Solution synthesis method of chalcogenide molybdenum amorphous powder

Abstract

The invention relates to the technical field of synthesis of chalcogenide compounds, in particular to a solution synthesis method of chalcogenide molybdenum amorphous powder. The method comprises the following steps: mixing a chalcogenide simple substance, a reducing agent and water to carry out reduction reaction, and reducing the chalcogenide simple substance into-2-valent ions to obtain a solution containing chalcogenide anions; mixing the solution containing the chalcogenide anions with a + 6-valent molybdenum source, and carrying out precipitation reaction to form amorphous chalcogenide molybdenum; the + hexavalent molybdenum source comprises ammonium molybdate or molybdenum acetylacetonate; the chemical formula of the amorphous molybdenum chalcogenide is MoX3, and X is S, Se or Te. Ammonium molybdate or molybdenum acetylacetonate is used as the molybdenum source, the sulfur group elementary substance is used as the sulfur source, the amorphous chalcogenide molybdenum is prepared through the solution synthesis method, the method has the advantages that the method is simple, raw materials are easy to obtain, cost is low, expensive equipment is not needed, expandability is good and the like, and the synthesized amorphous chalcogenide molybdenum is high in purity, uniform in particle size, uniform in element distribution and good in quality.

Description

Technical Field

[0001] The present invention relates to the technical field of chalcogenide synthesis, and particularly to a solution synthesis method of chalcogenide molybdenum-based amorphous powder. Background Art

[0002] Amorphous molybdenum sulfide exhibits extensive application potential in the fields of energy, catalysis, sensors, etc. due to its unique electronic structure and catalytic performance.

[0003] In related technologies, expensive ammonium tetrathiomolybdate is used to prepare amorphous molybdenum sulfide. Specifically, ammonium tetrathiomolybdate is dissolved in water, and the pH value is adjusted so that ammonium tetrathiomolybdate decomposes and precipitates into molybdenum sulfide.

[0004] The above synthesis method has the problems of cumbersome steps and high cost, poor scalability, and limits the wide industrial application of amorphous molybdenum sulfide. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a solution synthesis method of chalcogenide molybdenum-based amorphous powder. The synthesis method provided by the present invention is simple, the raw materials are easy to obtain, the cost is low, and the prepared amorphous chalcogenide molybdenum has reliable purity, uniform particle size, and good quality.

[0006] In order to achieve the above object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a solution synthesis method of amorphous chalcogenide molybdenum, comprising the following steps:

[0008] Mix a chalcogen element, a reducing agent, and water to carry out a reduction reaction, and the chalcogen element is reduced to a -2 valence ion to obtain a solution containing chalcogen negative ions; the chalcogen element is elemental sulfur, elemental selenium, or elemental tellurium;

[0009] When the chalcogen element is elemental selenium or elemental tellurium, mix the solution containing chalcogen negative ions with a +6 valence molybdenum source to carry out a precipitation reaction to form amorphous chalcogenide molybdenum;

[0010] When the chalcogen element is elemental sulfur, mix the solution containing chalcogen negative ions with a +6 valence molybdenum source, adjust the pH value of the obtained mixed solution to <1, carry out a precipitation reaction to form amorphous chalcogenide molybdenum;

[0011] The +6 valence molybdenum source is ammonium molybdate or molybdenum acetylacetonate; the chemical formula of the amorphous chalcogenide molybdenum is MoX3, where X is S, Se, or Te.

[0012] Preferably, the reducing agent includes sodium borohydride, potassium borohydride, or hydrazine hydrate.

[0013] Preferably, the molar ratio of the chalcogen element to the reducing agent is (1-2):1.

[0014] Preferably, the molar ratio of the chalcogenide anion in the chalcogenide anion-containing solution to molybdenum in the +6 valent molybdenum source is (2-3):1.

[0015] Preferably, the reagent used to adjust the pH value of the obtained mixed solution to <1 includes hydrochloric acid.

