Composite graphene modified reconstituted tobacco as well as preparation method and application thereof

Abstract

The invention provides composite graphene modified reconstituted tobacco and a preparation method and application thereof, the preparation method comprises the following steps: (1) mixing 2-aminoterephthalic acid with a solvent to obtain a ligand solution, mixing an iron source, a zinc source, polyvinylpyrrolidone functionalized graphene and the ligand solution, and carrying out an ultrasonic reaction to obtain a graphene metal composite framework material solution; and (2) tobacco powder, an atomizing agent, an adhesive and the graphene metal composite framework material solution are mixed to obtain tobacco thick paste, the tobacco thick paste is flatly laid on a heating steel belt, and the composite graphene modified reconstituted tobacco is obtained after pressing and drying. According to the method, the graphene metal composite framework material is added into the reconstituted tobacco, and the graphene metal composite framework material is composed of unique structures and elements, so that the combustion performance and smoke amount of the reconstituted tobacco can be improved, generation of highly focused objects in smoke can be reduced, and the reconstituted tobacco has the advantages of being high in reconstituted tobacco yield and high in reconstituted tobacco quality. And the release of highly concerned objects is reduced while the suction experience is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of traditional burning cigarettes and relates to a composite graphene-modified reconstituted tobacco leaf and a preparation method and application thereof. Background Art

[0002] Reconstituted tobacco is made from tobacco stems, tobacco fragments, tobacco dust, tobacco sticks and other tobacco materials, and is processed using papermaking technology to produce a product with the characteristic tobacco flavor. Reconstituted tobacco has been widely used in the tobacco industry due to its good processing resistance, significant tar reduction effect, and strong product quality plasticity.

[0003] Due to the complex composition of reconstituted tobacco leaves, their thermal conductivity is poor, which reduces the smoking experience. At the same time, due to incomplete combustion, a large amount of highly concerned substances will be produced, which affect human health.

[0004] CN118633773A discloses a method for preparing reconstituted tobacco leaves, and its products and applications. The method comprises: (1) extracting a first tobacco raw material in water and then performing solid-liquid separation to obtain a liquid phase and a solid phase, concentrating the liquid phase to obtain a concentrated solution, and mixing the concentrated solution with a liquid modifier to obtain a first spraying liquid; mixing the solid phase with an added fiber and then performing a pulping process and a papermaking process to obtain a substrate; mixing tobacco powder prepared from a second tobacco raw material with a smoke generating agent and an adhesive in water to obtain a second spraying liquid; and (2) spraying the first spraying liquid on one side of the substrate and the second spraying liquid on the other side, and drying the substrate to obtain the reconstituted tobacco leaves.

[0005] CN118556897A discloses a thick slurry reconstituted tobacco leaf and its preparation method and cigarette, which relates to the field of reconstituted tobacco leaf production. The thick slurry reconstituted tobacco leaf raw material components are composed of tobacco powder, sugar, fiber, and adhesive, and can be directly used as an auxiliary material in traditional cigarettes.

[0006] The above scheme improves the smoking experience by changing the composition of reconstituted tobacco leaves, but it cannot significantly improve the combustion performance and smoke volume of the reconstituted tobacco leaves, and the generation of highly concerned substances cannot be improved. Summary of the invention

[0007] The purpose of the present invention is to provide a composite graphene-modified reconstituted tobacco leaf, and a preparation method and application thereof. The present invention adds a graphene-metal composite skeleton material to the reconstituted tobacco leaf. The graphene-metal composite skeleton material, by virtue of its unique structure and element composition, can not only improve the combustion performance and smoke volume of the reconstituted tobacco leaf, but also reduce the generation of highly concerned substances in the smoke, thereby improving the smoking experience while reducing harm to the body.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a composite graphene-modified reconstituted tobacco leaf, the preparation method comprising the following steps:

[0010] (1) mixing 2-aminoterephthalic acid with a solvent to obtain a ligand solution, mixing an iron source, a zinc source, and graphene functionalized with polyvinyl pyrrolidone with the ligand solution and performing an ultrasonic reaction to obtain a graphene metal composite skeleton material solution;

[0011] (2) Tobacco powder, an atomizer, an adhesive and a graphene metal composite skeleton material solution are mixed to obtain a tobacco slurry, the tobacco slurry is spread on a heated steel belt, and then pressed and dried to obtain the composite graphene-modified reconstituted tobacco leaf.

