Mesoporous material formed by stacking CdS nanosheets and preparation method thereof
By using a long-chain amine template agent to form a micelle solution with a cadmium source precursor, CdS nanosheets were prepared by hydrothermal reaction, which solved the problems of high production cost and low yield in the prior art, and achieved efficient synthesis of ultra-thin nanosheets and excellent photocatalytic properties.
Patent Information
- Application Number
- CN202510509060.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-07-25
AI Technical Summary
In the prior art, the synthetic CdS ultra-thin nanosheets have high preparation cost, complex operation and low yield, and require an economical, simple operation and excellent yield synthesis method.
A long-chain amine template agent is used to form a micelle solution with a cadmium source precursor in ethanol solution. After adding sulfur source, hydrothermal reaction is carried out in a polytetrafluoroethylene lined reactor, and CdS nanosheet material is obtained by centrifugation and washing.
The ultra-thin structure of CdS nanosheets has been realized, with a large surface area and pore size, and exhibits excellent photocatalytic activity, especially in photocatalytic reduction of carbon dioxide to make synthesis gas.
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Figure CN120361922A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of novel CO2 photoreduction catalysts, and specifically refers to a mesoporous material formed by stacking CdS nanosheets and a preparation method thereof. Background Art
[0002] In recent decades, with the continuous growth of global energy demand, the research on finding new energy has attracted more and more attention. Hydrogen energy, as a secondary energy source, has many advantages such as being clean, efficient, safe, storable, and transportable. It has generally been regarded as an ideal pollution-free green energy in the new century, and thus has received great attention from various countries. CdS has a direct bandgap of 2.4 eV and an absorption edge up to 524 nm, and is widely used in CO2 photocatalytic reduction, hydrogen production, and solar cells.
[0003] So far, the synthesis of CdS nanosheets mainly uses triethanolamine, ethylenediamine, and triethanolamine as template agents.
[0004] The prior art generally uses triethanolamine as a template agent to synthesize CdS nanosheets dozens of nanometers thick. However, the nanosheets are relatively thick, and a synthesis strategy for ultra-thin CdS nanosheets needs to be developed. There has also been the use of diethylenetriamine to synthesize ultra-thin CdS nanosheets, but diethylenetriamine is a hygroscopic transparent viscous liquid with a pungent ammonia odor, is flammable, and is strongly alkaline.
[0005] It includes the synthesis of CdS nanosheets using octadecene and stearic acid as template agents and cadmium diethyldithiocarbamate. The reagents used are relatively complex and not easily obtained. However, ethylenediamine is flammable when exposed to heat, open flames, and oxidants, and has a medium combustion hazard.
[0006] Therefore, it is necessary to synthesize ultra-thin CdS nanosheets using cheap and easily available, and more environmentally friendly template agents. Summary of the Invention
[0007] The technical problem to be solved by the present invention is to provide a new method for preparing ultra-thin CdS nanosheets that is economical, simple to operate, and has excellent yield, aiming at the prominent problems existing in the current existing technology for synthesizing ultra-thin CdS nanosheets, such as too high preparation cost, complex operation conditions, and too low synthesis yield.
[0008] To solve the above technical problems, the technical solution provided by the present invention is: A preparation method of a mesoporous material formed by stacking CdS nanosheets, comprising the following steps:
[0009] S1: Add a long-chain amine template agent to an appropriate amount of ethanol to obtain solution A;
[0010] S2: Prepare solution B based on a cadmium source precursor;
[0011] S3: Mix and stir solution A and solution B to form a micellar solution;
[0012] S4: Add a sulfur source to the micellar solution obtained in S3 and stir.
[0013] S5: Stir the product of S4 or transfer it to a reaction kettle with a polytetrafluoroethylene liner for reaction and cooling.
[0014] S6: Centrifuge to collect the solid, and then obtain the CdS nanosheet material through washing with water, washing with ethanol, and vacuum drying.
[0015] Preferably, the long-chain amine template agent in S1 includes any one of: a single amine from decylamine to docosylamine, a mixture of decylamine to docosylamine and a short-chain amine, and a mixture of a heteroatom-containing chain amine and decylamine to docosylamine.
