A biological small molecule-based carbon aerogel and a preparation method and application thereof

Abstract

The present application relates to a kind of biological small molecule-based carbon aerogel and its preparation method and application.The present application has simple synthesis process, low cost, uses biological small molecule as main raw material, does not need additional template agent or corrosive agent, can be carbonized to obtain carbon aerogel with hollow structure in one step, process is green and environmental protection.The obtained carbon aerogel has many advantages, such as high specific surface area (can reach 590 m 2 / g);By simply adjusting reaction condition, the size of hollow structure can be controlled (tube wall can be adjusted from 16 nm to 177 nm;The diameter of hollow tube can be adjusted from 100 nm to 473 nm);The unique structure of one-dimensional carbon tube filled with graphenelike carbon nanosheet endows it with rich functionality and more broad application prospect.The carbon aerogel is applied to HER catalysis after loading metal and shows excellent electrocatalytic performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aerogel material preparation, and particularly relates to a biological small molecule-based carbon aerogel and a preparation method and application thereof. BACKGROUND

[0002] The energy released by burning fossil fuels is still the main energy required today, but the burning of fossil fuels causes environmental pollution, and people will inevitably face the problem of fossil fuel depletion. Utilizing renewable energy to realize the mutual conversion of electrical energy and chemical energy is considered to be a feasible method to alleviate the fossil fuel crisis. The conversion between electrical energy and chemical energy requires a large amount of energy, therefore, it is crucial to design a catalyst with high activity, selectivity and stability.

[0003] In recent decades, nanostructured electrocatalysts with large pores, different compositions and controllable structures have been widely studied, among which carbon materials are widely used in the field of electrocatalysis due to their extraordinary electrical conductivity and excellent mechanical and chemical properties. Carbon aerogel is a kind of porous carbon material with three-dimensional network structure prepared by sol-gel method, which is composed of nanoscale particles interconnected by small gap pores. Hollow carbon nanomaterials are a kind of carbon materials with hollow structure, the characteristic of which is a three-dimensional structure with a certain gap space surrounded by an outer wall. In addition, this structure also has the characteristics of variable internal cavity size, adjustable shell thickness and composition, and the cavity can be wrapped with other materials. The unique structure endows the hollow carbon material with many characteristics, such as low mass density, large specific surface area, high porosity and good surface permeability. These characteristics make this kind of material widely used in fuel cells, supercapacitors, gas storage, drug delivery and other fields.

[0004] Since Caruso et al. synthesized hollow silica spheres by colloidal template method in 1998 (Caruso F, Caruso RA, Mohwald H. Pore size of 2-20 nm hydroxyapatite shells for functionalization of hollow spheres. Science. 1998;282(5391):1111-4), the synthesis of hollow carbon materials has attracted much attention. Science,1998,282:1111-1114), the synthesis and application of hollow structures have made great progress, and currently researchers have developed various methods for preparing hollow carbon nanomaterials, which can be divided into template method and non-template method according to whether a template is used, wherein the template method can be divided into hard template method (Wong YJ, Zhu L, Teo W S, et al, J. Am. Chem. Soc., 2011, 133: 11422-11425), soft template method (Xu H, Wang W, Angew. Chem. Int. Ed., 2007, 46: 1489-1492) and self-template method (Zeng H, Curr. Nanosci., 2007, 3: 177-181), the hard template method can adjust the shape and size of the cavity freely according to the used hard template, but the removal of the hard template needs to use a strong corrosive solution and is easy to cause the residual of the hard template; the structure stability of the soft template is poor, and after the removal of the soft template, the skeleton has the risk of collapse. The non-template method (Motl NE, Mann AKP, Skrabalak SE, J. Mater. Chem. A, 2013, 1: 5193) is simple to operate and does not need post-treatment, but has poor controllability of the structure.

[0005] With the development of technology, complex hollow structures composed of multiple cavities and contents wrapped in the cavities are more favored by researchers, and such materials usually have more rich functionality and more broad application prospect. Therefore, it has important theoretical and practical significance to develop a simple and green method for controllably preparing carbon aerogels with complex hollow morphology. However, due to the complexity of the structure, it is still challenging to stably synthesize and accurately control such complex hollow structure materials. SUMMARY

[0006] In order to seek unique carbon aerogels with hollow nanostructure, the present application provides a kind of biological small molecule based carbon aerogel and its preparation method and application. The preparation method of the present application does not need additional template agent and catalyst, i.e. using biological small molecule as precursor, obtaining dry gel by sol-gel method, and then carbonizing to obtain carbon aerogel material with unique nano hollow structure.

