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 a graphene oxide dispersion liquid and an organic carbon source for hydrothermal reaction, and performing freeze-drying treatment on a mixed material obtained by the hydrothermal reaction to obtain reduced graphene oxide gel; (2) carrying out carbonization treatment on the reduced graphene oxide gel to obtain a composite graphene carbon material; and (3) preparing tobacco fibers into a substrate, mixing a tobacco extracting solution, perfume, an adhesive and the composite graphene carbon material to obtain tobacco composite pulp, and coating the surface of the substrate with the tobacco composite pulp to obtain the composite graphene modified reconstituted tobacco. The three-dimensional composite graphene carbon material is prepared through a special method, and the combustion efficiency, the smoke amount and the spice utilization rate of the reconstituted tobacco can be greatly improved by using the three-dimensional composite graphene carbon material to prepare the reconstituted tobacco.

Description

Technical Field

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

[0002] At present, there are two main methods for reconstituted tobacco: papermaking and pulping. Among them, papermaking is widely used in actual production. The papermaking method uses discarded tobacco stems, tobacco dust, low-grade tobacco fragments, etc. in the cigarette production process as raw materials, and first separates them into solid and liquid parts through extraction. The liquid part is used as the coating liquid raw material, and the solid part is made into a base material through the corresponding papermaking process; the coating liquid is coated on the base material to form reconstituted tobacco, and then made into tobacco substitute products in the form of tobacco shreds. This method can make full use of raw materials and reduce resource waste.

[0003] However, as people's living standards improve, the impact of smoking on people's health has attracted more and more attention from the market. During the smoking process, gases such as carbon monoxide produced by incomplete combustion of tobacco is one of the important factors affecting health. At the same time, since spices need to be added to reconstituted tobacco leaves to enhance the smoking experience, the utilization rate of spices in reconstituted tobacco leaves is low, which also increases the amount of spices added, resulting in a significant increase in costs.

[0004] CN115336781A discloses a reconstituted tobacco leaf and a preparation method and application thereof, the preparation method comprising the following steps: (1) steam-exploding tobacco stems to obtain exploded tobacco stems; (2) wet-grinding a portion of the exploded tobacco stems obtained in step (1) to obtain a slurry, extracting the slurry to obtain an extract and an extracted solid; (3) subjecting the extracted solid obtained in step (2) to pulping, papermaking and dehydration to obtain a reconstituted tobacco leaf base; (4) dehydrating and drying a portion of the exploded tobacco stems obtained in step (1), and then ball-milling to obtain tobacco stem ultrafine particles; (5) mixing the extract, tobacco stem ultrafine particles, a surfactant and a thickener to obtain a fragrance coating liquid; (6) spraying the fragrance coating liquid obtained in step (5) on the reconstituted tobacco leaf base obtained in step (3), and drying to obtain the reconstituted tobacco leaf.

[0005] CN111789279A discloses a method for preparing a tobacco-like reconstituted tobacco leaf, comprising the following steps: soaking plant raw materials in hot water, performing solid-liquid separation to obtain plant extract and plant fiber, filtering and concentrating the plant extract to obtain a concentrated solution, adding spices to prepare a coating solution, beating the plant fiber to obtain plant pulp and mixing it with wood pulp to obtain a pulp, and then placing it on a net to form a pulp, sprinkling short flax fibers on the pulp during the forming process, and then drying and coating the coating solution to obtain a finished product.

[0006] The combustion efficiency and flavor utilization rate of the reconstituted tobacco produced by the above scheme are both low, resulting in poor smoking experience and high cost. During the combustion process, there is also incomplete combustion, which easily produces harmful gases such as CO and leaf tar, which are harmful to health. 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 obtains a three-dimensional composite graphene carbon material by a special method. The reconstituted tobacco leaf prepared with the three-dimensional composite graphene carbon material can greatly improve the combustion efficiency, smoke volume and flavor utilization rate of the reconstituted tobacco leaf.

