CN112165845A

CN112165845A - A non-toxic preparation method of self-supporting all-carbon electrodes loaded with MOF-derived carbon

Info

Publication number: CN112165845A
Application number: CN202010993629.6A
Authority: CN
Inventors: 丁春艳; 吴松松; 陆美含; 王安英
Original assignee: Shandong University of Technology
Current assignee: Shandong University of Technology
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2021-01-01

Abstract

本发明公开了一种负载MOF衍生碳的自支撑全碳电极的无毒制备方法，包括如下步骤：将六水合硝酸锌溶入去离子水中，将2‑甲基咪唑溶入去离子水中，再将硝酸锌溶液与咪唑溶液在搅拌的条件下混合，搅拌。静置后，使用离心机对溶液进行固液分离,得到的样品用去离子水浸洗，放置于鼓风干燥箱中干燥成粉状备用。再取干燥后的ZIF样品与梧桐絮质量比为2：1，将ZIF样品放入研钵中，加入适量乙二醇使其变稠，再加入梧桐絮，充分研磨使得每根毛毛上都沾上ZIF样品。最后将研磨后的样品放入坩埚中，放入管式炉中进行900℃煅烧，得到成品。本发明属于电极材料技术领域，由此制得的成品具有良好的吸收电磁波的能力，并且可用作自支撑电极，具有广阔的应用前景。The invention discloses a non-toxic preparation method of a self-supporting full carbon electrode loaded with MOF-derived carbon, comprising the following steps: dissolving zinc nitrate hexahydrate in deionized water, dissolving 2-methylimidazole in deionized water, and then The zinc nitrate solution and the imidazole solution were mixed with stirring and stirred. After standing, a centrifuge was used to separate the solution from solid and liquid, and the obtained sample was immersed in deionized water and placed in a blast drying oven to dry into powder for later use. Then take the dried ZIF sample and the mass ratio of sycamore flakes to be 2:1, put the ZIF sample into a mortar, add an appropriate amount of ethylene glycol to make it thicker, then add the sycamore floc, and grind sufficiently so that each hair is stained. on ZIF samples. Finally, the ground samples were put into a crucible, and then put into a tube furnace for calcination at 900°C to obtain a finished product. The invention belongs to the technical field of electrode materials, and the finished product obtained therefrom has good ability of absorbing electromagnetic waves, can be used as a self-supporting electrode, and has broad application prospects.

Description

Non-toxic preparation method of self-supporting all-carbon electrode loaded with MOF (Metal organic framework) derived carbon

Technical Field

The invention provides a non-toxic preparation method of a self-supporting all-carbon electrode loaded with MOF derived carbon, belonging to the technical field of electrode materials.

Background

With the development of science and technology, electronic and electromagnetic equipment is rapidly developed, electromagnetic waves not only affect the normal use of the equipment, but also bring gradually serious electromagnetic pollution, and people are harmed. Therefore, wave-absorbing materials are receiving more and more attention. The method can be applied to electronic products and has a good development prospect in the field of military.

Carbon materials are widely used for preparing wave-absorbing materials due to the advantages of excellent mechanical and electrical properties, convenient material acquisition, small volume and the like, and porous carbon materials are increasingly used for preparing wave-absorbing materials due to the characteristics of rich pore structures, macropores, micropores and mesopores, good electrical conductivity and thermal conductivity, small density, good stability, good electromagnetic loss performance and the like. However, the dielectric constant of a single carbon material is large, which is not favorable for impedance matching and the wave absorption performance is not ideal. The phoenix tree seed-wadding is used as a biological material, the acquisition cost is low, and the wave-absorbing performance after calcination is good, however, the phoenix tree seed-wadding in the prior art is little used as a wave-absorbing material and an electrode. The invention provides a non-toxic preparation method for forming a self-supporting all-carbon electrode loaded with MOF (metal-organic framework material) derived carbon by compounding phoenix tree seed with ZIF (zeolitic imidazolate framework material). Has wide application prospect.

Disclosure of Invention

The invention aims to provide a non-toxic preparation method of a self-supporting all-carbon electrode loaded with MOF derived carbon.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

a non-toxic preparation method of a self-supporting all-carbon electrode loaded with MOF derived carbon specifically comprises the following steps:

(1) 1.17 g (37.5 mmol) of zinc nitrate hexahydrate are dissolved in 8 ml of deionized water, and 22.70 g (2695 mmol) of 2-methylimidazole are dissolved in 80 ml of deionized water;

(2) the zinc nitrate solution was mixed with the imidazole solution with stirring. Stirring for 5min;

(3) standing for 10h, performing solid-liquid separation on the solution by using a centrifugal machine (10000r/min), washing the obtained sample with deionized water for 2 to 3 times, and drying the sample in a forced air drying oven into powder for later use;

(4) taking a dried ZIF sample and the phoenix tree seed in a mass ratio of 2: 1, putting a ZIF sample into a mortar, adding a proper amount of ethylene glycol to thicken the ZIF sample, adding phoenix tree seed, and fully grinding to ensure that each phoenix tree seed is stained with the ZIF sample;

(5) placing the ground sample into a crucible, placing the crucible into a tubular furnace for calcination, introducing nitrogen at a constant speed in the whole process, heating the sample from room temperature to 900 ℃ at the heating rate of 5 ℃/min, preserving the temperature for 120min, cooling the sample to room temperature, and taking the sample out;

(6) the prepared wave-absorbing material is prepared from the following materials: paraffin = 1: 12, heating to mix evenly, pressing into a ring tube with the outer diameter of 7.0mm and the inner diameter of 3.0mm, and testing the wave-absorbing performance.

