Lubricating oil additive containing non-metallic element doped graphyne and preparation method thereof

Abstract

The present invention belongs to the technical field of lubricating materials, and specifically relates to a lubricating oil additive containing non-metallic elements doped with graphene and a preparation method thereof. The lubricating oil additive containing non-metallic elements doped with graphene includes the following components in parts by weight: 0.2 to 4 parts of non-metallic elements doped with graphene; 1 to 5 parts of base oil; 0.2 to 1 part of friction modifier; 0.05 to 2 parts of extreme pressure anti-wear agent; 0.1 to 2 parts of rust inhibitor; 0.01 to 3 parts of viscosity index improver; 0.5 to 4 parts of dispersant; 0.1 to 2 parts of antioxidant; 0.0001 to 0.03 parts of anti-foaming agent. The preparation method adopts the method of subjecting the above components to grouping homogeneous dispersion treatment and stirring at a certain temperature and then mixing and stirring. The obtained lubricating oil additive containing non-metallic elements doped with graphene can be added to the lubricating oil base oil to give the lubricating oil excellent extreme pressure and anti-wear properties.

Description

Technical Field

[0001] The invention belongs to the technical field of lubricating materials, and in particular relates to a lubricating oil additive containing non-metallic elements doped with graphyne and a preparation method thereof. Background Art

[0002] Mechanical wear and corrosion between parts is one of the basic reasons for the failure of engineering machinery and equipment, which will cause abnormal operation of mechanical equipment, accelerate equipment aging, increase operating energy consumption, affect product quality and may even cause safety accidents. In this regard, the use of lubricants with anti-wear and anti-corrosion properties can effectively avoid abnormal failure of parts. The use of lubricant base oil alone cannot provide good anti-wear and anti-corrosion effects. The anti-wear and anti-corrosion properties are mainly contributed by lubricant additives.

[0003] Since it was first synthesized in 2010, graphyne has received extensive international attention and has broad development prospects, but it is still rarely used in the field of lubricants. Graphyne is a layered two-dimensional carbon nanomaterial composed of benzene rings and acetylene bonds. The layered structure allows sliding between the two layers, which can show a good effect of reducing interface friction. It is an ideal lubricating material and can be used as a lubricant additive component. Summary of the invention

[0004] The present invention provides a lubricating oil additive containing graphyne doped with non-metallic elements and a preparation method thereof. The lubricating oil additive can significantly improve the extreme pressure, anti-wear and anti-corrosion properties of lubricating oil products, thus filling the technical gap in the field of graphyne lubricating oil additives.

[0005] Specifically, the present invention provides the following technical solutions.

[0006] A lubricating oil additive containing non-metallic elements doped with graphyne, comprising the following components in parts by weight:

[0007]

[0008]

[0009] Preferably, the above-mentioned lubricating oil additive containing non-metallic elements doped with graphyne comprises the following components in parts by weight:

[0010]

[0011] Preferably, in the non-metallic element-doped graphyne, the doping amount of the non-metallic element is 5wt% to 15wt%.

[0012] Preferably, in the non-metallic element-doped graphyne, the non-metallic element is selected from one or more of phosphorus, sulfur, and boron. As an emerging functional material, functional customization of graphyne can greatly promote the development of this material field. The extreme pressure and anti-wear properties of lubricating oil are related to elements such as sulfur, phosphorus, and boron. When high pressure is locally formed between the contact surfaces, the active sulfur or phosphorus in the extreme pressure and anti-wear agent can react with the interfacial metal to form a protective film to prevent metal wear and sintering, and the boron element can form a deposited film or a permeation layer on the metal surface to protect parts from wear. Therefore, using graphyne doped with these three non-metallic elements as an anti-wear and anti-corrosion additive as one of the additive compositions can form a protective film on the metal surface, which can improve the extreme pressure and anti-wear properties while protecting metal parts from corrosion.

[0013] Preferably, the non-metallic element-doped graphyne has a macromolecular structure formed by introducing non-metallic atoms (such as phosphorus, sulfur, boron) into the skeleton and edge of graphyne to replace the original carbon atoms of graphyne.

[0014] Preferably, the base oil is 150BS base oil.

[0015] Preferably, the friction modifier is selected from one or more of molybdenum dithiophosphate, dithiocarbamate, and salicylate, more preferably molybdenum dithiophosphate.

