CN107829168B

CN107829168B - Method for preparing carbon nanofibers by taking tobacco as raw material

Info

Publication number: CN107829168B
Application number: CN201711057799.8A
Authority: CN
Inventors: 沈培康; 刘洋
Original assignee: Guangxi University
Current assignee: Guangxi University
Priority date: 2017-11-01
Filing date: 2017-11-01
Publication date: 2020-01-21
Anticipated expiration: 2037-11-01
Also published as: CN107829168A

Abstract

The invention relates to a preparation method of carbon nanofibers, in particular to a method for preparing carbon nanofibers by taking tobacco as a raw material. A method for preparing carbon nanofibers by taking tobacco as a raw material comprises the following steps: (1) preparing a metal sample with catalytic activity; (2) and (2) placing the metal sample with catalytic activity obtained in the step (1) into an acidic solution, carrying out ultrasonic treatment for 0.5-3h, filtering the solution, rinsing the filter residue with ethanol or deionized water until the pH value is 7.0, collecting the filter residue, and drying to obtain the carbon nanofiber. The method for preparing the carbon nanofiber by taking the tobacco as the raw material has the advantages that the raw material is low in price, the application of the tobacco in other emerging industries is facilitated, and the carbon nanofiber prepared by the method is simple and safe in preparation process.

Description

Method for preparing carbon nanofibers by taking tobacco as raw material

Technical Field

The invention relates to a preparation method of carbon nanofibers, in particular to a method for preparing carbon nanofibers by taking tobacco as a raw material.

Background

The nano carbon fiber is a transition carbon material, and has many excellent properties, such as good electric conductivity, mechanical strength, thermal conductivity, large specific surface area, etc., and the properties are similar to those of graphite. The catalyst has strong stability to chemical erosion such as acid and alkali, has attracted people's attention from the beginning to the present, and has wide application, such as aerospace, catalyst, machinery industry, sports equipment, daily necessities and many other living fields. Carbon nanofibers with different morphologies have been synthesized through experiments around the world, the most common synthesis method of carbon nanofibers is to prepare and synthesize the carbon nanofibers by catalytic pyrolysis of hydrocarbon gases, and the vapor phase growth process is very complicated and involves many reactions, so that the radius, length and the like of the carbon nanofibers can be controlled by adopting different reaction parameters, and the carbon nanofibers have very different production morphologies, such as whisker shapes, branch shapes, bidirectional shapes, multidirectional shapes, spiral shapes and the like. In the process of preparing the carbon nanofibers by using the hydrocarbon gas, the hydrocarbon gas has certain danger in the preparation process because of the flammability, and the search for new raw materials and a synthesis method is very promising and necessary.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for preparing carbon nanofibers by taking tobacco as a raw material.

The technical scheme provided by the invention is as follows:

a method for preparing carbon nanofibers by taking tobacco as a raw material comprises the following steps:

(1) preparing two furnaces, namely a furnace 1 and a furnace 2 respectively, putting a certain mass of dried tobacco into the furnace 1, putting a metal sample with catalytic activity into the furnace 2, connecting the exhaust end of the furnace 1 with the gas inlet end of the furnace 2, and introducing inert gas into the gas inlet end of the furnace 1 so as to enable the inside of the furnace 1 and the inside of the furnace 2 to be in an inert atmosphere; then heating the two furnaces, wherein the maximum heating temperatures of the furnace 1 and the furnace 2 are respectively 600 ℃ and 800 ℃ at the temperature rise speed of 0.5-10 ℃/min, and taking out the metal sample with catalytic activity after cooling;

(2) and (2) placing the metal sample with catalytic activity obtained in the step (1) into an acid solution, treating for 0.5-3h by using an ultrasonic cleaning machine, filtering the solution, rinsing the filter residue by using ethanol or deionized water until the pH value is 7.0, collecting the filter residue, and drying to obtain the carbon nanofiber.

