阅读说明：本技术 一种结构可控的多维多孔碳材料及其制备方法 (Structure-controllable multi-dimensional porous carbon material and preparation method thereof ) 是由 仇实 徐晴 刘振凌 钱琛 单丹 杨瑞洪 谢伟 于 2020-06-05 设计创作，主要内容包括：本发明提供一种结构可控的多维多孔碳材料及其制备方法,属于多孔碳材料领域。该方法利用固体钾盐与甲阶酚醛树脂醇液的混合物,在经历溶剂蒸发、低温热处理、高温碳化和活化过程后,自然冷却获得原位热解产物并进行净化处理,制备出一种结构可控的多维多孔碳材料。本发明的优势在于,利用原位热解技术实现对多维多孔碳材料的结构设计和控制,制备工艺简单、操作条件可控、原料价格低廉、反应条件温和,易于实现工业化生产；不需借助额外添加活化剂,即可获得分级孔道,以及可调的比表面积和孔体积；通过设置模板中钾盐与碳源中甲阶酚醛树脂的质量比例,还能实现对三维多孔碳骨架上层叠上不同程度的二维碳片进行有效调控。(The invention provides a structure-controllable multi-dimensional porous carbon material and a preparation method thereof, belonging to the field of porous carbon materials. The method utilizes a mixture of solid potassium salt and resol alcohol solution, and after solvent evaporation, low-temperature heat treatment, high-temperature carbonization and activation processes, the mixture is naturally cooled to obtain an in-situ pyrolysis product and is subjected to purification treatment, so that the structure-controllable multi-dimensional porous carbon material is prepared. The method has the advantages that the structural design and control of the multi-dimensional porous carbon material are realized by utilizing the in-situ pyrolysis technology, the preparation process is simple, the operation condition is controllable, the raw material price is low, the reaction condition is mild, and the industrial production is easy to realize; the hierarchical pore channel, the adjustable specific surface area and the pore volume can be obtained without additionally adding an activating agent; by setting the mass ratio of the sylvite in the template to the resol in the carbon source, the effective regulation and control of two-dimensional carbon sheets with different degrees stacked on the three-dimensional porous carbon skeleton can be realized.)

1. A structure-controllable multi-dimensional porous carbon material and a preparation method thereof are characterized by comprising the following steps:

obtaining solid potassium salt powder, and tightly and uniformly stacking the potassium salt powder into a reactor to be used as a template;

obtaining resol, and preparing the resol into a carbon source with ethanol as a solvent;

adding the carbon source into a template according to a proportion to form a mixture, and sequentially carrying out solvent evaporation and low-temperature heat treatment to obtain a solid compound;

carrying out high-temperature carbonization and activation treatment on the solid compound in an inert atmosphere, and naturally cooling to obtain an in-situ pyrolysis product;

and purifying the in-situ pyrolysis product, and carrying out acid washing, water washing and low-temperature drying treatment in sequence to prepare the structure-controllable multi-dimensional porous carbon material.

2. The preparation method according to claim 1, wherein the potassium salt is selected from one of potassium carbonate and potassium oxalate, or a mixture of potassium carbonate and potassium oxalate.

3. The method according to claim 1, wherein the potassium salt powder has a mass per unit area of 0.1 to 0.5g/cm in the reactor²。

4. The preparation method according to claim 1, wherein the resol resin is a thermosetting alcohol-soluble resin, and the mass percentage of the resol resin in the carbon source is 5-15 wt%.

5. The preparation method of claim 1, wherein the addition amount of the carbon source impregnated template is regulated based on the mass ratio of the potassium salt in the template to the resole phenolic resin in the carbon source being (2:1) - (10: 1).

6. The preparation method according to claim 1, wherein the temperature and the residence time of the low-temperature heat treatment of the solid composite are respectively regulated between 100-140 ℃ and 12-24 h.

7. The preparation method according to claim 1, wherein the temperature and the residence time of the high-temperature treatment of the solid composite are regulated and controlled between 700-900 ℃ and 1-3 h respectively.

8. The method of claim 1, wherein the inert atmosphere is nitrogen or argon.

9. A structurally controllable multi-dimensional porous carbon material, characterized in that the multi-dimensional porous carbon material prepared according to the method of any one of claims 1 to 8.

Background

With the development of novel carbon materials, more requirements are put on the structural design and functional development thereof. The multi-dimensional porous carbon material is a carbon framework which is a carbon wall integrating pore passages with different sizes (micropores, mesopores or macropores) and is also coupled with structures with different dimensions (one-dimensional fibers or two-dimensional films). On one hand, the novel carbon material with the special morphology has rich hierarchical pore channels, can increase the active specific surface area of the material and provide multidirectional electron and ion transmission channels; on the other hand, the multi-dimensional composition can widen the application field of the low-dimensional material in the three-dimensional space. Therefore, the multi-dimensional porous carbon material has potential application prospects in the fields of material science, electronics, biomedicine and environment by virtue of excellent physical and chemical properties of the multi-dimensional porous carbon material.

The current synthetic route for preparing multi-dimensional porous Carbon materials is mainly to structurally couple Carbon materials of different dimensions by using special synthesis processes, such as chemical vapor deposition (Carbon,2015,86,358), liquid phase impregnation (j.mater.chem.a,2014,2,4739), hydrothermal self-assembly (adv.mater.2014,26,4855), and the like. However, the synthesis path requires the preparation of a formed single-dimensional carbon material in advance, the preparation process steps are relatively complicated, the coupled multi-dimensional porous carbon materials have the possibility of untight mutual structural connection, and particularly the micro-morphology of the multi-dimensional porous carbon material is difficult to realize controllable operation. Therefore, a simple and efficient preparation process is developed, so that the designed and constructed multi-dimensional porous carbon material has the morphology characteristic of controllable structure, and the novel carbon material can meet the requirements of special applications.