[0016] Preferably, the extreme pressure anti-wear agent is selected from one or more of di-n-butyl phosphite, isobutylene sulfide, and thiophosphate, more preferably thiophosphate.

[0017] Preferably, the rust inhibitor is selected from one or more of sulfonate, stearic acid, and sorbitan monooleate, more preferably sorbitan monooleate.

[0018] Preferably, the viscosity index improver is selected from one or more of polymethacrylate, hydrogenated styrene diene copolymer, and polyisobutylene, and more preferably polymethacrylate.

[0019] Preferably, the dispersant is selected from boronated polyisobutylene succinimide and / or boronated succinate.

[0020] Preferably, the antioxidant is selected from dialkyldiphenylamine and / or phenyl-α-naphthylamine.

[0021] Preferably, the anti-foaming agent is selected from polydimethylsiloxane and / or acrylate, more preferably polydimethylsiloxane.

[0022] The present invention also provides a method for preparing the above-mentioned lubricating oil additive containing non-metallic elements doped with graphyne, comprising the following steps:

[0023] (1) mixing a friction modifier, a rust inhibitor, a viscosity index improver, an antioxidant and a base oil according to a mass ratio at 40 to 80° C. and stirring for 1 to 5 hours to obtain a mixture A;

[0024] (2) treating the dispersant, non-metallic element-doped graphyne and extreme pressure anti-wear agent according to mass ratio at 40 to 100° C. using a homogenizer at a speed of 15,000 to 25,000 rpm for 1 to 5 h to obtain a mixture B;

[0025] (3) Mixing mixture A, mixture B and antifoaming agent at 50-90° C. for 0.5-1 h, and cooling to room temperature to obtain a finished lubricating oil additive.

[0026] The present invention also provides a lubricating oil, which contains 2wt% to 8wt% of the above-mentioned lubricating oil additive containing non-metallic elements doped with graphyne or the lubricating oil additive containing non-metallic elements doped with graphyne prepared by the above-mentioned preparation method.

[0027] The beneficial effects of the present invention are at least:

[0028] (1) The lubricating oil additive containing non-metallic elements doped with graphyne provided by the present invention has scientifically screened the components in the lubricating oil additive and scientifically limited the amount of each component added. It is suitable for lubricating oil for engineering machinery (hydraulic oil, industrial gear oil), lubricating oil for vehicles (transmission oil, engine oil), etc., and is particularly suitable for scenes where extreme pressure exists.

[0029] (2) The lubricating oil additive containing non-metallic element doped graphyne provided by the present invention uses non-metallic element doped graphyne as part of the extreme pressure anti-wear agent and rust inhibitor, and can form a physical and chemical protective film on the metal surface under extreme pressure conditions, thereby improving the extreme pressure anti-wear performance of the lubricating oil and preventing scratches and adhesion on the metal surface. At the same time, the protective film can protect the metal surface from corrosion, thereby improving the protective effect on the friction pair at multiple levels. At the same time, the oil change cycle of the lubricating oil is extended, bringing economic benefits.

[0030] (3) The preparation method of the lubricating oil additive containing non-metallic element doped graphyne provided by the present invention uses a homogenizer to process the additive, which can avoid the precipitation and agglomeration of the graphyne component. The operation is simple and convenient, and the possibility of uneven dispersion of the additive is effectively reduced. DETAILED DESCRIPTION

[0031] In order to more clearly reflect the technical scheme and function of the present invention, the anti-wear and anti-corrosion lubricating oil additive containing non-metallic elements doped with graphyne and some embodiments of its preparation described in the present invention are described in detail below. The embodiments are not used to limit the present invention, and all embodiments belong to the protection scope of the present invention.

[0032] Example 1

[0033] A phosphorus-doped graphyne anti-wear and anti-corrosion lubricant additive, comprising the following components in parts by mass:

[0034]

[0035] The method for preparing phosphorus-doped Graphyne is as follows:

[0036] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevating tubular furnace, put the material box into a quartz tube, place the quartz tube in the tubular furnace and set the vacuum mode, then introduce nitrogen; set the tubular furnace heating program, the heating rate is 10°C / min, the temperature is raised to 700°C, and phosphine gas is introduced in nitrogen for reaction, after keeping warm for 5h, stop introducing phosphine, terminate the temperature program, continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and obtain phosphorus-doped graphyne in the material box.