[0012] The present invention pre-prepares a graphene metal composite skeleton material, which has the advantages of large specific surface area, uniform pore distribution and high thermal conductivity, and contains iron and zinc which can play a certain catalytic role. The graphene metal composite skeleton material is applied to reconstituted tobacco leaves, which can increase the combustion performance and smoke volume of the reconstituted tobacco leaves, improve consumers' smoking satisfaction, and also help to improve the energy utilization rate of the heater. The iron and zinc contained in the graphene metal composite skeleton material are low in cost and rich in adsorbed oxygen, which can significantly improve the combustion performance of tobacco substances. At the same time, the iron and zinc can play a certain catalytic role in the decomposition of nitrogen oxides and carbon monoxide during use, thereby reducing the harm of smoke to the human body.

[0013] Preferably, the solvent in step (1) comprises N,N-dimethylformamide, ethanol and water.

[0014] Preferably, the volume ratio of N,N-dimethylformamide, ethanol and water is (10-20):(0.5-5):1, for example: 10:0.5:1, 15:1:1, 12:3:1, 18:5:1 or 20:5:1, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the iron source in step (1) comprises ferric acetate.

[0016] Preferably, the zinc source in step (1) comprises zinc acetate.

[0017] Preferably, the molar ratio of the iron element in the iron source to the zinc element in the zinc source in step (1) is (0.2-0.5):1, for example: 0.2:1, 0.25:1, 0.3:1, 0.4:1 or 0.5:1, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the polyvinyl pyrrolidone functionalized graphene in step (1) is prepared by the following method:

[0019] Polyvinyl pyrrolidone, graphene oxide and water are mixed and stirred, ammonia water and hydrazine hydrate are added during the stirring process, and the polyvinyl pyrrolidone functionalized graphene is obtained by solid-liquid separation after heating reaction.

[0020] Preferably, the mass ratio of the polyvinyl pyrrolidone, graphene oxide, ammonia water and hydrazine hydrate is (2.5-3.5):1:(100-200):(10-20), for example: 2.5:1:100:10, 3:1:150:15, 2.8:1:120:18, 3.2:1:120:16 or 3.5:1:200:20, etc., not limited to the listed values, other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the temperature of the heating reaction is 40-80°C, for example, 40°C, 50°C, 60°C, 70°C or 80°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the heating reaction time is 2 to 5 hours, for example, 2 hours, 2.5 hours, 3 hours, 4 hours or 5 hours, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the mass ratio of the polyvinyl pyrrolidone-functionalized graphene in step (1) to the 2-aminoterephthalic acid in the ligand solution is 1:(1-10), for example: 1:1, 1:2, 1:5, 1:8 or 1:10, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the molar ratio of the total molar amount of the iron source and the zinc source in step (1) to the 2-aminoterephthalic acid is 1:(20-50), for example: 1:20, 1:25, 1:30, 1:40 or 1:50, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the ultrasonic reaction time in step (1) is 4 to 10 hours, for example, 4 hours, 5 hours, 6 hours, 8 hours or 10 hours, etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the atomizer in step (2) comprises glycerol and / or propylene glycol.

[0027] Preferably, plant fibers are also added during the mixing process in step (2).

[0028] Preferably, the plant fibers include bagasse fibers.

[0029] Preferably, the mass ratio of the atomizer and the tobacco powder in step (2) is (0.1-0.3):1, for example: 0.1:1, 0.15:1, 0.2:1, 0.25:1 or 0.3:1, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the adhesive in step (2) comprises carboxymethyl cellulose.

