Stable isotopes 13 C-backbone labeled reduced graphene oxide ( 13 C-RGO), green synthesis methods and mechanism research methods

Abstract

The application provides a kind of stable isotope 13 The application provides a kind of stable isotope 13 The application provides a kind of stable isotope N The application provides a kind of stable isotope 3 The application provides a kind of stable isotope 13 The application provides a kind of stable isotope 13 The application provides a kind of stable isotope 13 The application provides a kind of stable isotope

Description

TECHNICAL FIELD

[0001] The present application relates to the field of graphene, in particular to a green synthesis method and mechanism research method of stable isotope 13C skeleton labeled reduced graphene oxide (C-RGO). 13 The present application relates to the field of graphene, in particular to a green synthesis method and mechanism research method of stable isotope 13C skeleton labeled reduced graphene oxide (C-RGO). 13 The present application relates to the field of graphene, in particular to a green synthesis method and mechanism research method of stable isotope 13C skeleton labeled reduced graphene oxide (C-RGO). 13 The present application relates to the field of graphene, in particular to a green synthesis method and mechanism research method of stable isotope 13C skeleton labeled reduced graphene oxide (C-RGO). BACKGROUND

[0002] Since graphene was discovered in 2004, it has become a research hotspot in various fields due to its excellent properties and unique structure. If we want to further study graphene and apply it in various fields, we need to be able to mass-produce it. The method of preparing graphene determines whether it can be widely used in industrial applications. So far, the methods of obtaining graphene can be roughly divided into physical methods and chemical methods. Among them, the physical methods include mechanical exfoliation, epitaxial growth, arc method and cutting carbon nanotubes, etc., and the chemical methods include chemical vapor deposition (CVD) method, organic synthesis method, redox method and electrochemical reduction method, etc. Among the many methods of preparing graphene at present, compared with other methods, the chemical reduction of graphene oxide has the characteristics of low cost, high yield and batch production, etc., and has become one of the best ways to realize the mass production of graphene.

[0003] The preparation of graphene by redox method first oxidizes the graphite raw material to generate a large number of oxygen-containing functional groups, such as hydroxyl, carboxyl, epoxy and carbonyl, on the basal plane and edge of the graphite sheet, and then ultrasonic exfoliation to obtain graphene oxide (GO). However, the presence of oxygen-containing functional groups introduces sp 3 Defects, which destroy the conjugated structure and lose good conductivity, limiting the application of graphene in the fields of electronics, energy, etc. Therefore, it is necessary to remove the oxygen-containing functional groups on GO and reduce it to reduced graphene oxide (RGO) to repair its conjugated structure and restore the conductivity of graphene.

[0004] In most cases, strong reducing agents such as hydrazine monohydrate, hydroquinone, sodium borohydride, hydroxylamine, phenylenediamine and hydroiodic acid have been used as reducing agents. However, these chemicals are highly toxic, strongly corrosive and explosive, which can damage the environment or be too costly in large-scale production of graphene. The presence of trace amounts of such toxic substances can have harmful effects, especially in biological applications. To overcome these problems, green nanotechnology using sugar, caffeic acid and proteins such as bovine serum albumin as reducing agents has also been reported for the reduction of graphene oxide. The use of environmentally friendly reducing agents to reduce graphene oxide has been successfully demonstrated to alleviate environmental problems. It would be very beneficial to achieve a sustainable alternative to such reducing agents, which in turn would facilitate the large-scale production of graphene from graphite oxide for various applications. L-ascorbic acid (Vc) is a non-toxic water-soluble reducing agent, which is characterized by good water solubility. In aqueous solution, a highly stable reduced graphene oxide suspension can be prepared, which is also stable to the generated RGO. Using Vc as a reducing agent, it was found that it was promising to replace hydrazine hydrate as a reducing agent for reducing GO solution in terms of reduction effect and safety, so Vc reduction not only avoids the use of toxic hydrazine or hydrazine reagent, but L-ascorbic acid (Vc) is a natural antioxidant, which is essential in many metabolic functions of living organisms and is widely used as a reducing agent in food additives.