[0016] Preferably, the reduction reaction is carried out in a vacuum environment or under the protection of an inert gas.

[0017] Preferably, the precipitation reaction is carried out in a vacuum environment or under the protection of an inert gas.

[0018] Preferably, after the precipitation reaction is completed, it further includes solid-liquid separation, solid washing and drying of the obtained product liquid containing amorphous molybdenum chalcogenide to obtain the amorphous molybdenum chalcogenide.

[0019] Preferably, the solid washing includes alternating washing with water and absolute ethanol until neutral.

[0020] Preferably, the drying temperature is 40-60 °C and the time is 4-8 h.

[0021] The present invention provides a solution synthesis method for amorphous molybdenum chalcogenide, including the following steps: mixing a chalcogen element, a reducing agent and water to carry out a reduction reaction, and the chalcogen element is reduced to a -2 valent ion to obtain a chalcogenide anion-containing solution; the chalcogen element is elemental sulfur, elemental selenium or elemental tellurium; when the chalcogen element is elemental selenium or elemental tellurium, mixing the chalcogenide anion-containing solution with a +6 valent molybdenum source to carry out a precipitation reaction to form amorphous molybdenum chalcogenide; when the chalcogen element is elemental sulfur, mixing the chalcogenide anion-containing solution with a +6 valent molybdenum source, adjusting the pH value of the obtained mixed solution to <1, and carrying out a precipitation reaction to form amorphous molybdenum chalcogenide; the +6 valent molybdenum source includes ammonium molybdate or molybdenum acetylacetonate; the chemical formula of the amorphous molybdenum chalcogenide is MoX3, where X is S, Se or Te. The present invention uses ammonium molybdate or molybdenum acetylacetonate as the molybdenum source and elemental chalcogen as the sulfur source, and prepares amorphous molybdenum chalcogenide by a solution synthesis method, which has the advantages of simple method, easy availability of raw materials, low cost, no need for expensive equipment, good scalability, etc., and the synthesized amorphous molybdenum chalcogenide has high purity, uniform particle size, uniform element distribution and good quality. Description of the Drawings

[0022] Figure 1 The structural characterization results of the amorphous molybdenum telluride powder prepared in Example 1, where a is the X-ray diffraction pattern of the amorphous molybdenum telluride powder, b is the element ratio of the amorphous molybdenum telluride powder, c is the transmission electron diffraction pattern of the amorphous molybdenum telluride powder, and d-f are the element surface distributions of the amorphous molybdenum telluride powder;

[0023] Figure 2Structural characterization results of the amorphous molybdenum chalcogenide powder prepared in Example 2. Among them, a is the X-ray diffraction pattern of the amorphous molybdenum chalcogenide powder, b is the elemental ratio of the amorphous molybdenum chalcogenide powder, c is the scanning electron micrograph of the amorphous molybdenum chalcogenide powder, and d is the transmission electron diffraction pattern of the amorphous molybdenum chalcogenide powder;

[0024] Figure 3 Structural characterization results of the amorphous molybdenum sulfide powder prepared in Example 3. Among them, a is the X-ray diffraction pattern of the amorphous molybdenum sulfide powder, b is the elemental ratio of the amorphous molybdenum sulfide powder, and c is the scanning electron micrograph of the amorphous molybdenum sulfide powder. Detailed implementation manners

[0025] The present invention provides a solution synthesis method of amorphous molybdenum chalcogenide, comprising the following steps:

[0026] Mix a chalcogen element, a reducing agent and water to carry out a reduction reaction, and the chalcogen element is reduced to -2 valence ions to obtain a solution containing chalcogen negative ions; the chalcogen element is elemental sulfur, elemental selenium or elemental tellurium;

[0027] When the chalcogen element is elemental selenium or elemental tellurium, mix the solution containing chalcogen negative ions with a +6-valent molybdenum source to carry out a precipitation reaction to form amorphous molybdenum chalcogenide;

[0028] When the chalcogen element is elemental sulfur, mix the solution containing chalcogen negative ions with a +6-valent molybdenum source, adjust the pH value of the obtained mixed solution to <1, and carry out a precipitation reaction to form amorphous molybdenum chalcogenide;

[0029] The +6-valent molybdenum source is ammonium molybdate or molybdenum acetylacetonate; the chemical formula of the amorphous molybdenum chalcogenide is MoX3, where X is S, Se or Te.

