Preparation method of bismuth nanoparticle-graphene oxide ordered laminated superstructure nanomaterial

Abstract

The invention provides a preparation method of a bismuth nanoparticle-graphene oxide ordered laminated superstructure material, which comprises the following steps: carrying out surface modification on hydrophilic two-dimensional graphene nanosheets through organic ligand molecules to obtain modified graphene oxide which is dissolved in a non-polar organic polar solvent and has ideal colloidal stability; then uniformly mixing with uniform bismuth nanoparticles which are prefabricated and dispersed in a non-polar solvent according to a ratio, and carrying out processes of solvent evaporation induced lamellar intercalation self-assembly and ligand pre-crosslinking, carbonization, high-temperature activation and the like; the Van der Waals interaction among ligand molecules is utilized to realize the collaborative ordered assembly and confinement of the bismuth nanoparticles among graphene oxide sheet layers, and a bismuth nanoparticle-graphene oxide laminated superstructure material product is obtained. The method is simple in process, low in cost, safe and reliable, has good universality, is convenient for large-scale preparation, is beneficial to popularization and application, and is suitable for the fields of battery negative electrodes, supercapacitors and the like.

Description

Technical Field

[0001] The present invention belongs to the fields of nanomaterials and electrochemistry, and particularly relates to a preparation method of a bismuth nanoparticle-graphene oxide ordered laminated superstructure nanomaterial. Background Art

[0002] In recent years, due to advantages such as high energy density and long cycle life, lithium-ion batteries have developed rapidly in fields such as portable electronic products. However, the scarcity and high demand of lithium resources limit the large-scale production of lithium-ion batteries. Sodium is the sixth most abundant element in the earth's crust, with uniform resource distribution and low price. Therefore, sodium-ion batteries are considered a powerful alternative to lithium-ion batteries. Currently, people are exploring high-performance cathode materials for sodium-ion batteries, especially anode materials. However, due to reasons such as service life and capacity, finding a more ideal anode material for sodium-ion batteries remains a great challenge. Therefore, the development of advanced anode materials is crucial for the large-scale application of sodium-ion batteries. Sodium-ion batteries have revived as an important alternative energy storage device for large-scale energy storage, which requires sodium-ion batteries to have a long cycle life and a high power density.

[0003] As an advanced battery anode material, bismuth-based materials have high theoretical capacity, low reaction potential, environmental friendliness, relatively abundant reserves, and stability in various electrolyte environments, thus enhancing the sustainability and cost-effectiveness of the battery system. However, despite these advantages of bismuth materials, some challenges are still faced during actual cycling, such as structural degradation and electrochemical performance decay caused by volume expansion, poor electrical contact and decreased cycling stability caused by particle fragmentation, and low ionic conductivity. In addition, the inherent semi-metallic conductivity of bismuth materials limits the diffusion of sodium ions and electron transport. In recent years, to overcome these drawbacks, researchers have proposed various strategies, including nanosizing bismuth particles, designing appropriate nanostructures, integrating multifunctional bismuth nanoparticles, preparing composite materials, and innovative surface modification or doping techniques. These methods have significantly improved the cycling stability and rate performance of bismuth anodes. Despite some progress, except for a few cases, the combination of bismuth with highly conductive materials as an anode material still introduces some new key challenges. These challenges include reduced volumetric capacity, low mass loading, particle aggregation, increased production cost and process complexity, and low Coulombic efficiency, mainly due to the inherent challenges during the composite process of bismuth nanoparticles, such as low density, high specific surface area, and complex manufacturing processes.