[0005] The reduction mechanism and reduction process of Vc-reduced graphene oxide are not yet clear, and the mechanism of chemical reduction of graphene oxide is still a pending problem. At present, the speculation of the reduction mechanism is S N 2 nucleophilic reaction, followed by a thermal elimination reaction. In this mechanism, Vc does not participate in the formation of the skeleton of reduced graphene oxide (Chemistry of Materials 2010, 22, 7, 2213-2218). Graphene oxide mainly contains two active substances, namely epoxide and hydroxyl. As for the epoxide, it can be opened by S - 2 nucleophilic attack of the oxygen anion of L-ascorbic acid (HOAO N ). After reduction, S N 2 nucleophilic attack can occur, releasing water and forming an intermediate. Finally, the intermediate can undergo thermal elimination, leading to the formation of reduced graphene. Ascorbic acid is oxidized to dehydroascorbic acid. The reduction of hydroxyl is similar to that of epoxide. The hydroxyl group can be replaced by the oxygen anion of L-ascorbic acid (-OAO - ), which has two S N2 nucleophilic attack, followed by further reduction by thermal elimination. How to resolve whether the graphene carbon skeleton participates in the reaction and its possible reaction mechanism is a major challenge and a key link to the controllable structure of reduced graphene oxide. It is the key to the integrity of the graphene skeleton structure and the excellent performance of conductive and other properties. Based on the research of stable isotope skeleton labeling synthesis of carbon nanomaterials for more than ten years by the research group (Particle and Fibre Toxicology (2016, 13, 14), Environmental Science & Technology (2016, 50, 10421-10427; 2017, 51, 10146-10153; 2018, 52, 12133-12141.), Environmental Science: Nano (2014, 1, 64-70; 2016, 3, 799-805; 2019, 6, 1077-1088; 2021, 8, 76-85), we found that stable isotopes 13 C non-radioactive, safe and stable, can be labeled in the carbon network skeleton system by skeleton substitution, which will not destroy the intrinsic structure and properties of carbon nanomaterials, and has strong stability, without considering the structure influence and stability problem of radioactive labeling or fluorescent group labeling such as addition, covalent or adsorption link, and stable isotopes 13 C is also often used to track the process of chemical reactions (ACS Catalysis 2021, 11, 7, 3867-3876). Therefore, 13 C labeling technology will become a powerful tool to explore the synthesis mechanism of Vc reduced graphene oxide and the changes and rules of its carbon skeleton and chemical groups. Stable isotopes 13 C as a nuclear analysis technology, due to its unique natural environment-friendly advantage, for carbon nanomaterials and environmental biological background, will not introduce other exogenous atoms or elements, can be used as in vivo tracking quantitative analysis technology, to study the intrinsic nanobiological effects of graphene nanomaterials in the biological environment under high carbon background, and environmental safety evaluation and application.

[0006] Stable isotopes 13 C non-radioactive, harmless to living organisms. Part of the skeleton carbon atoms of RGO are replaced by 12 C 13 C, according to the ratio change of 13 C / 12 C, the ratio of isotopes is detected by high-precision and sensitive mass spectrometer, combined with the structure and surface analysis of Raman, XPS, Fourier infrared spectrum and scanning electron microscope, which can clearly describe the fine structure change and process of reduction reaction, at the same time, stable isotopes 13As a high-sensitivity in vivo quantitative carbon nanomaterial nuclear analysis method, the C skeleton labeled RGO technology can objectively and faithfully reflect the migration, metabolism and transformation of RGO nanomaterial in the environment and organisms, and lay an important material foundation for in vivo quantitative analysis, which will have important practical significance for the application and development of RGO in the field of biological medicine. SUMMARY

[0007] The purpose of the present application is to overcome the defects of the prior art, solve the current unresolved reduction mechanism of Vc reduced graphene oxide, and provide a stable isotope 13 C skeleton labeled reduced graphene oxide (C-RGO), a green synthesis method and mechanism research method. 13 The present application analyzes the mechanism of green reduction and obtains C skeleton labeled reduced graphene oxide nanomaterial with excellent conductivity. 13 The method of the present application is green, environmentally friendly, simple and easy to obtain, does not add any stabilizer, and can synthesize stable isotope 13 C skeleton labeled reduced graphene oxide. 13 The C skeleton labeled reduced graphene oxide can be used to study the mechanism of Vc reduced graphene oxide: not only the nucleophilic addition reaction reported in the literature (Chemistry of Materials 2010, 22, 7, 2213-2218), but also the Diels-Alder skeletal cycloaddition reaction, that is, L-aa can act as a dienophile under heating conditions, and graphene oxide as a source of diene to undergo Diels-Alder cycloaddition reaction, and then L-aa dissociates two protons, which are transferred to graphene oxide, thereby generating a nucleophilic substance (C6H7O6 - ) oxygen anion of L-aa. N 2 reaction, the nucleophile attacks the sp 3 carbon of the alcohol group to generate an intermediate containing stable isotope 13 C label, and the intermediate undergoes a redox reaction induced by heating to form stable isotope 13 C skeleton labeled reduced graphene oxide (C-RGO). 13