[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 a graphene oxide dispersion and an organic carbon source for a hydrothermal reaction, and freeze-drying the mixture obtained by the hydrothermal reaction to obtain a reduced graphene oxide gel;

[0011] (2) carbonizing the reduced graphene oxide gel to obtain a composite graphene carbon material;

[0012] (3) Making tobacco fibers into a substrate, mixing tobacco extract, flavoring, adhesive and composite graphene carbon material to obtain tobacco composite slurry, coating the tobacco composite slurry on the surface of the substrate, and obtaining composite graphene-modified reconstituted tobacco leaves.

[0013] The present invention first mixes a graphene oxide dispersion with an organic carbon source to carry out a hydrothermal reaction. During the hydrothermal reaction, the organic carbon source can reduce the graphene oxide in the hydrothermal process, and the two are compounded in the reduction process. The organic carbon source is distributed on the surface and between layers of the reduced graphene oxide to construct a reduced graphene oxide gel with a three-dimensional structure. After freeze-drying, the reduced graphene oxide gel can retain its three-dimensional structure. The reduced graphene oxide gel is subjected to a high-temperature carbonization treatment, so that the derivatives generated by the organic carbon source in the hydrothermal process are completely converted into porous hard carbon, thereby obtaining a three-dimensional composite graphene carbon material with a large interlayer spacing and a high specific surface area. The three-dimensional composite graphene carbon material is mixed with tobacco extract, spices and other materials. The tobacco substances and spices in the tobacco extract are evenly distributed on the surface and between the layers of the three-dimensional composite graphene carbon material. Since the three-dimensional composite graphene carbon material has a large interlayer spacing and a high specific surface area, the amount of tobacco substances and spices contained is greatly increased. Moreover, due to its stable structure, the structure of the reconstructed tobacco leaves will not collapse during the smoking process, thereby increasing the oxygen intake, improving the heating efficiency and the amount of smoke, and reducing the generation of carbon monoxide. During the combustion process, the aroma of the spices can also be greatly improved, and the amount of spices used can be appropriately reduced to improve the utilization rate of the spices.

[0014] Preferably, the mass concentration of the graphene oxide dispersion in step (1) is 5 g / L to 10 g / L, for example, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L or 10 g / L, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the organic carbon source in step (1) comprises any one of glucose, fructose, lactose or maltose, or a combination of at least two of them. Typical but non-limiting combinations include a combination of glucose and maltose, a combination of lactose and maltose, or a combination of glucose and fructose.

[0016] Preferably, the mass ratio of the organic carbon source in step (1) to the graphene oxide in the graphene oxide dispersion is 1:(1-3), for example: 1:1, 1:1.5, 1:2, 1:2.5 or 1:3, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the temperature of the hydrothermal reaction in step (1) is 150°C to 180°C, for example, 150°C, 155°C, 160°C, 170°C or 180°C, etc., and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the time of the hydrothermal reaction in step (1) is 10 h to 20 h, for example, 10 h, 12 h, 15 h, 18 h or 20 h, etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the temperature of the carbonization treatment in step (2) is 800°C to 1200°C, for example, 800°C, 900°C, 1000°C, 1100°C or 1200°C, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the carbonization treatment time in step (2) is 5 h to 10 h, for example, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h, etc., not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] Preferably, the tobacco extract and tobacco fiber in step (3) are prepared by the following method:

[0022] The tobacco raw material is steam-exploded and then crushed, the crushed material, complex enzyme and water are mixed to obtain a mixed liquid, and the mixed liquid is subjected to a heating and leaching treatment to obtain tobacco fibers and tobacco extract.

[0023] Preferably, the tobacco raw material comprises tobacco leaves and / or tobacco stems.

