阅读说明：本技术 一种自掺杂硫元素的烟杆基活性炭电极材料及其制备方法和应用 (Tobacco stem-based activated carbon electrode material self-doped with sulfur element and preparation method and application thereof ) 是由 马柱文 陈俊标 魏彬 陈桢禄 袁清华 黄振瑞 于 2020-12-14 设计创作，主要内容包括：本发明涉及电极材料制备技术领域,具体公开了一种自掺杂硫元素的烟杆基活性炭电极材料及其制备方法和应用。所述的一种自掺杂硫元素的烟杆基活性炭电极材料的制备方法,其包含如下步骤：(1)种植烤烟；(2)取烟草秸秆,将烟草秸秆粉碎得烟秆粉,接着将烟秆粉进行干燥；(3)将干燥的烟秆粉进行热解处理,得到烟秆炭粉前驱体；(4)将烟秆炭粉前驱体与KOH混合后,加入水进行进一步研磨捏合,干燥后得烟秆碳粉/KOH混合物；(5)接着将烟秆碳粉/KOH混合物进行热处理；即得所述的自掺杂硫元素的烟杆基活性炭电极材料。采用本发明所述的烟杆基活性炭电极材料制备超级电容器,可以提高超级电容器的比电容,增加能量密度。(The invention relates to the technical field of electrode material preparation, and particularly discloses a tobacco stem-based activated carbon electrode material self-doped with sulfur element, and a preparation method and application thereof. The preparation method of the tobacco rod-based activated carbon electrode material self-doped with the sulfur element comprises the following steps: (1) planting flue-cured tobacco; (2) taking tobacco straws, crushing the tobacco straws to obtain tobacco straw powder, and then drying the tobacco straw powder; (3) carrying out pyrolysis treatment on the dried tobacco stalk powder to obtain a tobacco stalk carbon powder precursor; (4) mixing the tobacco stem carbon powder precursor with KOH, adding water for further grinding and kneading, and drying to obtain a tobacco stem carbon powder/KOH mixture; (5) then carrying out heat treatment on the tobacco stalk carbon powder/KOH mixture; and obtaining the tobacco stem-based active carbon electrode material self-doped with the sulfur element. The tobacco stem-based activated carbon electrode material is used for preparing the super capacitor, so that the specific capacitance of the super capacitor can be improved, and the energy density can be increased.)

1. A preparation method of a tobacco stem-based activated carbon electrode material self-doped with sulfur elements is characterized by comprising the following steps:

(1) planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws to obtain tobacco straw powder, and then drying the tobacco straw powder;

(3) carrying out pyrolysis treatment on the dried tobacco stalk powder to obtain a tobacco stalk carbon powder precursor;

(4) mixing the tobacco stem carbon powder precursor with KOH, adding water for further grinding and kneading, and drying to obtain a tobacco stem carbon powder/KOH mixture;

(5) then carrying out heat treatment on the tobacco stalk carbon powder/KOH mixture; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

wherein, in the flue-cured tobacco planting process in the step (1), compound fertilizer is applied to the tobacco; when the compound fertilizer is applied to the tobacco, the compound fertilizer and the picea japonica branch and leaf water extract are applied together.

2. The method for preparing a tobacco rod-based activated carbon electrode material self-doped with sulfur element as claimed in claim 1, wherein said compound fertilizer is composed of monopotassium phosphate fertilizer, diammonium phosphate, urea, potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate.

3. The method for preparing a sulfur-doped tobacco rod-based activated carbon electrode material as claimed in claim 1, wherein the total nitrogen application amount of the compound fertilizer is 90-100 kg/hm²。

4. The method for preparing tobacco rod-based activated carbon electrode material self-doped with sulfur element as claimed in claim 1, wherein P is N in the compound fertilizer₂O₅:K₂O＝1:2～3:3～4。

5. The preparation method of the tobacco stem-based activated carbon electrode material self-doped with the sulfur element as claimed in claim 1, wherein the picea javanica branch and leaf water extract is prepared by the following method: and (3) putting the schefflera octophylla branches and leaves into water, and soaking for 10-30 days to obtain the schefflera octophylla branch and leaf water extract.

6. The preparation method of the tobacco stem-based activated carbon electrode material self-doped with sulfur element as claimed in claim 1, wherein the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 3-10;

most preferably, the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 5.