[0016] Preferably, the short-chain amine includes any one of n-hexylamine to n-decylamine, and the heteroatom-containing chain amine includes any one of 3-propoxypropylamine, ethylene glycol bis(3-aminopropyl) ether, 3,3'-oxybis(propane-1-amine), 3-dodecyloxypropylamine, and N-propylethylenediamine.
[0017] Preferably, the cadmium source precursor in S2 includes any one of the hydrates or non-hydrates of cadmium acetate (II), cadmium nitrate (II), cadmium sulfate (II), and cadmium chloride (II).
[0018] Preferably, the sulfur source in S4 includes one or a combination of several of thioacetamide, sodium sulfide, sulfur, sodium thiosulfate, carbon disulfide, and thiourea, and the micelle formation temperature is 25 - 40 °C.
[0019] Preferably, in S5:
[0020] When stirring for the reaction, the temperature is 25 - 40 °C and stir for 10 days;
[0021] When the reaction kettle is used for the reaction, the hydrothermal treatment is carried out at 100 - 180 °C for 12 h - 72 h.
[0022] Preferably, in S6, the vacuum drying reaction temperature is 60 °C and the time is 8 h.
[0023] On the other hand, the present invention discloses a CdS nanosheet photocatalytic material, which is a mesoporous material formed by stacking CdS nanosheets. The obtained CdS nanosheets have a nanosheet morphology, a surface area of 5 - 150 m 2 ·g -1 , and an average pore diameter of 5 - 45 nm.
[0024] On the other hand, the present invention also discloses the application of the CdS nanosheet photocatalytic material as a catalyst for reducing carbon dioxide under light illumination conditions.
[0025] The advantages of the present invention compared with the prior art are:
[0026] (1) The preparation operation is simple and the conditions are relatively easy to achieve;
[0027] (2) By using this method of the present invention to synthesize CdS ultrathin nanosheets, the method is innovative. CdS is synthesized in a large range only by using a micelle solution formed by different amines as a template agent, and the material has an ultrathin nanosheet structure;
[0028] (3) Due to its ultrathin nanosheet structure, the synthesized ultrathin nanosheets have great application prospects in photocatalysis and have the potential to be excellent active catalysts. For example, they show excellent catalytic activity in photocatalytic reduction of carbon dioxide to syngas. Description of the Drawings
[0029] Figure 1 It is the SEM diagram of the present invention.
[0030] Figure 2 It is the BET pore size distribution diagram of CdS prepared in Example 1 of the present invention.
[0031] Figure 3 It is the BET adsorption and desorption diagram of CdS prepared in Example 1 of the present invention.
[0032] Figure 4 It is the UV-Vis diffuse reflectance spectrum of CdS prepared in Example 1 of the present invention.
[0033] Figure 5 It is the photocatalytic reduction of carbon dioxide test diagram of CdS prepared in Example 1 of the present invention. Detailed Description of the Invention
[0034] The present invention will be further described in detail below with reference to the drawings.
[0035] (1) Take dodecylamine and hexadecylamine and add them to an appropriate amount of ethanol to obtain solution A;
[0036] (2) Take cadmium sources such as cadmium(II) acetate dihydrate and add them to an appropriate amount to obtain solution B;
[0037] (3) Mix solution A and solution B and stir for a period of time to form a micelle solution;
[0038] (4) Add a sulfur source such as thioacetamide to the above micelle solution;
[0039] (5) Stir the above solution or transfer it to a reaction kettle lined with polytetrafluoroethylene, react at a certain temperature for a certain period of time, and cool to room temperature after the reaction;
[0040] (6) Centrifuge the reaction solution, collect the solid, and wash it several times with water and ethanol solution respectively;
[0041] (7) Collect the sample and perform vacuum drying treatment. Further, the molar ratio of the sulfur source to the cadmium source in the feeding is 2:1. Further, the stirring rate therein is 300 rpm. By preference, the stirring temperature in step (2) is 25 - 40 °C and the time is 0 - 0.5 h. By preference, the stirring temperature in step (3) is 25 - 40 °C and the time is 0 - 0.5 h. By preference, the stirring temperature in step (4) is 25 - 40 °C and the time is 0.5 - 1.5 h.