[0008]

[0009] *Position indicates that the carbon atom is a stable isotope 13 C

[0010] In order to achieve the above purpose, the first aspect of the present application provides a green synthesis method of stable isotope 13 C skeleton labeled reduced graphene oxide, comprising the following steps: ​

[0011] Step one: ultrasonic the mixture of graphene oxide and water for 30-60 min to obtain GO dispersion suspension;

[0012] Step two: dissolve the vitamin C labeled with C in pure water to obtain VC solution; 13 C labeled vitamin C and pure water are mixed and dissolved to obtain VC solution;

[0013] Step three: add the VC solution obtained in step two into the GO suspension obtained in step one, heat, stir, cool to room temperature, obtain reaction precipitate, vacuum filtration to obtain stable isotope 13 C skeleton labeled reduced graphene oxide.

[0014] Specifically, a green synthesis method of stable isotope 13 C skeleton labeled reduced graphene oxide comprises the following steps:

[0015] Step one: ultrasonic the mixture of graphene oxide and water for 30-60 min to obtain GO dispersion suspension.

[0016] Step two: weigh 13 C labeled vitamin C (white granular solid) into a centrifuge tube, add pure water to dissolve (shake to completely dissolve) to obtain VC transparent solution.

[0017] Step three: add the VC solution obtained in step two into the GO suspension obtained in step one, heat, stir for 5 hours, cool to room temperature, obtain reaction precipitate, vacuum filtration to obtain stable isotope 13 C skeleton labeled reduced graphene oxide.

[0018] The second aspect of the present application provides a stable isotope 13 C skeleton labeled reduced graphene oxide prepared by a simple green synthesis method, wherein the conductivity of graphene oxide is 1.26*10 -4 S·m -1 , and the conductivity of reduced graphene oxide is 1.48*10 -1 S·m -1 , which is improved by 1,000 times.

[0019] The third aspect of the present application provides a stable isotope 13 C skeleton labeled reduced graphene oxide, wherein 13 C / 12 The atomic number ratio of C to C is 4-12%. For example, in the stable isotope 13 C skeleton labeled reduced graphene oxide, 13 C / 12The percentage of carbon atoms is 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, 5.2%, 5.4%, 5.6%, 5.8%, 6%, 6.2%, 6.4%, 6.6%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, or 12%.

[0020] In a fourth aspect, the invention involves stabilizing isotopes. 13 C confirmed the reduction mechanism of Vc in graphene oxide.

[0021] The simple green synthesis provided by this invention 13 The C-backbone-labeled reduced graphene oxide technique has one or more of the following beneficial effects:

[0022] 1. This invention 13 The synthesis method of C-backbone labeled reduced graphene oxide is simple, feasible, environmentally friendly, readily available, and does not require the addition of any stabilizers.

[0023] 2. This invention 13 The synthesis method of C-backbone-labeled reduced graphene oxide can be used to explore the reduction mechanism of Vc-reduced graphene oxide and solve practical problems.

[0024] 3. The invention obtained 13 C-backbone labeled reduced graphene oxide, with labeling amounts ranging from 4% to 12%, and up to a maximum of 12%. Attached Figure Description

[0025] Figure 1 The reactant in Example 1 is graphene oxide. 12 C-GO) and the reactant graphene oxide in Example 2 ( 12 X-ray photoelectron spectrum of C-GO.

[0026] Figure 2 The reactant in Examples 1 and 2 is graphene oxide. 12 C-GO), and the reduced graphene oxide synthesized in Example 1 ( 12 C-RGO) and the stable isotopes synthesized in Example 2 13 C-labeled reduced graphene oxide ( 13 Raman spectrum of C-RGO.

