阅读说明：本技术 一种纳米级mil-47(v)金属有机框架化合物及其制备方法 (Nanoscale MI L-47 (V) metal organic framework compound and preparation method thereof ) 是由 包淑娟 谌昊 王伟 于 2020-03-20 设计创作，主要内容包括：本发明涉及一种纳米级MIL-47(V)金属有机框架化合物及其制备方法,属于纳米材料技术领域。该化合物按如下方法制备：将二硫化钒和对苯二甲酸加入甲醇溶液中,混匀后加酸调pH值至1-2,然后通过溶剂热法在140-180℃下反应12-36h,接着经洗涤、抽滤、干燥后得到粉末状产物,最后将所述粉末状产物在200-300℃下保温12-36h,即可。该化合物呈棒状,长为150-300nm,宽为15-45nm,尺寸比传统的低了接近两个数量级,将会更进一步拓宽和赋予MIL-47(V)金属有机框架化合物更多的应用,尤其是在气体吸附和催化领域,且其制备方法简单易操作,安全无毒,成本低,适合工业化生产。(The invention relates to a nanometer MI L-47 (V) metal organic framework compound and a preparation method thereof, belonging to the technical field of nanometer materials.)

1. A nanoscale MI L-47 (V) metal-organic framework compound is characterized in that the MI L-47 (V) metal-organic framework compound is rod-shaped, the length of the rod-shaped metal-organic framework compound is 150-300nm, and the width of the rod-shaped metal-organic framework compound is 15-45 nm.

2. The method of claim 1 for the preparation of nanoscale MI L-47 (V) metal organic framework compounds, said method comprising:

adding vanadium disulfide and terephthalic acid into a methanol solution, uniformly mixing, adding acid to adjust the pH value to 1-2, reacting for 12-36h at the temperature of 140-180 ℃ by a solvothermal method, washing, filtering, drying to obtain a powdery product, and finally preserving the heat of the powdery product for 12-36h at the temperature of 200-300 ℃.

3. The method of claim 2, wherein the mass ratio of the vanadium disulfide, terephthalic acid, and methanol solution is from 1:1 to 10: 200.

4. The method according to claim 2, wherein the volume fraction of the methanol solution is 95% or more.

5. The method of claim 2, wherein the blending specifically comprises: performing ultrasonic treatment in an ultrasonic machine with power of more than 100W for more than 5 min.

6. The method of claim 2, wherein the acid is one of hydrochloric acid or dilute sulfuric acid.

7. The method according to claim 2, wherein the washing is in particular: washing with methanol or ethanol.

8. The method according to claim 2, characterized in that the drying is in particular: drying at 40-80 deg.C under vacuum to constant weight.

Technical Field

The invention belongs to the technical field of nano materials, and particularly relates to a nano MI L-47 (V) metal organic framework compound and a preparation method thereof.

Background

The metal-organic framework compound is a crystal material with a regular structure formed by self-assembly of metal ions and multidentate organic ligands through coordination connection. Due to the molecular-level topological structure adjustability and the diversity of metals and organic ligands, various structures and different classes of metal-organic framework compounds are widely prepared in recent years, and the unique characteristics thereofMI L-47 (V) is a metal organic framework material which is firstly synthesized and reported in 2002 by Farrey project group of Lavartin research institute in France, takes vanadium as a metal center, takes 1, 4-dimethyl phthalate as a ligand and has a three-dimensional framework structure with diamond-shaped pore channels, and has high BET specific surface area (900 m) of the metal organic framework material²G), larger pore diameterIn particular high thermal stability, which makes it of interest to researchers, a great variety of applications around it have been explored successively, in particular in the field of gas adsorption storage and separation, and MI L-47 (V) has shown great application value, especially for H₂、CH₄、H₂The excellent adsorption and storage properties of gases such as S further increase the enthusiasm of researchers for research.

Since organic ligands must coordinate to metal ions, self-assemble, etc. in solution to form metal-organic frameworks, in metal-organic frameworks centered on vanadium, traditional inorganic vanadates, such as sodium vanadate (Na)₃VO₄) Although there has been recent research on MI L-47 (V), most reports continue to use the most primitive method reported in the F é rey group 2002 for the preparation of MI L-47 (V). in this method, vanadium trichloride (VCl) was used to obtain vanadium ions alone in solution₃) As a source of vanadium, VCl₃In addition, the severe reaction conditions of the method also enable the prepared MI L-47 (V) crystal powder to show a huge rod-shaped structure (about 1um thick), and the large particle structure also limits the MI L-47 (V) to fully exert the application potential.

