阅读说明：本技术 一种碳化铁-多孔碳复合材料及其制备方法和应用 (Iron carbide-porous carbon composite material and preparation method and application thereof ) 是由 包淑娟 朱洪久 李秋林 于 2019-10-31 设计创作，主要内容包括：本发明涉及一种碳化铁-多孔碳复合材料及其制备方法和应用,属于纳米材料技术领域,该复合材料由多孔碳和包覆在多孔碳中的碳化铁纳米颗粒组成,碳化铁纳米颗粒具有核壳结构。在制备该复合材料时,以金属掺杂的高聚物为模板,通过一步碳化得到。该材料中由于具有核壳结构的碳化铁被包覆在多孔碳中,其抗腐蚀性能得到进一步提升,另外,位于外层的多孔碳具有高的比表面积和独特的孔道结构等特点,使最终制备的复合材料集碳化铁特殊的电学性质以及多孔碳良好的传热性能等优点于一体,能够在催化、储能等领域具有广泛的应用前景。该复合材料制备方法简单易操作,且成本低,适合扩大化生产。(The invention relates to an iron carbide-porous carbon composite material and a preparation method and application thereof, belonging to the technical field of nano materials. When the composite material is prepared, the metal-doped high polymer is taken as a template and is obtained through one-step carbonization. In the material, the iron carbide with the core-shell structure is coated in the porous carbon, so that the corrosion resistance of the material is further improved, and in addition, the porous carbon positioned on the outer layer has the characteristics of high specific surface area, unique pore channel structure and the like, so that the finally prepared composite material integrates the advantages of special electrical property of the iron carbide, good heat transfer performance of the porous carbon and the like, and has wide application prospect in the fields of catalysis, energy storage and the like. The preparation method of the composite material is simple and easy to operate, has low cost and is suitable for expanded production.)

1. The iron carbide-porous carbon composite material is characterized by consisting of porous carbon and iron carbide nanoparticles coated in the porous carbon, wherein the iron carbide nanoparticles have a core-shell structure.

2. The iron carbide-porous carbon composite material according to claim 1, wherein the iron carbide nanoparticles have a particle size of 20 to 30 nm.

3. The iron carbide-porous carbon composite material according to claim 1, wherein the BET specific surface area of the porous carbon is 250-350m ²The pore size is less than or equal to 2 nm.

4. A method of preparing an iron carbide-porous carbon composite according to any one of claims 1 to 3, characterized in that it comprises:

dropwise adding the ferric salt ethanol solution into the 1, 8-diaminonaphthalene ethanol solution under stirring to obtain a reaction solution, continuously stirring the reaction solution for 16-24h, centrifuging to obtain the iron-doped poly-1, 8-diaminonaphthalene, washing and drying the iron-doped poly-1, 8-diaminonaphthalene, heating to 350-plus-fluid temperature of 450 ℃ at the speed of 3-6 ℃/min under a protective atmosphere, then preserving heat for 1-2h, heating to 700-plus-fluid temperature of 1000 ℃ at the speed of 0.5-1.5 ℃/min, then preserving heat for 2-4h, and cooling to obtain the iron carbide-porous carbon composite material.

5. The method according to claim 4, wherein the molar ratio of 1, 8-diaminonaphthalene to iron ions in the reaction solution is 7-12: 1.

6. The method of claim 4, wherein the iron salt in the ethanolic iron salt solution is one of ferric chloride hexahydrate, ferric acetylacetonate, or ferric nitrate nonahydrate.

7. The method as claimed in claim 4, wherein the stirring speed and the stirring continuation speed are both 600-800 r/min.

8. The method according to claim 4, wherein the washing solution used in the washing is ethanol; the drying is vacuum drying at 20-30 deg.C for 12-16 h.

9. The method of claim 4, wherein the protective atmosphere is hydrogen.

10. Use of an iron carbide-porous carbon composite according to any one of claims 1 to 3 in catalysis and/or energy storage.

Technical Field

The invention belongs to the technical field of nano materials, and particularly relates to an iron carbide-porous carbon composite material and a preparation method and application thereof.

Background

The porous carbon material has the characteristics of high specific area, low cost, easy preparation, unique pore channel structure, excellent chemical stability and the like, and is widely used as a lithium battery electrode material, a super capacitor electrode material, a catalyst carrier and the like. At present, there are several methods for synthesizing porous carbon materials: high polymer carbonization, biomass material carbonization, physical and chemical activation, chemical vapor deposition, and the like.

Among these methods, the high polymer carbonization method and the biomass carbonization method are the most widely used methods for preparing porous carbon because of their low cost, easy preparation, and large specific surface area of the produced carbon material. The biomass material carbonization method uses biomass materials as raw materials, but the biomass materials are influenced by different regions and different seasons, so that uncertainty exists, and the prepared materials can be different. The high polymer carbonization method has high repeatability because the high polymer is a specific species during carbonization, simultaneously has a plurality of usable substrates, and can prepare various porous carbons with different specific surface areas, unique pore channel structures and excellent electrochemical performance by a simple method at low cost.