[0031] Preferably, the mass ratio of the graphene metal composite skeleton material to the tobacco powder in the graphene metal composite skeleton material solution in step (2) is (1-5):100, for example: 1:100, 2:100, 3:100, 4:100 or 5:100, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the drying in step (2) includes one-stage drying and two-stage drying.

[0033] Preferably, the temperature of the first drying stage is 50-80°C, for example, 50°C, 55°C, 60°C, 70°C or 80°C, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] Preferably, the drying time is 1 to 5 minutes, for example, 1 minute, 2 minutes, 3 minutes, 4 minutes or 5 minutes, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, the temperature of the second stage drying is 100-120°C, for example, 100°C, 105°C, 110°C, 115°C or 120°C, etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, the second-stage drying time is 5 to 20 minutes, for example, 5 minutes, 8 minutes, 10 minutes, 15 minutes or 20 minutes, etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] In a second aspect, the present invention provides a composite graphene-modified reconstituted tobacco leaf, wherein the composite graphene-modified reconstituted tobacco leaf is prepared by the method described in the first aspect.

[0038] In a third aspect, the present invention provides a tobacco product, comprising reconstituted tobacco leaves modified with the composite graphene as described in the second aspect.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention adds a graphene metal composite skeleton material to reconstituted tobacco leaves. The graphene metal composite skeleton material, by virtue of its unique structure and element composition, can not only improve the combustion performance and smoke volume of the reconstituted tobacco leaves, but also reduce the generation of highly concerned substances in the smoke, thereby improving the smoking experience while reducing harm to the body. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0042] The polyvinyl pyrrolidone functionalized graphene used in the examples and comparative examples of the present invention was prepared by the following method:

[0043] First, add 7.5mL of 1mg / mL PVP aqueous solution to a conical flask, then add 2.5mL of 1mg / mL graphene oxide aqueous solution, and then add 9.57mL of water. To mix it evenly, place it on a magnetic stirrer and stir for 20 minutes. During the stirring process, add 400μL of ammonia water and 30μL of hydrazine hydrate. Put the conical flask containing the mixed solution into a water bath, adjust the water bath to 65°C, and the water bath time is 4h. After cooling to room temperature in the water bath, divide it into 10 2mL centrifuge tubes, centrifuge it at 12000rpm for 25 minutes, wash the obtained solid twice with secondary water, and dry it to obtain the polyvinyl pyrrolidone functionalized graphene.

[0044] Example 1

[0045] This embodiment provides a composite graphene-modified reconstituted tobacco leaf, wherein the composite graphene-modified reconstituted tobacco leaf is prepared by the following method:

[0046] (1) Weighing 68.0 mg of 2-aminoterephthalic acid and dispersing it in a mixed solution containing 16 mL of N,N-dimethylformamide, 1 mL of ethanol and 1 mL of water, and subjecting it to ultrasonic treatment to uniform dispersion to obtain a ligand solution, mixing iron acetate, zinc acetate and graphene functionalized with polyvinyl pyrrolidone with the ligand solution, and subjecting it to ultrasonic reaction for 6 hours to obtain a graphene metal composite skeleton material solution, wherein the molar ratio of zinc acetate to iron acetate is 0.3:1, and the molar ratio of the total molar amount of zinc acetate and iron acetate to the 2-aminoterephthalic acid is 1:30;

[0047] (2) Tobacco powder, glycerol, carboxymethyl cellulose and a graphene metal composite skeleton material solution are mixed to obtain a tobacco slurry, the tobacco slurry is spread on a heated steel belt, pressed, dried at 70° C. for 3 min, and then dried at 110° C. for 10 min to obtain the composite graphene-modified reconstituted tobacco leaf, wherein the mass ratio of glycerol to tobacco powder is 0.2:1, and the mass ratio of the graphene metal composite skeleton material to tobacco powder is 4:100.