7. The preparation method of the tobacco rod-based activated carbon electrode material self-doped with sulfur element as claimed in claim 5, wherein the weight ratio of the picea javanica branches and leaves to water is 1: 8-25;

most preferably, the weight ratio of the picea schlegeli branches and leaves to the water is 1: 15.

8. The preparation method of the tobacco rod-based activated carbon electrode material self-doped with sulfur element as claimed in claim 1,

the heat treatment conditions in the step (3) are as follows: under the atmosphere of nitrogen at 3-6 ℃ per minute^-1The temperature is increased to 500-600 ℃ and is kept for 1-3 h;

the heat treatment strip in the step (5)The parts are as follows: under the atmosphere of nitrogen at 3-6 ℃ per minute^-1The temperature is increased to 800-900 ℃ and kept for 1-3 h.

9. A tobacco rod-based activated carbon electrode material which is self-doped with sulfur and is prepared by the preparation method of any one of claims 1 to 8.

10. Use of the self-sulfur doped tobacco rod based activated carbon electrode material of claim 9 in the preparation of a capacitor.

Technical Field

The invention relates to the technical field of electrode material preparation, in particular to a tobacco stem-based activated carbon electrode material self-doped with sulfur element and a preparation method and application thereof.

Background

The tobacco stems are tobacco stems, and a large amount of tobacco stems are generated after tobacco leaves are picked every year; for tobacco straw, incineration and disposal are mainly adopted at present. However, the burning and discarding of the tobacco straw can cause certain pollution to the atmosphere and the environment; therefore, it is necessary to develop a method for recycling tobacco straw.

In order to reduce the pollution to the environment, improve the utilization rate of the tobacco straws and improve the economic value of tobacco planting, the preparation of the activated carbon electrode material by taking the tobacco straws as the raw material is one of the utilization modes of the tobacco straws.

The activated carbon electrode material is an electrode material for preparing a supercapacitor, and in order to improve the performance of the supercapacitor, a person skilled in the art generally dopes sulfur element in a carbon material. The sulfur element is doped in the activated carbon, the electron density of the surface of a sample can be improved through the synergistic activation of the conjugated C and the electron-rich element S, meanwhile, the existence of the S element can provide reversible reaction sites and provide pseudocapacitance, and the possible reaction formula is as follows:

the self-doping sulfur element means that the sulfur element is absorbed by the plant in the growth process, and then the sulfur element is left in the plant body to become a component of the plant; then, the plants containing the sulfur elements are used as raw materials to be pyrolyzed to obtain the tobacco stem-based active carbon electrode material doped with the sulfur elements.

The sulfur element is one of essential elements for tobacco leaf growth, however, the inventor finds that in the tobacco planting process, the content of the sulfur element precipitated in the tobacco straw is low, and the activated carbon electrode material prepared by taking the tobacco straw as a raw material cannot obtain the activated carbon electrode material doped with the high sulfur element, and the performance of the supercapacitor can be affected by taking the activated carbon electrode material as the electrode material of the supercapacitor. However, how to increase the sulfur content in the activated carbon electrode material by using the self-doping method to prepare the activated carbon electrode material is a technical difficulty in the field.

Disclosure of Invention

In order to overcome at least one technical problem mentioned in the background technology, the invention provides a preparation method of a tobacco stem-based activated carbon electrode material self-doped with sulfur element.

The technical problem to be solved by the invention is realized by the following technical scheme:

a preparation method of a tobacco stem-based activated carbon electrode material self-doped with sulfur elements comprises the following steps:

(1) planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws to obtain tobacco straw powder, and then drying the tobacco straw powder;

(3) carrying out pyrolysis treatment on the dried tobacco stalk powder to obtain a tobacco stalk carbon powder precursor;

(4) mixing the tobacco stem carbon powder precursor with KOH, adding water for further grinding and kneading, and drying to obtain a tobacco stem carbon powder/KOH mixture;

(5) then carrying out heat treatment on the tobacco stalk carbon powder/KOH mixture; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

wherein, in the flue-cured tobacco planting process in the step (1), compound fertilizer is applied to the tobacco; when the compound fertilizer is applied to the tobacco, the compound fertilizer and the picea japonica branch and leaf water extract are applied together.

