobalt at the vertices of the octahedron, and zinc distributed in the gaps between the [NCo6] octahedra.

[0016] The invention discloses an application of a cobalt-zinc-based electron-inverted perovskite nitride material, wherein the cobalt-zinc-based electron-inverted perovskite nitride material is used as a catalyst for photothermal catalytic carbon monoxide oxidation. The catalytic conditions are as follows: a mobile photothermal catalytic evaluation device is used, the light source is a xenon lamp, the reaction atmosphere is 1% CO + 1% O2 + 98% Ar, the mixed gas flow rate is 30 ml / min, and the light intensity is 0.4-1.1 W / cm 2 , the amount of catalyst ZnNCo3 used is 50 mg.

[0017] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0018] 1. The present invention provides a method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material. The preparation method has a simple process, readily available raw materials, low cost and good reproducibility. The prepared cobalt-zinc-based electron-inverted perovskite nitride material has the advantages of high material thermal stability, light absorption capacity covering the entire solar spectrum, and efficient photothermal conversion.

[0019] 2. The present invention applies the prepared cobalt-zinc-based electron-inverted perovskite nitride ZnNCo3 to the photothermal catalytic carbon monoxide oxidation reaction, achieving a carbon monoxide conversion rate close to 100% and long-term photothermal catalytic reaction stability under full-spectrum solar illumination, which can realize the rapid conversion of toxic carbon monoxide gas driven by solar energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a scanning electron microscope image of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention;

[0021] Figure 2 The cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention and its X-ray diffraction pattern after reacting for 1 day in the reaction atmosphere;

[0022] Figure 3 This is a crystal structure diagram of the cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention;

[0023] Figure 4 This is an X-ray photoelectron spectrum of the cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention;

[0024] Figure 5 This is an ultraviolet absorption spectrum of the cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention;

[0025] Figure 6 This is a performance graph of the carbon monoxide conversion rate of the cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention under different light intensities in the photothermal catalytic carbon monoxide oxidation reaction;

[0026] Figure 7 The cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 prepared in Example 1 of the present invention is applied to the long-term stability of the photothermal catalytic carbon monoxide oxidation reaction. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] See also Figures 1 to 7 .

[0029] Example 1

[0030] A method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material (ZnNCo3) comprises the following steps:

[0031] S1. Weigh 3 mmol of cobalt nitrate hexahydrate and 1 mmol of zinc nitrate hexahydrate, dissolve them in 80 ml of ethanol, and stir at room temperature at a speed of 600 rpm for 30 min to fully mix and dissolve to obtain a mixed solution;

[0032] S2. After the stirring is completed, the obtained mixed solution is ultrasonically dispersed for 30 minutes, and then transferred to a vacuum constant temperature oven at 80° C. for drying for 12 hours, to obtain a cobalt-zinc bimetallic precursor of a cobalt-zinc-based electron inversion perovskite nitride material after drying;

[0033] S3. Place the cobalt-zinc bimetallic precursor in a tube furnace, use a vacuum pump to extract the air in the tube furnace, then introduce argon to normal pressure, repeat the pumping three times, introduce high-purity ammonia, adjust the ammonia flow rate to 60 ml / min, heat to 600°C at a heating rate of 10°C / min and maintain for 10 hours, then introduce 60 ml / min of nitrogen during the cooling process and naturally cool to room temperature to obtain a cobalt-zinc-based electron inversion perovskite nitride material.

[0034] Example 2

[0035] A method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material (ZnNCo3) comprises the following steps:

[0036] S1. Weigh 3 mmol of cobalt acetate tetrahydrate and 1 mmol of zinc acetate dihydrate, dissolve them in 80 ml of ethanol, and stir at room temperature at a speed of 600 r / min for 30 min to fully mix and dissolve to obtain a mixed solution;

[0037] S2. After the stirring is completed, the obtained mixed solution is ultrasonically dispersed for 30 minutes, and then transferred to a vacuum constant temperature oven at 80° C. for drying for 12 hours, to obtain a cobalt-zinc bimetallic precursor of a cobalt-zinc-based electron inversion perovskite nitride material after drying;

[0038] S3. Place the cobalt-zinc bimetallic precursor in a tube furnace, use a vacuum pump to extract the air in the tube furnace, then introduce argon to normal pressure, repeat the pumping three times, introduce high-purity ammonia, adjust the ammonia flow rate to 60 ml / min, heat to 600°C at a heating rate of 10°C / min and maintain for 10 hours, then introduce 60 ml / min of nitrogen during the cooling process and naturally cool to room temperature to obtain a cobalt-zinc-based electron inversion perovskite nitride material.

