阅读说明：本技术 一种二维金属框架有机材料制备方法及其制备的二维金属框架有机材料 (Preparation method of two-dimensional metal frame organic material and two-dimensional metal frame organic material prepared by same ) 是由 覃晓丽 许思宇 唐带丽 苏招红 蒋红梅 于 2019-10-15 设计创作，主要内容包括：本发明公开了一种二维金属框架有机材料制备方法及其制备的二维金属框架有机材料,将金属锌盐或铜盐的水溶液和血红素的DMF溶液按照体积比1：1混合搅拌均匀,利用电化学方法在电极表面合成和沉积二维片状的金属有机框架材料Zn-hemin-MOFs和Cu-hemin-MOFs。本发明使用的锌盐和铜盐包括硝酸锌和硝酸铜,氯化锌和氯化铜、硫酸锌和硫酸铜等,使用的血红素包括血红素及其衍生物。本发明技术方案具有简单易行、绿色环保,与同类二维金属有机框架材料相比具有尺寸可调的优点。(The invention discloses a preparation method of a two-dimensional metal framework organic material and the prepared two-dimensional metal framework organic material, wherein the preparation method comprises the following steps of mixing an aqueous solution of metal zinc salt or copper salt and a DMF (dimethyl formamide) solution of heme according to the volume ratio of 1:1, uniformly mixing and stirring, and synthesizing and depositing two-dimensional flaky metal organic framework materials Zn-hemin-MOFs and Cu-hemin-MOFs on the surface of the electrode by an electrochemical method. The zinc salt and copper salt used in the present invention include zinc nitrate and copper nitrate, zinc chloride and copper chloride, zinc sulfate and copper sulfate, etc., and the heme used includes heme and its derivatives. The technical scheme of the invention is simple and easy to implement, green and environment-friendly, and has the advantage of adjustable size compared with the similar two-dimensional metal organic framework material.)

1. A preparation method of a two-dimensional metal framework organic material is characterized by comprising the following steps:

step 1, polishing a working electrode, sequentially and ultrasonically cleaning the working electrode for 3 minutes by using deionized water, ethanol and deionized water respectively, and drying the working electrode by using air;

step 2, dissolving zinc/copper salt in deionized water to prepare solution A, weighing heme and dissolving in DMF to prepare solution B, and mixing A, B solutions according to a volume ratio of 1:1, uniformly mixing, and stirring at room temperature for a period of time to prepare a deposition solution;

and 3, placing the working electrode processed in the step 1 in the deposition solution prepared in the step 2, and applying negative potential deposition to the working electrode by adopting a three-electrode method to obtain the Zn-hemin-MOFs or Cu-hemin-MOFs two-dimensional sheet material.

2. The method for preparing a two-dimensional metal frame organic material as claimed in claim 1, wherein: the working electrode in the step 1 is a glassy carbon electrode, an ITO electrode or a graphite electrode.

3. The method for preparing a two-dimensional metal frame organic material as claimed in claim 1, wherein: in the step 2, the zinc/copper salt is zinc nitrate, copper nitrate, zinc chloride, copper chloride, zinc sulfate or copper sulfate, and the concentration of the aqueous solution of the zinc/copper salt is 0.1 mg/mL-500 mg/mL.

4. The method for preparing a two-dimensional metal frame organic material as claimed in claim 1, wherein: in step 2, the heme is hemin or hemin, and the concentration of the heme in DMF solution is 0.01 mg/mL-100 mg/mL.

5. The method for preparing a two-dimensional metal frame organic material as claimed in claim 1, wherein: the stirring time in the step 2 is 10 min-120 min, preferably 60 min.

6. The method for preparing a two-dimensional metal frame organic material as claimed in claim 1, wherein: in step 3, the negative potential is applied in the range of-0.9V to-1.7V, preferably-1.3V.

7. The method for preparing a two-dimensional metal frame organic material as claimed in claim 1, wherein: the deposition time in the step 3 is 50 s-7200 s.

8. A two-dimensional metal-framed organic material prepared according to the method of any one of claims 1-7.

Technical Field

The invention relates to a metal-organic framework material, in particular to a preparation method of a two-dimensional sheet material Zn-hemin-MOFs or Cu-hemin-MOFs and the two-dimensional sheet metal-organic framework material prepared by the same.

Background

Two-dimensional materials were proposed with the success of separating single atomic layers of graphene materials by mechanical exfoliation in 2004 under the geom group of University of Manchester. Two-dimensional materials are an emerging class of materials with sheet-like structures with lateral dimensions greater than 100 nm, but with thicknesses of only a single atom or a few atoms thick, such as nano-films, superlattices, quantum wells. Since the discovery of single-layer graphene in 2004, the development of two-dimensional materials has yielded fruitful results in as little as a decade. Two-dimensional materials have attracted extensive scientific attention due to their unique band structures, higher electron mobility, excellent optical and electrical properties, etc.