The inventor researches and discovers that during the tobacco planting process, the content of sulfur elements enriched in tobacco stems is lower, and the content of sulfur elements precipitated in corresponding tobacco straws is also lower; therefore, the activated carbon electrode material prepared by taking tobacco straws as a raw material in a self-doping manner cannot be obtained, and the activated carbon electrode material doped with higher sulfur elements is obtained. In order to improve the content of sulfur element in the active carbon electrode material prepared in a self-doping mode. The inventor finds in research that when the compound fertilizer is applied to the tobacco, the compound fertilizer and the picea japonica branch and leaf water extract are applied together; the aqueous extract of the branches and leaves of the schefflera octophylla can promote the enrichment of sulfur elements in tobacco stems, and relatively more sulfur element content is precipitated in the corresponding tobacco straws; thereby effectively improving the sulfur content in the tobacco rod-based active carbon electrode material self-doped with sulfur.

Preferably, the compound fertilizer consists of monopotassium phosphate fertilizer, diammonium phosphate, urea, potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate.

Preferably, the total nitrogen application amount of the compound fertilizer is 90-100 kg/hm²。

Preferably, the N: P in the compound fertilizer₂O₅:K₂O＝1:2～3:3～4。

Preferably, the picea javanica branch and leaf water extract is prepared by the following method: and (3) putting the schefflera octophylla branches and leaves into water, and soaking for 10-30 days to obtain the schefflera octophylla branch and leaf water extract.

Preferably, the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 3-10.

Most preferably, the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 5.

Preferably, the weight ratio of the picea javanica branches and leaves to water is 1: 8-25.

Most preferably, the weight ratio of the picea schlegeli branches and leaves to the water is 1: 15.

Preferably, the heat treatment conditions in step (3) are: under the atmosphere of nitrogen at 3-6 ℃ per minute^-1The temperature is increased to 500-600 ℃ and is kept for 1-3 h;

in the step (5)The heat treatment conditions of (1) are as follows: under the atmosphere of nitrogen at 3-6 ℃ per minute^-1The temperature is increased to 800-900 ℃ and kept for 1-3 h.

The invention also provides the tobacco stem-based activated carbon electrode material self-doped with the sulfur element, which is prepared by the preparation method.

The invention also provides an application of the tobacco stem-based activated carbon electrode material self-doped with the sulfur element in preparing a capacitor.

Has the advantages that: the invention provides a brand-new preparation method of a tobacco stem-based activated carbon electrode material self-doped with sulfur element; the tobacco stem-based active carbon electrode material prepared by the method is self-doped with active sulfur element with higher content, and the specific capacitance of the super capacitor can be improved and the energy density can be increased by adopting the tobacco stem-based active carbon electrode material to prepare the super capacitor. In addition, the method is a brand-new method for recycling the tobacco straws; the method reduces the harm of burning and discarding the tobacco straws to the atmosphere and the environment, and improves the additional economic value of tobacco planting.

Detailed Description

The present invention is further explained below with reference to specific examples, which are not intended to limit the present invention in any way.

Example 1

(1) Planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws into 200 meshes to obtain tobacco straw powder, and then putting the tobacco straw powder into an oven to be dried for 24 hours at the temperature of 70 ℃;

(3) putting the dried tobacco stalk powder into a tube furnace under the atmosphere of nitrogen (the flow rate is 3 mL/min)^-1) At 5 ℃ in min^-1The temperature is increased to 550 ℃ and kept for 2 hours for pyrolysis treatment; cooling to room temperature along with the furnace after heat treatment, and taking out to obtain a tobacco stem carbon powder precursor;

(4) mixing the tobacco stalk carbon powder precursor with KOH, adding water for further grinding and kneading, then putting the mixture into a vacuum drying oven for drying at 70 ℃ for 12 hours, and drying to obtain a tobacco stalk carbon powder/KOH mixture;

(5) then the tobacco stalk carbon powder is putThe KOH mixture was placed in a tube furnace under nitrogen (flow rate 3 mL. min.)^-1) At 5 ℃ in min^-1The temperature is increased to 850 ℃ and kept for 2h, and then pyrolysis treatment is carried out; cooling to room temperature, taking out, and fully washing the obtained sample by using 1M hydrochloric acid solution; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

specifically, in the flue-cured tobacco planting process in the step (1), when compound fertilizer is applied to tobacco, the compound fertilizer is dissolved in the picea japonica branch and leaf water extract for fertilization; wherein the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 5; the picea javanica branch and leaf water extract is prepared by the following method: putting the dried schefflera octophylla branches and leaves into water, and soaking for 20 days to obtain the schefflera octophylla branch and leaf water extract; the weight ratio of the picea javanica branches and leaves to water is 1: 15.

