阅读说明：本技术 一种双原子硼修饰的二硫化钼纳米材料及其制备方法和应用 (Diatomic boron modified molybdenum disulfide nano material and preparation method and application thereof ) 是由 曹洋 于 2021-08-19 设计创作，主要内容包括：本发明公开了一种双原子硼修饰的二硫化钼纳米材料及其制备方法和应用,属于半导体二硫化钼纳米材料的掺杂领域。本发明提供了在MoS-(2)上以原子结构精确的方法修饰B-B双原子,实现了以非晶格取代的界面原子掺杂形式合成硼掺杂二硫化钼。(The invention discloses a diatomic boron modified molybdenum disulfide nano material as well as a preparation method and application thereof, belonging to the field of doping of semiconductor molybdenum disulfide nano materials. The invention provides a method for improving MoS 2 The B-B diatom is modified by an atomic structure accurate method, and the boron-doped molybdenum disulfide is synthesized in an interface atom doping mode substituted by an amorphous lattice.)

1. A diatomic boron modified molybdenum disulfide nano material is characterized by comprising a molybdenum disulfide nanosheet, wherein diatomic boron is doped and modified on the molybdenum disulfide nanosheet.

2. The diatomic boron-modified molybdenum disulfide nanomaterial of claim 1, wherein preparation of said molybdenum disulfide nanoplates comprises the steps of: in an oxygen-free inert atmosphere environment, heating a molybdenum disulfide material by using a n-butyllithium/n-hexane mixed solution, and carrying out ultrasonic-assisted chemical stripping and water washing treatment to obtain a single-layer or few-layer molybdenum disulfide nanosheet.

3. The diatomic boron-modified molybdenum disulfide nanomaterial of claim 2, wherein the source of molybdenum disulfide material comprises: the particle size of the block is micron or nano-grade molybdenum disulfide synthesized by a chemical method and a physical method.

4. The diatomic boron-modified molybdenum disulfide nanomaterial of any one of claims 1-3, wherein the step of doping modification of the diatomic boron into the molybdenum disulfide nanoplates comprises: dispersing molybdenum disulfide nanosheets into an organic solvent, adding a diboron compound, heating and reacting for 5-15 h at 80-100 ℃ under the protection of inert gas, reacting the molybdenum disulfide with diboron compound molecules, removing organic components of the diboron compound, simultaneously retaining and modifying diatomic boron on the molybdenum disulfide, and cleaning and drying to obtain a target product.

5. A preparation method of a diatomic boron modified molybdenum disulfide nano material is characterized by comprising the following steps: dispersing molybdenum disulfide nanosheets into an organic solvent, adding a diboron compound, heating and reacting for 5-15 h at 80-100 ℃ under the protection of inert gas, reacting the molybdenum disulfide nanosheets with diboron compound molecules, removing organic components of the diboron compound, simultaneously retaining and modifying diatomic boron on molybdenum disulfide, and cleaning and drying to obtain a target product.

6. The method for preparing the diatomic boron-modified molybdenum disulfide nanomaterial according to claim 5, wherein the preparation of the molybdenum disulfide nanosheets comprises the steps of: in an oxygen-free inert atmosphere environment, heating a molybdenum disulfide material by using a n-butyllithium/n-hexane mixed solution, and carrying out ultrasonic-assisted chemical stripping and water washing treatment to obtain a single-layer or few-layer molybdenum disulfide nanosheet.

7. The method of claim 6, wherein the source of the molybdenum disulfide material comprises: the particle size of the block is micron or nano-grade molybdenum disulfide synthesized by a chemical method and a physical method.

8. The method for preparing the diatomic boron-modified molybdenum disulfide nanomaterial of claim 5, wherein the diboron compound comprises: c₁₂H₂₄B₂O₄、C₁₀H₂₀B₂O₄、C₁₂H₈B₂O₄、B₂(OH)₄And C₈H₂₄B₂N₄One or more of (a).

9. The method for preparing the diatomic boron-modified molybdenum disulfide nanomaterial as claimed in claim 5, wherein the mass ratio of the diboron compound to the molybdenum disulfide nanosheets added is 0.001-0.5.

10. Use of the diatomic boron-modified molybdenum disulfide nanomaterial of any of claims 1-4 and the diatomic boron-modified molybdenum disulfide nanomaterial produced by the method of making the diatomic boron-modified molybdenum disulfide nanomaterial of any of claims 5-9 as a catalyst.

Technical Field

The invention relates to the field of doping of semiconductor molybdenum disulfide nano materials, in particular to a diatomic boron modified molybdenum disulfide nano material and a preparation method and application thereof.

