Method for synthesizing regular flower-ball-shaped nanometer sulfur indium magnesium by one-pot method

Abstract

The invention discloses a method for synthesizing regular flower-ball-shaped nanometer sulfur indium magnesium by a one-pot method, and relates to the technical field of inorganic synthesis. The preparation method specifically comprises the following steps: S1, uniformly dispersing a magnesium source, an indium source and polyvinylpyrrolidone in deionized water to obtain a magnesium-indium solution; s2, adding cysteine into the indium-magnesium solution, and stirring to obtain a precursor solution; s3, transferring the precursor solution into a high-pressure reaction kettle, carrying out heating reaction, and carrying out post-treatment to obtain ball-flower-shaped nano indium magnesium sulfide; the nano sulfur indium magnesium prepared by the method has regular flower-ball-shaped morphology, the sphere particle size is as low as 800nm, and the nano sulfur indium magnesium has excellent photocatalytic activity.

Description

Technical Field

[0001] The present invention relates to the technical field of inorganic synthesis, and specifically to a method for synthesizing regular flower-like spherical nano-magnesium indium sulfide by a one-pot method. Background Art

[0002] Under the background of the increasingly prominent energy crisis and various environmental pollution problems, the development of sustainable clean energy has become popular. The photocatalytic hydrogen evolution technology can convert solar energy into hydrogen energy, which can partially solve the human demand for clean energy. As a typical n-type ternary sulfide, magnesium indium sulfide (MgIn2S4) has strong visible light response ability, high thermal stability and chemical stability, and is crucial in the fields of visible light degradation of pollutants and hydrolysis for hydrogen production. However, at present, the main preparation methods of magnesium indium sulfide mainly include gas-phase method and solid-phase method. The gas-phase method has low yield and complex equipment, and the solid-phase method has high energy consumption and a wide particle size range of products. In the hydrothermal method, materials prepared using substances such as thioacetamide and thiourea as sulfur sources generally have relatively complete crystal forms and relatively simple processes. For example, in Luo, L.'s "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 materials with a flower-like spherical structure by the hydrothermal method. However, the prepared magnesium indium sulfide materials are irregular under SEM images, with a particle size of about 10 μm, which is difficult to meet the requirements of photocatalytic hydrogen evolution technology. Moreover, thioacetamide and thiourea as sulfur sources have certain environmental hazards and are difficult to use on a large scale.

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

[0004] The purpose of the present invention is to provide a method for synthesizing regular flower-like spherical nano-magnesium indium sulfide by a one-pot method to solve the problems raised in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A method for synthesizing regular flower-like spherical nano-magnesium indium sulfide by a one-pot method, comprising the following steps:

[0007] S1: Disperse a magnesium source, an indium source, and polyvinylpyrrolidone uniformly in deionized water to obtain a magnesium indium solution;

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

[0009] S3: Transfer the precursor solution to an autoclave for heating reaction, and perform post-treatment to obtain flower-like nano magnesium indium sulfide.

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

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

[0012] More preferably, the molecular weight of the polyvinylpyrrolidone is 1000 - 1500 kD.

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

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

[0015] More preferably, during the stirring process, the time is 2 - 2.5 h.

[0016] More preferably, during the heating reaction: the temperature is 150 - 180 °C, and the time is 5 - 10 h.

[0017] More preferably, the specific process of the post-treatment includes the following steps: After the reaction ends and naturally cools down, remove the supernatant, centrifuge the obtained precipitate twice with alcohol and water, and place it in an oven at 55 - 60 °C for drying.

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

[0019] (1) When preparing the regular flower-like nano magnesium indium sulfide material in the present 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 formation probability of the heterostructure; then, polyvinylpyrrolidone with a molecular weight of 1300 kD is preferably used as the surfactant, and the repulsive force generated by its hydrophobic carbon chain can prevent the aggregation of nano magnesium indium sulfide particles, thereby forming a regular flower-like nano magnesium indium sulfide material;

[0020] It can be seen from the scanning electron microscope image that the nano magnesium indium sulfide material prepared in the present invention has a particle size as low as 800 nm and good regularity. Compared with the method using thiourea or cysteine as the sulfur source, it has better regularity and smaller particle size, and thus also has higher photocatalytic activity.