[0037] The doping amount of the phosphorus-doped graphyne is 5wt%.

[0038] The specific preparation method of the phosphorus-doped graphyne anti-wear and anti-corrosion lubricating oil additive composition is as follows:

[0039] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0040] (2) Phosphorus-doped graphyne, thiophosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0041] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes, and then cooled to room temperature to obtain the finished product of Example 1.

[0042] Example 2

[0043] A phosphorus-doped graphyne anti-wear and anti-corrosion lubricant additive, comprising the following components in parts by mass:

[0044]

[0045] The method for preparing phosphorus-doped Graphyne is as follows:

[0046] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevating tubular furnace, put the material box into a quartz tube, place the quartz tube in the tubular furnace and set the vacuum mode, then introduce nitrogen; set the tubular furnace heating program, the heating rate is 10°C / min, the temperature is increased to 700°C, and phosphine gas is introduced in nitrogen for reaction, after keeping warm for 8h, stop introducing phosphine, terminate the temperature program, continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and obtain phosphorus-doped graphyne in the material box.

[0047] The doping amount of the phosphorus-doped graphyne is 8wt%.

[0048] The specific preparation method of the anti-wear and anti-corrosion lubricating oil additive composition containing non-metallic elements doped with graphyne described in Example 2 is as follows:

[0049] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0050] (2) Phosphorus-doped graphyne, thiophosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0051] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes, and then cooled to room temperature to obtain the finished product of Example 2.

[0052] Example 3

[0053] A phosphorus-doped graphyne anti-wear and anti-corrosion lubricant additive, comprising the following components in parts by mass:

[0054]

[0055] The method for preparing phosphorus-doped Graphyne is as follows:

[0056] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevating tubular furnace, put the material box into a quartz tube, place the quartz tube in the tubular furnace and set the vacuum mode, then introduce nitrogen; set the tubular furnace heating program, the heating rate is 10°C / min, the temperature is raised to 700°C, and phosphine gas is introduced in nitrogen for reaction, after keeping warm for 5h, stop introducing phosphine, terminate the temperature program, continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and obtain phosphorus-doped graphyne in the material box.

[0057] The doping amount of the phosphorus-doped graphyne is 5wt%.

[0058] The specific preparation method of the phosphorus-doped graphyne anti-wear and anti-corrosion lubricating oil additive composition described in Example 3 is as follows:

[0059] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0060] (2) Phosphorus-doped graphyne, thiophosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0061] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes, and then cooled to room temperature to obtain the finished product of Example 3.

[0062] Example 4

[0063] A phosphorus-doped graphyne-containing extreme pressure anti-wear lubricant additive, comprising the following components in parts by mass:

[0064]

[0065] The method for preparing phosphorus-doped Graphyne is as follows:

[0066] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevating tubular furnace, put the material box into a quartz tube, place the quartz tube in the tubular furnace and set the vacuum mode, then introduce nitrogen; set the tubular furnace heating program, the heating rate is 10°C / min, the temperature is raised to 700°C, and phosphine gas is introduced in nitrogen for reaction, after keeping warm for 5h, stop introducing phosphine, terminate the temperature program, continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and obtain phosphorus-doped graphyne in the material box.

[0067] The doping amount of the phosphorus-doped graphyne is 5wt%.

[0068] The specific preparation method of the phosphorus-doped graphyne anti-wear and anti-corrosion lubricating oil additive composition described in Example 4 is as follows:

[0069] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0070] (2) Phosphorus-doped graphyne, thiophosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0071] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes, and then cooled to room temperature to obtain the finished product of Example 4.

[0072] Example 5

[0073] A phosphorus-doped graphyne anti-wear and anti-corrosion lubricant additive, comprising the following components in parts by mass:

[0074]

[0075]

[0076] The method for preparing phosphorus-doped Graphyne is as follows:

[0077] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevating tubular furnace, put the material box into a quartz tube, place the quartz tube in the tubular furnace and set the vacuum mode, then introduce nitrogen; set the tubular furnace heating program, the heating rate is 10°C / min, the temperature is raised to 700°C, and phosphine gas is introduced in nitrogen for reaction, after keeping warm for 5h, stop introducing phosphine, terminate the temperature program, continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and obtain phosphorus-doped graphyne in the material box.