[0007] The technical scheme adopted by the present application is as follows:

[0008] A preparation method of biological small molecule based carbon aerogel is carried out according to the following steps:

[0009] S1: dispersing guanine in water, stirring and ultrasonicating to obtain a guanine suspension; adding a phenol source and an aldehyde source to the obtained guanine suspension, stirring to obtain a mixture; transferring the obtained mixture into a reaction kettle, placing the reaction kettle in an oven for heating and standing reaction; after the reaction is completed, taking the reaction kettle out of the oven, naturally standing and cooling, discarding the upper liquid, collecting the remaining solid product, dispersing in methanol, stirring, centrifuging, drying and grinding to obtain a biomacromolecule-based xerogel;

[0010] S2: carbonizing the biomacromolecule-based xerogel in an inert gas atmosphere, naturally cooling to obtain a biomacromolecule-based carbon aerogel.

[0011] Further, the phenol source is selected from any one or more of resorcinol, phloroglucinol, o-aminophenol, m-aminophenol and p-aminophenol, and the aldehyde source is selected from any one or more of formaldehyde and glyoxalic acid.

[0012] Further, the temperature of the heating and standing reaction is 70-120℃, and the time is 6-72h.

[0013] Further, the temperature of the carbonization treatment is 800-1200℃, and the time is 1-4h.

[0014] A biomacromolecule-based carbon aerogel prepared by the above preparation method.

[0015] The above biomacromolecule-based carbon aerogel is used in the preparation of a heterogeneous catalyst and an adsorption material.

[0016] Further, the biomacromolecule-based carbon aerogel is subjected to metal loading after heating treatment in an ammonia atmosphere, and is used in the preparation of a heterogeneous catalyst and an adsorption material; the temperature of the heating treatment is 800-1200℃, and the time is 5-60min; and the metal is selected from rhodium, platinum, ruthenium, cobalt, molybdenum, iron, nickel, manganese and copper.

[0017] The reaction mechanism of the present application is as follows: taking guanine as a biological small molecule, resorcinol as a phenol source, and formaldehyde as an aldehyde source as examples. Guanine can catalyze the phenolic aldehyde polycondensation reaction of resorcinol and formaldehyde to form RF prepolymer, meanwhile, guanine molecules self-assemble into supramolecular polymers due to hydrogen bonding and π-π interaction, and the amino group on guanine has a slight positive charge in the solution, which can attract the negatively charged RF prepolymer, and with the reaction proceeding, the coral-like core-shell structure product GRF with a phenolic aldehyde resin shell wrapping guanine core is formed. After one-step high-temperature carbonization of the product GRF, due to the carbon residue rate of the phenolic aldehyde resin being about 60%, and the original morphology can be maintained after carbonization, and the carbon residue rate of guanine is below 10%, and the product after carbonization is a sheet-like product similar to graphene, therefore, the carbonized product GC presents a unique structure of carbon nanometer hollow tube filled with graphene-like sheets, and the carbon tubes are connected to each other, and finally form carbon aerogel. The unique structure and in-situ doping of nitrogen and oxygen elements in the material make the material exhibit excellent catalytic performance when applied to HER catalysis after loading metal.

[0018] Compared with the prior art, the present application has the following advantages:

[0019] 1) simple synthesis process and low cost;

[0020] 2) without additional template agent or etchant, a unique hollow structure can be obtained by one-step carbonization, and the process is green and environmentally friendly;

[0021] 3) by simply adjusting the reaction conditions, the size of the hollow structure can be controlled;

[0022] 4) the unique structure of one-dimensional carbon tube filled with graphene-like carbon nanometer sheets endows it with rich functionality and more broad application prospects, for example, the material exhibits excellent electrocatalytic performance when applied to HER catalysis after loading metal. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 : a, FESEM image of GRF1; b-c, FESEM images of GC1; d, FESEM image of GCN1-Rh1.5.

[0024] Figure 2 : a, FETEM image of GCN1-Rh1.5; b-f, EDS energy spectrum analysis images of GCN1-Rh1.5.

[0025] Figure 3 : a, FESEM image of GC2; b, FESEM image of GC3.

