CN-121988352-A - MoS with core-shell structure2@SnS2@SnO2Method for preparing nano material

Abstract

The invention discloses a preparation method of a MoS 2 @SnS 2 @SnO 2 nano material with a core-shell structure. The method comprises the following steps of 1, ultrasonically dispersing the SnO 2 nano material with the exposed high-energy surface in water or a low-carbon alcohol or alcohol amine solvent. 2. And sequentially adding a sulfur source, a tin source and a molybdenum source precursor into the solvent, and regulating and controlling the types of precursor raw materials to form a suspension. 3. Regulating and controlling the material proportion in the solvent. 4. Transferring the obtained suspension into a closed system, and crystallizing by microwave heating or electric heating. 5. After crystallization, separating a solid product, washing and drying to obtain the MoS 2 @SnS 2 @SnO 2 nano material which takes SnO 2 as a core and sequentially coats the SnS 2 and the MoS 2 shell from inside to outside. The synthesis method has the advantages of mild conditions, simple operation, high yield and the like, and the prepared core-shell structure MoS 2 @SnS 2 @SnO 2 nano material has the characteristics of high exposure of hydrogenation active sites and good high-temperature high-pressure stability.

Inventors

• WANG DONGE
• ZHU YUANYUAN
• TIAN ZHIJIAN
• QIAN YUFENG
• ZHONG YUXIAN

Assignees

• 中国科学院大连化学物理研究所

Dates

Publication Date

20260508

Application Date

20241105

Claims (9)

1. 1. A preparation method of a MoS 2 @SnS 2 @SnO 2 nano material is characterized by comprising the steps of dispersing a SnO 2 nano material in a solvent, adding a sulfur source, a tin source and a molybdenum source into the solvent to form a suspension, transferring the obtained suspension into a closed system or a container, heating for crystallization, and separating a solid product after crystallization is completed to obtain the MoS 2 @SnS 2 @SnO 2 nano material which takes SnO 2 as a core and sequentially coats SnS 2 and MoS 2 shells from inside to outside.
2. 2. The method of claim 1, wherein the SnO 2 nanomaterial is one or more of (111) high-energy-surface-exposed SnO 2 nanomaterial with a particle size of 50-300 nm.
3. 3. The method for preparing MoS 2 @SnS 2 @SnO 2 nanometer material as claimed in claim 1, wherein the sulfur source is one or more than two of sodium sulfide, potassium sulfide, ammonium thiocyanate, thiourea, thioacetamide, L-cysteine, glutathione and other soluble sulfur sources.
4. 4. The method for preparing MoS 2 @SnS 2 @SnO 2 nanometer materials according to claim 1, wherein the tin source is one or more of tin dichloride, stannous nitrate, tin tetrachloride or tin nitrate, and the molar concentration of Sn in the solvent is 0.001M-0.1M, preferably 0.01M-0.05M.
5. 5. The method for preparing MoS 2 @SnS 2 @SnO 2 nanometer materials according to claim 1, wherein the molybdenum source is one or a mixture of more than two of ammonium heptamolybdate, sodium molybdate, ammonium molybdate, phosphomolybdic acid and ammonium tetrathiomolybdate, and the molar concentration of Mo in the solvent is 0.001M-0.1M, preferably 0.01M-0.05M.
6. 6. The method of claim 1, wherein the solvent is water, monohydric, dihydric and trihydric alcohols of C1-C4, or one or more of diethanolamine, diisopropanolamine and triethanolamine.
7. 7. The method for preparing MoS 2 @SnS 2 @SnO 2 nano-material according to any one of claims 1 to 6, wherein the molar ratio of S/(Mo+Sn) in the solvent is 1.0 to 4.0, preferably 1.5 to 2.5, the molar ratio of Sn/Mo in the solvent is 0.1 to 10.0, preferably 0.5 to 2.0, and the molar ratio of metallic Mo to SnO 2 is 0.1 to 10.0, preferably 0.2 to 2.0.
8. 8. The preparation method of the MoS 2 @SnS 2 @SnO 2 nanometer material according to claim 1 is characterized in that the crystallization mode is a hydrothermal or solvothermal process under a closed system, the heating mode is microwave heating or electric heating, the crystallization temperature is 120-220 ℃, preferably 140-180 ℃, the crystallization time is 3-72 h, preferably 18-36 h, and the crystallization pressure is 0.01-5.0 MPa, preferably 0.04-0.5 MPa.
9. 9. The method of claim 1, wherein the step of separating the solid product comprises the steps of suction filtration or centrifugation, washing with deionized water and absolute ethyl alcohol in sequence, vacuum drying or freeze drying to obtain the SnS 2 and MoS 2 shell MoS 2 @SnS 2 @SnO 2 nanomaterial coated with SnO 2 as a core.