Specifically, the compound fertilizer consists of a monopotassium phosphate fertilizer, diammonium phosphate, urea, a potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate; the total nitrogen application amount of the compound fertilizer is 97.5kg/hm²(ii) a P in the compound fertilizer₂O₅:K₂O＝1:2:3.5。

Specifically, the weight ratio of the tobacco stalk carbon powder precursor to KOH in the step (4) is 1: 5; the ratio of the added weight of the water to the total weight of the tobacco stalk carbon powder precursor and the KOH in the step (4) is 1: 1.

Example 2

(1) Planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws into 100 meshes to obtain tobacco straw powder, and then putting the tobacco straw powder into an oven to be dried for 24 hours at the temperature of 70 ℃;

(3) putting the dried tobacco stalk powder into a tube furnace under the atmosphere of nitrogen (the flow rate is 3 mL/min)^-1) At 3 ℃ min^-1The temperature is increased to 500 ℃ and is preserved for 3 hours for pyrolysis treatment; cooling to room temperature along with the furnace after heat treatment, and taking out to obtain a tobacco stem carbon powder precursor;

(4) mixing the tobacco stalk carbon powder precursor with KOH, adding water for further grinding and kneading, then putting the mixture into a vacuum drying oven for drying at 70 ℃ for 12 hours, and drying to obtain a tobacco stalk carbon powder/KOH mixture;

(5) then putting the tobacco stalk carbon powder/KOH mixture into a tube furnace under the atmosphere of nitrogen (the flow rate is 3mL & min)^-1) At 3 ℃ min^-1The temperature is increased to 800 ℃ and is preserved for 3 hours for pyrolysis treatment; cooling to room temperature, taking out, and fully washing the obtained sample by using 1M hydrochloric acid solution; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

specifically, in the flue-cured tobacco planting process in the step (1), when compound fertilizer is applied to tobacco, the compound fertilizer is dissolved in the picea japonica branch and leaf water extract for fertilization; wherein the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 3; the picea javanica branch and leaf water extract is prepared by the following method: putting the dried schefflera octophylla branches and leaves into water, and soaking for 10 days to obtain the schefflera octophylla branch and leaf water extract; the weight ratio of the schefflera octophylla branches and leaves to the water is 1: 8.

Specifically, the compound fertilizer consists of a monopotassium phosphate fertilizer, diammonium phosphate, urea, a potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate; the total nitrogen application amount of the compound fertilizer is 90kg/hm²(ii) a P in the compound fertilizer₂O₅:K₂O＝1:2:4。

Specifically, the weight ratio of the tobacco stalk carbon powder precursor to KOH in the step (4) is 1: 3; the ratio of the added weight of the water to the total weight of the tobacco stalk carbon powder precursor and the KOH in the step (4) is 1: 1.

Example 3

(1) Planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws into 300 meshes to obtain tobacco straw powder, and then putting the tobacco straw powder into an oven to be dried for 24 hours at the temperature of 70 ℃;

(3) putting the dried tobacco stalk powder into a tube furnace under the atmosphere of nitrogen (the flow rate is 3 mL/min)^-1) At 6 ℃ min^-1The temperature is increased to 600 ℃ and kept for 1h for pyrolysis treatment; cooling to room temperature along with the furnace after heat treatment, and taking out to obtain a tobacco stem carbon powder precursor;

(4) mixing the tobacco stalk carbon powder precursor with KOH, adding water for further grinding and kneading, then putting the mixture into a vacuum drying oven for drying at 70 ℃ for 12 hours, and drying to obtain a tobacco stalk carbon powder/KOH mixture;

