CN105060272A - Method for preparation of carbon nanotube with artemia cyst shell as carbon source at low temperature - Google Patents

Abstract

A method for preparing carbon nanotubes at low temperature using Artemia eggshells as a carbon source, which mainly uses Artemia eggshells as a carbon source, metal nickel salt as a catalyst, and potassium hydroxide as a precipitating agent. The nickel-doped graphitized carbon material is catalyzed and synthesized under the condition; then the obtained nickel-doped graphitized carbon material is mixed with potassium hydroxide in a certain mass ratio, and calcined at 600-900 DEG C to obtain carbon nanotubes. The notable feature of the present invention is that the hollow carbon nanotubes are synthesized under normal pressure and low temperature conditions by using biomass carbon sources, and has many advantages such as low raw material prices, simple equipment, good repeatability, easy realization of low-cost industrial production, and the like. The carbon nanotubes prepared by the method have the advantages of high degree of graphitization, good electrical conductivity, etc., and have high application prospects in supercapacitors, lithium ion battery electrode materials, catalyst supports, and the like.

Description

A method for preparing carbon nanotubes at low temperature using Artemia eggshells as a carbon source

technical field

The invention relates to a functional material, especially a preparation method for synthesizing carbon nanotubes.

Background technique

As an important class of functional materials, carbon nanotubes are widely used in supercapacitors, lithium-ion batteries, fuel cell catalysts and other fields. The specific one-dimensional graphite structure of carbon nanotubes makes this kind of research have great theoretical significance and potential application value. The unique structure of carbon nanotubes is an ideal one-dimensional material model; the huge aspect ratio makes it expected to be used as a tough carbon fiber, its strength is 100 times that of steel, and its weight is only 1/6 of steel; good conductivity, ion The advantages of fast transmission speed and hollow structure make it an ideal material for supercapacitors, lithium-ion batteries and catalyst supports.

In recent years, great progress has been made in the preparation of carbon nanotubes using CVD technology using transition metals (such as iron, cobalt, nickel) as catalysts. People often use different carbon sources, different metal catalysts and different methods to synthesize carbon nanotubes with different properties. For example, Fan et al. ([J].AdvancedMaterials, 2010,22(33):3723-3728.) and Wei et al. ([J].AdvancedMaterials, 2014,26(41):7051-7058) reported the use of microwave The combination of heating and high-temperature calcination uses cobalt as a catalyst to synthesize graphene/carbon nanotubes with a sandwich structure and iron/molybdenum/magnesium/aluminum quaternary layered hydroxide as a catalyst by using graphene oxide and hydrogen reduction to Methane and formamide were used as carbon sources to generate dendritic carbon nanotubes. These graphitized carbon materials have shown excellent performance in the application of supercapacitors, but the existing preparation process is relatively complicated, the precursor of carbon materials needs to be purchased, which increases the production cost, and the prepared carbon nanotubes are difficult to produce on a large scale.

Contents of the invention

The purpose of the present invention is to provide a method for preparing carbon nanotubes at low temperature using artemia eggshell as a carbon source with mild reaction conditions, simple preparation process, low production cost and large-scale production. The present invention mainly uses the biological artemia eggshell as the carbon precursor, does not need the atmosphere containing hydrocarbons (such as methane, acetylene, etc.) as the carbon source, and makes the catalyst evenly loaded on the solid carbon source at a relatively low temperature , without adding additional catalyst substrate materials, the amorphous carbon of the multi-level channel structure of Artemia eggshells is first transformed into a highly graphitized carbon material, and then carbon nanotubes are grown on the graphitized carbon.

Technical scheme of the present invention comprises the steps:

(1) Clean the Artemia eggshells, dry them at 120°C, and ball mill them for 6 hours, then wash the Artemia eggshell powder with 3mol/L hydrochloric acid and deionized water until pH=7 to remove residual impurities, and finally drying;

(2) dissolving nickel acetate in deionized water so that its concentration is 0.024～0.1mol/L;

(3) Add Artemia egg shells processed in step (1) to the nickel acetate solution prepared in step (2), wherein the mass ratio of Artemia egg shells to nickel acetate R=1:1～4:1 , fully stirred for 0.5 to 2 hours, so that the nickel ions in the nickel acetate solution are evenly distributed on the eggshell carbon surface;

(4) Add potassium hydroxide to the mixture in step (3), keep the mass ratio of Artemia eggshells to potassium hydroxide R = 1:1-1:4, _and stir at 60-80°C for 3-8 hours at high speed ;