[0042] Example 1
[0043] Take 4.2 g of dodecylamine and 0.56 g of hexadecylamine and add them to 20 mL of anhydrous ethanol solution. Take 1.55 g of cadmium(II) acetate dihydrate and add it to 90 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium acetate and stir at 300 rpm for 30 min. Add 0.88 g of thiourea and stir at 300 rpm in the dark at room temperature for 10 days. Centrifuge to collect the solid, wash it with distilled water and anhydrous ethanol solution respectively for several times, and then vacuum dry it at 60 °C for 8 h to obtain the product.
[0044] Data analysis:
[0045] 1. BET pore size distribution analysis
[0046] Figure 2 This is the BET pore size distribution diagram of CdS prepared in Example 1 of the present invention. It can be seen from the figure that the morphology of CdS synthesized by stirring at room temperature presents a porous structure.
[0047] 2. BET adsorption - desorption analysis
[0048] Figure 3 This is the nitrogen adsorption - desorption isotherm curve of CdS prepared in Example 1 of the present invention. It can be seen from the figure that the synthesized CdS has a large adsorption capacity.
[0049] 3. UV test
[0050] Figure 4 This is the UV - Vis diffuse reflectance spectrum of CdS prepared in Example 1 of the present invention.
[0051] 5. Test on the performance of photocatalytic reduction of carbon dioxide
[0052] Figure 5Performance test chart of CdS prepared in Example 1 of the present invention as a catalyst for the photocatalytic reduction of carbon dioxide to carbon monoxide. The amount of the catalyst is 5 mg, the amount of CoCl2·6H2O is 2 μmol, and the amount of 2,2-bipyridine is 15 mg. The efficiency of CdS as a catalyst for reducing carbon dioxide to carbon monoxide at 30 °C is measured to be 470 μmol / g·h.
[0053] Example 2
[0054] Take 0.77 g of cadmium(II) acetate dihydrate and add it to 45 mL of distilled water, and stir at a speed of 300 rpm for 10 min. Take 2.1 g of dodecylamine and 0.25 g of hexadecylamine and add them to 10 mL of anhydrous ethanol solution, and stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium acetate and stir at a speed of 300 rpm for 30 min. Add 0.44 g of thiourea and continue to stir until dissolved, then transfer the above solution to a 100 mL Teflon-lined reaction kettle, and react at 120 °C for 48 h. After the reaction is completed and cooled, centrifuge to collect the solid, wash it with distilled water and anhydrous ethanol solution respectively for several times, and then vacuum dry it at 60 °C for 8 h to obtain the product.
[0055] Example 3
[0056] Take 1.55 g of cadmium(II) acetate dihydrate and add it to 90 mL of distilled water, and stir at a speed of 300 rpm for 10 min. Take 1.98 g of n-pentylamine and 0.62 g of octadecylamine and add them to 20 mL of anhydrous ethanol solution, and stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium acetate and stir at a speed of 300 rpm for 30 min. Add 0.87 g of thioacetamide and stir at a speed of 300 rpm in the dark at room temperature for 10 days. Centrifuge to collect the solid, wash it with distilled water and anhydrous ethanol solution respectively for several times, and then vacuum dry it at 60 °C for 8 h to obtain the product.
[0057] Example 4
[0058] Take 1.79 g of cadmium(II) nitrate tetrahydrate and add it to 90 mL of distilled water, and stir at a speed of 300 rpm for 10 min. Take 2.93 g of n-octylamine and 0.56 g of hexadecylamine and add them to 20 mL of anhydrous ethanol solution, and stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium nitrate and stir at a speed of 300 rpm for 30 min. Add 0.87 g of thioacetamide and stir at a speed of 300 rpm in the dark at room temperature for 10 days. Centrifuge to collect the solid, wash it with distilled water and anhydrous ethanol solution respectively for several times, and then vacuum dry it at 60 °C for 8 h to obtain the product.