[0030] In the present invention, unless otherwise specified, the raw materials used are all commercially available products well-known in the art.

[0031] The present invention mixes a chalcogen element, a reducing agent and water to carry out a reduction reaction, and the chalcogen element is reduced to -2 valence ions to obtain a solution containing chalcogen negative ions.

[0032] In the present invention, the chalcogen element is elemental sulfur, elemental selenium or elemental tellurium. In the examples of the present invention, the elemental sulfur is specifically S8. In the present invention, the chalcogen element is preferably used in the form of powder.

[0033] In the present invention, the reducing agent preferably includes sodium borohydride, potassium borohydride or hydrazine hydrate, and more preferably sodium borohydride. In the present invention, the molar ratio of the chalcogen element to the reducing agent is preferably (1-2):1, and in specific examples, it can be 1:1, 1.5:1 or 2:1.

[0034] In the present invention, the water is preferably deionized water. The present invention has no special requirement for the amount of the water, as long as it can completely dissolve the reduction reaction product.

[0035] In the present invention, the mixing of the chalcogen simple substance, the reducing agent and the water preferably includes: adding the chalcogen simple substance and the reducing agent to the water.

[0036] In the present invention, the reduction reaction is preferably carried out under a vacuum environment or an inert gas protection. The present invention has no special requirement for the type of the inert gas, and any inert gas well-known in the art can be used, such as nitrogen, argon; the temperature of the reduction reaction is preferably room temperature (that is, no additional heating or cooling is required). The present invention has no special requirement for the time of the reduction reaction, and it is sufficient to obtain a clear solution. The present invention preferably carries out the reduction reaction under stirring conditions.

[0037] In the process of the reduction reaction of the present invention, the chalcogen simple substance is reduced to -2 valence ions, and a solution containing chalcogen negative ions is obtained. Taking sodium borohydride as an example, the equation of the reduction reaction is shown in Formula 1:

[0038]

[0039] After obtaining the solution containing chalcogen negative ions, the present invention selects corresponding steps to carry out a precipitation reaction according to the type of the chalcogen simple substance.

[0040] In the present invention, when the chalcogen simple substance is elemental selenium or elemental tellurium, the present invention mixes the solution containing chalcogen negative ions with a +6-valent molybdenum source to carry out a precipitation reaction to form amorphous molybdenum chalcogenide. In the present invention, the +6-valent molybdenum source is ammonium molybdate or molybdenum acetylacetonate; the molar ratio of the chalcogen negative ions in the solution containing chalcogen negative ions to molybdenum in the +6-valent molybdenum source is preferably (2-3):1, and can be 2:1, 2.5:1 or 3:1 in specific embodiments. The present invention uses ammonium molybdate or molybdenum acetylacetonate as the molybdenum source, which has the advantages of wide source and low price.

[0041] In the present invention, the mixing of the solution containing chalcogen negative ions with the +6-valent molybdenum source is preferably: adding the +6-valent molybdenum source to the solution containing chalcogen negative ions. The present invention preferably mixes the solution containing chalcogen negative ions with the +6-valent molybdenum source under a vacuum environment or an inert gas protection.

[0042] In the present invention, the precipitation reaction is preferably carried out under a vacuum environment or an inert gas protection; the temperature of the precipitation reaction is preferably room temperature (that is, no additional heating or cooling is required). The present invention does not make a special limitation on the time of the precipitation reaction, and it is sufficient to wait until the precipitation no longer increases. The present invention preferably carries out the precipitation reaction under stirring conditions.

