A method for preparing hollow metal sulfides based on a mild calcium carbonate templating method

Abstract

This invention discloses a method for preparing hollow metal sulfides based on a mild template method using calcium carbonate. Calcium chloride powder and potassium carbonate powder are uniformly dispersed separately in an alcohol solution. The two solutions are then mixed and allowed to stand for aging to obtain solution A. Simultaneously, thioacetamide is dissolved in the alcohol solution to obtain solution B, and a chloride is dissolved in the alcohol solution to obtain solution C. The chloride is either stannous chloride or copper chloride. Then, solutions B and C are added sequentially to solution A at a molar ratio of thioacetamide to chloride of 2:1 and mixed uniformly to obtain solution D. Solution D is then placed in a polytetrafluoroethylene (PTFE) reactor and reacted at 140–180°C for 12 hours. Carbon dioxide is then continuously bubbled through the reactor for 2–3 hours. The mixture is filtered and washed with water and ethanol to obtain the hollow metal sulfides. This invention can obtain hollow metal sulfides with different morphologies and avoids the contamination problems associated with high-temperature calcination or acid dissolution for template removal.

Description

Technical Field

[0001] This invention belongs to the field of hollow material synthesis technology, specifically relating to a method for preparing hollow metal sulfides based on a mild template method using calcium carbonate. Background Technology

[0002] Transition metal sulfides possess unique structures characterized by diverse morphologies, high stability, and high efficiency, making them promising candidates for applications in electrochemistry and catalysis. For instance, hollow metal sulfides, with their numerous active centers and wide internal structure, allow for the transport of a large number of ions and electrons, thus demonstrating broad application potential. The preparation of morphologically controllable and ordered hollow nanostructures generally includes hard template methods, soft template methods, template-free methods, and other template-based methods. Among these, the hard template method is widely used, but it still has shortcomings. Firstly, achieving uniform coating is difficult, and compatibility issues exist between the template and the desired shell. Secondly, template removal is cumbersome. For example, when using calcium carbonate as a hard template to prepare hollow materials, template removal is mostly achieved through high-temperature calcination or acid dissolution, a process that is both environmentally unfriendly and tedious, hindering the large-scale production of hollow materials. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention discloses a method for preparing hollow metal sulfides based on a mild template method using calcium carbonate. This method not only yields hollow metal sulfides with different morphologies but also avoids the environmental pollution problems caused by high-temperature calcination or acid dissolution to remove the template.

[0004] This invention is achieved using the following technical solution:

[0005] A method for preparing hollow metal sulfides based on a mild template method using calcium carbonate includes the following steps:

[0006] (1) Calcium chloride powder and potassium carbonate powder are uniformly dispersed in an alcohol solution, and then the two solutions are mixed and left to stand for aging to obtain solution A, wherein solution A contains 10% calcium carbonate by mass.

[0007] (2) Thioacetamide is dissolved in an alcohol solution to obtain solution B, wherein solution B contains 0.25% to 0.5% by mass of thioacetamide, and chloride is dissolved in an alcohol solution to obtain solution C, wherein solution C contains 0.25% to 0.5% by mass of chloride, wherein the chloride is either stannous chloride or copper chloride. Then, according to the molar ratio of thioacetamide to chloride of 2:1, solution B and solution C are added to solution A in sequence and mixed evenly to obtain solution D.

[0008] (3) Place solution D into a polytetrafluoroethylene reactor and react at 140-180°C for 12 hours. Then continuously introduce carbon dioxide for 2-3 hours. Filter to obtain the precipitate and wash with water and ethanol to obtain hollow metal sulfide.

[0009] Furthermore, in step (1), the two solutions are mixed and left to stand for more than 24 hours to obtain solution A.

[0010] Furthermore, in step (1), calcium chloride powder and potassium carbonate powder are uniformly dispersed in an alcohol solution at 20-70°C.