Preferably, the two furnaces in step (1) are furnaces having inlet and outlet ports and capable of being temperature-controlled.

Preferably, the metal sample having catalytic activity described in step (1).

Preferably, the metal sample with catalytic activity is at least one of iron, cobalt, nickel and copper.

Preferably, the catalytically active metal sample is a nanoparticle or a macro-scale metal.

Preferably, the inert gas in step (1) is nitrogen, argon or helium.

Preferably, the aeration rate of the inert gas is 0.01-10 ml/min.

Preferably, the temperature of the furnace 1 in step (1) reaches 500 ℃ already when the temperature of the furnace 2 reaches 300 ℃.

Preferably, the acidic solution in step (2) is a sulfuric acid solution, a hydrochloric acid solution, a nitric acid solution, an acetic acid solution or a formic acid solution.

Preferably, the concentration of the acidic solution in step (2) is 0.1 to 1M.

Compared with the prior art, the invention has the following beneficial effects:

the method for preparing the carbon nanofiber by taking the tobacco as the raw material has the advantages that the raw material cost is low, the application of the traditional crop, namely the tobacco, in other emerging industries is facilitated, and the method for preparing the carbon nanofiber by the method is simple and safe.

Drawings

FIG. 1 is a scanning electron micrograph of a carbon nanofiber prepared in example 1, illustrating the carbon nanofiber at 300 nm;

FIG. 2 is a scanning electron micrograph of the carbon nanofiber prepared in example 1, illustrating the carbon nanofiber with a 500 μm image;

FIG. 3 is a scanning electron micrograph of the carbon nanofiber prepared in example 1, illustrating a 1 μm;

FIG. 4 is a scanning electron micrograph of the carbon nanofiber prepared in example 1, illustrating a 5 μm image.

Detailed Description

The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the invention easier to understand by those skilled in the art, and thus will clearly and clearly define the scope of the invention.

Example 1：

A method for preparing carbon nanofibers by taking tobacco as a raw material comprises the following operation steps:

(1) two tube furnaces, furnace 1 and furnace 2, were prepared, and 5g of dried tobacco was placed in furnace 1, and the area was 1cm²The foamed nickel is put into a furnace 2, an exhaust port of the furnace 1 is connected with an air inlet of the furnace 2, the air inlet of the furnace 1 is connected with nitrogen, the aeration rate of the nitrogen is 1ml/min, the two furnaces start heating at the same time, the temperature of the furnace 1 is raised to 240 ℃ at the rate of 2 ℃/min, then raised to 500 ℃ at the rate of 2.6 ℃/min, the temperature is preserved for 1 hour, the heating is stopped, and the temperature is naturally reduced. The temperature of the furnace 2 is raised to 600 ℃ at the speed of 5 ℃/min, then raised to 800 ℃ at the speed of 2 ℃/min, the temperature is kept for 1 hour, then the heating is stopped, the temperature is naturally reduced, and the furnace is openedAnd 2, taking out the foamed nickel.

(2) And (2) putting the foamed nickel in the step (1) into 1 mol of hydrochloric acid aqueous solution, putting the foamed nickel into an ultrasonic cleaning machine for treatment for 30 minutes, then taking out the foamed nickel, carrying out suction filtration on the solution, cleaning the filter residue to be neutral by using deionized water, then collecting the filter residue and drying to obtain the carbon nanofiber.

Example 2：

(1) two tube furnaces, furnace 1 and furnace 2, were prepared, and 5g of dried tobacco was placed in furnace 1, and the area was 1cm²The foamed nickel is put into a furnace 2, an exhaust port of the furnace 1 is connected with an air inlet of the furnace 2, the air inlet of the furnace 1 is connected with nitrogen, the aeration rate of the nitrogen is 1ml/min, the two furnaces start heating at the same time, the temperature of the furnace 1 is raised to 500 ℃ at the rate of 2 ℃/min, the heating is stopped after the temperature is maintained for 1 hour, and the temperature is naturally reduced. And (3) heating the furnace 2 to 600 ℃ at a speed of 4 ℃/min, then heating to 800 ℃ at a speed of 2 ℃/min, preserving heat for 1 hour, stopping heating, naturally cooling, opening the furnace 2, and taking out the foamed nickel.

