CN-122025431-A - Cobalt and nitrogen co-doped carbon nanotube composite material, preparation method and application thereof, electrode material and application thereof

CN122025431ACN 122025431 ACN122025431 ACN 122025431ACN-122025431-A

Abstract

The invention relates to the field of desalination, and discloses a cobalt and nitrogen co-doped carbon nano tube composite material, a preparation method and application thereof, an electrode material and application thereof. The method comprises the steps of S1, mixing carbon nanotubes with a nitrogen-containing compound for hydrothermal reaction to obtain a hydrothermal reaction product, S2, contacting the hydrothermal reaction product with cobalt salt, adding a reducing agent under alkaline conditions for reduction reaction to obtain a solid phase and a reducing solution, and then carrying out heat treatment on the solid phase. According to the method, the carbon nano tube is coated by the nitrogen-containing compound, and then the cobalt element is doped, so that the cobalt and nitrogen co-doped carbon nano tube composite material prepared by the method has high specific capacitance, the desalination performance is remarkably improved, the preparation method is simple and convenient, the production cost is low, and the application value and the development prospect are high.

Inventors

Zhang Daiyang
LI HAILONG
CAO ZONGLUN
SUN JIE
QIN QIMING
GUO MINWEN

Assignees

中国石油化工股份有限公司
中石化(北京)化工研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20241111

Claims (10)

1. A method for preparing a cobalt and nitrogen co-doped carbon nanotube composite material, the method comprising: s1, mixing a carbon nano tube and a nitrogen-containing compound for hydrothermal reaction to obtain a hydrothermal reaction product; S2, contacting the hydrothermal reaction product with cobalt salt, adding a reducing agent under alkaline conditions for reduction reaction to obtain a solid phase and a reducing solution, and then carrying out heat treatment on the solid phase.
2. The preparation method according to claim 1, wherein the mass ratio of the carbon nanotubes to the nitrogen-containing compound is 1:1-2, preferably 1:1-1.5; and/or the nitrogen-containing compound is selected from at least one of dicyandiamide, ethylenediamine and melamine; and/or the hydrothermal reaction conditions comprise that the hydrothermal temperature is 60-80 ℃ and the hydrothermal time is 1-2h.
3. The preparation method according to claim 1 or 2, wherein the mass ratio of cobalt salt to hydrothermal reaction product is 1:1-3, preferably 1:1-2, on a dry basis; and/or the cobalt salt is selected from at least one of cobalt acetate, cobalt chloride, cobalt nitrate and hydrates thereof.
4. The method according to claim 1 or 2, wherein in step S2, the reducing agent is selected from at least one of NaBH 4 solution, sodium citrate and ascorbic acid; And/or the conditions of the reduction reaction comprise a temperature of 25-30 ℃, a reaction time of 1-2h and a pH value of 10-12.
5. The method according to claim 1 or 2, wherein the conditions of the heat treatment comprise heating the solid phase to 600-800 ℃ at a heating rate of 8-15 ℃ per minute under a protective atmosphere and maintaining the temperature for 2-4 hours; And/or the protective atmosphere is nitrogen and/or inert gas.
6. A cobalt and nitrogen co-doped carbon nanotube composite material, characterized in that it is produced by the production method according to any one of claims 1 to 5.
7. An electrode material, characterized in that the electrode material comprises a conductive agent, a binder and an active substance; Wherein the active substance is the cobalt and nitrogen co-doped carbon nano tube composite material as claimed in claim 6.
8. The electrode material of claim 7, wherein the conductive agent is selected from acetylene black and/or conductive graphite; and/or the binder is selected from polyvinyl alcohol solution and/or polyvinylidene fluoride.
9. The electrode material according to claim 7 or 8, wherein the mass fraction of the conductive agent is 80-90wt%, the mass fraction of the binder is 5-10wt%, and the mass fraction of the active material is 5-10wt%, based on the total mass of the conductive agent, binder, and active material.
10. Use of the cobalt and nitrogen co-doped carbon nanotube composite of claim 6 or the electrode material of any one of claims 7-9 in the desalination field.