[0043] In the present invention, when the chalcogen element is elemental sulfur, after obtaining the solution containing chalcogen anions, the present invention mixes the solution containing chalcogen anions with a molybdenum source with a valence of +6, adjusts the pH value of the obtained mixed solution to be <1, and a precipitation reaction occurs to form amorphous molybdenum chalcogenide.

[0044] In the present invention, the type of the molybdenum source with a valence of +6 and the dosage relationship with the solution containing chalcogen anions are the same as above, and will not be elaborated here.

[0045] The present invention preferably uses hydrochloric acid to adjust the pH value of the obtained mixed solution to be <1. In the present invention, the concentration of the hydrochloric acid is preferably 0.1 mol / L.

[0046] In the present invention, taking ammonium molybdate as an example, the equation of the precipitation reaction is shown in Equation 2:

[0047]

[0048] After completing the precipitation reaction, the present invention preferably further includes performing solid-liquid separation, washing the solid, and drying on the obtained product liquid containing amorphous molybdenum chalcogenide to obtain the amorphous molybdenum chalcogenide.

[0049] The present invention has no special requirements for the method of solid-liquid separation, and any well-known solid-liquid separation methods in the art can be used, such as filtration and centrifugation. In the embodiments of the present invention, centrifugation is specifically used for solid-liquid separation, the rotation speed of the centrifugation is 5000 r / min, and the time of the centrifugation is 10 min.

[0050] In the present invention, the solid washing preferably includes: washing alternately with water and absolute ethanol until neutral.

[0051] In the present invention, the drying is preferably vacuum drying, the drying temperature is preferably 40-60 °C, and the time is preferably 4-8 h; in specific embodiments, the drying temperature can be 40 °C, 50 °C or 60 °C, and the drying time can be 4 h, 5 h, 6 h, 7 h or 8 h.

[0052] The present invention uses a solution synthesis method to prepare amorphous molybdenum chalcogenide, which has the advantages of simple method, easy availability of raw materials, low cost, no need for expensive equipment, good scalability, and the prepared amorphous molybdenum chalcogenide has high purity, uniform particle size, uniform element distribution, and good quality.

[0053] The following combines examples to elaborate in detail on the solution synthesis method of amorphous molybdenum chalcogenide provided by the present invention, but they cannot be understood as limiting the protection scope of the present invention.

[0054] Example 1

[0055] Preparation of amorphous molybdenum telluride (MoTe3) powder:

[0056] 1) Under room temperature and nitrogen gas protection, add 20 mL of deionized water to a three-necked flask, then add 30 mmol of elemental tellurium and 2 g of NaBH4, and continuously stir with a magnetic stirrer for 20 min to ensure complete reaction, obtaining a solution containing Te 2- .

[0057] 2) Under room temperature and nitrogen gas protection, add 10 mmol of (NH4)2MoO4 powder to the obtained solution containing Te 2- , and continue to stir at room temperature for 20 min to ensure sufficient reaction.

[0058] 3) Transfer the solution after the reaction is completed to a centrifuge tube and centrifuge at a speed of 5000 r / min for 10 min to separate the solid product.

[0059] 4) Wash the solid product three times each with deionized water and absolute ethanol to remove residual reactants and by-products.

[0060] 5) Carefully transfer the washed solid product to a vacuum drying oven and dry at 60 °C for 6 h to obtain amorphous molybdenum telluride powder.

[0061] Example 2

[0062] Preparation of amorphous molybdenum selenide (MoSe3) powder:[[]]

[0063] 1) Under room temperature and argon gas protection, add 20 mL of deionized water to a three-necked flask, then add 30 mmol of elemental selenium and 2 g of NaBH4, and continuously stir with a magnetic stirrer for 40 min to ensure complete reaction, obtaining a solution containing Se 2- .