[0024] Preferably, the temperature of the steam explosion is 130°C to 150°C, for example, 130°C, 135°C, 140°C, 145°C or 150°C, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the steam explosion time is 2 min to 5 min, for example, 2 min, 2.5 min, 3 min, 4 min or 5 min, etc., and is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the complex enzyme comprises cellulase and protease.

[0027] Preferably, the mass ratio of cellulase to protease in the complex enzyme is 1:(0.5-2), for example: 1:0.5, 1:0.8, 1:1, 1:1.5 or 1:2, etc., not limited to the listed values, other values ​​not listed in the numerical range are also applicable

[0028] Preferably, the temperature of the heating and leaching treatment is 120°C to 150°C, for example, 120°C, 125°C, 130°C, 140°C or 150°C, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the step (3) of making the tobacco fiber into a substrate comprises the following steps:

[0030] The tobacco fibers are pulped and mixed with porous calcium carbonate and starch, and then aerated, paper-made, shaped and dried to obtain a base sheet.

[0031] Preferably, the mass ratio of the porous calcium carbonate to the starch is 1:(0.5-1), for example: 1:0.5, 1:0.6, 1:0.8, 1:0.9 or 1:1, etc., not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the mass ratio of the porous calcium carbonate to the tobacco fiber is 1:(8-10), for example: 1:8, 1:8.5, 1:9, 1:9.5 or 1:10, etc., and is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the adhesive in step (3) comprises sodium carboxymethyl cellulose.

[0034] Preferably, the mass ratio of the composite graphene carbon material, adhesive and flavor in the tobacco composite pulp in step (3) is 1:(0.2-1):(0.01-0.05), for example: 1:0.5:0.01, 1:0.3:0.02, 1:0.5:0.05, 1:0.8:0.02 or 1:1:0.05, etc., not limited to the listed values, other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, the tobacco composite pulp is concentrated before coating in step (3).

[0036] Preferably, the coating in step (3) is followed by drying.

[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 preparation method described in the first aspect.

[0038] In a third aspect, the present invention provides a cigarette comprising the composite graphene-modified reconstituted tobacco leaf as described in the second aspect.

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

[0040] (1) The present invention prepares a three-dimensional composite graphene carbon material with a large interlayer spacing and a high specific surface area, and mixes the three-dimensional composite graphene carbon material with tobacco extract, spices and other materials. The tobacco substances and spices in the tobacco extract are evenly distributed on the surface and between the layers of the three-dimensional composite graphene carbon material. Since the three-dimensional composite graphene carbon material has a large interlayer spacing and a high specific surface area, the amount of tobacco substances and spices contained is greatly increased. Moreover, since its structure is stable, the structure of the reconstructed tobacco leaves will not collapse during the smoking process, thereby increasing the oxygen intake, improving the combustion efficiency and smoke volume, and reducing the generation of carbon monoxide. During the combustion process, the aroma of the spices can also be greatly improved, and the amount of spices used can be appropriately reduced, thereby improving the utilization rate of the spices.

[0041] (2) The smoldering rate of the composite graphene-modified reconstituted tobacco leaves of the present invention can reach within 67s / 150mm, and the sum of the peak areas of the pyrolysis products can reach more than 75%. According to GB5606.4-2005 "Technical Requirements for Sensory Tobacco", the aroma sensory evaluation score can reach more than 25.5. By adjusting the condition parameters in the preparation process, the smoldering rate of the composite graphene-modified reconstituted tobacco leaves can reach within 63s / 150mm, and the sum of the peak areas of the pyrolysis products can reach more than 82%. According to GB5606.4-2005 "Technical Requirements for Sensory Tobacco", the aroma sensory evaluation score can reach more than 30.5. DETAILED DESCRIPTION

[0042] 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.