[0059] Example 5
[0060] Take 0.89 g of cadmium(II) nitrate tetrahydrate and add it to 45 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 3.25 g of n-nonylamine and 0.26 g of pentadecylamine and add them to 10 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium nitrate and stir at a speed of 300 rpm for 30 min. Add 0.44 g of thioacetamide and continue stirring until dissolved. Then transfer the above solution to a 100 mL reaction kettle with a polytetrafluoroethylene liner. React at 140 °C for 36 h. After the reaction is completed and cooled, centrifuge to collect the solid. Wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it in vacuum at 60 °C for 8 h to obtain the product.
[0061] Example 6
[0062] Take 0.89 g of cadmium(II) nitrate tetrahydrate and add it to 45 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 1.15 g of n-hexylamine and 0.35 g of eicosylamine and add them to 10 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium nitrate and stir at a speed of 300 rpm for 30 min. Add 0.19 g of sulfur powder and continue stirring until dissolved. Then transfer the above solution to a 100 mL reaction kettle with a polytetrafluoroethylene liner. React at 120 °C for 48 h. After the reaction is completed and cooled, centrifuge to collect the solid. Wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it in vacuum at 60 °C for 8 h to obtain the product.
[0063] Example 7
[0064] Take 1.02 g of cadmium(II) sulfate octahydrate and add it to 45 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 1.30 g of n-heptylamine and 0.37 g of docosylamine and add them to 10 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium sulfate and stir at a speed of 300 rpm for 30 min. Add 0.19 g of sulfur powder and continue stirring until dissolved. Then transfer the above solution to a 100 mL reaction kettle with a polytetrafluoroethylene liner. React at 160 °C for 24 h. After the reaction is completed and cooled, centrifuge to collect the solid. Wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it in vacuum at 60 °C for 8 h to obtain the product.
[0065] Example 8
[0066] Take 2.04 g of cadmium(II) sulfate octahydrate and add it to 90 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 3.93 g of ethylene glycol bis(3-aminopropyl) ether and 0.2 g of pentadecylamine and add them to 20 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous cadmium sulfate solution and stir at a speed of 300 rpm for 30 min. Add 0.37 g of sulfur powder and stir at a speed of 300 rpm in the dark at room temperature for 10 days. Centrifuge to collect the solid, wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it under vacuum at 60 °C for 8 h to obtain the product.
[0067] Example 9
[0068] Take 1.02 g of cadmium(II) sulfate octahydrate and add it to 45 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 2.53 g of 3,3'-oxybis(prop-1-amine) and 0.25 g of hexadecylamine and add them to 10 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous cadmium sulfate solution and stir at a speed of 300 rpm for 30 min. Add 0.73 g of sodium sulfate nonahydrate and continue stirring until dissolved. Then transfer the above solution to a 100 mL Teflon-lined autoclave. React at 180 °C for 130 min. After the reaction is completed and cooled, centrifuge to collect the solid, wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it under vacuum at 60 °C for 8 h to obtain the product.
[0069] Example 10
[0070] Take 0.53 g of cadmium(II) chloride and add it to 45 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 2.76 g of 3-dodecyloxypropylamine and 0.31 g of octadecylamine and add them to 10 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous cadmium chloride solution and stir at a speed of 300 rpm for 30 min. Add 0.73 g of sodium sulfate nonahydrate and continue stirring until dissolved. Then transfer the above solution to a 100 mL Teflon-lined autoclave. React at 140 °C for 36 h. After the reaction is completed and cooled, centrifuge to collect the solid, wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it under vacuum at 60 °C for 8 h to obtain the product.
[0071] Example 11
[0072] Take 1.06 g of cadmium(II) chloride and add it to 90 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 2.32 g of N-propylethylenediamine and 0.68 g of eicosylamine and add them to 20 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium chloride and stir at a speed of 300 rpm for 30 min. Add 1.46 g of sodium sulfate nonahydrate and stir at a speed of 300 rpm in the dark at room temperature for 10 days. Centrifuge to collect the solid, wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it in vacuo at 60 °C for 8 h to obtain the product.