[0064] 2) Under room temperature and argon gas protection, add 10 mmol of (NH4)2MoO4 powder to the obtained solution containing Se 2- , and continue to stir at room temperature for 40 min to ensure sufficient reaction.

[0065] 3) Transfer the solution after the reaction is completed to a centrifuge tube and centrifuge at a speed of 5000 r / min for 10 min to separate the solid product.

[0066] 4) Wash the solid product three times each with deionized water and absolute ethanol to remove residual reactants and by-products.

[0067] 5) Carefully transfer the washed solid product to a vacuum drying oven and dry at 60 °C for 6 h to obtain amorphous molybdenum selenide powder.

[0068] Example 3

[0069] Preparation of amorphous molybdenum sulfide (MoS3) powder:

[0070] 1) At room temperature and in a vacuum environment, add 20 mL of deionized water to a three-necked flask, then add 30 mmol of elemental sulfur (specifically S8) and 2 g of NaBH4, and continuously stir with a magnetic stirrer for 1 h to ensure complete reaction, obtaining a solution containing S 2- .

[0071] 2) At room temperature and in a vacuum environment, add 10 mmol of (NH4)2MoO4 powder to the obtained solution containing S 2- , add 10 mL of 0.1 mol / L hydrochloric acid to adjust the pH < 1, and continue to stir at room temperature for 1 h to ensure sufficient reaction.

[0072] 3) Transfer the solution after the reaction is completed to a centrifuge tube and centrifuge at a speed of 5000 r / min for 10 min to separate the solid product.

[0073] 4) Wash the solid product three times each with deionized water and absolute ethanol to remove residual reactants and by-products.

[0074] Carefully transfer the washed solid product to a vacuum drying oven and dry it at 60 °C for 6 h until completely dry to obtain amorphous molybdenum sulfide powder.

[0075] Example 4

[0076] Preparation of amorphous molybdenum sulfide (MoS3) powder:

[0077] 1) Under the protection of argon gas at room temperature, add 20 mL of deionized water to a three-necked flask, then add 30 mmol of elemental sulfur (specifically S8) and 2 g of NaBH4, and continuously stir with a magnetic stirrer for 1 h to ensure complete reaction, obtaining a solution containing S 2- .

[0078] 2) Under the protection of argon gas at room temperature, add 10 mmol of molybdenum acetylacetonate powder to the obtained solution containing S 2- , add 10 mL of 0.1 mol / L hydrochloric acid to adjust the pH < 1, and continue to stir at room temperature for 1 h to ensure sufficient reaction.

[0079] 3) Transfer the solution after the reaction is completed to a centrifuge tube and centrifuge at a speed of 5000 r / min for 10 min to separate the solid product.

[0080] 4) Wash the solid product three times each with deionized water and absolute ethanol to remove residual reactants and by-products.

[0081] Carefully transfer the washed solid product to a vacuum drying oven and dry it at 60 °C for 6 h until completely dry to obtain amorphous molybdenum sulfide powder.

[0082] Structure characterization:

[0083] Perform structure characterization on the amorphous molybdenum telluride powder prepared in Example 1. The results are shown in Figure 1 , where a is the X-ray diffraction pattern of the amorphous molybdenum telluride powder, b is the element ratio of the amorphous molybdenum telluride powder, c is the transmission electron diffraction pattern of the amorphous molybdenum telluride powder, and d-f are the elemental surface distributions of the amorphous molybdenum telluride powder. From Figure 1 a, it can be seen that molybdenum telluride is a uniform amorphous product, and its XRD pattern does not contain impurity element peaks; Figure 1 b shows that the elemental stoichiometry of the product is exactly the same as expected, basically 3:1, indicating that the purity of the product is relatively high; Figure 1 c shows that the product is completely amorphous and does not contain crystalline components, which also reflects the relatively high purity of the product; Figure 1 d-f give the distribution of elements. It can be seen that the distributions of molybdenum elements and tellurium elements are very uniform, which completely corresponds to the SEM morphology. And Figure 1 from the morphology diagram in d, it can also be seen that the particle size of the powder is very uniform.