[0026] Figure 4 : a, FESEM image of GC1-ST12; b, FESEM image of GAF.

[0027] Figure 5 : BET test result figure of GC1, GC2, GC3.

[0028] Figure 6 : LSV performance figure of GCN1-Rh0.5, GCN1-Rh1.0, GCN1-Rh1.5, GCN1-Rh2.0, GC1-Rh1.5 applied to HER test. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] The conditions for testing in the embodiments of the present application are as follows: the transmission electron microscope (TEM) testing instrument is Talo F200S; the scanning electron microscope (SEM) testing instrument is Regulus 8100; the nitrogen physical adsorption-desorption testing instrument is micromeritics ASAP 2060, the testing condition is 77K, and the sample is degassed at 120℃ in a vacuum environment for 10h before testing; the HER performance test is performed by using a Shanghai Chenhua CHI660e electrochemical workstation, the HER electrocatalytic performance of the sample is tested in 1M KOH, the electrolyte is purged with nitrogen for 30min before testing, and the test is performed in a three-electrode system electrolytic cell, wherein the counter electrode is a carbon rod electrode, the reference electrode is an Ag / AgCl electrode, the catalyst is loaded on carbon paper, and the loading amount is 1mg / cm 2 .

[0031] Embodiment 1:

[0032] S1: 1.5g guanine was dispersed in 45ml deionized water, stirred at a speed of 1200rpm at room temperature for 10min, and then placed in a cell disrupter for ultrasonic treatment at room temperature for 5min to obtain a guanine suspension; 1.235g resorcinol and 2.4ml formaldehyde were added to the obtained guanine suspension, stirred at room temperature for 10min to obtain a mixed solution; the obtained mixed solution was transferred into a reaction kettle, the reaction kettle was placed in an oven, and reaction was carried out at 85℃ for 72h; after the reaction was completed, the reaction kettle was taken out of the oven, naturally cooled to room temperature, and the upper liquid was discarded, and the remaining solid product was collected, which was light yellow; the obtained solid product was dispersed in 50ml methanol, stirred at room temperature for 12h, and then centrifuged (room temperature, 6000rpm, 10min), the precipitate was dried in a 60℃ oven for 12h, and then fully ground to obtain a biomacromolecule-based xerogel (denoted as GRF1).

[0033] S2: The biomacromolecule-based dry gel obtained in S1 was placed in a tube furnace in a nitrogen atmosphere, and carbonized at 1100°C for 2h at a heating rate of 5°C / min, and then naturally cooled to room temperature to obtain a biomacromolecule-based carbon aerogel (denoted as GC1), which was black.

[0034] S3: The biomacromolecule-based carbon aerogel obtained in S2 was placed in a tube furnace in an ammonia atmosphere, and heated at 1000°C for 15min at a heating rate of 5°C / min, and then naturally cooled to room temperature to obtain an ammonia-treated biomacromolecule-based carbon aerogel (denoted as GCN1).

[0035] S4: 14mg, 28mg, 42mg and 56mg of a 10wt% Rh(NO3)3solution were diluted with 0.1M HNO3to 1.5ml, respectively, and then added dropwise to 100mg of the carbon aerogel material prepared above, respectively; after the material was fully wetted, it was placed in an ultrasonic cleaner and ultrasonically treated for 30min; then the material was placed in a fume hood and naturally dried at room temperature; after complete drying, the material was transferred to a crucible, and then placed in a 10% H2-90% N2mixed gas atmosphere tube furnace, and reduced at 250°C for 2h at a heating rate of 5°C / min, and then taken out after natural cooling to room temperature, and fully ground to obtain a supported material, which was denoted as GCN1-Rh0.5, GCN1-Rh1.0, GCN1-Rh1.5, GCN1-Rh2.0, respectively.

[0036] Example 2:

[0037] S1: 1.5g of guanine was dispersed in 45ml of deionized water, and stirred at room temperature at a speed of 1200rpm for 10min, and then placed in a cell disrupter for ultrasonic treatment at room temperature for 5min to obtain a guanine suspension; 1.235g of resorcinol and 2.4ml of formaldehyde were added to the obtained guanine suspension, and stirred at room temperature for 10min to obtain a mixed solution; the mixed solution was transferred to a reaction kettle, and the reaction kettle was placed in an oven and statically reacted at 85°C for 72h; after the reaction was completed, the reaction kettle was taken out of the oven, and naturally statically cooled to room temperature, and the upper liquid was discarded, and the remaining solid product was collected, which was light yellow; the obtained solid product was dispersed in 50ml of methanol, and stirred at room temperature for 12h, and then centrifuged (room temperature, 6000rpm, 10min), and the precipitate was dried in a 60°C oven for 12h and then fully ground to obtain a biomacromolecule-based dry gel (denoted as GRF1).