(5) then putting the tobacco stalk carbon powder/KOH mixture into a tube furnace under the atmosphere of nitrogen (the flow rate is 3mL & min)^-1) At 6 ℃ min^-1The temperature is increased to 900 ℃ and kept for 1h for pyrolysis treatment; cooling to room temperature, taking out, and fully washing the obtained sample by using 1M hydrochloric acid solution; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

specifically, in the flue-cured tobacco planting process in the step (1), when compound fertilizer is applied to tobacco, the compound fertilizer is dissolved in the picea japonica branch and leaf water extract for fertilization; wherein the weight ratio of the compound fertilizer to the picea javanica branch and leaf water extract is 1: 8; the picea javanica branch and leaf water extract is prepared by the following method: putting the dried schefflera octophylla branches and leaves into water, and soaking for 30 days to obtain the schefflera octophylla branch and leaf water extract; the weight ratio of the picea javanica branches and leaves to water is 1: 25.

Specifically, the compound fertilizer consists of a monopotassium phosphate fertilizer, diammonium phosphate, urea, a potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate; the total nitrogen application amount of the compound fertilizer is 100kg/hm²(ii) a P in the compound fertilizer₂O₅:K₂O＝1:3:3。

Specifically, the weight ratio of the tobacco stalk carbon powder precursor to KOH in the step (4) is 1: 8; the ratio of the added weight of the water to the total weight of the tobacco stalk carbon powder precursor and the KOH in the step (4) is 1: 1.

Comparative example 1

(1) Planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws into 200 meshes to obtain tobacco straw powder, and then putting the tobacco straw powder into an oven to be dried for 24 hours at the temperature of 70 ℃;

(3) putting the dried tobacco stalk powder into a tube furnace under the atmosphere of nitrogen (the flow rate is 3 mL/min)^-1) At 5 ℃ in min^-1The temperature is increased to 550 ℃ and kept for 2 hours for pyrolysis treatment; cooling to room temperature along with the furnace after heat treatment, and taking out to obtain a tobacco stem carbon powder precursor;

(4) mixing the tobacco stalk carbon powder precursor with KOH, adding water for further grinding and kneading, then putting the mixture into a vacuum drying oven for drying at 70 ℃ for 12 hours, and drying to obtain a tobacco stalk carbon powder/KOH mixture;

(5) then putting the tobacco stalk carbon powder/KOH mixture into a tube furnace under the atmosphere of nitrogen (the flow rate is 3mL & min)^-1) At 5 ℃ in min^-1The temperature is increased to 850 ℃ and kept for 2h, and then pyrolysis treatment is carried out; cooling to room temperature, taking out, and fully washing the obtained sample by using 1M hydrochloric acid solution; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

specifically, in the flue-cured tobacco planting process in the step (1), when compound fertilizer is applied to tobacco, the compound fertilizer is dissolved in water for fertilization; wherein the weight ratio of the compound fertilizer to the water is 1: 5.

Specifically, the compound fertilizer consists of a monopotassium phosphate fertilizer, diammonium phosphate, urea, a potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate; the total nitrogen application amount of the compound fertilizer is 97.5kg/hm²(ii) a P in the compound fertilizer₂O₅:K₂O＝1:2:3.5。

Specifically, the weight ratio of the tobacco stalk carbon powder precursor to KOH in the step (4) is 1: 5; the ratio of the added weight of the water to the total weight of the tobacco stalk carbon powder precursor and the KOH in the step (4) is 1: 1.

Comparative example 1 is different from example 1 in that comparative example 1 does not apply the aqueous extract of the twig and leaf of schefflera octophylla simultaneously during the fertilization process.

Comparative example 2

(1) Planting flue-cured tobacco;

(2) taking tobacco straws, crushing the tobacco straws into 200 meshes to obtain tobacco straw powder, and then putting the tobacco straw powder into an oven to be dried for 24 hours at the temperature of 70 ℃;

(3) putting the dried tobacco stalk powder into a tube furnace under the atmosphere of nitrogen (the flow rate is 3 mL/min)^-1) At 5 ℃ in min^-1The temperature is increased to 550 ℃ and kept for 2 hours for pyrolysis treatment; cooling to room temperature along with the furnace after heat treatment, and taking out to obtain a tobacco stem carbon powder precursor;

(4) mixing the tobacco stalk carbon powder precursor with KOH, adding water for further grinding and kneading, then putting the mixture into a vacuum drying oven for drying at 70 ℃ for 12 hours, and drying to obtain a tobacco stalk carbon powder/KOH mixture;