Background

The molybdenum disulfide material has wide application, such as lubrication, thermocatalysis, electrocatalysis and the like, is a potential material of a transistor with excellent performance, and has very important significance for performing controllable modification on the disulfide material. Boron doping is applied to doping of various materials, and can play roles in improving carrier mobility, improving reaction activity of a catalyst, serving as a catalytic reaction active site and the like.

In patent document CN104445413, von willebrand university of Hunan lake, etc., discloses a preparation method of a boron and nitrogen double-doped molybdenum disulfide fluorescent nano material, which is characterized in that boric acid, melamine and molybdenum disulfide are calcined to synthesize boron and nitrogen co-doped molybdenum disulfide. The boron and nitrogen double-doped molybdenum disulfide fluorescent nano material is obtained by doping molybdenum disulfide by respectively using boric acid and melamine as a boron source and a nitrogen source, and the fluorescence effect of the boron and nitrogen double-doped molybdenum disulfide fluorescent nano material is effectively improved. The doping mode has requirements on the dispersion degree of the boron source and the nitrogen source, needs calcination treatment, has complex preparation process and high requirements on equipment, and the doping amount is difficult to control.

In a patent document with publication number CN102343260, liu gang of the institute of metals of the chinese academy of sciences and the like, a method for preparing a boron-doped titanium dioxide crystal containing a specific crystal face is disclosed, and boron can be doped with monatomic boron during the growth of titanium dioxide through partial hydrolysis in the hydrothermal synthesis of titanium boride. In the technical scheme, the titanium dioxide with the specific crystal surface can be doped with boron, the whole treatment process is complex, and the boron doping is influenced by the growth environment of the titanium dioxide.

Patent document No. CN104058389 discloses boron-doped graphene and a preparation method thereof, wherein graphene oxide is irradiated by laser repeatedly for many times, so that the graphene oxide reacts with boron trichloride under the action of laser to realize boron atom doping. The method has the disadvantages that boron atoms cannot be accurately doped on the graphene by laser-induced reaction doping, complex instruments are required, the quality of the substrate graphene is high, the quality of processed samples is low, and the synthesis of a large amount of doped graphene is difficult to realize.

Although boron doping technology is developed in various materials at present, the current method has the problems that the doping amount is difficult to control, the steps are complex, only single-atom boron can be doped, and diatomic boron cannot be doped.

Disclosure of Invention

The invention aims to provide a diatomic boron modified molybdenum disulfide nano material, and a preparation method and application thereof, so as to solve the problem that boron atoms, especially diboron atoms, cannot be accurately introduced into the existing molybdenum disulfide material.

The technical scheme for solving the technical problems is as follows:

the invention provides a diatomic boron modified molybdenum disulfide nano material which comprises a molybdenum disulfide nanosheet, wherein diatomic boron is doped and modified on the molybdenum disulfide nanosheet.

Further, the preparation of the molybdenum disulfide nanosheet comprises the following steps: in an oxygen-free inert atmosphere environment, heating a molybdenum disulfide material by using a n-butyllithium/n-hexane mixed solution, and carrying out ultrasonic-assisted chemical stripping and water washing treatment to obtain a single-layer or few-layer molybdenum disulfide nanosheet.

Further, the molybdenum disulfide material sources include: the particle size of the block is micron or nano-grade molybdenum disulfide synthesized by a chemical method and a physical method.

The molybdenum disulfide material used in the present invention is not limited to bulk molybdenum disulfide, but also includes molybdenum disulfide synthesized according to the relevant chemical (hydrothermal synthesis, chemical vapor deposition), physical methods (atomic layer deposition, magnetic sputtering).

Further, the step of doping and modifying the diatomic boron in the molybdenum disulfide nanosheet comprises: dispersing molybdenum disulfide nanosheets into an organic solvent, adding a diboron compound, heating and reacting for 5-15 h at 80-100 ℃ under the protection of inert gas, reacting the molybdenum disulfide with diboron compound molecules, removing organic components of the diboron compound, simultaneously retaining and modifying diatomic boron on the molybdenum disulfide, and cleaning and drying to obtain a target product.

In the present invention, the organic solvent includes one or more of ethanol, methanol, benzene, toluene, acetone, acetonitrile, n-hexane, and ethyl acetate.

The invention provides a preparation method of a diatomic boron modified molybdenum disulfide nano material, which comprises the following steps: dispersing molybdenum disulfide nanosheets into an organic solvent, adding a diboron compound, heating and reacting for 5-15 h at 80-100 ℃ under the protection of inert gas, reacting the molybdenum disulfide nanosheets with diboron compound molecules, removing organic components of the diboron compound, simultaneously retaining and modifying diatomic boron on molybdenum disulfide, and cleaning and drying to obtain a target product.