[0073] Example 12
[0074] Take 0.53 g of cadmium(II) chloride and add it to 45 mL of distilled water. Stir at a speed of 300 rpm for 10 min. Take 0.28 g of 3-dodecyloxypropylamine and 0.37 g of docosene and add them to 10 mL of anhydrous ethanol solution. Stir at a speed of 300 rpm for 10 min. Pour it into the aqueous solution of cadmium chloride and stir at a speed of 300 rpm for 30 min. Add 1.66 g of sodium thiosulfate and stir until dissolved. Then transfer the above solution to a 100 mL Teflon-lined autoclave. React at 180 °C for 130 min. After the reaction is completed and cooled, centrifuge to collect the solid, wash it several times with distilled water and anhydrous ethanol solution respectively, and then dry it in vacuo at 60 °C for 8 h to obtain the product.
[0075] The present invention and its embodiments have been described above. Such description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar structural modes and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.
Claims
1. A preparation method for a mesoporous material formed by stacking CdS nanosheets, characterized in that: It includes the following steps: S1: Add a long-chain amine template agent to an appropriate amount of ethanol to obtain solution A; S2: Prepare solution B based on a cadmium source precursor; S3: Mix and stir solution A and solution B to form a micellar solution; S4: Add a sulfur source to the micellar solution obtained in S3 and stir; S5: Stir or transfer the product of S4 to a reaction kettle with a polytetrafluoroethylene liner for reaction and cooling; S6: Centrifuge to collect the solid, and then obtain the CdS nanosheet material through washing with water, washing with ethanol, and vacuum drying.
2. The preparation method of a mesoporous material formed by stacking CdS nanosheets according to claim 1, characterized in that: The long-chain amine template agent in S1 includes any one of: a single decylamine to docosylamine, a mixture of decylamine to docosylamine and a short-chain amine, and a mixture of a heteroatom-containing chain amine and decylamine to docosylamine.
3. The preparation method of a mesoporous material formed by stacking CdS nanosheets according to claim 2, characterized in that: The short-chain amine includes any one of n-hexylamine to n-decylamine, and the heteroatom-containing chain amine includes any one of 3-propoxypropylamine, ethylene glycol bis(3-aminopropyl) ether, 3,3'-oxybis(prop-1-amine), 3-dodecyloxypropylamine, and N-propylethylenediamine.
4. The preparation method of a mesoporous material formed by stacking CdS nanosheets according to claim 1, wherein: The cadmium source precursor in S2 includes any one of the hydrates or non-hydrates of cadmium acetate (II), cadmium nitrate (II), cadmium sulfate (II), and cadmium chloride (II).
5. The preparation method of a mesoporous material formed by piling up CdS nanosheets according to claim 1, wherein: The sulfur source in S4 includes one or a combination of several of thioacetamide, sodium sulfide, sulfur, sodium thiosulfate, carbon disulfide, and thiourea, and the micelle formation temperature is 25-40 °C.
6. The preparation method of a mesoporous material formed by stacking CdS nanosheets according to claim 1, wherein: In S5: When stirring for reaction, the temperature is 25-40 °C and stir for 10 days; When reacting in the reaction kettle, the hydrothermal temperature is 100-180 °C and the time is 12h-72h.
7. The preparation method of a mesoporous material formed by stacking CdS nanosheets according to claim 1, characterized in that: In S6, the vacuum drying reaction temperature is 60 °C and the time is 8h.
8. A CdS nanosheet photocatalytic material prepared by the method according to any one of claims 1-7, characterized in that: The CdS nanosheet photocatalytic material is a mesoporous material formed by stacking CdS nanosheets. The obtained CdS nanosheets have a nanosheet morphology, a surface area of 5 - 150 m 2 ·g -1 , and an average pore diameter of 5 - 45 nm.
9. The application of the CdS nanosheet photocatalytic material as claimed in claim 9 as a catalyst for reducing carbon dioxide under light irradiation conditions.