[0027] Figure 3 The reactant in Examples 1 and 2 is graphene oxide. 12 C-GO), and the reduced graphene oxide synthesized in Example 1 ( 12 C-RGO) and the stable isotopes synthesized in Example 2 13Fourier transform infrared spectrum of stable isotope 13 C-labeled reduced graphene oxide (C-RGO).

[0028] Figure 4 12 X-ray photoelectron spectrum of stable isotope

[0029] Figure 5 12 Scanning electron micrograph of stable isotope

[0030] Figure 6 13 X-ray photoelectron spectrum of stable isotope 13 C-labeled reduced graphene oxide (C-RGO).

[0031] Figure 7 13 Scanning electron micrograph of stable isotope 13 C-labeled reduced graphene oxide (C-RGO).

[0032] Figure 8 13 X-ray photoelectron spectrum of stable isotope 13 C-labeled graphene oxide (C-GO).

[0033] Figure 9 13 Scanning electron micrograph of stable isotope 13 C-labeled graphene oxide (C-GO) and stable isotope 13 C-labeled reduced graphene oxide (C-RGO). 13 C-labeled reduced graphene oxide (C-RGO).

[0034] Figure 10 13 Fourier transform infrared spectrum of stable isotope 13 C-labeled graphene oxide (C-GO) and stable isotope 13 C-labeled reduced graphene oxide (C-RGO). 13 C-labeled reduced graphene oxide (C-RGO).

[0035] Figure 11 13 Scanning electron micrograph of stable isotope 13 C-labeled graphene oxide (C-GO).

[0036] Figure 12 ​​​​​​​​, is the stable isotope synthesized in Comparative Example 1. 13 C-labeled reduced graphene oxide ( 13 X-ray photoelectron spectrum of C-RGO.

[0037] Figure 13 , is the stable isotope synthesized in Comparative Example 1. 13 C-labeled reduced graphene oxide ( 13 Scanning electron microscope image of C-RGO.

[0038] Figure 14 For the income 13 C-labeled reduced graphene oxide ( 13 Scanning electron microscope image of C-RGO. Detailed Implementation

[0039] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0040] According to the present invention 13 C-backbone labeled reduced graphene oxide, with stable isotopes 13 Vitamin C with the C label 13 C / 12 The percentage of C atoms is ≥98%.

[0041] According to the present invention 13 Methods for synthesizing C-framework-labeled reduced graphene oxide include:

[0042] Step 1: Sonicate the mixture of graphene oxide and water for 30-60 minutes to obtain a GO dispersion suspension.

[0043] Step 2: Weighing 13 C-labeled vitamin C (white granular solid) was placed in a centrifuge tube and dissolved in purified water (the solution was shaken to dissolve completely) to obtain a clear VC solution.

[0044] Step 3: Add the Vc solution obtained in Step 2 to the GO suspension obtained in Step 1, stir at 60°C for 5 hours, cool to room temperature, obtain the reaction precipitate, and perform vacuum filtration to obtain stable isotopes. 13 C-backbone labeled reduced graphene oxide.

[0045] According to the method of the present invention, the graphene oxide in step one can be prepared by the Brodie method or the Hummers method.

[0046] The present application provides a stable isotope prepared according to the synthetic method 13 C skeleton labeled reduced graphene oxide.

[0047] The present application 13 C skeleton labeled reduced graphene oxide, which is prepared by oxidizing a stable isotope 13 The C labeled vitamin C is prepared by a simple chemical reaction method of oxidation and reduction.

[0048] The present application also deeply studies the reduction mechanism of Vc reduced graphene oxide, and further understands the reduction mechanism thereof.

[0049] Unless otherwise specified, the reagents and instruments used in the following examples are commercially available products.

[0050] The scanning electron microscope (SEM) used in the following examples and comparative examples is a Hitachi S-4800 type scanning electron microscope (SEM);

[0051] The X-ray photoelectron spectroscopy (XPS) test device is an ESCALAB250Xi type X-ray photoelectron spectroscopy (XPS) instrument of Thermo Fisher Scientific Corporation, USA, monochromatic Al Ka (hv = 1486.6eV), power 150W, 500μm beam spot; binding energy is calibrated with C1s 284.8;

[0052] The isotopic ratio test device is a MAT-253 type isotopic ratio mass spectrometer (IRMS) of Thermo Electron-Finnigan Corporation, USA;

[0053] The Raman test device is a LabRAM HR800 of Horiba Jobin Yvon Corporation, France, and the experimental excitation wavelength is 532nm;

[0054] The Fourier infrared spectroscopy test device is a Nicolet iS5 type Fourier infrared spectrometer (FT-IR) of Nicolet Corporation, USA.

