A one-pot method for synthesizing regularly shaped, flower-shaped nano-magnesium indium sulfide

Abstract

This invention discloses a one-pot method for synthesizing regularly shaped, flower-like nano-magnesium indium sulfide, relating to the field of inorganic synthesis technology. Specifically, it includes the following steps: S1: Dispersing magnesium source, indium source, and polyvinylpyrrolidone evenly in deionized water to obtain a magnesium-indium solution; S2: Adding cysteine ​​to the indium-magnesium solution and stirring to obtain a precursor solution; S3: Transferring the precursor solution to a high-pressure reactor for heating and reaction, followed by post-treatment to obtain flower-like, flower-shaped nano-magnesium indium sulfide. The nano-magnesium indium sulfide prepared by this invention has a regular, flower-like morphology, with a particle size as low as 800 nm, and exhibits excellent photocatalytic activity.

Description

Technical Field

[0001] This invention relates to the field of inorganic synthesis technology, specifically a one-pot method for synthesizing regularly shaped, spherical nano-indium magnesium sulfide. Background Technology

[0002] Against the backdrop of the energy crisis and increasingly prominent environmental pollution problems, the development of sustainable clean energy has become a hot topic. Photocatalytic hydrogen evolution technology can convert solar energy into hydrogen energy, which can partially solve the human demand for clean energy. Magnesium indium sulfide (MgIn2S4), as a typical n-type ternary sulfide, has strong visible light response and high thermal and chemical stability, making it crucial in the fields of visible light degradation of pollutants and water electrolysis for hydrogen production. However, the main preparation methods for magnesium indium sulfide (MgS2S4) are currently gas-phase and solid-phase methods. The gas-phase method has low yield and complex equipment, while the solid-phase method has high energy consumption and a wide range of product particle sizes. In contrast, the hydrothermal method, which generally uses substances such as thioacetamide and thiourea as sulfur sources, produces materials with relatively complete crystal structures and a simpler process. For example, in Luo, L.'s paper "Construction of MgIn2S4 / ZnIn2S4 micro-flowers: Efficient degradation of tetracycline hydrochloride over a wide pH range," thioacetamide was used as a sulfur source to prepare magnesium indium sulfide with a flower-like structure using a hydrothermal method. However, the magnesium indium sulfide prepared under SEM images was irregular, with a particle size of about 10 μm, which is difficult to meet the requirements of photocatalytic hydrogen evolution technology. Furthermore, thioacetamide and thiourea as sulfur sources have certain environmental hazards and are difficult to use on a large scale.

[0003] In summary, providing a method for preparing regular nano-indium magnesium sulfide materials is of great significance in order to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a one-pot method for synthesizing regularly shaped, spherical nano-indium magnesium sulfide, in order to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A one-pot method for synthesizing regularly shaped, flower-shaped nano-magnesium indium sulfide includes the following steps:

[0007] S1: Disperse magnesium source, indium source and polyvinylpyrrolidone evenly in deionized water to obtain magnesium-indium solution;

[0008] S2: Add cysteine ​​to the indium magnesium solution and stir to obtain the precursor solution;

[0009] S3: The precursor solution was transferred to a high-pressure reactor and heated for reaction. After post-treatment, flower-shaped nano-indium magnesium sulfide was obtained.

[0010] Preferably, the magnesium source includes one or more of magnesium chloride, magnesium sulfate, and magnesium nitrate.

[0011] Preferably, the indium source includes one or more of indium chloride, indium sulfate, and indium nitrate.

[0012] Preferably, the molecular weight of the polyvinylpyrrolidone is 1000-1500 kDa.

[0013] Preferably, the molar ratio of the magnesium source, indium source, and polyvinylpyrrolidone is 1:1:(3.75×10⁻⁶). -5 ~1.5×10 -4 ).

[0014] More preferably, the molar ratio of cysteine ​​to indium source is (8-25):6.

[0015] Preferably, the stirring process takes 2 to 2.5 hours.

[0016] Preferably, during the heating reaction, the temperature is 150–180°C and the time is 5–10 hours.

[0017] Preferably, the post-treatment process includes the following steps: after the reaction is completed and the mixture is naturally cooled, the supernatant is removed, the resulting precipitate is centrifuged twice with alcohol and water, and then dried in an oven at 55-60°C.

[0018] Compared with the prior art, the beneficial effects of this application are as follows:

[0019] (1) In the preparation of regular flower-shaped nano-indium magnesium sulfide material in this invention, cysteine, which is slightly soluble in water, is used as the sulfur source, which can delay the sulfidation rate of magnesium and indium and enhance the probability of heterostructure formation; then, polyvinylpyrrolidone with a molecular weight of 1300kD is preferably used as a surfactant, and the repulsive force generated by its hydrophobic carbon chain can prevent the nano-indium magnesium sulfide particles from agglomerating, thereby forming a regular flower-shaped nano-indium magnesium sulfide material.