[0039] Example 3

[0040] A method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material (ZnNCo3) comprises the following steps:

[0041] S1. Weigh 3 mmol of cobalt nitrate hexahydrate and 1 mmol of zinc acetate dihydrate, dissolve them in 80 ml of ethanol, and stir at room temperature at a speed of 600 rpm for 30 min to fully mix and dissolve to obtain a mixed solution;

[0042] S2. After the stirring is completed, the obtained mixed solution is ultrasonically dispersed for 30 minutes, and then transferred to a vacuum constant temperature oven at 80° C. for drying for 12 hours, to obtain a cobalt-zinc bimetallic precursor of a cobalt-zinc-based electron inversion perovskite nitride material after drying;

[0043] S3. Place the cobalt-zinc bimetallic precursor in a tube furnace, use a vacuum pump to extract the air in the tube furnace, then introduce argon to normal pressure, repeat the pumping three times, introduce high-purity ammonia, adjust the ammonia flow rate to 60 ml / min, heat to 600°C at a heating rate of 10°C / min and maintain for 10 hours, then introduce 60 ml / min of nitrogen during the cooling process and naturally cool to room temperature to obtain a cobalt-zinc-based electron inversion perovskite nitride material.

[0044] Example 4

[0045] A method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material (ZnNCo3) comprises the following steps:

[0046] S1. Weigh 3 mmol of cobalt chloride hexahydrate and 1 mmol of zinc chloride, dissolve them in 80 ml of ethanol, and stir at room temperature at a speed of 600 rpm for 30 min to fully mix and dissolve to obtain a mixed solution;

[0047] S2. After the stirring is completed, the obtained mixed solution is ultrasonically dispersed for 30 minutes, and then transferred to a vacuum constant temperature oven at 80° C. for drying for 12 hours, to obtain a cobalt-zinc bimetallic precursor of a cobalt-zinc-based electron inversion perovskite nitride material after drying;

[0048] S3. Place the cobalt-zinc bimetallic precursor in a tube furnace, use a vacuum pump to extract the air in the tube furnace, then introduce argon to normal pressure, repeat the pumping three times, introduce high-purity ammonia, adjust the ammonia flow rate to 60 ml / min, heat to 600°C at a heating rate of 10°C / min and maintain for 10 hours, then introduce 60 ml / min of nitrogen during the cooling process and naturally cool to room temperature to obtain a cobalt-zinc-based electron inversion perovskite nitride material.

[0049] The SEM image of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 obtained in Example 1 is as follows: Figure 1 As shown, the sample is a flake structure composed of hundreds of nanoparticles with a size between 100-200nm.

[0050] The X-ray diffraction test of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 obtained in Example 1, Example 2, Example 3 and Example 4 showed the same test results. Taking the XRD of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 obtained in Example 1 as an example, Figure 2 As shown in the figure, the ZnNCo3 prepared by the above method exhibits good crystallinity. In addition, the XRD of the material remains basically unchanged after one day of reaction in the reaction atmosphere, indicating that ZnNCo3 has good stability in the reaction atmosphere. The crystal structure of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 is shown in the figure. Figure 3 As shown, ZnNCo3 has a cubic crystal phase. In the crystal structure, N and Co coordinate to form an octahedron, with N at the center of the octahedron, Co at the vertex of the octahedron, and Zn distributed in the gaps between the [NCo6] octahedrons.

[0051] The X-ray photoelectron spectrum of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 obtained in Example 1 is as follows: Figure 4 As shown, the main peak of Zn 2p in ZnNCo3 can be decomposed into 2p 1 / 2 and 2p 3 / 2 , located at 1044.48eV and 1021.44eV respectively, while the Co element is mainly Co 3+ and Co 2+ The XRD and XPS tests further confirmed that the present invention successfully synthesized the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3.