(5) Put the mixture obtained in step (4) into a tube furnace, heat up to 600-900°C at a rate of 1-10°C/min under the protection of high-purity argon for calcination, and keep the temperature for 1-5 hours to obtain Nickel-doped graphitized carbon materials;

(6) Grinding and mixing the mixture obtained in step (5) with potassium hydroxide uniformly, keeping the mass ratio R=1:1～1:4 of the mixture and potassium hydroxide, the above-mentioned solid mixture of the gained is under the protection of high-purity argon, Raise the temperature to 600-900°C at a rate of 1-10°C/min for calcination, keep it warm for 1-5 hours, and take out the product after the sample is sintered;

(7) The product obtained in step (6) was washed successively with 3 mol/L hydrochloric acid and deionized water until pH = 7, filtered and dried to obtain carbon nanotubes with a high degree of graphitization.

Compared with the prior art, the present invention has the following advantages:

1. The present invention uses a solid carbon source to synthesize hollow carbon nanotubes under normal pressure and low temperature under inert atmosphere conditions. The prepared carbon nanotubes have the advantages of high degree of graphitization and good conductivity, and can be applied to supercapacitors , lithium-ion battery electrode materials and catalyst supports.

2. The raw materials are easy to obtain, the source is wide, and the price is cheap.

3. The preparation method is simple, the equipment is simple, the cost is greatly saved, and the production process is shortened.

4. The reaction conditions are mild, easy to control and repeatable, and the product quality is stable, which is suitable for industrial mass production.

Description of drawings

FIG. 1 is an SEM image of carbon nanotubes prepared in Example 1 of the present invention.

Fig. 2 is a TEM image of carbon nanotubes prepared in Example 7 of the present invention.

Detailed ways

Example 1

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them into 100 ml of nickel acetate solution with a concentration of 0.024 mol/L, and fully stir for 0.5 hours. After dissolving, add 2.4 g of potassium hydroxide and stir at 60°C for 3 hours at high speed. The resulting mixture was placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 600°C at a rate of 1°C/min for calcination, and the temperature was kept for 1 hour, then the sample was mixed with 2.4 grams of potassium hydroxide powder and ground evenly , and placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 600°C at a rate of 1°C/min for calcination, and the temperature was kept for 1 hour. Washing with hydrochloric acid and deionized water until PH=7, filtering and drying to obtain carbon nanotubes, its SEM image is shown in Figure 1, it can be seen from the figure that the carbon nanotubes synthesized by this embodiment are about several Microns, smaller in diameter.

Example 2

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them into 100 ml of 0.05 mol/L nickel acetate solution, and stir them thoroughly for 1 hour. After dissolving, add 4.8 g of potassium hydroxide and stir at 60° C. for 4 hours at high speed. The resulting mixture was placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 650°C at a rate of 2°C/min for calcination, and the temperature was kept for 3 hours. Then the sample was mixed with 2.4 grams of potassium hydroxide powder and ground evenly , and placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 650°C at a rate of 2°C/min for calcination, and the heat preservation was carried out for 1 hour. Washing with hydrochloric acid and deionized water until pH = 7, filtering and drying to obtain carbon nanotubes.

Example 3

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them into 100 ml of nickel acetate solution with a concentration of 0.06 mol/L, and fully stir for 1.5 hours. After dissolving, add 3.6 g of potassium hydroxide and stir at 60°C for 5 hours at high speed. The resulting mixture was placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 700°C at a rate of 4°C/min for calcination, and the temperature was kept for 2 hours. Then the sample was mixed with 7.2 grams of potassium hydroxide powder and ground evenly , and placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 700°C at a rate of 4°C/min for calcination, and the temperature was kept for 4 hours. Washing with hydrochloric acid and deionized water until pH = 7, filtering and drying to obtain carbon nanotubes.

Example 4

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them into 100 ml of nickel acetate solution with a concentration of 0.07 mol/L, and fully stir for 1 hour. After dissolving, add 7.2 g of potassium hydroxide and stir at 60°C for 6 hours at high speed. The resulting mixture was placed in a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 750°C at a rate of 6°C/min for calcination, and the temperature was kept for 4 hours. Then the sample was mixed with 3.6 grams of potassium hydroxide powder and ground evenly , and put it into a vacuum drying tube, under the protection of high-purity argon, the temperature was raised to 750°C at a rate of 6°C/min for calcination, and the temperature was kept for 4 hours. Washing with hydrochloric acid and deionized water until pH = 7, filtering and drying to obtain carbon nanotubes.