The nano iron carbide is an excellent electro-catalyst and is widely applied to reactions such as electro-catalytic oxygen reduction, hydrogen evolution, oxygen evolution and the like. Because the conductivity of the iron carbide is low, and the porous carbon has excellent conductivity, the catalytic performance of the iron carbide can be further improved after the iron carbide and the porous carbon form a composite material. Moreover, the catalytic performance of the catalyst is greatly improved by doping other transition metals. Therefore, the research and development of the iron carbide-porous carbon composite material can expand the application range of the iron carbide, and simultaneously can ensure that the composite material has wide application prospects in the fields of catalysis, energy storage and the like.

Disclosure of Invention

In view of the above, an object of the present invention is to provide an iron carbide-porous carbon composite material; the second purpose is to provide a preparation method of the iron carbide-porous carbon composite material; the third purpose is to provide the application of the iron carbide-porous carbon composite material in catalysis and/or energy storage.

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

1. the composite material consists of porous carbon and iron carbide nanoparticles coated in the porous carbon, wherein the iron carbide nanoparticles have a core-shell structure.

Preferably, the particle size of the iron carbide nanoparticles is 20-30 nm.

Preferably, the BET specific surface area of the porous carbon is 250-350m ²The pore size is less than or equal to 2 nm.

2. The preparation method of the iron carbide-porous carbon composite material comprises the following steps:

dropwise adding the ferric salt ethanol solution into the 1, 8-diaminonaphthalene ethanol solution under stirring to obtain a reaction solution, continuously stirring the reaction solution for 16-24h, centrifuging to obtain the iron-doped poly-1, 8-diaminonaphthalene, washing and drying the iron-doped poly-1, 8-diaminonaphthalene, heating to 350-plus-fluid temperature of 450 ℃ at the speed of 3-6 ℃/min under a protective atmosphere, then preserving heat for 1-2h, heating to 700-plus-fluid temperature of 1000 ℃ at the speed of 0.5-1.5 ℃/min, then preserving heat for 2-4h, and cooling to obtain the iron carbide-porous carbon composite material.

Preferably, the molar ratio of the 1, 8-diaminonaphthalene to the iron ions in the reaction solution is 7-12: 1.

Preferably, the ferric salt in the ferric salt ethanol solution is one of ferric trichloride hexahydrate, ferric acetylacetonate or ferric nitrate nonahydrate.

Preferably, the stirring speed during stirring and the stirring continuing is both 600-800 r/min.

Preferably, the washing solution used in the washing is ethanol; the drying is vacuum drying at 20-30 deg.C for 12-16 h.

Preferably, the protective atmosphere is hydrogen.

3. The iron carbide-porous carbon composite material is applied to catalysis and/or energy storage.

The invention has the beneficial effects that: the invention provides an iron carbide-porous carbon composite material and a preparation method and application thereof, wherein the iron carbide-porous carbon composite material is a hierarchical composite material formed by porous carbon-coated iron carbide with a core-shell structure, the iron carbide with the core-shell structure is coated in the porous carbon in the material, so that the corrosion resistance of the material is further improved, in addition, the porous carbon positioned at the outer layer has the characteristics of high specific surface area, unique pore channel structure and the like, so that the finally prepared composite material integrates the advantages of special electrical properties of the iron carbide, good heat transfer performance of the porous carbon and the like, and has wide application prospects in the fields of catalysis, energy storage and the like. The preparation method of the composite material is simple and easy to operate, has low cost and is suitable for expanded production.

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 scanning electron micrograph of iron-doped poly-1, 8-diaminonaphthalene prepared in example 1;

FIG. 2 is a scanning electron micrograph of an iron carbide-porous carbon composite prepared in example 1;

FIG. 3 is a transmission electron micrograph of an iron carbide-porous carbon composite prepared in example 1;

FIG. 4 is an XRD pattern of the iron carbide-porous carbon composite prepared in example 1;

FIG. 5 is a graph of the desorption of nitrogen for the iron carbide-porous carbon composite prepared in example 1;

FIG. 6 is a nitrogen pore size distribution plot for the iron carbide-porous carbon composite prepared in example 1;

FIG. 7 is a scanning electron micrograph of an iron carbide-porous carbon composite prepared in example 2;

FIG. 8 is a transmission electron micrograph of an iron carbide-porous carbon composite prepared in example 2;

FIG. 9 is a scanning electron micrograph of an iron carbide-porous carbon composite prepared in example 3;

FIG. 10 is a transmission electron micrograph of an iron carbide-porous carbon composite prepared in example 3;

FIG. 11 is a graph showing the results of an electrocatalytic oxygen reduction performance test of the iron carbide-porous carbon composite prepared in example 1;

FIG. 12 is a graph showing the results of an electrocatalytic oxygen reduction performance test of the iron carbide-porous carbon composite prepared in example 2;

fig. 13 is a graph showing the results of the electrocatalytic oxygen reduction performance test of the iron carbide-porous carbon composite prepared in example 3.

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.