[0048] Example 2

[0049] This embodiment provides a composite graphene-modified reconstituted tobacco leaf, wherein the composite graphene-modified reconstituted tobacco leaf is prepared by the following method:

[0050] (1) Weighing 68.0 mg of 2-aminoterephthalic acid and dispersing it in a mixed solution containing 10 mL of N,N-dimethylformamide, 0.5 mL of ethanol and 1 mL of water, and subjecting it to ultrasonic treatment to uniform dispersion to obtain a ligand solution, mixing iron acetate, zinc acetate, and graphene functionalized with polyvinyl pyrrolidone with the ligand solution, and subjecting it to ultrasonic reaction for 4 hours to obtain a graphene metal composite skeleton material solution, wherein the molar ratio of zinc acetate to iron acetate is 0.2:1, and the molar ratio of the total molar amount of zinc acetate and iron acetate to the 2-aminoterephthalic acid is 1:20;

[0051] (2) Tobacco powder, glycerol, carboxymethyl cellulose and a graphene metal composite skeleton material solution are mixed to obtain a tobacco slurry, the tobacco slurry is spread on a heated steel belt, pressed, dried at 50° C. for 5 min, and then dried at 100° C. for 20 min to obtain the composite graphene-modified reconstituted tobacco leaf, wherein the mass ratio of glycerol to tobacco powder is 0.1:1, and the mass ratio of the graphene metal composite skeleton material to tobacco powder is 1:100.

[0052] Example 3

[0053] This embodiment provides a composite graphene-modified reconstituted tobacco leaf, wherein the composite graphene-modified reconstituted tobacco leaf is prepared by the following method:

[0054] (1) Weighing 68.0 mg of 2-aminoterephthalic acid and dispersing it in a mixed solution containing 20 mL of N,N-dimethylformamide, 5 mL of ethanol and 1 mL of water, and ultrasonically treating it to make it evenly dispersed to obtain a ligand solution, mixing iron acetate, zinc acetate, and graphene functionalized with polyvinyl pyrrolidone with the ligand solution, and subjecting it to ultrasonic reaction for 4 hours to obtain a graphene metal composite skeleton material solution, wherein the molar ratio of zinc acetate to iron acetate is 0.5:1, and the molar ratio of the total molar amount of zinc acetate and iron acetate to the 2-aminoterephthalic acid is 1:50;

[0055] (2) Tobacco powder, glycerol, carboxymethyl cellulose and a graphene metal composite skeleton material solution are mixed to obtain a tobacco slurry, the tobacco slurry is spread on a heated steel belt, pressed, dried at 80°C for 1 min, and then dried at 120°C for 5 min to obtain the composite graphene-modified reconstituted tobacco leaf, wherein the mass ratio of glycerol to tobacco powder is 0.3:1, and the mass ratio of the graphene metal composite skeleton material to tobacco powder is 5:100.

[0056] Example 4

[0057] The only difference between this embodiment and embodiment 1 is that the molar ratio of ferric acetate to zinc acetate is 0.1:1, and other conditions and parameters are exactly the same as those in embodiment 1.

[0058] Example 5

[0059] The only difference between this embodiment and embodiment 1 is that the molar ratio of ferric acetate to zinc acetate is 0.8:1, and other conditions and parameters are exactly the same as those in embodiment 1.

[0060] Example 6

[0061] The only difference between this embodiment and embodiment 1 is that the molar ratio of the total molar amount of ferric acetate and zinc acetate to the 2-aminoterephthalic acid is 1:10, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0062] Example 7

[0063] The only difference between this embodiment and embodiment 1 is that the molar ratio of the total molar amount of ferric acetate and zinc acetate to the 2-aminoterephthalic acid is 1:80, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0064] Example 8

[0065] The only difference between this embodiment and embodiment 1 is that the mass ratio of the graphene metal composite skeleton material to the tobacco powder is 0.5:100, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0066] Example 9

[0067] The only difference between this embodiment and Embodiment 1 is that the mass ratio of the graphene metal composite skeleton material to the tobacco powder is 8:100, and the other conditions and parameters are exactly the same as those in Embodiment 1.