Metal-organic framework Materials (MOFs) have many unique properties, such as highly ordered pore structure, high porosity, large specific surface area, and adjustable structure [ Stassen, i.; burtch, n.; talin, a.; falcaro, p.; allendorf, m.; ameloot, R., chem.Soc.Rev.2017,46,3185-3241. On this basis, two-dimensional MOF materials also have more highly available active sites due to their ultra-thin thickness and extremely large specific surface area [ Peng, y; li, Y.; ban, y.; yang, W.; angew. chem. int. ed.2017,56,1-6 ]. At present, two-dimensional MOFs materials are widely used in the fields of catalysis, gas separation, sensors and the like, and show better performance.

Conventional metal organic frameworks are generally synthesized by evaporative solvent methods, diffusion methods, hydrothermal or solvothermal methods, ultrasonic and microwave methods, and the like. Researchers in the basf laboratory in 2005 reported that a metal organic framework was synthesized by an electrochemical method for the first time, and in recent years, the electrochemical method is adopted by more and more researchers due to the advantages of simple preparation and environmental friendliness. However, the study was mainly focused on the electrochemical synthesis of HKUST-1.

Disclosure of Invention

The invention aims to provide a preparation method of a two-dimensional sheet material Zn-hemin-MOFs or Cu-hemin-MOFs and a two-dimensional sheet metal organic framework material prepared by the same.

In order to achieve the purpose of the invention, the invention provides a preparation method of a two-dimensional metal framework organic material, which comprises the following steps:

step 1, polishing a working electrode, sequentially and ultrasonically cleaning the working electrode for 3 minutes by using deionized water, ethanol and deionized water respectively, and drying the working electrode by using air;

step 2, dissolving zinc/copper salt in deionized water to prepare solution A, weighing heme (hemin) and dissolving in DMF (N, N-dimethylformamide) to prepare solution B, and mixing A, B solutions according to a volume ratio of 1:1, uniformly mixing, and stirring at room temperature for a period of time to prepare a deposition solution;

and 3, placing the working electrode processed in the step 1 in the deposition solution prepared in the step 2, and applying negative potential deposition to the working electrode by adopting a three-electrode method to obtain the Zn-hemin-MOFs or Cu-hemin-MOFs two-dimensional sheet material.

The working electrode in the step 1 is a glassy carbon electrode, an ITO electrode or a graphite electrode. Methods of grinding the working electrode include dry grinding and wet grinding.

In the step 2, the zinc/copper salt is zinc nitrate, copper nitrate, zinc sulfate, copper sulfate, zinc chloride or copper chloride, and the concentration of the aqueous solution of the zinc/copper salt is 0.1 mg/mL-500 mg/mL.

In step 2, the heme is hemin or hemin, and the concentration of the heme in DMF solution is 0.01 mg/mL-100 mg/mL.

The stirring time in the step 2 is 10 min-120 min, preferably 60min, and the negatively charged ligand ions and the positively charged metal ions can be better electrostatically attracted to each other through stirring.

In step 3, the negative potential is applied in the range of-0.9V to-1.7V, preferably-1.3V. The applied negative potential can generate OH^-To control the rate of deprotonation and crystallization of the carboxyl groups of the ligand to allow for the desired growth of the metal-organic framework on the electrode surface.

The deposition time in the step 3 is 50 s-7200 s. The different deposition time causes the nucleation rate of the metal organic framework material to be different, so that the generated crystal structure and size are different.

Based on the same inventive concept, the invention provides the two-dimensional metal organic framework material prepared by the method.

The two-dimensional metal organic framework material prepared by the invention is characterized by a transmission electron microscope scanning electron microscope, and as can be seen from fig. 1-3, the two-dimensional metal organic framework material prepared by the invention has a two-dimensional lamellar structure, and the size of the two-dimensional metal organic framework material can be artificially regulated and controlled along with the setting of the deposition time.

The preparation method has the characteristics of simple and convenient operation, good universality, environmental protection, easy acquisition of raw materials, quick preparation and the like, realizes the preparation of Zn-MOFs and Cu-MOFs 2D metal organic framework materials taking the heme as a ligand, obtains satisfactory results in structural characterization, and can be widely used for the electrochemical preparation of metal organic frameworks taking the heme and analogues thereof as ligands.

Drawings

FIG. 1: a transmission electron microscope characterization image (deposition time is 1200s) of the Zn-hemin-MOFs two-dimensional material obtained in the first embodiment of the invention after ultrasonic stripping;

FIG. 2: according to the preparation method, a scanning electron microscope representation picture (deposition time is 1200s) of the Zn-hemin-MOFs two-dimensional material prepared in the first embodiment of the invention on the surface of an electrode is obtained;

FIG. 3: the invention embodiment I prepares an XPS characterization chart of a Zn-hemin-MOFs two-dimensional material.

Detailed Description

The present invention will be described in further detail with reference to examples.