[0021] (2) This method opens up a new way for the synthesis of regular flower-like nano magnesium indium sulfide materials. Description of the Drawings

[0022] Figure 1 Flow chart for preparing regular flower-like nano magnesium indium sulfide in the present invention;

[0023] Figure 2 SEM comparison diagrams of nano magnesium indium sulfide prepared in the examples and comparative examples of the present invention;

[0024] Figure 3 X-ray diffraction pattern of regular flower-like nano magnesium indium sulfide prepared in Example 1 of the present invention. Detailed implementation manners

[0025] Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

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

[0027] In the following examples, "parts" are parts by mass, and the above-mentioned and unmentioned raw materials are all commercially available.

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

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

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

[0031] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 180 °C for 10 h, perform post-treatment. After the reaction ends and cools naturally, remove the supernatant. Centrifuge the obtained precipitate twice with alcohol and water, and place it in an oven at 60 °C to dry to obtain flower-like nano magnesium indium sulfide, labeled as 3-MgIn2S4.

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

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

[0034] S2: Add 0.49 g of cysteine to the indium-magnesium solution and stir for 2 h to obtain a precursor solution;

[0035] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 160 °C for 5 h, perform post-treatment, remove the supernatant after natural cooling at the end of the reaction, centrifuge the obtained precipitate twice with alcohol and water, and dry it in an oven at 60 °C to obtain flower-shaped nano magnesium indium sulfide, labeled as 4-MgIn2S4.

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

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

[0038] S2: Add 0.97 g of cysteine to the indium-magnesium solution and stir for 2 h to obtain a precursor solution;

[0039] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 170 °C for 8 h, perform post-treatment, remove the supernatant after natural cooling at the end of the reaction, centrifuge the obtained precipitate twice with alcohol and water, and dry it in an oven at 60 °C to obtain flower-shaped nano magnesium indium sulfide, labeled as 5-MgIn2S4.

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

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

[0042] S2: Add 0.97 g of cysteine to the indium-magnesium solution and stir for 2 h to obtain a precursor solution;

[0043] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 160 °C for 10 h, perform post-treatment, remove the supernatant after natural cooling at the end of the reaction, centrifuge the obtained precipitate twice with alcohol and water, and dry it in an oven at 60 °C to obtain flower-shaped nano magnesium indium sulfide, labeled as 6-MgIn2S4.

[0044] Comparative Example 1: Based on Example 1, without adding polyvinylpyrrolidone and replacing cysteine with thiourea, with the rest of the process unchanged, specifically as follows:

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

[0046] S2: Add 0.97 g of cysteine to the indium-magnesium solution and stir for 2 h to obtain a precursor solution;

[0047] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 180 °C for 10 h, and perform post-treatment. After the reaction ends and naturally cools, remove the supernatant. Centrifuge the obtained precipitate twice with alcohol and water, and dry it in an oven at 60 °C to obtain flower-like nano magnesium indium sulfide, labeled as 1-MgIn2S4.

[0048] Comparative Example 2: Based on Example 1, replace cysteine with thiourea, and keep the rest of the process unchanged. The specific steps are as follows:

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

[0050] S2: Add 0.97 g of cysteine to the indium-magnesium solution and stir for 2 h to obtain a precursor solution;

[0051] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 180 °C for 10 h, and perform post-treatment. After the reaction ends and naturally cools, remove the supernatant. Centrifuge the obtained precipitate twice with alcohol and water, and dry it in an oven at 60 °C to obtain flower-like nano magnesium indium sulfide, labeled as 2-MgIn2S4.

[0052] Comparative Example 3: Based on Example 1, replace the sulfur source with thioacetamide, and keep the rest of the process unchanged. The specific steps are as follows:

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

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

[0055] S3: Transfer the precursor solution to a high-pressure reaction kettle, react at 180 °C for 10 h, and perform post-treatment. After the reaction ends and naturally cools, remove the supernatant. Centrifuge the obtained precipitate twice with alcohol and water, and dry it in an oven at 60 °C to obtain flower-like nano magnesium indium sulfide, labeled as 7-MgIn2S4.

[0056] Comparative Example 4: Based on Example 1, increase the amount of cysteine, and keep the rest of the process unchanged. The specific steps are as follows:

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

[0058] S2: Add 1.52 g of cysteine to the indium-magnesium solution and stir for 2 h to obtain a precursor solution;

[0059] S3: Transfer the precursor solution to a high-pressure reactor, react at 180 °C for 10 h, and perform post-treatment. After the reaction ends and cools naturally, remove the supernatant. Centrifuge the obtained precipitate twice with alcohol and water, and place it in an oven at 60 °C to dry to obtain flower-like nanosized magnesium indium sulfide, labeled as 8-MgIn2S4.