[0011] Furthermore, in step (2), thioacetamide is dissolved in an alcohol solution at 20-25°C to obtain solution B, and chloride is dissolved in ethylene glycol to obtain solution C.

[0012] Furthermore, in step (3), the precipitate is filtered and washed with water 2 to 3 times, and then washed with ethanol 2 to 3 times to obtain hollow metal sulfide.

[0013] Furthermore, the alcohol solution is a 30% ethylene glycol solution or a 30% propylene glycol solution.

[0014] Compared with existing technologies, this technical solution has the following advantages:

[0015] This invention proposes a mild template method for preparing hollow metal sulfides. It utilizes the surface functional groups (-OH) of CaCO3 to provide a growth substrate for nanocrystals, and the morphological diversity of calcium carbonate improves the anisotropic interatomic bonding within the nanocrystal structure, playing a decisive role in the formation of nanosheet structures. After the sulfur atoms of thioacetamide and the metal atoms in the chloride reach random positions on the target substrate CaCO3, the atoms nucleate and grow in various mixed-phase states, thus obtaining a composite nanostructure of metal sulfides grown on the CaCO3 surface. Subsequently, CO2 is introduced to convert calcium carbonate into calcium bicarbonate, and the calcium carbonate template is removed in solution. This one-pot method achieves the preparation of hollow metal sulfides, avoiding the collapse and environmental pollution caused by high-temperature calcination or acid dissolution to remove the template. It also allows for the control of different morphologies of hollow metal sulfides; that is, during the preparation process, the proportions can be adjusted according to requirements to make the calcium carbonate morphology spherical, rod-shaped, cubic, etc., thereby diversifying the hollow nanostructures. Furthermore, this invention has a simple process, is easy to operate, and is suitable for the large-scale, automated production of hollow sulfides. Attached Figure Description

[0016] Figure 1 This is a SEM image of the hollow spherical SnS obtained in Example 1.

[0017] Figure 2This is a SEM image of the hollow rod-shaped SnS obtained in Example 2.

[0018] Figure 3 This is a SEM image of the hollow cubic SnS obtained in Example 3.

[0019] Figure 4 These are XRD patterns of hollow SnS with different shapes obtained in Examples 1 to 3, where curve 1 is hollow cubic SnS, curve 2 is hollow rod-shaped SnS, and curve 3 is hollow spherical SnS. Detailed Implementation

[0020] The present invention is further illustrated by the following examples, but these are not intended to limit the invention. Specific experimental conditions and methods not specified in the following examples are generally conventional methods well known to those skilled in the art.

[0021] Example 1: A method for preparing hollow tin sulfide metal based on a mild template method using calcium carbonate, comprising the following steps:

[0022] (1) At 25°C, calcium chloride powder and potassium carbonate powder are uniformly dispersed in a propylene glycol solution with a mass fraction of 30%. Then, the two solutions are mixed and left to stand for 48 hours to obtain solution A, which contains 10% spherical calcium carbonate by mass.

[0023] (2) Thioacetamide is dissolved in a 30% propylene glycol solution at 23°C to obtain solution B, wherein solution B contains 0.5% thioacetamide. Stannous chloride is dissolved in a 30% propylene glycol solution to obtain solution C, wherein solution C contains 0.5% stannous chloride. Then, solutions B and C are added to solution A in sequence according to the molar ratio of thioacetamide to stannous chloride of 2:1 and mixed evenly to obtain solution D.

[0024] (3) Solution D was placed in a polytetrafluoroethylene reactor and reacted at 160°C for 12 hours. Then, carbon dioxide was continuously introduced for 2.5 hours. The precipitate was obtained by filtration and washed twice with water and then twice with ethanol to obtain the following precipitate. Figure 1 The hollow spherical tin sulfide shown is hollow.