In the present invention, the organic solvent includes one or more of ethanol, methanol, benzene, toluene, acetone, acetonitrile, n-hexane, and ethyl acetate.

Further, the preparation of the molybdenum disulfide nanosheet comprises the following steps: in an oxygen-free inert atmosphere environment, heating a molybdenum disulfide material by using a n-butyllithium/n-hexane mixed solution, and carrying out ultrasonic-assisted chemical stripping and water washing treatment to obtain a single-layer or few-layer molybdenum disulfide nanosheet.

Further, the molybdenum disulfide material sources include: the particle size of the block is micron or nano-grade molybdenum disulfide synthesized by a chemical method and a physical method.

The molybdenum disulfide material used in the present invention is not limited to bulk molybdenum disulfide, but also includes molybdenum disulfide synthesized according to the relevant chemical (hydrothermal synthesis, chemical vapor deposition), physical methods (atomic layer deposition, magnetic sputtering).

Further, the diboron compound comprises: c₁₂H₂₄B₂O₄、C₁₀H₂₀B₂O₄、C₁₂H₈B₂O₄、B₂(OH)₄And C₈H₂₄B₂N₄One or more of (a).

Further, the adding mass ratio of the diboron compound to the molybdenum disulfide nanosheet is 0.001-0.5.

The invention also provides the diatomic boron modified molybdenum disulfide nanomaterial and application of the diatomic boron modified molybdenum disulfide nanomaterial prepared by the preparation method of the diatomic boron modified molybdenum disulfide nanomaterial as a catalyst. The diatomic boron modified molybdenum disulfide nano material is prepared by reacting a diboron compound containing a B-B bond with molybdenum disulfide nanosheets to remove organic components of the diboron compound, and simultaneously, diatomic boron remains and is modified on molybdenum disulfide. According to the invention, boron atoms are introduced into molybdenum disulfide in a boron modification mode, and the introduction mode is a diboron atom. The introduction mode is different from the common doping mode, the boron element doping is introduced in a mode of replacing sulfur atom sites, and the physical property and the catalytic property of the molybdenum disulfide can be regulated and controlled to a certain degree. The introduction mode of the application is to modify the sulfur atom nearby by chemical bonding and retain the intrinsic sulfur atom. In addition, the diatomic boron containing B-B bonds is introduced, compared with the common monoatomic boron, the diatomic boron can better influence and regulate the intrinsic physical property and catalytic property of the molybdenum disulfide, and simultaneously can further modify metal atoms with catalytic action on diatomic boron sites.

According to the preparation reaction of the molybdenum disulfide nanosheet, n-butyl lithium reagent is needed to treat disulfide, and in the process, n-butyl lithium and molybdenum disulfide are subjected to oxidation reduction reaction to reduce molybdenum disulfide and cause molybdenum disulfide to contain a large amount of negative charges, so that in the subsequent reaction process with a diatomic boron-containing diboron compound, abundant electrons in molybdenum disulfide can be subjected to oxidation reduction reaction with molybdenum disulfide, and the diatomic boron molecules are reduced to diatomic boron and modified on molybdenum disulfide. The step can be carried out by heating with the redox reaction of the diboron compound, and diatomic boron modification can be carried out well at the preferred temperature of 80-100 ℃.

The invention has the following beneficial effects:

the invention aims to develop a molybdenum disulfide (MoS)₂) The BB diatomic structure is modified by an atomic structure precise method, compared with the previously reported technology, the method is improved, boron is doped to replace a sulfur atom site in the previous work, and the boron atom is modified near the sulfur atom by chemical bonding, so that the doping form is different. The doping method is usually carried out in a mode of lattice substitution by doping atoms, and the doping method is doped in an interfacial chemisorption mode in the invention, and the positions and chemical bonding modes of the atoms are different. Meanwhile, the boron atoms are doped in a diatomic form with a defined structure in the invention. Therefore, compared with the previous reports, the boron doping of the molybdenum disulfide is realized in the form of interface atom doping substituted by amorphous lattices. The doping process causes lattice distortion to be generated near the doping site, the crystal phase of the molybdenum disulfide is promoted to be converted from a semiconductor crystal phase 2H to a metal phase 1T, and the conductivity and the electrocatalytic activity of the metal phase 1T of the molybdenum disulfide are better than those of the 2H crystal phase, so that the conductivity of the molybdenum disulfide is improved due to the modification of the diatomic boron, and the electrocatalytic activity is further improved. The doping atoms modify the interface rather than doping the lattice sitesThe compound can be used as a catalytic reaction active site for electrocatalytic and thermocatalytic reactions, such as hydrogen production by water decomposition, ammonia preparation by nitrogen reduction, and the like.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a raman spectrum of the diatomic boron-modified molybdenum disulfide nanomaterial prepared in example 1 of the present invention;

FIG. 2 is an X-ray crystallography data diagram (XRD) of the diatomic boron modified molybdenum disulfide nanomaterial prepared in example 1 of the present invention;

FIG. 3 is a nuclear magnetic diagram of a diatomic boron-modified molybdenum disulfide nanomaterial prepared in example 1 of the present invention;

fig. 4 is an infrared spectrum of the diatomic boron-modified molybdenum disulfide nanomaterial prepared in example 1 of the present invention.

