CN114604870A

CN114604870A - Method for preparing foam carbon material from wood block

Info

Publication number: CN114604870A
Application number: CN202210190873.8A
Authority: CN
Inventors: 仇鹏翔; 潘钰璟; 朱佳威; 李伯启; 徐康
Original assignee: Jiangsu Xindaruikang Environmental Protection Technology Co ltd; Nanjing Zhihui Environmental Meteorological Industry Research Institute Co ltd; Nanjing University of Information Science and Technology
Current assignee: Jiangsu Xindaruikang Environmental Protection Technology Co ltd; Nanjing Zhihui Environmental Meteorological Industry Research Institute Co ltd; Nanjing University of Information Science and Technology
Priority date: 2022-02-24
Filing date: 2022-02-24
Publication date: 2022-06-10

Abstract

The invention relates to a method for preparing a foam carbon material by using wood blocks, which comprises the following steps: preparing a sodium bicarbonate solution, soaking the wood blocks in the sodium bicarbonate solution, taking out and drying, placing the wood blocks in an inert gas atmosphere at a constant speed for heating, performing constant temperature reaction, then performing constant speed cooling, cleaning with ultrapure water and ethanol, and drying to obtain the foam carbon material. The invention adopts wood blocks as raw materials, and the wood blocks are soaked, dried, heated, cooled, washed and dried in sodium bicarbonate solution, and the foam carbon material is prepared by common materials and simple process steps.

Description

Method for preparing foam carbon material from wood block

Technical Field

The invention relates to a method for preparing a foam carbon material from wood blocks, and belongs to the technical field of carbon materials.

Background

Carbon foam has made a great progress in recent years as one of the research hotspots in the field of carbon materials. The foam carbon is a light porous material which is composed of porous bubbles and interconnected porous bubble walls and has a three-dimensional net structure, has small density, high temperature resistance and large specific surface area, and has excellent conductivity, so that the foam carbon is widely applied to the fields of catalysis, adsorption separation and the like.

The existing methods for preparing the foam carbon comprise a supercritical method, a template method and a radiation method, and the preparation process is relatively complex; the precursors for preparing the foam carbon at home and abroad mainly comprise asphalt, polyurethane, phenolic resin and biomass.

However, in the process of preparing the carbon foam from the above materials, the carbon foam is generally subjected to high temperature, high pressure and pressure release, and the preparation process has high requirements on equipment and consumes energy.

The invention provides a method for preparing a foam carbon material from wood blocks, which aims to realize simple, convenient and rapid preparation of excellent foam carbon by using low-cost materials.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for preparing a foam carbon material by using wood blocks, which has the following specific technical scheme:

a method for preparing a foam carbon material by using wood blocks comprises the following steps:

step 1: adding sodium bicarbonate into deionized water, stirring and dissolving to obtain a sodium bicarbonate solution;

step 2: soaking and activating the wood blocks in sodium bicarbonate solution, taking out, drying at 60-90 ℃, and soaking and activating for 1.5-2.5 h;

and step 3: placing the dried wood block in a corundum tube, heating to 720-730 ℃ at a heating rate of 5 ℃/min in an inert gas atmosphere, and reacting at constant temperature for 2 h;

and 4, step 4: cooling to room temperature at a rate of 5 ℃/min, sequentially cleaning with ultrapure water and ethanol for 4-5 times, after washing, immersing the obtained material in the ultrapure water, replacing the ultrapure water every 10 minutes until the pH of the leachate is between 7.0-7.5, and drying the wood block obtained by the last immersion at 60-90 ℃;

the mass ratio of the deionized water to the sodium bicarbonate is 3.7:1-5.5: 1;

the mass ratio of the sodium bicarbonate solution to the wood blocks ranges from 5.5:1 to 6.5: 1.

Further, the mass ratio of the deionized water to the sodium bicarbonate is 4.8:1-5.2: 1.

Further, the mass ratio of the sodium bicarbonate solution to the wood blocks is 5.7:1-6.3: 1.

Further, the wood block is soaked in the sodium bicarbonate solution for 1.8-2.2 h.

Further, the isothermal reaction was carried out at 725 ℃.

Further, the soaking activates that the wood blocks are completely immersed in the solution and the wood blocks are not contacted with each other.

The invention has the beneficial effects that: the invention adopts wood blocks as raw materials, and the wood blocks are soaked, dried, heated, cooled, washed and dried in sodium bicarbonate solution, and the foam carbon material is prepared by common materials and simple process steps.