[0004] In contrast, preparing composite materials using highly conductive materials is an effective synthesis method. Graphene shows great potential in the anode of sodium-ion batteries due to its high specific surface area, excellent electrical conductivity, and mechanical properties. At the same time, it is cost-effective in industry, showing good mass loading, volume capacity, energy density, Coulomb efficiency, and practicality. However, such composite materials are susceptible to volume fluctuations and high strains during cycling, which usually leads to severe mechanical fracture and instability of the solid electrolyte interface layer, ultimately resulting in rapid capacity decay. In addition, due to the relatively slow sodium-ion storage kinetics after the composite of bismuth particles and graphene, it is more vulnerable to non-uniform sodium intercalation, leading to a decrease in reversible capacity and rate performance. Therefore, designing a bismuth-based composite electrode structure to achieve fast charging, extended cycle life, and significant volume capacity is still challenging under high current density and high mass loading conditions.

[0005] In the present invention, taking advantage of the low melting point of bismuth particles, we prepare a bismuth nanoparticle-reduced graphene oxide hybrid laminated superstructure nanomaterial through the method of synergistic and ordered intercalation assembly of bismuth nanoparticles and graphene oxide, realizing the in-plane confinement sintering of graphene. The bismuth nanoparticles between the graphene layers can play the role of nanoconfinement. The reaction conditions of the whole preparation process are mild, safe, and easy to operate. Using oxygen in the air as an oxidant, no catalytic additives are required, the production cost is low, the chemical activity is high, and it is expected to be applied in fields such as metal-ion batteries, supercapacitors, and photocatalysis. At the same time, it has good dispersibility in non-polar solvents and is easy to co-process with polymer materials. Summary of the Invention

[0006] The object of the present invention is to propose a preparation method for a bismuth nanoparticle-reduced graphene oxide ordered laminated superstructure nanomaterial.

[0007] A preparation method for a bismuth nanoparticle-reduced graphene oxide ordered laminated superstructure nanomaterial proposed by the present invention first prepares modified graphene oxide through ligand exchange, and then ultrasonically mixes it evenly with uniform bismuth nanoparticles. After solvent evaporation self-assembly and carbonization, a bismuth nanoparticle-reduced graphene oxide ordered laminated superstructure nanomaterial is obtained.

[0008] At the same time, the present invention also provides the bismuth nanoparticle-reduced graphene oxide ordered laminated superstructure nanomaterial obtained by the above preparation method.

[0009] The preparation method for a bismuth nanoparticle-reduced graphene oxide ordered laminated superstructure nanomaterial proposed by the present invention includes the following steps: (1) Prepare a dispersion of modified graphene oxide Graphene oxide is added to non-polar solvent Ⅰ to obtain a mixture of graphene oxide, and then an organic amine is added to the mixture of graphene oxide. After ultrasonic dispersion treatment for 1 - 200 min, a dispersion Ⅰ is obtained; then an organic acid is added to dispersion Ⅰ, and ultrasonic dispersion treatment is carried out again for 1 - 200 min to obtain a dispersion Ⅱ; after adding a polar solvent to dispersion Ⅱ, the supernatant is discarded by centrifugation, and the lower precipitate is the modified graphene oxide; the precipitate is dispersed in non-polar solvent Ⅱ to obtain a dispersion of modified graphene oxide; (2) Prepare a uniform dispersion of bismuth nanoparticles Bismuth neodecanoate is added to 5 mL of 1-octadecene. Under vacuum conditions, the mixed solution is degassed at 115 - 125 °C for 1.5 - 2.5 hours to remove moisture and oxygen therein; the obtained solution is heated to 75 - 85 °C, and strong stirring is carried out, then 0.24 mL of dodecanethiol is added, and the solution is maintained at this temperature for 4.5 - 5.5 minutes. The solution turns yellow, indicating the formation of bismuth dodecanethiol complex. 1 - 2 mL of trioctylphosphine is injected into the bismuth dodecanethiol complex, and then the solution is cooled to the growth temperature and further aged at this growth temperature. After aging for a certain time at the growth temperature, a solution is obtained. By adding a mixture of acetone and tetrahydrofuran to the solution and centrifuging and washing multiple times, a powder of bismuth nanoparticles is collected; the powder is dispersed in non-polar solvent Ⅱ to obtain a dispersion of modified bismuth nanoparticles; the growth temperature is 55 - 80 °C; the aging time is 30 min - 2 h; meanwhile, by adjusting the amount of trioctylphosphine added, the growth temperature and the aging time, the size of the nanoparticles can be controlled; (3)Intercalation assembly to prepare a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial The dispersion of modified graphene oxide prepared in step (1) and the uniform dispersion of bismuth nanoparticles prepared in step (2) are mixed in proportion. After ultrasonic dispersion treatment, through solvent evaporation-induced intercalation self-assembly, an ordered stacked bismuth nanoparticle-graphene oxide stacked superstructure is obtained; the bismuth nanoparticle-graphene oxide stacked superstructure is heat-treated in an inert atmosphere at a heating rate of 0.5 - 50 °C / min to obtain a carbon-coated bismuth nanoparticle-graphene oxide stacked superstructure nanomaterial.