Compared with other processes, the method has the characteristics that:

(1) the used raw materials have low cost and convenient operation;

(2) the material carbonized at 900 ℃ has better electromagnetic wave absorption capacity, the RL value reaches about-17 dB when the coating thickness is 1.5mm and the frequency is 17GHz, the RL value is-16 dB when the frequency is 12GHz and the coating thickness is 2mm, and the coverage bandwidth is 3.7 GHz;

(3) after the carbon material is compounded with the ZIF material, a series of chemical reactions are generated during calcination, so that the material can be used as a self-supporting electrode material.

Drawings

FIG. 1 is a diagram of a sample of ZIF material prepared from example 1.

Figure 2 is a sample of the wave-absorbing material prepared in example 1.

FIG. 3 is a wave absorption diagram of the sample prepared in example 1.

Detailed Description

The present invention is further illustrated by the following examples.

Example 1

The phoenix tree wadding obtained in the embodiment is used for testing wave-absorbing performance, and the method specifically comprises the following steps: 1.17 g (37.5 mmol) of zinc nitrate hexahydrate are dissolved in 8 ml of deionized water, and 22.70 g (2695 mmol) of 2-methylimidazole are dissolved in 80 ml of deionized water. The zinc nitrate solution was mixed with the imidazole solution with stirring. Stirring for 5 min.

Standing for 10h, performing solid-liquid separation on the solution by using a centrifugal machine (10000r/min), washing the obtained sample with deionized water for 2-3 times, and drying in a forced air drying oven to obtain powder for later use. Taking a dried ZIF sample and the phoenix tree seed in a mass ratio of 2: 1, putting a ZIF sample into a mortar, adding a proper amount of ethylene glycol to thicken the ZIF sample, adding phoenix tree seed, and fully grinding to make each phoenix tree seed be stained with the ZIF sample. And putting the ground sample into a crucible, putting the crucible into a tubular furnace for calcination, introducing nitrogen at a constant speed in the whole process, heating the sample from room temperature to 900 ℃ at the heating rate of 5 ℃/min, preserving the temperature for 120min, cooling the sample to the room temperature, and taking the sample out. The prepared wave-absorbing material is prepared from the following materials: paraffin = 1: 12, heating to mix evenly, pressing into a ring tube with the outer diameter of 7.0mm and the inner diameter of 3.0mm, and testing the wave-absorbing performance.

FIG. 1 is a wave-absorbing performance result diagram of the wave-absorbing material obtained in example 1, and it can be seen that the RL value of each coating thickness exceeds-10 dB, the wave-absorbing degree reaches 90%, the RL value reaches about-17 dB when the coating thickness is 1.5mm and the frequency is 17GHz, the RL value is-16 dB when the frequency is 12GHz and the coating thickness is 2mm, and the coverage bandwidth is 3.7 GHz.

As can be seen by comparing fig. 2 to fig. 3, the prepared ZIF material had turned from white to black after composite calcination with phoenix tree batting.

The above description is only a preferred embodiment of the present invention, and it should be understood by those skilled in the art that the present invention is not limited by the examples, and several modifications and decorations can be made, and these modifications and decorations are also within the scope of the present invention.

Claims

1. a non-toxic preparation method of the self-supporting all-carbon electrode of load MOF-derived carbon, is characterized in that, comprises the steps:

(1) dissolve 1.17 g (37.5 mmol) of zinc nitrate hexahydrate into 8 ml of deionized water to form solution 1, and dissolve 22.70 g (2695 mmol) of 2-methylimidazole into 80 ml of deionized water to form solution 2;

(2) Mix the zinc nitrate solution with the imidazole solution under stirring;

Stir for 5min;

(3) After allowing the mixed solution obtained in step 2 to stand for 10 hours, use a centrifuge (10000r/min) to separate the solution from solid and liquid. The obtained sample is washed with deionized water for 2 to 3 times and placed in a blast drying oven. Dry into powder for later use;

(4) The mass ratio of the dried ZIF sample in step 3 to the sycamore flocculent is 2:1, put the ZIF sample in a mortar, add an appropriate amount of ethylene glycol to make it thicker, and then add the sycamore floc to fully grind;

(5) Put the sample prepared in step 4 into a crucible, then put it into a tube furnace for calcination, keep it at a certain temperature, and take it out after cooling to room temperature;

(6) The wave absorbing material prepared in step 5 and the paraffin are heated according to a certain proportion until they are evenly mixed, and pressed into a ring-shaped tube.

2. The method according to claim 1, wherein the zinc ion concentration in the solution 1 is 4.6875 mmol/ml.

3. The method according to claim 1, wherein the 2-methylimidazole concentration in the solution 1 is 33.6875 mmol/ml.

4. method according to claim 1, is characterized in that, the mol ratio of each composition in the synthetic solution formed after solution 1 is mixed with solution 2 is: zinc ion: 2-methylimidazole: water=1: 70: 1238 .

5. The method according to claim 1, characterized in that, sufficient grinding needs to make ZIF samples all stained on each sycamore floc.

6 . The method according to claim 1 , wherein the dried material is moved to a tube furnace at a heating rate of 5° C./min from room temperature to 900° C. and kept at 900° C. for 120 minutes. 7 .

7. method according to claim 1, is characterized in that the wave absorbing material is heated to mix uniformly according to the ratio of material: paraffin=1:12, is pressed into the annular tube that outer diameter is 7.0mm, and inner diameter is 3.0mm to test absorption. wave performance.