[0038] S2: The biomacromolecule-based dry gel obtained in S1 was placed in a tube furnace in a nitrogen atmosphere, and carbonized at 1100 °C for 2 h at a heating rate of 5 °C / min, and then naturally cooled to room temperature to obtain a biomacromolecule-based carbon aerogel (denoted as GC1), which was black.

[0039] S3: 42 mg of a 10 wt% Rh(NO3)3solution was diluted to 1.5 ml with 0.1 M HNO3, and then added dropwise to 100 mg of the carbon aerogel material prepared above; after the material was fully wetted, it was placed in an ultrasonic cleaner and ultrasonically treated for 30 min; then the material was placed in a fume hood and naturally dried at room temperature; after complete drying, the material was transferred to a crucible, and then placed in a 10% H2-90% N2mixed gas atmosphere tube furnace, and reduced at 250 °C for 2 h at a heating rate of 5 °C / min, and then removed after natural cooling to room temperature, and fully ground to obtain a supported material, which was denoted as GC1-Rh1.5.

[0040] Example 3:

[0041] S1: 0.75 g of guanine was dispersed in 45 ml of deionized water, and stirred at room temperature at a speed of 1200 rpm for 10 min, and then placed in a cell disrupter for ultrasonic treatment at room temperature for 5 min to obtain a guanine suspension; 1.235 g of resorcinol and 2.4 ml of formaldehyde were added to the obtained guanine suspension, and stirred at room temperature for 10 min to obtain a mixed solution; the mixed solution was transferred to a reaction kettle, and the reaction kettle was placed in an oven and left to react at 85 °C for 72 h; after the reaction was completed, the reaction kettle was removed from the oven, and naturally cooled to room temperature, and the upper liquid was discarded, and the remaining solid product was collected, which was light yellow; the obtained solid product was dispersed in 50 ml of methanol, and stirred at room temperature for 12 h, and then centrifuged (room temperature, 6000 rpm, 10 min), and the precipitate was dried in a 60 °C oven for 12 h, and then fully ground to obtain a biomacromolecule-based dry gel (denoted as GRF2).

[0042] S2: The biomacromolecule-based dry gel obtained in S1 was placed in a tube furnace in a nitrogen atmosphere, and carbonized at 1100 °C for 2 h at a heating rate of 5 °C / min, and then naturally cooled to room temperature to obtain a biomacromolecule-based carbon aerogel (denoted as GC2), which was black.

[0043] Example 4:

[0044] S1: 3 g of guanine was dispersed in 45 ml of deionized water, stirred at a speed of 1200 rpm at room temperature for 10 min, and then placed in a cell disrupter for ultrasonic treatment at room temperature for 5 min to obtain a guanine suspension; 1.235 g of resorcinol and 2.4 ml of formaldehyde were added to the obtained guanine suspension, stirred at room temperature for 10 min to obtain a mixed solution; the obtained mixed solution was transferred into a reaction kettle, and the reaction kettle was placed in an oven for reaction at 85 °C for 72 h; after the reaction was completed, the reaction kettle was taken out of the oven, and naturally cooled to room temperature; the upper liquid was discarded, and the remaining solid product was collected; the solid product was yellowish; the obtained solid product was dispersed in 50 ml of methanol, stirred at room temperature for 12 h, and then centrifuged (at room temperature, 6000 rpm, 10 min); the precipitate was dried in a 60 °C oven for 12 h, and then fully ground to obtain a biomacromolecule-based xerogel (denoted as GRF3).

[0045] S2: The biomacromolecule-based xerogel obtained in S1 was placed in a tube furnace in a nitrogen atmosphere, and carbonized at a temperature increasing rate of 5 °C / min to 1100 °C for 2 h, and then naturally cooled to room temperature to obtain a biomacromolecule-based carbon aerogel (denoted as GC3), which was black.