Disclosure of Invention

In view of the above, the present invention provides a nanoscale MI L-47 (V) metal-organic framework compound, and a preparation method of the nanoscale MI L-47 (V) metal-organic framework compound.

In order to achieve the purpose, the invention provides the following technical scheme:

1. a nanoscale MI L-47 (V) metal-organic framework compound is rod-shaped, and has a length of 150-300nm and a width of 15-45 nm.

2. The preparation method of the nanoscale MI L-47 (V) metal-organic framework compound comprises the following steps:

adding vanadium disulfide and terephthalic acid into a methanol solution, uniformly mixing, adding acid to adjust the pH value to 1-2, reacting for 12-36h at the temperature of 140-180 ℃ by a solvothermal method, washing, filtering, drying to obtain a powdery product, and finally preserving the heat of the powdery product for 12-36h at the temperature of 200-300 ℃.

Preferably, the mass ratio of the vanadium disulfide to the terephthalic acid to the methanol solution is 1:1-10: 200.

Preferably, the volume fraction of the methanol solution is 95% or more.

Preferably, the blending specifically comprises: performing ultrasonic treatment in an ultrasonic machine with power of more than 100W for more than 5 min.

Preferably, the acid is one of hydrochloric acid or dilute sulfuric acid.

Preferably, the washing is specifically: washing with methanol or ethanol.

Preferably, the drying specifically comprises: drying at 40-80 deg.C under vacuum to constant weight.

The invention has the beneficial effects that the invention provides the nanometer MI L-47 (V) metal organic framework compound and the preparation method thereof, in the method, the cheap, safe and chemical property mild vanadium disulfide is used as a vanadium source, the vanadium disulfide is dissolved under the acidic condition by adjusting the pH value of a reaction solution, vanadium ions are slowly released, and terephthalic acid and the vanadium ions are coordinated to form the nanometer MI L-47 (V) metal organic framework compound, so that the V with high toxicity, high activity, strong irritation and high price is avoided on one handCl₃The use of (1) makes the whole preparation process safe and nontoxic and low in cost, and on the other hand, avoids the defect that the finally prepared metal organic framework compound has larger size due to violent reaction in the prior art, ensures that the finally prepared MI L-47 (V) metal organic framework compound has the length of 150-300nm and the width of 15-45nm, wherein the pH value is adjusted to 1-2 because the vanadium disulfide cannot be effectively dissolved when the pH value exceeds 2, so that enough free vanadium ions cannot be formed in a reaction system, the purity of the finally prepared compound cannot be ensured, the product is more complex and is doped with vanadium disulfide which is not completely reacted, and when the pH value is less than 1, the vanadium disulfide is dissolved too fast, so that the finally generated MI L-47 (V) metal organic framework compound has overlarge crystals, the crystal structure and the morphology of the compound are influenced, and a heterogeneous phase is generated.

In addition, the method uses a methanol solution as a solvent, the high polarity of the methanol solution can ensure the dissolution of terephthalic acid, and the weak acidity presented by hydroxyl in the molecular formula of the methanol is more favorable for the reaction, so that the finally prepared MI L-47 (V) metal organic framework compound can be ensured to present a more uniform and regular appearance.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic representation of the crystal structure of the nanoscale MI L-47 (V) metal-organic framework compounds prepared in examples 1-3;

FIG. 2 is an XRD pattern of the nanoscale MI L-47 (V) metal-organic framework compound prepared in example 1;

FIG. 3 is a field emission scanning electron microscope image of the nanoscale MI L-47 (V) metal-organic framework compound prepared in example 1;

FIG. 4 is a thermogravimetric plot of the nanoscale MI L-47 (V) metal-organic framework compounds prepared in example 1;

FIG. 5 is a field emission scanning electron microscope image of the nanoscale MI L-47 (V) metal-organic framework compound prepared in example 2;

FIG. 6 is a field emission scanning electron microscope photograph of the nanoscale MI L-47 (V) metal-organic framework compound prepared in example 3;

FIG. 7 is an XRD pattern of the product prepared in comparative example 1;

FIG. 8 is a field emission scanning electron microscope photograph of the product prepared in comparative example 1;

FIG. 9 is an XRD pattern of the product prepared in comparative example 2;

FIG. 10 is a field emission scanning electron microscope photograph of the product prepared in comparative example 2.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.