[0055] Example 1

[0056] (i) Weigh the freeze-dried graphene oxide (GO): 5mg.

[0057] (ii) Put the GO weighed in (i) into a 20ml sample bottle, add 5ml Wahaha pure water, and ultrasonic treat for 60min (ultrasonic power 100%, ultrasonic temperature: 40℃), to obtain a GO dispersed suspension, and the solution is light brown.

[0058] (iii) Weigh 30 mg of vitamin C (white granular solid), put it into a 2 mL centrifuge tube, add 1 mL of purified water to dissolve (shake to dissolve completely) to obtain a clear vitamin C solution.

[0059] (iv) The GO suspension obtained in (ii) was magnetically stirred at 60°C. When the temperature reached 55°C, 1 mL of VC solution was added to the centrifuge tube in (iii). The centrifuge tube was then rinsed repeatedly with 1 mL of purified water to ensure that the VC solution was completely immersed in the reaction solution. At this point, the reaction volume was 12 mL. The mixture was stirred for 5 hours and then cooled to room temperature to obtain the reaction precipitate. (v) Vacuum filtration was performed to finally obtain reduced graphene oxide.

[0060] X-ray photoelectron spectroscopy showed that the C / O ratio of graphene oxide before reduction was 2.02, which increased to 4.16 after reduction.

[0061] The X-ray photoelectron spectrum, Raman spectrum, and Fourier transform infrared spectrum of the reactant GO are as follows: Figure 1 , Figure 2 , Figure 3 As shown.

[0062] The resulting reduced graphene oxide ( 12 The X-ray photoelectron spectrum, Raman spectrum, Fourier transform infrared spectrum, and scanning electron microscope image of C-RGO are as follows: Figure 4 , Figure 5 , Figure 3 and Figure 6 As shown.

[0063] Example 2

[0064] (i) Weigh 5 mg of freeze-dried GO.

[0065] (ii) Place the GO weighed in (i) into a 20ml sample bottle, add 5ml of Wahaha purified water, and sonicate for 60min (ultrasonic power 100%, ultrasonic temperature: 40℃) to obtain a GO dispersion suspension. The solution is light brown.

[0066] (iii) Weighing stable isotopes 13 30 mg of C-labeled vitamin C (white granular solid) was placed in a 2 mL centrifuge tube and dissolved in 1 mL of purified water (shaking to dissolve completely) to obtain a clear vitamin C solution.

[0067] (iv) The GO suspension obtained in (ii) was magnetically stirred at a temperature of 60°C. When the temperature rose to 55°C, 1 mL of VC solution was added to the centrifuge tube in (iii). The centrifuge tube was then rinsed repeatedly with 1 mL of purified water to ensure that the VC solution was completely placed in the reaction solution. At this time, the reaction volume of the solution was 12 mL. The mixture was stirred for 5 hours and cooled to room temperature to obtain the reaction precipitate.

[0068] (v) Perform vacuum filtration to obtain the final result. 13 C-labeled reduced graphene oxide ( 13 C-RGO, detected by isotope ratio mass spectrometry, yielded reduced graphene oxide. 13 C / 12 The proportion of carbon atoms reaches 5.8%.

[0069] X-ray photoelectron spectroscopy showed that the C / O ratio of graphene oxide before reduction was 2.02, which increased to 3.89 after reduction.

[0070] The X-ray photoelectron spectrum, Raman spectrum, and Fourier transform infrared spectrum of the reactant GO are as follows: Figure 1 , Figure 2 , Figure 3 As shown.

[0071] income 13 The X-ray photoelectron spectroscopy, Raman spectrum, Fourier transform infrared spectrum, and scanning electron microscope image of C-labeled reduced graphene oxide are shown below. Figure 7 , Figure 5 , Figure 3 and Figure 8 As shown.

[0072] In step (i), the electrical conductivity of the freeze-dried graphene oxide is 1.26 × 10⁻⁶. -4 S·m -1 The result obtained in step (v) 13 The conductivity of C-labeled reduced graphene oxide is 1.48 × 10⁻⁶. -1 S·m -1 It increased a thousandfold.