[0010] In the present invention, in step (1), the mass ratio of graphene oxide to non-polar solvent Ⅰ is 1:1 - 1:100; the volume ratio of the organic amine to non-polar solvent Ⅰ is 1:1 - 1:100; the volume ratio of the organic amine to the organic acid is 1:0.1 - 1:10; the volume ratio of non-polar solvent Ⅰ to the polar solvent is 1:0.5 - 1:10.

[0011] In the present invention, in step (2), the volume ratio of acetone to tetrahydrofuran is 10:1; the mass ratio of bismuth nanoparticles to non-polar solvent II is 1:1 to 1:100.

[0012] In the present invention, in step (2), the centrifugation speed is 4000 - 5000 rpm, the centrifugation time is 5 - 15 min, and the number of times is 2 - 4 times; the specific selection is determined by the size requirements of the final product.

[0013] In the present invention, in step (2), the size of the size-controllable bismuth nanoparticles is 6 - 27 nm.

[0014] In the present invention, in steps (1) and (2), the non-polar solvent is one or more of n-hexane, toluene, chloroform, cyclohexane, carbon tetrachloride, dichloromethane, octane, bromoethane, carbon disulfide or tetrachloroethylene.

[0015] In the present invention, in step (3), the temperature of graphitization is 350 - 800 °C; preferably, the graphitization time is 2 - 6 h; preferably, the graphitization is carried out in an N 2 / Ar protective atmosphere.

[0016] The beneficial effects of the present invention are as follows: The present invention prepares bismuth nanoparticle-graphene oxide hybrid laminated superstructure nanomaterials by the method of synergistic and ordered intercalation assembly of bismuth nanoparticles and graphene oxide, realizing the in-layer sintering of graphene. The bismuth nanoparticles between the graphene layers can play the role of nano-confinement. The reaction conditions in the whole preparation process are mild, safe and easy to operate. Using oxygen in the air as an oxidant, no catalytic additives are required, the production cost is low, the chemical activity is high, and it is expected to be applied in the fields of metal ion batteries, supercapacitors, photocatalysis, etc. At the same time, it has good dispersibility in non-polar solvents and is easy to co-process with polymer materials. Description of the Drawings

[0017] Figure 1 It is a scanning electron microscope image of graphene oxide prepared in Example 1 of the present invention; Figure 2 It is a transmission electron microscope image of uniform bismuth nanoparticles prepared in Example 1 of the present invention; Figure 3 It is a scanning electron microscope image of the intercalation-assembled bismuth nanoparticle-graphene oxide laminated superstructure material prepared in Example 1 of the present invention; Figure 4 It is a scanning electron microscope image of the intercalation-assembled bismuth nanoparticle-graphene oxide laminated superstructure material prepared in Example 2 of the present invention; Figure 5 It is a scanning electron microscope image of the intercalation-assembled bismuth nanoparticle-graphene oxide laminated superstructure material prepared in Example 3 of the present invention; Figure 6 It is the scanning electron microscope image of the bismuth nanoparticle-graphene oxide composite material prepared in Comparative Example 1 of the present invention. Detailed implementation manners