[0043] Example 1

[0044] This embodiment provides a composite graphene-modified reconstituted tobacco leaf, and the preparation method of the composite graphene-modified reconstituted tobacco leaf is as follows:

[0045] (1) mixing a graphene oxide dispersion having a mass concentration of 8 g / L with glucose in a mass concentration of glucose to graphene oxide of 1:2, performing a hydrothermal reaction at 160° C. for 15 h, and freeze-drying the mixture obtained by the hydrothermal reaction to obtain a reduced graphene oxide gel;

[0046] (2) carbonizing the reduced graphene oxide gel at 1000° C. for 8 h to obtain a composite graphene carbon material;

[0047] (3) The tobacco and tobacco leaves are subjected to steam explosion treatment at 140°C for 3 minutes and then crushed, the crushed materials are mixed with a composite enzyme (cellulase and protease mass ratio is 1:1), and the crushed materials are subjected to leaching treatment at 130°C to obtain tobacco fibers and tobacco extract. The tobacco fibers are pulped and mixed with porous calcium carbonate and starch in a mass ratio of 9:1:0.6, and aerated, paper-made, shaped, and dried to obtain a substrate, and the tobacco extract, spices, sodium carboxymethyl cellulose and composite graphene carbon materials are mixed to obtain a tobacco composite pulp (composite graphene carbon material, sodium carboxymethyl cellulose, spices mass ratio is 1:0.5:0.02), and after concentration, the tobacco composite pulp is coated on the surface of the substrate and dried to obtain composite graphene modified reconstituted tobacco leaves.

[0048] Example 2

[0049] This embodiment provides a composite graphene-modified reconstituted tobacco leaf, and the preparation method of the composite graphene-modified reconstituted tobacco leaf is as follows:

[0050] (1) mixing a graphene oxide dispersion having a mass concentration of 5 g / L with glucose in a mass concentration of glucose to graphene oxide of 1:1, performing a hydrothermal reaction at 150° C. for 20 h, and freeze-drying the mixture obtained by the hydrothermal reaction to obtain a reduced graphene oxide gel;

[0051] (2) carbonizing the reduced graphene oxide gel at 800° C. for 10 h to obtain a composite graphene carbon material;

[0052] (3) The tobacco and tobacco leaves are subjected to steam explosion treatment at 130° C. for 5 min and then crushed, the crushed materials are mixed with a composite enzyme (the mass ratio of cellulase and protease is 1:0.5), and the crushed materials are subjected to leaching treatment at 120° C. to obtain tobacco fibers and tobacco extract. The tobacco fibers are pulped and mixed with porous calcium carbonate and starch in a mass ratio of 8:1:0.5, and aerated, paper-made, shaped, and dried to obtain a substrate, and the tobacco extract, spices, sodium carboxymethyl cellulose, and composite graphene carbon materials are mixed to obtain a tobacco composite pulp (the mass ratio of composite graphene carbon materials, sodium carboxymethyl cellulose, and spices is 1:0.2:0.01), and after concentration, the tobacco composite pulp is coated on the surface of the substrate and dried to obtain composite graphene-modified reconstituted tobacco leaves.

[0053] Example 3

[0054] This embodiment provides a composite graphene-modified reconstituted tobacco leaf, and the preparation method of the composite graphene-modified reconstituted tobacco leaf is as follows:

[0055] (1) mixing a graphene oxide dispersion having a mass concentration of 10 g / L with glucose in a mass concentration of glucose to graphene oxide of 1:3, performing a hydrothermal reaction at 180° C. for 15 h, and freeze-drying the mixture obtained by the hydrothermal reaction to obtain a reduced graphene oxide gel;

[0056] (2) carbonizing the reduced graphene oxide gel at 1200° C. for 5 h to obtain a composite graphene carbon material;

[0057] (3) The tobacco and tobacco leaves are subjected to steam explosion treatment at 150° C. for 2 min and then crushed, the crushed materials are mixed with a composite enzyme (cellulase and protease mass ratio is 1:2), and the crushed materials are subjected to leaching treatment at 150° C. to obtain tobacco fibers and tobacco extract. The tobacco fibers are pulped and mixed with porous calcium carbonate and starch in a mass ratio of 10:1:1, and a substrate is obtained by aeration, papermaking, shaping, and drying. The tobacco extract, spices, sodium carboxymethyl cellulose and composite graphene carbon material are mixed to obtain tobacco composite pulp (composite graphene carbon material, sodium carboxymethyl cellulose, spices mass ratio is 1:1:0.05), and after concentration, the tobacco composite pulp is coated on the surface of the substrate and dried to obtain composite graphene modified reconstituted tobacco leaves.