(5) then putting the tobacco stalk carbon powder/KOH mixture into a tube furnace under the atmosphere of nitrogen (the flow rate is 3mL & min)^-1) At 5 ℃ in min^-1The temperature is increased to 850 ℃ and kept for 2h, and then pyrolysis treatment is carried out; cooling to room temperature, taking out, and fully washing the obtained sample by using 1M hydrochloric acid solution; obtaining the tobacco stem-based active carbon electrode material self-doped with sulfur element;

specifically, in the flue-cured tobacco planting process in the step (1), when compound fertilizer is applied to tobacco, the compound fertilizer is dissolved in the camphor tree branch and leaf water extract for fertilization; wherein the weight ratio of the compound fertilizer to the camphor tree branch and leaf water extract is 1: 5; the camphor tree branch and leaf water extract is prepared by the following method: putting dried branches and leaves of the cinnamomum camphora into water, and soaking for 20 days to obtain the cinnamomum camphora branch and leaf water extract; the weight ratio of the branches and leaves of the camphor trees to the water is 1: 15.

Specifically, the compound fertilizer consists of a monopotassium phosphate fertilizer, diammonium phosphate, urea, a potassium nitrate fertilizer, calcium phosphate, potassium sulfate and magnesium sulfate; the total nitrogen application amount of the compound fertilizer is 97.5kg/hm²(ii) a P in the compound fertilizer₂O₅:K₂O＝1:2:3.5。

Specifically, the weight ratio of the tobacco stalk carbon powder precursor to KOH in the step (4) is 1: 5; the ratio of the added weight of the water to the total weight of the tobacco stalk carbon powder precursor and the KOH in the step (4) is 1: 1.

Comparative example 2 differs from example 1 in that comparative example 2 applies an aqueous extract of the branches and leaves of cinnamomum camphora at the same time during the fertilization process.

The sulfur content in the tobacco rod-based activated carbon electrode material self-doped with sulfur prepared in examples 1 to 3 and comparative examples 1 and 2 was measured by using an elemental analysis tester, and the test results are shown in table 1.

TABLE 1 determination of sulfur content in sulfur-doped tobacco rod-based activated carbon electrode materials

	Elemental sulfur content
		EXAMPLE 1 tobacco-based activated carbon electrode Material self-doped with elemental Sulfur	4.38％
EXAMPLE 2 tobacco-rod-based activated carbon electrode Material self-doped with elemental Sulfur	3.91％
		EXAMPLE 3 tobacco-straw-based activated carbon electrode Material self-doped with elemental Sulfur	3.74％
Comparative example 1 tobacco rod-based active carbon electrode material self-doped with sulfur element	0.62％
		Comparative example 2 tobacco rod based active carbon electrode material self-doped with sulfur element	0.77％

As can be seen from the test data in Table 1, the sulfur content in the tobacco rod-based activated carbon electrode material self-doped with sulfur prepared in examples 1-3 is greatly improved compared with that in comparative example 1; the method is characterized in that when the compound fertilizer is applied to the tobacco, the compound fertilizer and the picea japonica branch and leaf water extract are applied together; the aqueous extract of the branches and leaves of the schefflera octophylla can promote the enrichment of sulfur elements in tobacco stems, and more sulfur elements are precipitated in corresponding tobacco straws; further improving the sulfur content in the tobacco rod-based active carbon electrode material self-doped with sulfur.

As can be seen from the test data in table 1, the sulfur content in the tobacco stem-based activated carbon electrode material self-doped with sulfur prepared in comparative example 2 is not significantly increased compared to that in comparative example 1 in examples 1 to 3, which indicates that when applying a compound fertilizer to tobacco, the compound fertilizer and the water extract of the branches and leaves of cinnamomum camphora are applied together; the cinnamomum camphora branch and leaf water extract cannot promote the enrichment of sulfur elements in tobacco stems and cannot effectively improve the sulfur element content of the tobacco stem-based active carbon electrode material doped with sulfur elements. This also suggests that not any aqueous extract will promote sulfur enrichment in the tobacco stems; only the aqueous extract of the branches and leaves of the schefflera octophylla can promote the enrichment of sulfur elements in tobacco stems, and further the sulfur element content of the tobacco stem-based active carbon electrode material self-doped with sulfur elements can be improved.