[0018] The technical solutions of the present invention will be further described below in conjunction with specific embodiments. The raw materials used in the following embodiments can be obtained from conventional commercial channels without special instructions; the processes adopted, without special instructions, are all conventional processes in the art. Example 1

[0019] (1) Preparation of modified graphene oxide dispersion 40 mg of graphene oxide was added to 20 mL of n-hexane to obtain a mixture of graphene oxide and n-hexane. Then, 2 mL of oleylamine was added to this mixture, and after 20 min of ultrasonic dispersion treatment, dispersion I was obtained; further, 2 mL of oleic acid was added to dispersion I, and ultrasonic dispersion treatment was carried out again for 20 min to obtain dispersion II; further, 20 mL of ethanol was added to dispersion II, and the supernatant was discarded by centrifugation. The precipitate in the lower layer was the modified graphene oxide material; further, 10 mL of chloroform was added to obtain the modified graphene oxide dispersion; (2) Preparation of uniform bismuth nanoparticles 0.732 g of bismuth neodecanoate was added to 5 mL of 1-octadecene. Under vacuum conditions, the mixed solution was degassed at 120 °C for 2 hours to remove the moisture and oxygen therein; subsequently, the solution was heated to 80 °C and vigorously stirred, then 0.24 mL of dodecanethiol was added, and the solution was maintained at this temperature for 5 minutes. The solution turned yellow, indicating the formation of bismuth dodecanethiol complex; subsequently, 1 mL of trioctylphosphine was injected into the solution, and then the solution was cooled to 65 °C and further aged at this temperature for 30 min; finally, the bismuth nanoparticles were centrifuged in a mixed solvent of acetone:tetrahydrofuran = 10:1 at a speed of 4000 rpm for 10 min, and the above centrifugation step was repeated 3 times to collect the bismuth nanoparticles in powder form; the powder was dispersed in chloroform to form a stable bismuth nanoparticle dispersion III; (3) Preparation of intercalated assembled bismuth nanoparticle-graphene oxide laminated superstructure material Mix the modified graphene oxide dispersion prepared in step (1) and the uniform bismuth nanoparticle dispersion III prepared in step (2) in a ratio of 3:1. After ultrasonic dispersion treatment, an ordered stacked bismuth nanoparticle-graphene oxide laminated superstructure is obtained through solvent evaporation-induced intercalation self-assembly. Heat-treat the bismuth nanoparticle-graphene oxide laminated superstructure at a heating rate of 2 °C / min in an inert atmosphere (N2 / Ar). The heat-treatment temperature is 650 °C. After maintaining for 2 hours, slowly cool it to room temperature at a cooling rate of 2 °C / min to obtain a carbon-coated bismuth nanoparticle-graphene oxide laminated superstructure material; Figure 1 Figure 3 is the transmission electron microscopy image of the modified graphene oxide prepared in Example 1 of the present invention. The monolayer nature of graphene oxide can be seen from its edge; Figure 2 Figure 4 is the transmission electron microscopy image of the uniform bismuth nanoparticles prepared in Example 1 of the present invention. The image shows uniform-sized twin nanocrystals with a particle size of about 11 nm; Figure 3 Figure 5 is the scanning electron microscopy image of the intercalated assembled bismuth nanoparticle-graphene oxide laminated superstructure material prepared in Example 1 of the present invention. It can be seen that: bismuth nanoparticles are uniformly assembled between graphene oxide layers, stacked alternately, and there is no obvious phase separation; although the low melting point of bismuth will cause particle melting, the present invention realizes its confined sintering between graphene layers, and the bismuth nanoparticles between graphene layers can play a role in nano-confinement. Example 2