[0020] Scanning electron microscopy images show that the nano-indium magnesium sulfide material prepared by this invention has a particle size as low as 800 nm and good regularity. Compared with the method of using thiourea or cysteine ​​as sulfur source, it has better regularity and smaller particle size, and therefore also has higher photocatalytic activity.

[0021] (2) This method opens up a new route for the synthesis of regular flower-shaped nano-indium magnesium sulfide materials. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the preparation of regularly shaped, flower-like nano-indium magnesium sulfide according to the present invention;

[0023] Figure 2 The images show a comparison of scanning electron microscope (SEM) images of nano-indium magnesium sulfide prepared in the embodiments and comparative examples of the present invention.

[0024] Figure 3 The X-ray diffraction pattern of the regularly shaped, flower-shaped nano-indium magnesium sulfide prepared in Example 1 of this invention. Detailed Implementation

[0025] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that there are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: magnesium chloride CAS number: 7791-18-6; indium nitrate CAS number: 13465-14-0; magnesium nitrate CAS number: 10213-15-7; indium chloride CAS number: 10025-82-8; magnesium sulfate CAS number: 14168-73-1; indium sulfate CAS number: 13464-82-9; cysteine ​​CAS number: 52-90-4; polyvinylpyrrolidone, molecular weight 1300kD; thiourea CAS number: 62-56-6.

[0027] In the following examples, parts refer to parts by weight, and all raw materials mentioned above and not mentioned above are commercially available.

[0028] Example 1: The preparation method of regular flower-shaped nano-indium magnesium sulfide includes the following steps:

[0029] S1: 0.61g magnesium chloride, 0.96g indium nitrate, and 0.15g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0030] S2: Add 0.97g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0031] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 180°C for 10 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60°C to obtain flower-shaped nano-indium magnesium sulfide, labeled as 3-MgIn2S4.

[0032] Example 2: The preparation method of regular flower-shaped nano-indium magnesium sulfide includes the following steps:

[0033] S1: 0.61g magnesium chloride, 0.96g indium nitrate, and 0.5g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0034] S2: Add 0.49g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0035] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 160℃ for 5 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60℃ to obtain flower-shaped nano-indium magnesium sulfide, labeled as 4-MgIn2S4.

[0036] Example 3: The preparation method of regular flower-shaped nano-indium magnesium sulfide includes the following steps:

[0037] S1: 0.77g magnesium nitrate, 0.66g indium chloride, and 0.4g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0038] S2: Add 0.97g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0039] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 170℃ for 8 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The resulting precipitate was centrifuged twice with alcohol and water and dried in an oven at 60℃ to obtain flower-shaped nano-indium magnesium sulfide, labeled as 5-MgIn2S4.

[0040] Example 4: The preparation method of regular flower-shaped nano-indium magnesium sulfide includes the following steps:

[0041] S1: Disperse 0.42g magnesium sulfate, 1.55g indium sulfate, and 0.6g polyvinylpyrrolidone evenly in 30mL of deionized water by ultrasonication to obtain a magnesium-indium solution;

[0042] S2: Add 0.97g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0043] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 160℃ for 10 h. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60℃ to obtain flower-shaped nano-indium magnesium sulfide, labeled as 6-MgIn2S4.

[0044] Comparative Example 1: Based on Example 1, without the addition of polyvinylpyrrolidone, and by replacing cysteine ​​with thiourea, while keeping the rest of the process unchanged, as follows:

[0045] S1: 0.61g magnesium chloride, 0.96g indium nitrate, and 0.15g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0046] S2: Add 0.97g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0047] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 180°C for 10 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60°C to obtain flower-shaped nano-indium magnesium sulfide, labeled as 1-MgIn2S4.

[0048] Comparative Example 2: Based on Example 1, cysteine ​​was replaced with thiourea, while the rest of the process remained unchanged, as follows:

[0049] S1: 0.61g magnesium chloride, 0.96g indium nitrate, and 0.15g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0050] S2: Add 0.97g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0051] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 180°C for 10 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60°C to obtain flower-shaped nano-indium magnesium sulfide, labeled as 2-MgIn2S4.

[0052] Comparative Example 3: Based on Example 1, the sulfur source was replaced with thioacetamide, while the rest of the process remained unchanged, as follows:

[0053] S1: 0.61g magnesium chloride, 0.96g indium nitrate, and 0.15g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0054] S2: Add 0.60 g of thioacetamide to an indium magnesium solution and stir for 2 h to obtain a precursor solution;

[0055] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 180°C for 10 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was naturally cooled. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60°C to obtain flower-shaped nano-indium magnesium sulfide, labeled as 7-MgIn2S4.