Description

Cobalt and nitrogen co-doped carbon nanotube composite material, preparation method and application thereof, electrode material and application thereof Technical Field The invention relates to the field of desalination, in particular to a cobalt and nitrogen co-doped carbon nano tube composite material, a preparation method and application thereof, an electrode material and application thereof. Background With the rapid development of global economy, the problem of fresh water shortage is increasingly serious. Therefore, water treatment technology and sea water desalination technology are increasingly paid attention to, and technologies such as multi-effect distillation, electrodialysis, reverse osmosis, ion exchange and the like are continuously developed, but the technologies still have certain defects such as overhigh energy consumption, strict operation conditions, high production cost and the like. The capacitive desalting technology based on the double-layer capacitance mechanism adsorbs ions through the double-layer electrode, is easy to regenerate and has high desorption rate, and the external electrode is generally not more than 2V in the desalting process to prevent side reaction, so that the energy-saving effect is good. Therefore, the technology has the advantages of low production cost, cleanness, high efficiency, safe operation, simple maintenance and the like, and has good application prospect. The electrode material is the most critical factor affecting the effect of capacitive desalination, and carbon-based materials are considered to be the most ideal electrode materials due to their high specific surface area, good conductivity, and stable chemical properties. Among them, a Carbon Nanotube (CNT) material is an electrode material with a promising development prospect. Compared with activated carbon with high specific surface area, the specific surface area of the carbon nanotube is at a medium level, but the carbon nanotube has high specific capacitance. The specific capacitance of the single-wall carbon nano tube (SWNTs) can reach 180F/g, the specific capacitance of the multi-wall carbon nano tube (MWNTs) can also reach about 90F/g, and the specific surface area of the active carbon with the same specific surface area is only tens of Farads per gram. The characteristic of the carbon nano tube is that the carbon nano tube has a unique mesoporous structure, electrolyte ions can be quickly transferred and form an electric double layer, the specific capacitance is obviously increased, and the characteristic of the carbon nano tube has a great advantage in the capacitance desalination process. However, in order to further increase the desalination efficiency, the multiwall carbon nanotubes still need to be modified to increase their specific capacitance. Disclosure of Invention The invention aims to solve the problems of complex preparation method and low desalination rate of the desalination material in the prior art, and provides a cobalt and nitrogen co-doped carbon nano tube composite material, a preparation method and application thereof, an electrode material and application thereof, wherein the preparation method of the cobalt and nitrogen co-doped carbon nano tube composite material firstly utilizes a nitrogen-containing compound to coat carbon nano tubes, then the cobalt and nitrogen co-doped carbon nano tube composite material prepared by the method is used in the desalination field, has high specific capacitance, obviously improves desalination performance, is simple and convenient in preparation method, has lower production cost and has higher application value and development prospect. In order to achieve the above object, a first aspect of the present invention provides a method for preparing a cobalt and nitrogen co-doped carbon nanotube composite material, wherein the method comprises: s1, mixing a carbon nano tube and a nitrogen-containing compound for hydrothermal reaction to obtain a hydrothermal reaction product; S2, contacting the hydrothermal reaction product with cobalt salt, adding a reducing agent under alkaline conditions for reduction reaction to obtain a solid phase and a reducing solution, and then carrying out heat treatment on the solid phase. In a second aspect, the invention provides a cobalt and nitrogen co-doped carbon nanotube composite material, wherein the composite material is prepared by the preparation method in the first aspect. The third aspect of the present invention provides an electrode material, wherein the electrode material comprises a conductive agent, a binder and an active substance; Wherein the active substance is the cobalt and nitrogen co-doped carbon nano tube composite material according to the second aspect of the invention. In a fourth aspect, the invention provides an application of the cobalt and nitrogen co-doped carbon nano tube composite material according to the second aspect or the electrode material according to the third aspe