[0084] Perform structure characterization on the amorphous molybdenum selenide powder prepared in Example 2. The results are shown in Figure 2 , where a is the X-ray diffraction pattern of the amorphous molybdenum selenide powder, b is the element ratio of the amorphous molybdenum selenide powder, c is the SEM image of the amorphous molybdenum selenide powder, and d is the transmission electron diffraction pattern of the amorphous molybdenum selenide powder. From Figure 2 it can be seen that the molybdenum selenide prepared in Example 2 is amorphous and has relatively high purity and uniform particle size.

[0085] Perform structure characterization on the amorphous molybdenum sulfide powder prepared in Example 3. The results are shown in Figure 3 , where a is the X-ray diffraction pattern of the amorphous molybdenum sulfide powder, b is the element ratio of the amorphous molybdenum sulfide powder, and c is the SEM image of the amorphous molybdenum sulfide powder. From Figure 3 it can be seen that the molybdenum sulfide prepared in Example 3 is amorphous and has relatively high purity and uniform particle size.

[0086] Perform structure characterization on the amorphous molybdenum sulfide powder prepared in Example 4. The results show that the prepared molybdenum sulfide is amorphous and has relatively high purity and uniform particle size.

[0087] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for synthesizing amorphous molybdenum sulfide solution, characterized in that: The following steps are involved: A chalcogenide element, a reducing agent and water are mixed to perform a reduction reaction, wherein the chalcogenide element is reduced to -2 valent ions to obtain a solution containing chalcogenide anions; the chalcogenide element is elemental sulfur, elemental selenium or elemental tellurium; When the chalcogenide element is selenium or tellurium, the solution containing the chalcogenide anion is mixed with a +6-valent molybdenum source to undergo a precipitation reaction to form an amorphous molybdenum chalcogenide; When the chalcogenide element is elemental sulfur, the solution containing the chalcogenide anion is mixed with a +6-valent molybdenum source, and the pH value of the resulting mixed solution is adjusted to less than 1, and a precipitation reaction occurs to form amorphous molybdenum chalcogenide; The +6 valent molybdenum source is ammonium molybdate or molybdenum acetylacetonate; the chemical formula of the amorphous molybdenum sulfide is MoX3, wherein X is S, Se or Te.

2. The solution synthesis method according to claim 1, characterized in that: The reducing agent includes sodium borohydride, potassium borohydride or hydrazine hydrate.

3. The solution synthesis method according to claim 1 or 2, characterized in that: The molar ratio of the sulfur element to the reducing agent is (1-2):

1.

4. The solution synthesis method according to claim 1, characterized in that: The molar ratio of the sulfide anions in the solution containing the sulfide anions to the molybdenum in the +6-valent molybdenum source is (2-3):

1.

5. The solution synthesis method according to claim 1, characterized in that: The reagent used for adjusting the pH value of the mixed solution to less than 1 includes hydrochloric acid.

6. The solution synthesis method according to claim 1 or 2, characterized in that: The reduction reaction is carried out in a vacuum environment or under the protection of an inert gas.

7. The solution synthesis method according to claim 1, characterized in that: The precipitation reaction is carried out in a vacuum environment or under the protection of an inert gas.

8. The solution synthesis method according to claim 1 or 7, characterized in that: After the precipitation reaction is completed, the method further includes subjecting the obtained product liquid containing amorphous molybdenum sulfide to solid-liquid separation, solid washing and drying to obtain the amorphous molybdenum sulfide.

9. The solution synthesis method according to claim 8, characterized in that: The solid washing comprises washing with water and anhydrous ethanol alternately until the solid is neutral.

10. The solution synthesis method according to claim 8, characterized in that: The drying temperature is 40-60° C. and the drying time is 4-8 hours.

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