Detailed Description

The principles and features of the present invention are described below in conjunction with the embodiments and the accompanying drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

Mixing 1 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Then washing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nano single layer or few layer MoS₂And (3) nano materials. Then 100mg of exfoliated MoS₂Dispersing in methanol solvent, adding 200mg C₁₂H₈B₂O₄Heating the mixture to 80 ℃ under the protection of Ar atmosphere for reacting for 8h, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

By the boron-doped MoS obtained₂The prepared modification is carried out on a glassy carbon electrode for electrocatalytic water decomposition reaction test, and the result shows that the electrocatalytic effect is more than that of the unmodified MoS₂The electrocatalytic performance of (2) is better. The electrochemical performance test result shows that the boron is doped with MoS₂The electrochemical water decomposition activity is obviously improved, and the current density is 10mA cm^-2The electro-catalysis overpotential is reduced by 15 percent, the electric energy required for preparing the hydrogen is effectively reduced, and when the current density is 10mA cm^-2Exfoliation of MoS undoped with boron atoms₂MoS doped with diboron atoms₂The overpotential of the water decomposition hydrogen production reaction is 260mV and 210mV respectively.

Doping boron with MoS₂Performance tests were performed, and Raman spectrum results in FIG. 1 show that BB diboron atom modification leads to MoS₂The crystalline phase of (a) is converted from a 2H semiconductor to a 1T metal phase. The X-ray diffraction peak data results of fig. 2 show that the diboron atom modification results in MoS₂The crystal structure of (a) is significantly changed. The nuclear magnetic results in fig. 3 show that the heat treatment process resulted in a more pronounced chemical shift peak intensity of the boron atoms as demonstrated by the solid nuclear magnetic data, which corresponds to good binding of boron to disulfide. The infrared spectroscopy characterization results of fig. 4 show that the heat treatment process results in the elimination of the organic component of the diboron organic molecule, forming a diatomic boron modification.

Example 2

Mixing 1 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Then washing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nano single layer or few layer MoS₂And (3) nano materials. Then 100mg of exfoliated MoS₂Dispersing in methanol solvent, adding 100mg C₁₂H₈B₂O₄Heating the mixture to 80 ℃ under the protection of Ar atmosphere for reaction for 10h, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

Example 3

Mixing 1 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Then washing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nano single layer or few layer MoS₂And (3) nano materials. Subsequently 20mg of exfoliated MoS₂Dispersing in methanol solvent, adding 200mg C₁₂H₈B₂O₄Heating the mixture to 80 ℃ under the protection of Ar atmosphere for 2 hours for reaction, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

Example 4

Mixing 1 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Then washing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nano single layer or few layer MoS₂And (3) nano materials. Then 100mg of exfoliated MoS₂Dispersing in methanol solvent, adding 200mg C₁₂H₈B₂O₄Heating the mixture to 100 ℃ under the protection of Ar atmosphere for reacting for 8h, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

Example 5

0.5 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Then washing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nano single layer or few layer MoS₂And (3) nano materials. Then 100mg of exfoliated MoS₂Dispersing in methanol solvent, adding 200mg C₁₂H₈B₂O₄Heating the mixture to 100 ℃ under the protection of Ar atmosphere for reacting for 8h, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

Example 6

0.2 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Followed by steamingWashing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nanometer single layer or few layer MoS₂And (3) nano materials. Then 100mg of exfoliated MoS₂Dispersing in methanol solvent, adding 200mg C₁₂H₈B₂O₄Heating the mixture to 100 ℃ under the protection of Ar atmosphere for reacting for 8h, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

Example 7

Mixing 1 g of nano MoS₂The powder was dispersed in 100mL of a cyclohexane solvent containing n-butyllithium, and the mixture was heated to 80 ℃ under an Ar atmosphere for 2 days. Then washing with distilled water, and performing ultrasonic treatment for 1h to obtain stripped nano single layer or few layer MoS₂And (3) nano materials. Then 100mg of exfoliated MoS₂Dispersing in methanol solvent, adding 200mg C₁₂H₂₄B₂O₄Heating the mixture to 80 ℃ under the protection of Ar atmosphere for reacting for 8h, and then washing the obtained product by ethanol to obtain the MoS modified by the double B atoms₂A material.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.