(2) And (2) putting the foamed nickel in the step (1) into 1 mol of hydrochloric acid aqueous solution, putting the foamed nickel into an ultrasonic cleaning machine for treatment for 3h, then taking out the foamed nickel, carrying out suction filtration on the solution, cleaning the filter residue to be neutral by using deionized water, then collecting the filter residue and drying to obtain the carbon nanofiber.

Example 3：

(1) two tube furnaces, furnace 1 and furnace 2, were prepared, and 5g of dried tobacco was placed in furnace 1, and the area was 1cm²The foamed nickel is put into a furnace 2, an exhaust port of the furnace 1 is connected with an air inlet of the furnace 2, the air inlet of the furnace 1 is connected with nitrogen, the aeration rate of the nitrogen is 1ml/min, the two furnaces start heating at the same time, the temperature of the furnace 1 is raised to 500 ℃ at 4 ℃/min, the heating is stopped after the temperature is maintained for 1 hour, and the temperature is naturally reduced. The temperature of the furnace 2 is raised to 600 ℃ at a rate of 10 ℃/min, and then is raised to 800 ℃ at a rate of 3 ℃/minAnd (4) keeping the temperature for 1 hour, stopping heating, naturally cooling, opening the furnace 2, and taking out the foamed nickel.

(2) And (2) putting the foamed nickel in the step (1) into 1 mol of hydrochloric acid aqueous solution, putting the foamed nickel into an ultrasonic cleaning machine for treatment for 60 minutes, then taking out the foamed nickel, carrying out suction filtration on the solution, cleaning the filter residue to be neutral by using deionized water, then collecting the filter residue and drying to obtain the carbon nanofiber.

As can be seen from fig. 1, the prepared carbon nanofiber has a diameter of about 28nm and a shape of a folded filament; as can be seen from fig. 2 and 3, the roots of the carbon nanofibers are on a nickel substrate; it can be seen from fig. 4 that the carbon nanofibers grow over a large area.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. A method for preparing carbon nanofibers by taking tobacco as a raw material is characterized by comprising the following steps:

(2) placing the metal sample with catalytic activity obtained in the step (1) in an acid solution, treating for 0.5-3h by using an ultrasonic cleaning machine, filtering the solution, rinsing filter residue by using ethanol or deionized water until the pH value is 7.0, collecting the filter residue, and drying to obtain the carbon nanofiber;

the two furnaces in the step (1) are furnaces which are provided with air inlets and air outlets and can be controlled by a program temperature;

the metal sample with catalytic activity is at least one of iron, cobalt, nickel and copper.

2. The method for preparing nano carbon fiber by using tobacco as raw material according to claim 1, wherein the metal sample with catalytic activity is nano particles or macro scale metal.

3. The method for preparing carbon nanofibers from tobacco as claimed in claim 1, wherein the inert gas in step (1) is nitrogen, argon or helium.

4. The method for preparing filamentous nanocarbon using tobacco as a raw material according to claim 3, wherein the inert gas is introduced at a flow rate of 0.01 to 10 ml/min.

5. The method for preparing filamentous nanocarbon using tobacco as a raw material according to claim 1, wherein the temperature of the furnace 1 reaches 300 ℃ and the temperature of the furnace 2 reaches 500 ℃ already in step (1).

6. The method for preparing filamentous nanocarbon from tobacco as claimed in claim 1, wherein the acidic solution in step (2) is sulfuric acid solution, hydrochloric acid solution, nitric acid solution, acetic acid solution or formic acid solution.

7. The method for preparing filamentous nanocarbon using tobacco as a raw material according to claim 1, wherein the concentration of the acidic solution in the step (2) is 0.1 to 1M.