[0052] The ultraviolet absorption spectrum of the cobalt-zinc-based electron inversion perovskite nitride material ZnNCo3 obtained in Example 1 is as follows: Figure 5 As shown, ZnNCo3 has good absorption in the entire spectrum range and exhibits excellent photothermal properties.

[0053] The cobalt-zinc-based electron-inverted perovskite nitride material ZnNCo3 obtained in Example 1 was applied to the photothermal catalytic carbon monoxide oxidation reaction. A flow-type photothermal catalytic evaluation device was used, 50 mg of the catalyst was weighed into the reaction tube, and the carbon monoxide conversion rate of the carbon monoxide oxidation reaction under different light intensities was tested. Figure 6 It can be seen that as the light intensity increases, the carbon monoxide conversion rate gradually increases. When the light intensity is 1.1W / cm 2 When the ZnNCo3 is heated for 24 hr, the carbon monoxide conversion rate can reach 100%, showing excellent performance of photothermal catalytic carbon monoxide oxidation reaction; and the long-term performance of ZnNCo3 is also tested. Figure 7 It can be seen that ZnNCo3 can still maintain a 100% carbon monoxide conversion rate after 168 hours, indicating that it has good stability as a photothermal catalytic material in the carbon monoxide oxidation reaction.

[0054] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material, characterized in that: Here are the steps: S1. Add cobalt salt and zinc salt to ethanol and stir thoroughly at room temperature to obtain a mixed solution; S2. Ultrasonic dispersion of the mixed solution is performed, and the mixture is subsequently transferred to a vacuum constant temperature oven for vacuum drying. After drying, a cobalt-zinc bimetallic precursor of a cobalt-zinc-based electron-inverted perovskite nitride material can be obtained; S3, placing the cobalt-zinc bimetallic precursor material in a tube furnace, performing a nitridation treatment in an ammonia atmosphere with a certain flow rate during a programmed temperature rise process, and then introducing nitrogen during a temperature drop process and naturally cooling to room temperature to obtain a cobalt-zinc-based electron inversion perovskite nitride material; In step S3, the purity of ammonia is ≥98%, the purity of nitrogen is ≥98%, the flow rate of ammonia is 10-60 mL / min, and the flow rate of nitrogen is 10-60 mL / min; the nitriding treatment temperature is 550-650° C., and the nitriding treatment time is 6-10 h.

2. The method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material according to claim 1, wherein: The cobalt salt in step S1 is one or more of cobalt nitrate, cobalt acetate, and cobalt chloride.

3. The method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material according to claim 1, wherein: The zinc salt in step S1 is one or more of zinc nitrate, zinc acetate, and zinc chloride.

4. The method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material according to claim 1, wherein: In step S1, the molar ratio of the cobalt salt to the zinc salt is (2-4):1, the amount of ethanol used is 60-100 ml, and the stirring rate is 400-1000 r / min.

5. The method for preparing a cobalt-zinc-based electron-inverted perovskite nitride material according to claim 1, wherein: The ultrasonic dispersion time in step S2 is 20-60 min, the vacuum drying time is 500-800 min, and the drying temperature is 70-90°C.

6. A cobalt-zinc-based electron-inverted perovskite nitride material, characterized in that: The cobalt-zinc-based electron-inverted perovskite nitride material is prepared by the preparation method of any one of claims 1 to 5; the cobalt-zinc-based electron-inverted perovskite nitride material has a chemical formula of ZnNCo3, has a cubic crystal phase, and in the crystal structure, N and Co coordinate to form an octahedron, N is at the center of the octahedron, Co is at the vertex of the octahedron, and Zn is distributed in the gaps between the [NCo6] octahedrons.

7. A use of the cobalt-zinc-based electron inversion perovskite nitride material according to claim 6, characterized in that: The cobalt-zinc-based electron-inverted perovskite nitride material is used as a catalyst for photothermal catalytic carbon monoxide oxidation. The catalytic conditions are: a flow-type photothermal catalytic evaluation device is used, the light source is a xenon lamp, the reaction atmosphere is 1% CO + 1% O2 + 98% Ar, the mixed gas flow rate is 30 ml / min, and the light intensity is 0.4-1.1 W / cm 2 , the amount of catalyst ZnNCo3 used is 50 mg.

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