[0068] Comparative Example 1

[0069] The only difference between this comparative example and Example 1 is that zinc acetate is not added, and other conditions and parameters are exactly the same as those in Example 1.

[0070] Comparative Example 2

[0071] The only difference between this comparative example and Example 1 is that ferric acetate is not added, and other conditions and parameters are exactly the same as those in Example 1.

[0072] Comparative Example 3

[0073] The only difference between this comparative example and Example 1 is that no graphene metal composite skeleton material is added, and other conditions and parameters are exactly the same as those in Example 1.

[0074] Performance Testing:

[0075] The reconstituted tobacco leaves prepared in the examples and comparative examples were peeled, cut into shreds, and rolled into tobacco, and the obtained tobacco was tested, wherein the aroma sensory evaluation score was measured according to GB5606.4-2005 "Technical Requirements for Sensory Evaluation of Cigarettes", and the test results are shown in Table 1:

[0076] Table 1

[0077]

[0078] As can be seen from Table 1, from Examples 1-9, the smoldering rate of the tobacco made from the reconstituted tobacco leaves prepared by the method of the present invention can reach within 68s / 150mm, the sum of the peak areas of the pyrolysis products can reach more than 75%, the aroma sensory evaluation score can reach more than 26, and the CO can reach within 4.12mg / stick. By adjusting the content of each component, the smoldering rate of the tobacco can reach within 63s / 150mm, the sum of the peak areas of the pyrolysis products can reach more than 82%, the aroma sensory evaluation score can reach more than 30.5, and the CO can reach within 3.69mg / stick.

[0079] By comparing Example 1 with Examples 4-5, it can be seen that in the preparation process of the composite graphene-modified reconstituted tobacco leaves of the present invention, the molar ratio of iron to zinc will affect its effect. Controlling the molar ratio of iron to zinc at 0.2-0.5:1 can further improve the effect of the prepared reconstituted tobacco leaves. If the amount of iron added is too low, the reduction effect of carbon monoxide is poor and the amount of carbon monoxide generated cannot be effectively reduced. If the amount of iron added is too high, the catalytic reduction of nitrogen oxides catalyzed by zinc is affected, resulting in an increase in the amount of nitrogen oxides generated.

[0080] By comparing Example 1 with Examples 6-7, it can be seen that in the preparation process of the composite graphene-modified reconstituted tobacco leaves of the present invention, the molar ratio of the total molar amount of iron and zinc to the 2-aminoterephthalic acid will affect the effect. Controlling the molar ratio of the total molar amount of iron and zinc to the 2-aminoterephthalic acid within the range of 1:20 to 50 can further improve the effect of the prepared reconstituted tobacco leaves. If the amount of 2-aminoterephthalic acid added is too low, a complete skeleton structure cannot be generated, and the iron and zinc ions are partially in a free state, which affects the stability of the reconstituted tobacco leaves. If the amount of 2-aminoterephthalic acid added is too high, the excess ligands will affect the smoking effect of the reconstituted tobacco leaves.

[0081] By comparing Example 1 and Examples 8-9, it can be seen that in the preparation process of the composite graphene-modified reconstituted tobacco leaves of the present invention, the mass ratio of the graphene metal composite skeleton material to the tobacco powder will affect its effect. Controlling the mass ratio of the graphene metal composite skeleton material to the tobacco powder at 1 to 5:100 can further improve the effect of the prepared reconstituted tobacco leaves. If the graphene metal composite skeleton material is too low, the effect of the reconstituted tobacco leaves cannot be significantly improved. If the amount of the graphene metal composite skeleton material added is too high, the proportion of tobacco powder will be reduced, and the smoking experience of the reconstituted tobacco leaves will decrease.

[0082] By comparing Example 1 with Comparative Examples 1-2, it can be seen that the present invention uses a graphene metal composite skeleton material containing iron and zinc. The two metal elements are rich in adsorbed oxygen, which can significantly improve the combustion performance of tobacco substances. At the same time, the two can synergistically catalyze and play a certain role in catalyzing the decomposition of nitrogen oxides and carbon monoxide, thereby reducing the harm of smoke to the human body.