[0058] Example 4

[0059] The only difference between this embodiment and embodiment 1 is that the temperature of the hydrothermal reaction is 120° C., and the other conditions and parameters are exactly the same as those in embodiment 1.

[0060] Example 5

[0061] The only difference between this embodiment and embodiment 1 is that the temperature of the hydrothermal reaction is 200° C., and the other conditions and parameters are exactly the same as those in embodiment 1.

[0062] Example 6

[0063] The only difference between this embodiment and embodiment 1 is that the mass ratio of glucose to graphene oxide is 1:0.5, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0064] Example 7

[0065] The only difference between this embodiment and embodiment 1 is that the mass ratio of glucose to graphene oxide is 1:4, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0066] Comparative Example 1

[0067] The only difference between this comparative example and Example 1 is that the composite graphene carbon material is replaced with a commercially available graphene material (purchased from Zhejiang Lanmupu Technology Co., Ltd.), and the other conditions and parameters are exactly the same as those in Example 1.

[0068] Comparative Example 2

[0069] The only difference between this comparative example and Example 1 is that no composite graphene carbon material is added, and other conditions and parameters are exactly the same as those in Example 1.

[0070] Performance Test:

[0071] The sum of the peak areas of the reconstituted tobacco leaves and the pyrolysis products prepared in the test examples and comparative examples was tested, and the aroma sensory evaluation scores were tested according to GB5606.4-2005 "Technical Requirements for Sensory Evaluation of Cigarettes". The test results are shown in Table 1:

[0072] Table 1

[0073]

[0074]

[0075] As can be seen from Table 1, according to Examples 1-8, the smoldering rate of the composite graphene-modified reconstituted tobacco leaves of the present invention can reach within 67s / 150mm, the sum of the peak areas of the pyrolysis products can reach more than 75%, and the aroma sensory evaluation score obtained by testing according to GB5606.4-2005 "Technical Requirements for Sensory Tobacco" can reach more than 25.5. By adjusting the condition parameters in the preparation process, the smoldering rate of the composite graphene-modified reconstituted tobacco leaves can reach within 63s / 150mm, the sum of the peak areas of the pyrolysis products can reach more than 82%, and the aroma sensory evaluation score obtained by testing according to GB5606.4-2005 "Technical Requirements for Sensory Tobacco" can reach more than 30.5.

[0076] 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 temperature of the hydrothermal reaction will affect the structure of the obtained composite graphene carbon material and thus affect the effect of the reconstituted tobacco leaves. When the temperature of the hydrothermal reaction is controlled at 150°C to 180°C, the effect of obtaining the reconstituted tobacco leaves is better. If the temperature of the hydrothermal reaction is too low, the reduction of the graphene oxide is incomplete, the amount of reduced graphene oxide is reduced, and the structural stability of the composite graphene material is reduced. If the temperature of the hydrothermal reaction is too high, the structure of the composite graphene carbon material is destroyed and collapsed, resulting in reduced stability of the material.

[0077] By comparing Example 1 with Examples 6-7, it can be seen that in the preparation process of the composite graphene-modified reconstructed tobacco leaves described in the present invention, the mass ratio of the organic carbon source to the graphene oxide will affect the structure of the composite graphene carbon material and thus affect the effect of the reconstructed tobacco leaves. When the mass ratio of the organic carbon source to the graphene oxide is controlled at 1:1-3, the effect of preparing the reconstructed tobacco leaves is better. If the addition amount of glucose (organic carbon source) is too low, the reduction of the graphene oxide is incomplete, the amount of reduced graphene oxide is reduced, and the structural stability of the composite graphene material is reduced. If the addition amount of the organic carbon source is too high, the carbon material is filled in the structure of the graphene in large quantities, resulting in a decrease in the filling amount of tobacco substances and flavors, resulting in a poor effect of the reconstructed tobacco leaves.