Example 5

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them to 100 ml of nickel acetate solution with a concentration of 0.036 mol/L, and fully stir for 1.5 hours. After dissolving, add 4.8 g of potassium hydroxide and stir at 65°C for 7 hours at high speed. The resulting mixture is placed in a vacuum drying tube under the protection of high-purity argon to heat up to 800°C at a rate of 8°C/min for calcination, and keep the temperature for 3 hours, then add 2.4 grams of potassium hydroxide powder to the sample and grind it evenly, and Put it into a vacuum drying tube, under the protection of high-purity argon, heat up to 800°C at a rate of 8°C/min for calcination, keep it warm for 2 hours, take out the product after the sample is sintered, and wash the obtained product with 3mol/L hydrochloric acid successively 1. Washing with deionized water until pH = 7, filtering and drying to obtain carbon nanotubes.

Example 6

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them to 100 ml of nickel acetate solution with a concentration of 0.08 mol/L, and stir thoroughly for 2 hours. After dissolving, 4.8 g of potassium hydroxide was added and stirred at a high speed at 70° C. for 5 hours. The resulting mixture was placed in a vacuum drying tube under the protection of high-purity argon to heat up to 850°C at a rate of 9°C/min for calcination, and kept for 3 hours, then the sample was added with 2.4 grams of potassium hydroxide powder and ground evenly, and Put it into a vacuum drying tube and heat it up to 850°C at a rate of 9°C/min under the protection of high-purity argon for calcination, keep it warm for 2 hours, take out the product after the sample is sintered, and wash the obtained product with 3mol/L hydrochloric acid successively 1. Washing with deionized water until pH = 7, filtering and drying to obtain carbon nanotubes.

Example 7

Clean the Artemia egg shells, dry them at 120°C, and ball mill them for 6 hours. Wash the Artemia egg shell powder with an excess of 3mol/L hydrochloric acid in turn, then clean them with deionized water until PH=7, and finally dry them; Take 2.4 grams of the above-mentioned treated Artemia egg shells and add them into 100 ml of 0.1 mol/L nickel acetate solution, and stir them thoroughly for 2 hours. After dissolving, add 9.6 g of potassium hydroxide and stir at 80°C for 8 hours at high speed. The resulting mixture was placed in a vacuum drying tube under the protection of high-purity argon to heat up to 900°C at a rate of 10°C/min for calcination, and kept for 5 hours, then the sample was added to 9.6 grams of potassium hydroxide powder to grind evenly, and Put it into a vacuum drying tube, under the protection of high-purity argon, heat up to 900°C at a rate of 10°C/min for calcination, keep it warm for 5 hours, take out the product after the sample sintering is completed, and wash the obtained product with 3mol/L hydrochloric acid and Wash with deionized water to PH=7, filter and dry to obtain carbon nanotubes, its TEM figure is as shown in Figure 2, it can be seen from the figure that the carbon nanotubes synthesized by this embodiment have different shapes, if any Spiral, linear, etc., and the diameter of the tube is also different.

Claims (1)

1. under carbon source low temperature, prepare a method for carbon nanotube using artemia cysts shell, it is characterized in that:

(1) cleaned up by artemia cysts shell, 120 DEG C of oven dry, ball milling, after 6 hours, is used 3mol/L hydrochloric acid and washed with de-ionized water to PH=7 successively, is finally dried;

(2) nickelous acetate is dissolved in deionized water, makes its concentration be 0.024 ~ 0.1mol/L;

(3) the artemia cysts shell handled well in step (1) is added in the obtained Ni-acetate solution of step (2), the wherein mass ratio R=1:1 ~ 4:1 of artemia cysts shell and nickelous acetate, stir, make metal ion in catalyst solution be evenly distributed on chorion carbon surface;

(4) product to step (3) adds potassium hydroxide, keeps the chorion of step (3) and the mass ratio of potassium hydroxide to be R=1:1 ~ 1:4, stirs to pasty state at 60 ~ 80 DEG C;

(5) gained mixture in step (4) is put into tube furnace, under high-purity argon gas protection, be warming up to 600 ~ 900 DEG C with the speed of 1 ~ 10 DEG C/min calcine, be incubated 1 ~ 5 hour;

(6) by gained mixture in step (5) and potassium hydroxide ground and mixed even, the mass values keeping mixture and potassium hydroxide is R=1:1 ~ 1:4, the above-mentioned solid mixture of gained is under high-purity argon gas protection, be warming up to 600 ~ 900 DEG C with the speed of 1 ~ 10 DEG C/min to calcine, be incubated 1 ~ 5 hour, after sample has sintered, take out product;

(7) product priority 3mol/L hydrochloric acid step (6) obtained and washed with de-ionized water, to PH=7, are filtered, are dried, obtain the carbon nanotube that degree of graphitization is high.