[0025] Example 2: A method for preparing hollow tin sulfide metal based on a mild template method using calcium carbonate, comprising the following steps:

[0026] (1) At 70°C, calcium chloride powder and potassium carbonate powder are uniformly dispersed in a propylene glycol solution with a mass fraction of 30%. Then, the two solutions are mixed and left to stand for 48 hours to obtain solution A, which contains 10% rod-shaped calcium carbonate by mass.

[0027] (2) Thioacetamide is dissolved in a 30% propylene glycol solution at 25°C to obtain solution B, wherein solution B contains 0.25% thioacetamide. Stannous chloride is dissolved in a 30% propylene glycol solution to obtain solution C, wherein solution C contains 0.25% stannous chloride. Then, solutions B and C are added to solution A in sequence according to the molar ratio of thioacetamide to stannous chloride of 2:1 and mixed evenly to obtain solution D.

[0028] (3) Solution D was placed in a polytetrafluoroethylene reactor and reacted at 180°C for 12 hours. Then, carbon dioxide was continuously introduced for 2.5 hours. The precipitate was obtained by filtration and washed twice with water and then twice with ethanol to obtain the following precipitate. Figure 2 The hollow rod-shaped hollow tin sulfide metal shown.

[0029] Example 3: A method for preparing hollow tin sulfide metal based on a mild template method using calcium carbonate, comprising the following steps:

[0030] (1) At 50°C, calcium chloride powder and potassium carbonate powder are uniformly dispersed in a 30% ethylene glycol solution. Then, the two solutions are mixed and left to stand for 24 hours to obtain solution A, which contains 10% cubic calcium carbonate.

[0031] (2) Thioacetamide is dissolved in a 30% ethylene glycol solution at 23°C to obtain solution B, wherein solution B contains 0.5% thioacetamide. Stannous chloride is dissolved in a 30% ethylene glycol solution to obtain solution C, wherein solution C contains 0.5% stannous chloride. Then, solutions B and C are added to solution A in sequence according to the molar ratio of thioacetamide to stannous chloride of 2:1 and mixed evenly to obtain solution D.

[0032] (3) Solution D was placed in a polytetrafluoroethylene reactor and reacted at 140°C for 12 hours. Then, carbon dioxide was continuously introduced for 2.5 hours. The precipitate was obtained by filtration and washed twice with water and then twice with ethanol to obtain the following precipitate. Figure 3 The hollow cubic tin sulfide shown is a hollow tin sulfide.

[0033] Figure 4 The XRD patterns of hollow tin sulfide metals of different shapes obtained in Examples 1-3 are shown. Figure 4 It can be seen that the hollow material is SnS, indicating that the method of the present invention can effectively remove the calcium carbonate template, and the preparation of hollow metal sulfides by the calcium carbonate mild template method is feasible.

[0034] Example 4: A method for preparing hollow copper metal sulfide based on a mild template method using calcium carbonate, comprising the following steps:

[0035] (1) At 65°C, calcium chloride powder and potassium carbonate powder are uniformly dispersed in a propylene glycol solution with a mass fraction of 30%. Then, the two solutions are mixed and left to stand for 72 hours to obtain solution A, which contains 10% rod-shaped calcium carbonate by mass.

[0036] (2) Thioacetamide is dissolved in a 30% propylene glycol solution at 20°C to obtain solution B, wherein solution B contains 0.3% thioacetamide. Copper chloride is dissolved in a 30% propylene glycol solution to obtain solution C, wherein solution C contains 0.3% copper chloride. Then, solutions B and C are added to solution A in sequence according to the molar ratio of thioacetamide to copper chloride of 2:1 and mixed evenly to obtain solution D.

[0037] (3) Place solution D into a polytetrafluoroethylene reactor and react at 170°C for 12 hours. Then continuously introduce carbon dioxide for 2.5 hours. Filter to obtain a precipitate and wash it twice with water and then twice with ethanol to obtain hollow rod-shaped hollow copper sulfide.