[0078] By comparing Example 1 and Comparative Example 1, it can be seen that conventional commercially available graphene has a relatively low interlayer spacing and specific surface area. During the use of reconstituted tobacco leaves, it is difficult to ensure its structural stability and structural collapse will occur. The three-dimensional structured reduced graphene oxide constructed by the present invention not only has a larger interlayer spacing and a high specific surface area, but also greatly improves its structural stability and will not collapse during use.

[0079] 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 a graphene oxide dispersion and an organic carbon source for a hydrothermal reaction, and freeze-drying the mixture obtained by the hydrothermal reaction to obtain a reduced graphene oxide gel; (2) carbonizing the reduced graphene oxide gel to obtain a composite graphene carbon material; (3) Making tobacco fibers into a substrate, mixing tobacco extract, flavoring, adhesive and composite graphene carbon material to obtain tobacco composite slurry, coating the tobacco composite slurry on the surface of the substrate, and obtaining composite graphene-modified reconstituted tobacco leaves.

2. The preparation method according to claim 1, characterized in that The mass concentration of the graphene oxide dispersion in step (1) is 5 g / L to 10 g / L; Preferably, the organic carbon source in step (1) comprises any one of glucose, fructose, lactose or maltose, or a combination of at least two thereof; Preferably, the mass ratio of the organic carbon source in step (1) to the graphene oxide in the graphene oxide dispersion is 1:(1-3).

3. The preparation method according to claim 1 or 2, characterized in that: The temperature of the hydrothermal reaction in step (1) is 150° C. to 180° C.; Preferably, the hydrothermal reaction time in step (1) is 10 h to 20 h.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The temperature of the carbonization treatment in step (2) is 800° C. to 1200° C.; Preferably, the carbonization treatment time in step (2) is 5 h to 10 h.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The tobacco extract and tobacco fiber in step (3) are prepared by the following method: The tobacco raw material is steam-exploded and then crushed, the crushed material, a composite enzyme and water are mixed to obtain a mixed liquid, and the mixed liquid is subjected to a heating and leaching treatment to obtain tobacco fibers and a tobacco extract; Preferably, the tobacco raw material comprises tobacco leaves and / or tobacco stems; Preferably, the temperature of the steam explosion is 130°C to 150°C; Preferably, the steam explosion time is 2 min to 5 min; Preferably, the complex enzyme comprises cellulase and protease; Preferably, the mass ratio of cellulase to protease in the complex enzyme is 1:(0.5-2); Preferably, the temperature of the heating and leaching treatment is 120°C to 150°C.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The step (3) of making the tobacco fiber into a substrate comprises the following steps: The tobacco fibers are beaten and mixed with porous calcium carbonate and starch, and then aerated, paper-made, shaped and dried to obtain a substrate; Preferably, the mass ratio of the porous calcium carbonate to the starch is 1:(0.5-1); Preferably, the mass ratio of the porous calcium carbonate to the tobacco fiber is 1:(8-10).

7. The preparation method according to any one of claims 1 to 6, characterized in that: The adhesive in step (3) comprises sodium carboxymethyl cellulose; Preferably, the mass ratio of the composite graphene carbon material, the adhesive and the flavor in the tobacco composite slurry in step (3) is 1:(0.2-1):(0.01-0.05).

8. The preparation method according to any one of claims 1 to 7, characterized in that: Step (3) before coating, the tobacco composite pulp is concentrated; Preferably, the coating in step (3) is followed by drying.

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

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

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