Disclosure of Invention

The invention provides a structure-controllable multi-dimensional porous carbon material and a preparation method thereof, aiming at solving the problem that a synthesis process of a novel carbon material which is designed and constructed and simultaneously has multi-dimensional and hierarchical pore passages needs complicated preparation steps.

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

a preparation method of a structure-controllable multi-dimensional porous carbon material comprises the following steps:

obtaining solid potassium salt powder, and tightly and uniformly stacking the potassium salt powder into a reactor to be used as a template;

obtaining resol, and preparing the resol into a carbon source with ethanol as a solvent;

adding the carbon source into a template according to a proportion to form a mixture, and sequentially carrying out solvent evaporation and low-temperature heat treatment to obtain a solid compound;

carrying out high-temperature carbonization and activation treatment on the solid compound in an inert atmosphere, and naturally cooling to obtain an in-situ pyrolysis product;

and purifying the in-situ pyrolysis product, and carrying out acid washing, water washing and low-temperature drying treatment in sequence to prepare the structure-controllable multi-dimensional porous carbon material.

Preferably, the potassium salt can be one of potassium carbonate and potassium oxalate, or a mixture of potassium carbonate and potassium oxalate.

Further preferably, the potassium salt powder has a mass per unit area in the reactor of 0.1 to 0.5g/cm²I.e. 1m²The mass of the potassium salt uniformly covered on the bottom area of the reactor is 1-5 kg.

In a preferred scheme, the resol is a thermosetting alcohol-soluble resin, and the mass percentage of the resol in the carbon source is 5-15 wt%.

Preferably, the addition amount of the carbon source impregnation template is regulated and controlled based on the mass ratio of the potassium salt in the template to the resol in the carbon source of (2:1) - (10: 1).

In a preferable scheme, the temperature and the residence time of the low-temperature heat treatment of the solid compound are respectively regulated and controlled between 100-140 ℃ and 12-24 hours.

In the preferable scheme, the temperature and the residence time of the high-temperature treatment of the solid compound are respectively regulated and controlled between 700-900 ℃ and 1-3 h.

Preferably, the inert atmosphere is nitrogen or argon.

The multidimensional porous carbon material with a controllable structure is prepared by the method.

The invention has the beneficial effects that:

(1) the invention realizes the structure control of the multidimensional porous carbon material by utilizing the in-situ pyrolysis technology, has simple preparation process, controllable operation condition, low raw material price and mild reaction condition, and is easy to realize industrial production.

(2) The invention fully utilizes the potassium salt component, on one hand, the function of the potassium salt component in the synthesis process is exerted, on the other hand, the activation of the potassium salt component on the wall of the carbonaceous pore is realized, and finally, the synthesis steps are obviously simplified.

(3) The multi-dimensional porous carbon material prepared by the invention shows the cross-linking composition of the two-dimensional carbon sheet and the three-dimensional porous carbon skeleton, the special micro-morphology can realize the construction and regulation of the two-dimensional carbon sheets with different degrees stacked on the three-dimensional porous carbon skeleton by controlling the mass ratio of the sylvite in the template to the resol in the carbon source, and the defect of untight structural connection of the multi-dimensional porous carbon material is overcome, so that the aims of optimizing the performance of a single material with a single structure and widening the application field of the multi-dimensional porous carbon material are fulfilled.

The conception, specific material structure and technical effects of the present invention will be further described in conjunction with the accompanying drawings to fully understand the objects, features and effects of the present invention.

Drawings

FIG. 1 is a 10000 times scanning electron micrograph of the multi-dimensional porous carbon material obtained in example 1 of the present invention;

FIG. 2 is a 30000 times scanning electron microscope image of the multi-dimensional porous carbon material obtained in example 1 of the present invention;

FIG. 3 shows the multi-dimensional porous structure obtained in example 1 of the present inventionN of carbon material₂Adsorption and desorption isothermal curves;

FIG. 4 is a DFT pore size distribution curve of the multi-dimensional porous carbon material obtained in example 1 of the present invention;

FIG. 5 is a 1000-fold scanning electron micrograph of a multi-dimensional porous carbon material obtained in example 2 of the present invention;

FIG. 6 is a 5000-fold scanning electron micrograph of a multi-dimensional porous carbon material obtained in example 2 of the present invention;

FIG. 7 is a 5000-fold scanning electron micrograph of a multi-dimensional porous carbon material obtained in example 3 of the present invention;

FIG. 8 is a 10000 times scanning electron micrograph of the multi-dimensional porous carbon material obtained in example 3 of the present invention;

FIG. 9 is a 10000 times scanning electron micrograph of the multi-dimensional porous carbon material obtained in example 4 of the present invention;

FIG. 10 is a 10000 times scanning electron micrograph of the multi-dimensional porous carbon material obtained in example 5 of the present invention;

FIG. 11 is a 10000 times scanning electron micrograph of the multi-dimensional porous carbon material obtained in example 6 of the present invention;

FIG. 12 is a scanning electron micrograph of a multi-dimensional porous carbon material obtained in example 6 of the present invention magnified 50000 times;

FIG. 13 is a 10000 times scanning electron micrograph of the multi-dimensional porous carbon material obtained in example 7 of the present invention;

FIG. 14 is a scanning electron micrograph of a multi-dimensional porous carbon material obtained in example 7 of the present invention magnified 50000 times.

Detailed Description

The present invention is described in further detail below with reference to the attached drawings and specific examples, it being understood that the following specific examples are illustrative of the present invention only and are not intended to limit the scope of the present invention.