[0046] Example 5:

[0047] 1.5 g of guanine was dispersed in 45 ml of deionized water, stirred at a speed of 1200 rpm at room temperature for 10 min, and then placed in a cell disrupter for ultrasonic treatment at room temperature for 5 min to obtain a guanine suspension; 1.235 g of resorcinol and 2.4 ml of formaldehyde were added to the obtained guanine suspension, and stirred at 85 °C for 12 h to obtain a mixed solution; the obtained mixed solution was transferred into a reaction kettle, and the reaction kettle was placed in an oven for reaction at 85 °C for 60 h; after the reaction was completed, the reaction kettle was taken out of the oven, and naturally cooled to room temperature; the upper liquid was discarded, and the remaining solid product was collected; the solid product was yellowish; the obtained solid product was dispersed in 50 ml of methanol, stirred at room temperature for 12 h, and then centrifuged (at room temperature, 6000 rpm, 10 min); the precipitate was dried in a 60 °C oven for 12 h, and then fully ground to obtain a biomacromolecule-based xerogel (denoted as GRF1-ST12).

[0048] S2: The biomacromolecule-based xerogel obtained in S1 was placed in a tube furnace in a nitrogen atmosphere, and carbonized at a temperature increasing rate of 5 °C / min to 1100 °C for 2 h, and then naturally cooled to room temperature to obtain a biomacromolecule-based carbon aerogel (denoted as GC1-ST12), which was black.

[0049] Example 6:

[0050] The guanine was dispersed in 45 ml of deionized water, stirred at 1200 rpm for 10 min at room temperature, and then treated with ultrasonic in a cell disrupter at room temperature for 5 min to obtain a guanine suspension; 1.222 g of 3-aminophenol and 2.4 ml of formaldehyde were added to the obtained guanine suspension, stirred at room temperature for 10 min to obtain a mixture; the mixture was transferred into a reaction kettle, and the reaction kettle was placed in an oven and reacted at 85°C for 72 h; after the reaction was completed, the reaction kettle was taken out of the oven, naturally cooled to room temperature, and the upper liquid was discarded, and the remaining solid product was collected, which was light yellow; the obtained solid product was dispersed in 50 ml of methanol, stirred at room temperature for 12 h, and then centrifuged (at room temperature, 6000 rpm, 10 min); the precipitate was dried in a 60°C oven for 12 h and then ground thoroughly to obtain a biomacromolecule-based dry gel (denoted as GAF).

[0051] Figure 1 The field emission scanning electron microscope (FESEM) images of GRF1, GC1 and GCN1-Rh1.5. As shown in Figure 1 a, GRF1 is a coral-like structure composed of rod-like units several microns long and connected to each other. For GC1, as shown in Figure 1 b, the external morphology has little change compared with that before carbonization, and the coral-like structure composed of rod-like units connected to each other is well preserved; Figure 1 c is a radial section view of the rod-like unit of GC1, revealing the special morphology of hollow tubes filled with graphene-like nanosheets, and the outer diameter of the obtained hollow carbon tube is about 100 nm, and the tube wall thickness is about 16 nm. GC1 was treated with ammonia and loaded with noble metal Rh, and as shown in Figure 1 d, the morphology has little change, and no Rh nanoparticles are observed on the surface of the nanocarbon tube within the field of view.

[0052] The morphology and structure of GCN1-Rh1.5 were further observed and analyzed by field emission scanning electron microscope (FESEM), as shown in Figure 2 a, GCN1-Rh1.5 exhibits the special morphology of hollow tubes filled with graphene-like nanosheets, and no metal particles are observed, which is consistent with the observation by FESEM. To further analyze the element composition and distribution of GCN1-Rh1.5, GCN1-Rh1.5 was observed by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and the element distribution on the surface of the material was directly observed by EDS, as shown in Figure 2 b to Figure 2 f, the EDS element surface distribution map shows that C, N, O and Rh are uniformly distributed on the surface of GCN1-Rh1.5, indicating the successful loading of Rh, and no obvious agglomeration phenomenon occurs.

[0053] The biological small-molecule-based carbon aerogels prepared with different amounts of guanine were observed using a field emission scanning electron microscope (FESEM), as shown in Figure 3 . As shown in Figure 3 a, when the amount of guanine was reduced from 1.5 g to 0.75 g, the number of rod-like units of GC2 increased and the length of the rod-like units decreased compared with GC1; as shown in Figure 3 b, when the amount of guanine was increased from 1.5 g to 3 g, the rod-like units of GC3 decreased and the shape was more fragmented compared with GC1, and the graphenes obtained by high-temperature treatment of guanine significantly increased.