[0020] (1) Preparation of modified graphene oxide dispersion Add 50 mg of graphene oxide to 25 mL of n-hexane to obtain a mixture of graphene oxide and n-hexane. Then add 2.5 mL of oleylamine to the mixture. After 20 min of ultrasonic dispersion treatment, dispersion I is obtained. Further, add 2.5 mL of oleic acid to dispersion I and perform ultrasonic dispersion treatment for another 20 min to obtain dispersion II. Further, add 25 mL of ethanol to dispersion II, centrifuge and discard the supernatant. The lower precipitate is the modified graphene oxide material. Further, add 10 mL of chloroform to obtain the modified graphene oxide dispersion; (2) Preparation of uniform bismuth nanoparticles 7.32 g of bismuth neodecanoate was added to 50 mL of 1-octadecene. Under vacuum conditions, the mixed solution was degassed at 120 °C for 2 hours to remove the moisture and oxygen therein. Subsequently, the solution was heated to 80 °C and vigorously stirred, then 2.4 mL of dodecanethiol was added and maintained at this temperature for 5 minutes. The solution turned yellow, indicating the formation of bismuth dodecanethiol complex. Subsequently, 10 mL of trioctylphosphine was injected into the solution, and then the solution was cooled to 65 °C and further aged at this temperature for 30 min. Finally, the bismuth nanoparticles were centrifuged at 4000 rpm for 10 min by dispersing them in a mixed solvent of acetone:tetrahydrofuran = 10:1. The above centrifugation step was repeated 3 times to collect the bismuth nanoparticles in powder form. The powder was dispersed in chloroform to form a stable bismuth nanoparticle dispersion III. (3) Preparation of intercalated assembled bismuth nanoparticle-graphene oxide laminated superstructure material The modified graphene oxide dispersion prepared in step (1) and the uniform bismuth nanoparticle dispersion III prepared in step (2) were mixed at a ratio of 4:1. After ultrasonic dispersion treatment, an ordered stacked bismuth nanoparticle-graphene oxide laminated superstructure was obtained by solvent evaporation-induced intercalation self-assembly. The bismuth nanoparticle-graphene oxide laminated superstructure was heat-treated in an inert atmosphere (N2 / Ar) at a heating rate of 2 °C / min, the heat treatment temperature was 650 °C, and after holding for 2 hours, it was slowly cooled to room temperature at a cooling rate of 2 °C / min to obtain a carbon-coated bismuth nanoparticle-graphene oxide laminated superstructure material. Figure 4 It is the scanning electron microscope image of the intercalated assembled bismuth nanoparticle-graphene oxide laminated superstructure material prepared in Example 2 of the present invention. Example 3

[0021] (1) Preparation of modified graphene oxide dispersion 120 mg of graphene oxide was added to 60 mL of n-hexane to obtain a mixture of graphene oxide and n-hexane. Then, 6 mL of oleylamine was added to the mixture, and after 20 min of ultrasonic dispersion treatment, dispersion I was obtained. Further, 6 mL of oleic acid was added to dispersion I, and ultrasonic dispersion treatment was carried out again for 20 min to obtain dispersion II. Further, 60 mL of ethanol was added to dispersion II, and the supernatant was centrifuged and discarded. The lower precipitate was the modified graphene oxide material. Further, 30 mL of chloroform was added to obtain the modified graphene oxide dispersion. Preparation of uniform bismuth nanoparticles 14.64 g of bismuth neodecanoate was added to 100 mL of 1-octadecene. Under vacuum conditions, the mixed solution was degassed at 120 °C for 2 hours to remove moisture and oxygen therein. Subsequently, the solution was heated to 80 °C and vigorously stirred, then 4.8 mL of dodecanethiol was added and maintained at this temperature for 5 minutes. The solution turned yellow, indicating the formation of bismuth dodecanethiol complex. Subsequently, 20 mL of trioctylphosphine was injected into the solution. Then the solution was cooled to 65 °C and further aged at this temperature for 30 min. Finally, the bismuth nanoparticles were centrifuged at 4000 rpm for 10 min by dispersing them in a mixed solvent of acetone:tetrahydrofuran = 10:1. The above centrifugation step was repeated 3 times to collect the bismuth nanoparticles in powder form. The powder was dispersed in chloroform to form a stable bismuth nanoparticle dispersion III. (3) Preparation of intercalated assembled bismuth nanoparticle-graphene oxide laminated superstructure material The modified graphene oxide dispersion prepared in step (1) and the uniform bismuth nanoparticle dispersion III prepared in step (2) were mixed at a ratio of 5:1. After ultrasonic dispersion treatment, an ordered stacked bismuth nanoparticle-graphene oxide laminated superstructure was obtained through solvent evaporation-induced intercalated self-assembly. The bismuth nanoparticle-graphene oxide laminated superstructure was heat-treated in an inert atmosphere (N2 / Ar) at a heating rate of 2 °C / min, the heat treatment temperature was 650 °C, and after holding for 2 hours, it was slowly cooled to room temperature at a cooling rate of 2 °C / min to obtain a carbon-coated bismuth nanoparticle-graphene oxide laminated superstructure material. Figure 5 It is the scanning electron microscope image of the intercalated assembled bismuth nanoparticle-graphene oxide laminated superstructure material prepared in Example 3 of the present invention.