[0083] By comparing Example 1 and Comparative Example 3, it can be seen that the graphene metal composite skeleton material of the present invention has the advantages of large specific surface area, uniform pore distribution and high thermal conductivity, and the iron and zinc contained therein can play a certain catalytic role. The graphene metal composite skeleton material is applied to reconstituted tobacco leaves, which can increase the combustion performance and smoke volume of the reconstituted tobacco leaves, enhance consumers' smoking satisfaction, and is also beneficial to improving the energy utilization rate of the heater.

[0084] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing composite graphene-modified reconstituted tobacco, characterized in that: The preparation method comprises the following steps: (1) mixing 2-aminoterephthalic acid with a solvent to obtain a ligand solution, mixing an iron source, a zinc source, and graphene functionalized with polyvinyl pyrrolidone with the ligand solution, and obtaining a graphene metal composite skeleton material solution through ultrasonic reaction; (2) Tobacco powder, an atomizer, an adhesive and a graphene metal composite skeleton material solution are mixed to obtain a tobacco slurry, the tobacco slurry is spread on a heated steel belt, and then pressed and dried to obtain the composite graphene-modified reconstituted tobacco leaf.

2. The preparation method according to claim 1, characterized in that The solvent in step (1) comprises N,N-dimethylformamide, ethanol and water; Preferably, the volume ratio of N,N-dimethylformamide, ethanol and water is (10-20):(0.5-5):

1.

3. The preparation method according to claim 1 or 2, characterized in that: The iron source in step (1) comprises ferric acetate; Preferably, the zinc source in step (1) comprises zinc acetate; Preferably, the molar ratio of the iron element in the iron source in step (1) to the zinc element in the zinc source is (0.2-0.5):

1.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The polyvinyl pyrrolidone functionalized graphene in step (1) is prepared by the following method: The polyvinyl pyrrolidone, graphene oxide and water are mixed and stirred, ammonia water and hydrazine hydrate are added during the stirring process, and solid-liquid separation is performed after heating reaction to obtain the polyvinyl pyrrolidone functionalized graphene; Preferably, the mass ratio of polyvinyl pyrrolidone, graphene oxide, ammonia water and hydrazine hydrate is (2.5-3.5):1:(100-200):(10-20); Preferably, the temperature of the heating reaction is 40 to 80°C; Preferably, the heating reaction time is 2 to 5 hours.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The mass ratio of the polyvinyl pyrrolidone functionalized graphene to the 2-aminoterephthalic acid in the ligand solution in step (1) is 1:(1-10); Preferably, the molar ratio of the total molar amount of the iron source and the zinc source in step (1) to the 2-aminoterephthalic acid is 1:(20-50); Preferably, the ultrasonic reaction time in step (1) is 4 to 10 hours.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The atomizer in step (2) includes glycerol and / or propylene glycol; Preferably, plant fiber is also added during the mixing process in step (2); Preferably, the plant fiber comprises bagasse fiber; Preferably, the mass ratio of the atomizer and tobacco powder in step (2) is (0.1-0.3):1; Preferably, the adhesive in step (2) comprises carboxymethyl cellulose.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The mass ratio of the graphene metal composite skeleton material to the tobacco powder in the graphene metal composite skeleton material solution in step (2) is (1-5):

100.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The drying in step (2) includes a first stage drying and a second stage drying; Preferably, the temperature of the first stage of drying is 50-80°C; Preferably, the drying period is 1 to 5 minutes; Preferably, the temperature of the second stage drying is 100-120°C; Preferably, the second stage drying time is 5 to 20 minutes.

9. A composite graphene-modified reconstituted tobacco leaf, characterized in that: The composite graphene-modified reconstituted tobacco leaf is prepared by the method as described in any one of claims 1 to 8.

10. A tobacco product, characterized in that: The tobacco product comprises the composite graphene-modified reconstituted tobacco leaf as claimed in claim 9.

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