Description

Preparation method of MoS 2@SnS2@SnO2 nano material with core-shell structure Technical Field The invention relates to a preparation method of a MoS 2@SnS2@SnO2 nanometer material with a core-shell structure, belonging to the controllable preparation field of novel high-efficiency nanometer catalysts with structures. Background The transition metal sulfide MoS 2 has a typical layered structure, the layers are combined by weak van der Waals force, the stripping is easy, each molybdenum atom in the monoatomic layer is surrounded by six sulfur atoms, the monoatomic layer is triangular prism-shaped, and a plurality of Mo-S prism faces are exposed and can be used as catalytic active centers. (see CHIANELLI, r.r.catalyst. Rev.2006,48 (1), 1-41) has increased interest in the study of layered MoS 2 materials, due to its higher hydrogenation activity and good poisoning resistance. Therefore, the use of MoS 2 catalyst for heavy oil hydrogenation and light reactions has become a recent research focus. The catalytic hydrogenation activity of the (Al-Attas T.A.energy fuels 2019,33,7917-7949) MoS 2 material is closely related to the structural characteristics, and the catalytic hydrogenation active center of MoS 2 is mainly positioned on the side surface, so that the surface energy is higher, the surface activity is 0.7J/m 2, the surface activity is unstable, and the active center of the heterogeneous catalytic hydrogenation reaction can be provided. Reducing the size of the catalyst and the number of stacked layers can effectively increase the exposure of the hydrogenation active side position of the MoS 2, thereby obtaining the hydrogenation catalyst with high activity. Heretofore, there are various methods for preparing nano MoS 2, and the morphology of the product is also various. CN 103086436 discloses a preparation method of flower-shaped and rod-shaped nano MoS 2 in a reaction system, wherein inorganic salt is added in the method to prepare flower-shaped and rod-shaped nano MoS 2 in an auxiliary regulation and control mode. CN201410436988.6 discloses a method for hydrothermally synthesizing uniform MoS 2 nanometer flower spheres by using citric acid as complexing agent. CN2015108639802 discloses a method for hydrothermally synthesizing polyhedral hollow MoS 2 particles assisted by ionic liquid. CN201410758657.4 discloses a method for preparing MoS 2 microsphere in reverse microemulsion system. The MoS 2 material is synthesized by wet chemical synthesis, the size of the nano-sheet stacking assembly is in the order of hundreds of nanometers or even micrometers, and the number of nano-sheet stacking layers is large, so that the exposure of active sites is not facilitated. However, since the MoS 2 nanoplatelets produced during wet synthesis have extremely high surface energy, they are agglomerated into micro/nanospheres, nanoflower, hollow cages, etc. morphology during crystallization to reduce the surface energy, which undoubtedly results in many catalytically active sites being embedded and covered. In addition, the stability of the self-agglomerated MoS 2 material in a heavy oil slurry bed hydrogenation system at high temperature and high pressure is also to be improved. An improvement to the above problems is to anchor the MoS 2 nanoplatelets to the nanomaterial surface by chemical action to reduce the surface energy, avoiding self-agglomeration of the MoS 2 nanoplatelets. The preparation of the high-activity MoS 2 catalyst is realized through the chemical anchoring effect, so that the active site can be furthest exposed, and the high stability of the catalyst in a high-temperature high-pressure system can be ensured. Disclosure of Invention The invention aims to solve the problems and provide a preparation method of a MoS 2@SnS2@SnO2 nano material with a core-shell structure. The method adopted by the invention is as follows: 1. Preparing a solution, namely dispersing the SnO 2 nano material into water, low-carbon alcohol or alcohol amine solvent, and sequentially dissolving a sulfur source, a tin source and a molybdenum source into the solvent to form uniform suspension. 2. And (3) crystallizing, namely transferring the suspension into a closed crystallizing system, and performing crystallizing at 120-220 ℃ under 0.01-5.0 MPa for 3-72 h by microwave or electric heating to perform hydrothermal or solvothermal crystallization. 3. Separating the product by adopting conventional separation means such as suction filtration and centrifugation, washing the precipitate with deionized water and absolute ethyl alcohol, and vacuum or freeze-drying to obtain the black MoS 2@SnS2@SnO2 nano material which sequentially coats the SnS 2 and MoS 2 shells by taking SnO 2 as a core. The SnO 2 nano material is one or a mixture of more than two of self-made or commercial (111) high-energy-surface-exposed SnO 2 nano materials, the sulfur source is one or a mixture of more than two of sodium sulfide, potassium sulfide, ammonium thiocya