[0022] Comparative example: In this comparative example, a traditional physical grinding and mixing method was used to prepare a bismuth nanoparticle-graphene oxide composite material, which specifically included the following steps:

[0023] 40 mg of graphene oxide was added to 20 mL of n-hexane to obtain a mixture of graphene oxide and n-hexane. Then 2 mL of oleylamine was added to this mixture, and after 20 min of ultrasonic dispersion treatment, a dispersion I was obtained. Further, 2 mL of oleic acid was added to dispersion I, and ultrasonic dispersion treatment was carried out again for 20 min to obtain dispersion II. Further, 20 mL of ethanol was added to dispersion II, and the supernatant was centrifuged and discarded. The lower precipitate was the modified graphene oxide material. Further, 10 mL of chloroform was added to obtain a modified graphene oxide dispersion. 7.32 g of bismuth neodecanoate was added to 50 mL of 1-octadecene. Under vacuum conditions, the mixed solution was degassed at 120 °C for 2 hours to remove the moisture and oxygen therein. Subsequently, the solution was heated to 80 °C and vigorously stirred, then 2.4 mL of dodecanethiol was added and maintained at this temperature for 5 minutes. The solution turned yellow, indicating the formation of bismuth dodecanethiol complex. Subsequently, 10 mL of trioctylphosphine was injected into the solution. Then the solution was cooled to 65 °C and further aged at this temperature for 30 min. Finally, the bismuth nanoparticles were centrifuged at 4000 rpm for 10 min by dispersing them in a mixed solvent of acetone:tetrahydrofuran = 10:1. The above centrifugation step was repeated 3 times to collect the bismuth nanoparticles in powder form. The powder was dispersed in chloroform to form a stable bismuth nanoparticle dispersion III; The modified graphene oxide dispersion and the bismuth nanoparticle dispersion III were respectively carbonized according to the method in step (3) of Example 1 to obtain powders. Subsequently, the graphene and bismuth nanoparticle powders were mixed at a ratio of 4:1 and assembled by physical grinding to obtain a bismuth nanoparticle-graphene oxide composite material; Figure 6 It is the scanning electron microscope image of the bismuth nanoparticle-graphene oxide composite material prepared in Comparative Example 1 of the present invention. It can be seen that there is a serious phase separation phenomenon in the figure, which may be due to the rapid process of the physical grinding mixing method, inhibiting the ordered co-assembly of the two components; The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial, characterized in that The steps include: (1) Preparation of modified graphene oxide dispersion Adding graphene oxide to a non-polar solvent I to obtain a graphene oxide mixture, then adding an organic amine to the graphene oxide mixture, subjecting the mixture to ultrasonic dispersion treatment for 30 to 60 minutes, to obtain a dispersion I; then adding an organic acid to the dispersion I, subjecting the mixture to ultrasonic dispersion treatment for 30 to 60 minutes, to obtain a dispersion II; adding a polar solvent to the dispersion II, centrifuging and discarding the supernatant, and the lower precipitate is the modified graphene oxide; dispersing the precipitate in a non-polar solvent II, to obtain a modified graphene oxide dispersion; (2) Preparation of uniform bismuth nanoparticle dispersion Bismuth neodecanoate is added to 5 mL of 1-octadecene, and the mixed solution is degassed at 115-125° C. for 1.5-2.5 hours under vacuum conditions to remove moisture and oxygen therein; the obtained solution is heated to 75-85° C. and vigorously stirred, and then 0.24 mL of dodecanethiol is added and maintained at this temperature for 4.5-5.5 min, and the solution turns yellow, indicating the formation of a bismuth dodecanethiol complex, and 1-2 mL of trioctylphosphine is injected into the bismuth dodecanethiol complex, and then the solution is cooled to a growth temperature and further aged at the growth temperature to obtain a solution after aging at the growth temperature for a certain period of time; a mixture of acetone and tetrahydrofuran is added to the solution, and the powder of bismuth nanoparticles is collected by centrifugation and washing multiple times; the powder of bismuth nanoparticles is dispersed in a non-polar solvent II to obtain a modified bismuth nanoparticle dispersion; the growth temperature is 55-80° C.; the aging time is 30 min-2 h; at the same time, the size of the nanoparticles can be controlled by adjusting the amount of trioctylphosphine added, the growth temperature and the aging time; (3) Preparation of Bismuth Nanoparticle-Graphene Oxide Ordered Laminated Superstructure Nanomaterials by Intercalation Assembly The modified graphene oxide dispersion obtained in step (1) and the uniform bismuth nanoparticle dispersion obtained in step (2) are mixed in proportion, and after ultrasonic dispersion treatment, intercalation self-assembly is induced by solvent volatilization to obtain an orderly stacked bismuth nanoparticle-graphene oxide laminated superstructure; the bismuth nanoparticle-graphene oxide laminated superstructure is heat-treated at a heating rate of 0.5-50°C / min in an inert atmosphere to obtain a carbon-coated bismuth nanoparticle-graphene oxide laminated superstructure nanomaterial.