[0056] Comparative Example 4: Based on Example 1, the amount of cysteine ​​was increased, while the rest of the process remained unchanged, as follows:

[0057] S1: 0.61g magnesium chloride, 0.96g indium nitrate, and 0.15g polyvinylpyrrolidone were ultrasonically dispersed in 30mL of deionized water to obtain a magnesium-indium solution;

[0058] S2: Add 1.52g of cysteine ​​to an indium magnesium solution and stir for 2 hours to obtain a precursor solution;

[0059] S3: The precursor solution was transferred to a high-pressure reactor and reacted at 180°C for 10 hours. After post-treatment, the supernatant was removed after the reaction was completed and the supernatant was cooled naturally. The precipitate was centrifuged twice with alcohol and water and dried in an oven at 60°C to obtain flower-shaped nano-indium magnesium sulfide, labeled as 8-MgIn2S4.

[0060] Performance testing: (1) The samples prepared in each embodiment and comparative example were tested by scanning electron microscopy, and the data are as follows: Figure 2 As shown; (2) The samples prepared in each example and comparative example were applied to photocatalytic hydrogen production. The specific process was as follows: a xenon lamp was used as the light source, triethanolamine aqueous solution (the volume ratio of triethanolamine to water was 1:4) was used as the sacrificial agent solution, the amount of nano-indium magnesium sulfide added was 10 mg, the reaction time was 60 min, and the hydrogen production was measured. The experimental data are shown in Table 1.

[0061] Table 1

[0062]

[0063]

[0064] Conclusion: From Figure 2 It can be seen that the magnesium indium sulfide materials prepared in Comparative Examples 1 and 2 are amorphous and have uneven particle sizes; while the magnesium indium sulfide materials prepared in Examples 1 to 4 have a regular flower-like morphology, are uniformly distributed, and have a particle size as low as 800 nm. This is mainly attributed to the use of cysteine, which is slightly soluble in water, as a sulfur source, which can slow down the sulfidation rate of magnesium and indium and increase the probability of heterogeneous structure formation. In addition, the use of polyvinylpyrrolidone 1.3 million as a surfactant can prevent the agglomeration of magnesium indium sulfide nanoparticles by the repulsive force generated by its hydrophobic carbon chains, thereby forming a regularly shaped flower-like magnesium indium sulfide nanoparticle material.

[0065] As shown in Table 1, the hydrogen production of the regularly flower-shaped nano-magnesium indium sulfide obtained in Examples 1-4 (281-340 mmol / h) is significantly higher than that of the ordinary magnesium indium sulfide obtained in Comparative Examples 1-3 (70-135 mmol / h). Therefore, compared with ordinary magnesium indium sulfide, the magnesium indium sulfide prepared in Examples 1-4 has a more regular flower-shaped microstructure, smaller particle size, and more uniform distribution, resulting in higher photocatalytic activity. Furthermore, in Comparative Example 4 (330 mmol / h), further increasing the amount of cysteine ​​added resulted in a decrease in photocatalytic activity; therefore, the optimal amount added should be lower than this in the optimal examples.

[0066] In summary, the nano-indium magnesium sulfide prepared by this invention has a regular flower-like morphology, small particle size, and excellent photocatalytic activity.

[0067] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A one-pot method for synthesizing regularly shaped, spherical nano-indium magnesium sulfide, characterized in that: Includes the following steps: S1: Disperse magnesium source, indium source and polyvinylpyrrolidone evenly in deionized water to obtain magnesium-indium solution; S2: Add cysteine ​​to the indium magnesium solution and stir to obtain the precursor solution; S3: The precursor solution was transferred to a high-pressure reactor and heated for reaction. After post-treatment, flower-shaped nano-indium magnesium sulfide was obtained. The molecular weight of the polyvinylpyrrolidone is 1000~1500kD; The molar ratio of the magnesium source, indium source, and polyvinylpyrrolidone is 1:1:(3.75×10⁻⁶). -5 ~1.5×10 -4 ); The molar ratio of cysteine ​​to indium source is (8~25):

6.

2. The method for one-pot synthesis of regularly shaped, flower-shaped nano-magnesium indium sulfide according to claim 1, characterized in that: The magnesium source includes one or more of magnesium chloride, magnesium sulfate, and magnesium nitrate.

3. The method for one-pot synthesis of regularly shaped, flower-shaped nano-magnesium indium sulfide according to claim 1, characterized in that: The indium source includes one or more of indium chloride, indium sulfate, and indium nitrate.

4. The method for one-pot synthesis of regularly shaped, flower-shaped nano-magnesium indium sulfide according to claim 1, characterized in that: During the stirring process, the time is 2~2.5h; during the heating reaction process, the temperature is 150~180℃ and the time is 5~10h.

5. The method for one-pot synthesis of regularly shaped, flower-shaped nano-magnesium indium sulfide according to claim 1, characterized in that: The specific post-processing includes the following steps: after the reaction is completed and the mixture is naturally cooled, the supernatant is removed, the resulting precipitate is centrifuged twice with alcohol and water, and then dried in an oven at 55~60℃.

6. Nano-indium sulfide magnesium prepared by a one-pot synthesis method for regular flower-shaped nano-indium sulfide magnesium according to any one of claims 1 to 5.

Images