[0073] Comparative Example 1

[0074] (i) Accurately weigh 5 mg of stable isotope 13 GO with C tag 13 C-RGO), its 13 C-labeled graphene oxide was detected by isotope ratio mass spectrometry. 13 C-labeled graphene oxide 13 C / 12 The proportion of carbon atoms reached 4.78%.

[0075] (ii) accurately weighed stable isotope 13 C-labeled GO 13 C-RGO) into a sample bottle, 5ml Wahaha purified water was added, and ultrasonic treatment was performed for 60min (ultrasonic power 100%, ultrasonic temperature: 40℃) to obtain 13 C-GO dispersion suspension, and the solution was light brown.

[0076] (iii) 30mg of vitamin C (white granular solid) was accurately weighed and placed into a centrifuge tube, 1mL purified water was added to dissolve it (shaking to completely dissolve) to obtain a Vc transparent solution.

[0077] (iv) the stable isotope 13 C-labeled GO suspension obtained in (ii) was subjected to magnetic stirring, the temperature was set to 60℃, and when the temperature was raised to 55℃, 1mL Vc transparent solution in the centrifuge tube in (iii) was added, and the centrifuge tube was repeatedly rinsed with 1mL purified water to ensure that the VC solution was completely placed in the reaction solution, and stirring was performed for 4 hours, and the reaction precipitate was obtained after cooling at room temperature.

[0078] (v) vacuum filtration was performed, and finally 13 C-labeled reduced graphene oxide was obtained, and the reduced graphene oxide 13 C / 12 C atomic number ratio was 4.42%, compared with the stable isotope 13 C-labeled GO 13 C-GO) which 13 C / 12 C atomic number ratio decreased from 4.78% to 4.42%. Part of the 12 C skeleton in Vc was embedded into the carbon skeleton, which 13 C / 12 C was diluted in proportion, resulting in 13 C / 12 C atomic number ratio decreased.

[0079] According to the X-ray photoelectron spectroscopy determination, the C / O of graphene oxide before reduction was about 1.91, and after reduction, it rose to 3.16.

[0080] The reactant 13 C-GO X-ray photoelectron spectroscopy, Raman spectrum, Fourier infrared spectrum and scanning electron microscope are shown in Figure 9 、 Figure 10 、 Figure 11 and Figure 12 respectively.

[0081] The obtained 13 C-labeled reduced graphene oxide 13The X-ray photoelectron spectrum, Raman spectrum, Fourier transform infrared spectrum, and scanning electron microscope image of C-RGO are as follows: Figure 13 , Figure 10 , Figure 11 and Figure 14 As shown.

[0082] In summary, based on Example 2, 13 C-labeled graphene oxide 13 C / 12 The C atom ratio increased to 5.5%, as in Comparative Example 1, reducing graphene oxide. 13 C / 12 The number of C atoms is determined by the original stable isotopes. 13 GO with C tag 13 The C-RGO content decreased from 4.78% to 4.42%, which verifies that some carbon skeletons in Vc are embedded or replaced in the graphene carbon skeleton, thus obtaining stable isotopes. 13 C-backbone labeled reduced graphene oxide.

[0083] The parts of this invention not described in detail are well-known to those skilled in the art. The embodiments described above are merely preferred embodiments of the invention, and do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Various modifications and improvements to the technical solutions of this invention made by those skilled in the art without departing from the spirit of the invention should fall within the protection scope defined by the claims of this invention.

Claims

1. A stable isotope 13 A green synthesis method of skeleton-labeled reduced graphene oxide, characterized by, The method comprises the following steps: Step one: ultrasonicating a mixture of graphene oxide and water for 30-60 minutes to obtain a GO dispersion suspension; Step two: mix the vitamin C labeled with C and pure water, dissolve to get VC solution 13 C labeled vitamin C and pure water mixed, dissolved, VC solution Step three: adding the VC solution obtained in step two into the GO suspension obtained in step one, heating, stirring, cooling to room temperature, obtaining a reaction precipitate, vacuum filtration, and obtaining stable isotopes 13 Reduced graphene oxide labeled with C skeleton.

2. A stable isotope produced according to the method of claim 1 13 C skeleton labeled reduced graphene oxide.

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