2. The method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial according to claim 1, characterized in that In step (1), the mass ratio of the graphene oxide to the non-polar solvent I is 1:1-1:100; the volume ratio of the organic amine to the non-polar solvent I is 1:1-1:100; the volume ratio of the organic amine to the organic acid is 1:0.1-1:10; and the volume ratio of the non-polar solvent I to the polar solvent is 1:0.5-1:

10.

3. The method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial according to claim 1, characterized in that In step (2), the volume ratio of acetone to tetrahydrofuran is 10:1; the mass ratio of bismuth nanoparticles to non-polar solvent II is 1:1-1:

100.

4. The method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial according to claim 1, characterized in that The centrifugal washing described in step (2) has a centrifugal speed of 4000-5000 rpm, a centrifugal time of 5-15 min, and a number of times of 2-4 times; the specific selection is determined by the size requirements of the final product.

5. The method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial according to claim 1, characterized in that The size of the controllable bismuth nanoparticles in step (2) is 6-27 nm.

6. The method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial according to claim 1, characterized in that The non-polar solvent in step (1) and step (2) is one or more of n-hexane, toluene, chloroform, cyclohexane, carbon tetrachloride, dichloromethane, octane, ethyl bromide, carbon disulfide or tetrachloroethylene.

7. The method for preparing a bismuth nanoparticle-graphene oxide ordered stacked superstructure nanomaterial according to claim 1, characterized in that The graphitization temperature in step (3) is 350-800°C; the graphitization time is 2-6 h; and the graphitization is carried out in a N2 / Ar protective atmosphere.

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