CN112165845A

CN112165845A - Non-toxic preparation method of self-supporting all-carbon electrode loaded with MOF (Metal organic framework) 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

The invention discloses a non-toxic preparation method of a self-supporting all-carbon electrode loaded with MOF derived carbon, which comprises the following steps: dissolving zinc nitrate hexahydrate in deionized water, dissolving 2-methylimidazole in deionized water, mixing the zinc nitrate solution and the imidazole solution under the condition of stirring, and stirring. After standing, performing solid-liquid separation on the solution by using a centrifugal machine, washing the obtained sample by using deionized water, and drying the sample into powder in a forced air drying oven for later use. And taking the 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 hair is stained with the ZIF sample. And finally, putting the ground sample into a crucible, and putting the crucible into a tubular furnace for calcining at 900 ℃ to obtain a finished product. The invention belongs to the technical field of electrode materials, and the finished product prepared by the method has good electromagnetic wave absorption capability, can be used as a self-supporting electrode, and has wide application prospect.

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 a self-supporting all-carbon electrode loaded with MOF-derived carbon is characterized by comprising the following steps of:

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

(2) mixing a zinc nitrate solution and an imidazole solution under the condition of stirring;

stirring for 5min;

(3) standing the mixed solution obtained in the step 2 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 the dried ZIF sample obtained in the step 3 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, and adding phoenix tree seed for full grinding;

(5) putting the sample prepared in the step 4 into a crucible, then putting the crucible into a tubular furnace for calcination, preserving heat at a certain temperature, cooling to room temperature, and taking out;

(6) and (4) heating the wave-absorbing material prepared in the step (5) and paraffin according to a certain proportion until the materials are uniformly mixed, and pressing the materials into a ring-shaped pipe.

2. The method of claim 1, wherein the concentration of zinc ions in the solution 1 is 4.6875 mmol/ml.

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

4. The method of claim 1, wherein the molar ratio of the components in the composition formed by mixing solution 1 and solution 2 is zinc ion to 2-methylimidazole to water = 1: 70: 1238.

5. The method of claim 1, wherein sufficient grinding is performed to allow each phoenix tree seed to be stained with ZIF samples.

6. The method according to claim 1, wherein the dried material is transferred to a tube furnace to be heated from room temperature to 900 ℃ at a heating rate of 5 ℃/min and is maintained at 900 ℃ for 120 min.

7. The method according to claim 1, characterized in that the wave-absorbing material is prepared by mixing 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.