[0060] Performance test: (1) The samples prepared in each example and comparative example were tested by scanning electron microscopy, and the data are as Figure 2 shown; (2) The samples prepared in each example and comparative example were applied to photocatalytic hydrogen production. The specific process was as follows: Using a xenon lamp as the light source, an aqueous triethanolamine solution (volume ratio of triethanolamine to water is 1:4) as the sacrificial agent solution, the addition amount of nanosized magnesium indium sulfide 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: As Figure 2 can be seen, the magnesium indium sulfide materials prepared in Comparative Examples 1-2 are amorphous and have uneven particle sizes; while the magnesium indium sulfide materials prepared in Examples 1-4 have a regular flower-like morphology, are evenly distributed, and the particle size of the spheres is as low as 800 nm; this is mainly attributed to using cysteine, which is slightly soluble in water, as the sulfur source, which can delay the sulfidation rate of magnesium and indium and enhance the formation probability of heterostructures. In addition, using polyvinylpyrrolidone with a molecular weight of 1.3 million as the surfactant, the repulsive force generated by its hydrophobic carbon chain can prevent the aggregation of nanosized magnesium indium sulfide particles, and thus form a flower-like nanosized magnesium indium sulfide material with regular morphology.

[0065] As can be seen from Table 1, the hydrogen production of the regular flower-like nanosized magnesium indium sulfide obtained in Examples 1-4 (281-340 mmol / h) is much 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-like microstructure, smaller particle size and uniform distribution, and higher photocatalytic activity; while in Comparative Example 4 (330 mmol / h), when the addition amount of cysteine is continuously increased, it can be found that the photocatalytic activity decreases. Therefore, the addition amount in the optimal example needs to be lower than this amount.

[0066] In summary, the nano-magnesium thioindate prepared by the present invention has a regular flower-like spherical morphology, the particle size of the sphere is low and small, and it has excellent photocatalytic activity.

[0067] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used 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 recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for synthesizing regular flower-like spherical nano-magnesium indium sulfide by a one-pot method, characterized in that: It includes the following steps: S1: Disperse a magnesium source, an indium source, and polyvinylpyrrolidone evenly in deionized water to obtain a magnesium-indium solution; S2: Add cysteine to the indium-magnesium solution and stir to obtain a precursor solution; S3: Transfer the precursor solution to a high-pressure reactor for heating reaction and post-treatment to obtain flower-like nano magnesium indium sulfide.

2. The method for synthesizing regular flower-like nano-magnesium thioindate by a one-pot method according to claim 1, wherein: The magnesium source includes one or more of magnesium chloride, magnesium sulfate, and magnesium nitrate.

3. The method for synthesizing regular flower-like spherical nano magnesium thioindate by a one-pot method according to claim 1, characterized in that: The indium source includes one or more of indium chloride, indium sulfate, and indium nitrate.

4. A method for synthesizing regular flower-like spherical nano-magnesium thioindate by a one-pot method according to claim 1, characterized in that: The molecular weight of the polyvinylpyrrolidone is 1000-1500 kD.

5. A method for synthesizing regular flower-like spherical nano magnesium indium sulfide by a one-pot method according to claim 1, characterized in that: The molar ratio of the magnesium source, indium source, and polyvinylpyrrolidone is 1:1:(3.75×10 -5 ~1.5×10 -4 ).

6. A method for synthesizing regular flower-like spherical nano-magnesium indium sulfide by a one-pot method according to claim 1, characterized in that: The molar ratio of the cysteine to the indium source is (8-25):

6.

7. A method for synthesizing regular flower-like spherical nano-magnesium thioindate by a one-pot method according to claim 1, characterized in that: During the stirring process, the time is 2-2.5 h; during the heating reaction process: the temperature is 150-180 °C and the time is 5-10 h.

8. A method for synthesizing regular flower-like spherical nano-magnesium thioindate by a one-pot method according to claim 1, characterized in that: The specific process of the post-treatment includes the following steps: After the reaction ends and cools naturally, remove the supernatant, centrifuge the obtained precipitate twice with alcohol and water, and place it in an oven at 55-60 °C for drying.

9. Nano magnesium indium sulfide prepared by the method for synthesizing regular flower-like nano magnesium indium sulfide by a one-pot method according to any one of claims 1-8.

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