Drawings

Figure 1 is a process diagram of the present invention,

FIG. 2 is a graph showing hydrogen peroxide yield at-0.6V for carbon foams prepared in accordance with examples of the present invention and conventional carbon materials,

FIG. 3 is a graph of SMX degradation efficiency of a carbon foam material prepared according to an embodiment of the present invention and a conventional carbon material,

FIG. 4 is an SEM image of the structure of a carbon foam material prepared by the embodiment of the invention.

Detailed Description

The present invention is further illustrated by the following figures and specific examples, which are to be understood as illustrative only and not as limiting the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalent modifications thereof which may occur to those skilled in the art upon reading the present specification.

As shown in figure 1, the method for preparing the foam carbon material by the wood block comprises the steps of taking the wood block as a raw material, adding 15 g of sodium bicarbonate into 70 mL of deionized water, stirring until the sodium bicarbonate is dissolved, soaking the wood block in the deionized water for 2 hours, drying at 60 ℃, placing the dried material into a corundum tube, heating to 725 ℃ by using a tube furnace in an inert gas atmosphere at a heating rate of 5 ℃/min, reacting at a constant temperature for 2 hours, cooling to room temperature at a cooling rate of 5 ℃/min, washing with ultrapure water and ethanol for 4-5 times, soaking the material into the ultrapure water after washing, replacing the ultrapure water every 10 minutes until the pH of a leaching solution is between 7.0 and 7.5, placing the wood block obtained by the last soaking at 60 ℃ for drying to obtain the foam carbon, and performing experiments until the mass ratio of the wood block to the sodium bicarbonate solution is preferably 1:6, an SEM image of the prepared carbon foam structure is shown in fig. 4.

The selected wood block materials can be plant, mineral and industrial waste materials, the materials are easy to obtain, and the lower the ash content in the adopted raw materials is, the better the performance of the prepared carbon foam is.

The wood block is soaked in a weak alkaline environment provided by sodium bicarbonate solution, the state of the wood block is improved, and therefore a more excellent pore structure can be formed in the reaction process.

The carbon foam prepared in the example of the present invention and the carbon material prepared by the conventional method were added under-0.6V, respectively, to perform a hydrogen peroxide production reaction, and the hydrogen peroxide production was recorded with time, to obtain a hydrogen peroxide production graph as shown in fig. 2.

In fig. 2, after 60min of reaction, the concentration of hydrogen peroxide collected by the reaction system in which the carbon material prepared by the conventional method is added is lower than 30ppm, and the concentration of hydrogen peroxide collected by the reaction system in which the carbon foam material prepared by the present invention is added reaches 60ppm, so that it is obvious that the carbon foam prepared by the embodiment of the present invention has higher selectivity for the electron oxygen reduction reaction.

The carbon foam prepared by the embodiment of the invention and the carbon material prepared by the traditional method are respectively used for carrying out catalytic degradation on sulfamethoxazole SMX, so that a curve showing the content ratio of the residual reactant to the total reactant along with the change of time is obtained, wherein the curve is shown in figure 3.

From fig. 3, it can be obtained that after 60min of reaction, the reaction system added with the carbon foam material prepared by the present invention completely catalyzes and degrades sulfamethoxazole SMX, while the reaction system added with the carbon material prepared by the conventional method only converts 30%, so that the carbon foam prepared by the embodiment of the present invention has far better catalytic effect on the degradation reaction efficiency of sulfamethoxazole SMX than the carbon material prepared by the conventional method.

Fig. 4 is an SEM image of the carbon foam material prepared according to the embodiment of the present invention, and it can be seen that the carbon foam material has a rich pore structure.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A method for preparing a foam carbon material by using wood blocks is characterized by comprising the following steps: the method comprises the following steps:

and 4, step 4: cooling to room temperature at a rate of 5 ℃/min, sequentially cleaning with ultrapure water and ethanol for 4-5 times, after washing, soaking the obtained material in the ultrapure water, replacing the ultrapure water every 10 minutes until the pH of the leachate is between 7.0-7.5, and drying the wood block obtained by the last soaking at 60-90 ℃;

2. The method for preparing a carbon foam material from a wood block according to claim 1, wherein: the mass ratio of the deionized water to the sodium bicarbonate is 4.8:1-5.2: 1.

3. The method for preparing a carbon foam material from a wood block according to claim 1, wherein: the mass ratio of the sodium bicarbonate solution to the wood blocks is 5.7:1-6.3: 1.

4. The method for preparing a carbon foam material from a wood block according to claim 1, wherein: the wood block is soaked in the sodium bicarbonate solution for 1.8-2.2 h.

5. The method for preparing a carbon foam material from a wood block according to claim 1, wherein: the isothermal reaction was carried out at 725 ℃.

6. The method for preparing a carbon foam material from a wood block according to claim 1, wherein: the soaking is activated, the wood blocks are completely immersed in the solution, and the wood blocks are not contacted with each other.