[0054] The GC1-ST12 and GAF were observed using a field emission scanning electron microscope (FESEM). As shown in Figure 4 a, when the stirring was performed for 12 h and then the reaction was allowed to stand for 60 h after heating, the tube diameter of the rod-like units of the obtained product GC1-ST12 significantly increased compared with GC1, the tube wall increased from 16 nm to 177 nm, and the diameter of the hollow tube increased from 100 nm to 473 nm, and it can be seen that the size of the hollow structure of the obtained product can be regulated by simply changing the reaction conditions. As shown in Figure 4 b, when 3-aminophenol was used as the phenol source, a coral-like structure product formed by the mutual connection of rod-like units was also obtained, indicating that the preparation method has good universality.

[0055] The pore structure of the biological small-molecule-based carbon aerogels prepared with different amounts of guanine was characterized and analyzed by N2 physical adsorption-desorption experiments. Figure 5 As shown in the N2 physical adsorption-desorption isotherms of GC1-GC3 at 77 K liquid nitrogen temperature, it can be known from the calculation using the Brunauer-Emmett-Teller (BET) method that the specific surface areas of GC1, GC2 and GC3 were 352.6 m 2 / g, 590.5 m 2 / g and 504.7 m 2 / g, respectively.

[0056] Regarding the HER performance test, a series of Rh loadings (0.5%, 1.0%, 1.5% and 2%) of materials with GCN1 as the carrier and 1.5% Rh loading of materials with GC1 as the carrier were tested by linear voltammetry (LSV), as shown in Figure 6 . At 10 mA / cm 2The overpotential of GCN1-Rh0.5, GCN1-Rh1.0, GCN1-Rh1.5 and GCN1-Rh2.0 is 110 mv, 55 mv, 14 mv and 16 mv respectively under the current density, and the overpotential of GC1-Rh1.5 is 62 mv, which indicates that GCN1 has the most excellent HER performance under the Rh loading of 1.5%.

[0057] The above merely describes preferred embodiments of the present application, and any equivalent changes and modifications made within the scope of the present application should be included in the scope of the present application.

Claims

1. A method for preparing a bio-based small molecule carbon aerogel, characterized in that: Follow these steps: S1: Guanine is dispersed in water, stirred and sonicated to obtain a guanine suspension; phenol and aldehyde sources are added to the obtained guanine suspension and stirred to obtain a mixture; the obtained mixture is transferred to a reaction vessel, and the reaction vessel is placed in an oven for heating and static reaction; after the reaction is completed, the reaction vessel is removed from the oven, allowed to cool naturally, the upper liquid is discarded, the remaining solid product is collected, dispersed in methanol, stirred, centrifuged, dried and ground to obtain a bio-small molecule-based dry gel; S2: Carbonize the bio-based small molecule aerogel in an inert gas atmosphere and cool it naturally to obtain a bio-based small molecule carbon aerogel.

2. The preparation method according to claim 1, characterized in that: The phenol source is selected from any one or more of resorcinol, phloroglucinol, o-aminophenol, m-aminophenol, and p-aminophenol, and the aldehyde source is selected from any one or more of formaldehyde and glyoxylic acid.

3. The preparation method according to claim 1, characterized in that: The temperature for the heating and static reaction is 70~120℃, and the time is 6~72h.

4. The preparation method according to claim 1, characterized in that: The carbonization process is carried out at a temperature of 800~1200℃ for 1~4 hours.

5. A bio-based small molecule carbon aerogel prepared by the preparation method according to any one of claims 1 to 4.

6. The application of the bio-based small molecule carbon aerogel according to claim 5 in the preparation of heterogeneous catalysts and adsorbent materials.

7. The application according to claim 6, characterized in that: Biomolecule-based carbon aerogels were heated in an ammonia atmosphere and then loaded with metals to prepare heterogeneous catalysts and adsorbent materials.

8. The application according to claim 7, characterized in that: The heat treatment is performed at a temperature of 800~1200℃ for 5~60 min.

9. The application according to claim 7, characterized in that: The metal is selected from rhodium, platinum, ruthenium, cobalt, molybdenum, iron, nickel, manganese, and copper.

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