[0038] Example 5: A method for preparing hollow copper metal sulfide based on a mild template method using calcium carbonate, comprising the following steps:

[0039] (1) At 20°C, calcium chloride powder and potassium carbonate powder are uniformly dispersed in a propylene glycol solution with a mass fraction of 30%. Then, the two solutions are mixed and left to stand for 36 hours to obtain solution A, which contains 10% spherical calcium carbonate by mass.

[0040] (2) Thioacetamide is dissolved in a 30% propylene glycol solution at 25°C to obtain solution B, wherein solution B contains 0.5% thioacetamide. Copper chloride is dissolved in a 30% propylene glycol solution to obtain solution C, wherein solution C contains 0.5% copper chloride. Then, solutions B and C are added to solution A in sequence according to the molar ratio of thioacetamide to copper chloride of 2:1 and mixed evenly to obtain solution D.

[0041] (3) Place solution D into a polytetrafluoroethylene reactor and react at 150°C for 12 hours. Then continuously introduce carbon dioxide for 2.5 hours. Filter to obtain a precipitate and wash it with water 3 times and then with ethanol 3 times to obtain hollow spherical copper sulfide.

[0042] Example 6: A method for preparing hollow copper metal sulfide based on a mild template method using calcium carbonate, comprising the following steps:

[0043] (1) At 45°C, calcium chloride powder and potassium carbonate powder are uniformly dispersed in a 30% ethylene glycol solution. Then, the two solutions are mixed and left to stand for 36 hours to obtain solution A, which contains 10% cubic calcium carbonate.

[0044] (2) Thioacetamide is dissolved in a 30% ethylene glycol solution at 25°C to obtain solution B, wherein solution B contains 0.4% thioacetamide. Copper chloride is dissolved in a 30% ethylene glycol solution to obtain solution C, wherein solution C contains 0.4% copper chloride. Then, solutions B and C are added to solution A in sequence according to the molar ratio of thioacetamide to copper chloride of 2:1 and mixed evenly to obtain solution D.

[0045] (3) Place solution D into a polytetrafluoroethylene reactor and react at 150°C for 12 hours. Then continuously introduce carbon dioxide for 2.5 hours. Filter to obtain a precipitate and wash it twice with water and then twice with ethanol to obtain hollow cubic copper sulfide.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing hollow metal sulfides based on a mild template method using calcium carbonate, characterized in that: Includes the following steps: (1) Calcium chloride powder and potassium carbonate powder are uniformly dispersed in an alcohol solution at 20-70℃. Then the two solutions are mixed and allowed to stand for aging to obtain solution A, which contains 10% calcium carbonate by mass. (2) Thioacetamide is dissolved in an alcohol solution at 20-25°C to obtain solution B, wherein solution B contains 0.25%-0.5% thioacetamide by mass, and chloride is dissolved in an alcohol solution to obtain solution C, wherein solution C contains 0.25%-0.5% chloride by mass, wherein the chloride is either stannous chloride or copper chloride. Then, solutions B and C are added to solution A in sequence according to a molar ratio of 2:1 of thioacetamide to chloride and mixed evenly to obtain solution D. (3) Place solution D into a polytetrafluoroethylene reactor and react at 140-180°C for 12 hours. Then continuously introduce carbon dioxide for 2-3 hours. Filter to obtain the precipitate and wash with water and ethanol to obtain hollow metal sulfide.

2. The method for preparing hollow metal sulfides based on the calcium carbonate mild template method according to claim 1, characterized in that: In step (1), the two solutions are mixed and left to stand for more than 24 hours to obtain solution A.

3. The method for preparing hollow metal sulfides based on the calcium carbonate mild template method according to claim 1, characterized in that: In step (3), the precipitate is obtained by filtration and washed with water 2 to 3 times, and then washed with ethanol 2 to 3 times to obtain hollow metal sulfide.

4. The method for preparing hollow metal sulfides based on the mild template method using calcium carbonate according to any one of claims 1 to 3, characterized in that: The alcohol solution is a 30% ethylene glycol solution or a 30% propylene glycol solution.

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