[0078] The doping amount of the phosphorus-doped graphyne is 5wt%.

[0079] The specific preparation method of the phosphorus-doped graphyne anti-wear and anti-corrosion lubricating oil additive composition described in Example 5 is as follows:

[0080] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0081] (2) Phosphorus-doped graphyne, thiophosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0082] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes, and then cooled to room temperature to obtain the finished product of Example 5.

[0083] Example 6

[0084] A sulfur-doped graphyne-containing anti-wear and anti-corrosion lubricating oil additive, comprising the following components in parts by mass:

[0085]

[0086]

[0087] The sulfur-doped Graphyne preparation method is as follows:

[0088] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevated tubular furnace, put the material box into a quartz tube, place the quartz tube in the tubular furnace and set the vacuum mode, then introduce nitrogen; set the tubular furnace heating program, the heating rate is 10°C / min, the temperature is increased to 500°C, and hydrogen sulfide gas is introduced in nitrogen for reaction. After keeping warm for 5h, stop introducing hydrogen sulfide, terminate the temperature program, continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and sulfur-doped graphyne is obtained in the material box.

[0089] The doping amount of the sulfur-doped graphyne is 5wt%.

[0090] The specific preparation method of the sulfur-doped graphyne anti-wear and anti-corrosion lubricating oil additive composition described in Example 6 is as follows:

[0091] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0092] (2) The sulfur-doped graphyne, sulfurized phosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0093] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes, and then cooled to room temperature to obtain the finished product of Example 6.

[0094] Example 7

[0095] A boron-doped graphyne-containing anti-wear and anti-corrosion lubricating oil additive, comprising the following components in parts by mass:

[0096]

[0097] The method for preparing boron-doped Graphene is as follows:

[0098] Take 1g of dried graphyne and place it in a material box of a programmed temperature-elevated tubular furnace. Put the material box into a quartz tube. After placing the quartz tube in the tubular furnace, set the vacuum mode and then introduce nitrogen. Set the tubular furnace heating program with a heating rate of 10°C / min to 500°C. At the same time, introduce borohydride gas in nitrogen for reaction. After keeping warm for 5h, stop introducing borohydride and terminate the temperature program. Continue to introduce nitrogen until the temperature in the tubular furnace drops to room temperature, and obtain boron-doped graphyne in the material box.

[0099] The doping amount of the boron-doped graphyne is 5wt%.

[0100] The specific preparation method of the anti-wear and anti-corrosion lubricating oil additive composition containing boron-doped graphyne described in Example 7 is as follows:

[0101] (1) Molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, dialkyl diphenylamine and base oil were mixed and stirred at 50° C. for 3 hours to obtain a mixture A.

[0102] (2) Boron-doped graphyne, thiophosphate and boronated polyisobutylene succinimide were stirred at 55° C. for 2 hours at a speed of 20,000 rpm using a homodispersion instrument to obtain a mixture B.

[0103] (3) Mixture A, mixture B and polydimethylsiloxane were mixed and stirred at 60° C. for 40 minutes and cooled to room temperature to obtain the finished product of Example 7.

[0104] Comparative Example 1

[0105] A lubricating oil additive composition is composed of the following components:

[0106]

[0107] The specific preparation method of the lubricating oil additive composition proposed in Comparative Example 1 is as follows: molybdenum dithiophosphate, polymethacrylate, boronated polyisobutylene succinimide, dialkyl diphenylamine and polydimethylsiloxane are stirred at 60° C. for 2 hours according to the ratio described in Comparative Example 1, and cooled to room temperature to obtain the finished product of Comparative Example 1.

[0108] Comparative Example 2

[0109] A lubricating oil additive composition is composed of the following components:

[0110]

[0111] The specific preparation method of the lubricating oil additive composition proposed in Comparative Example 2 is as follows: molybdenum dithiophosphate, sulfurized phosphate ester, polymethacrylate, boronated polyisobutylene succinimide, dialkyl diphenylamine and polydimethylsiloxane are stirred at 60°C for 2 hours according to the ratio described in Comparative Example 2, and cooled to room temperature to obtain the finished product of Comparative Example 2.

[0112] Comparative Example 3

[0113] A lubricating oil additive composition is composed of the following components:

[0114]

[0115] The specific preparation method of the lubricating oil additive composition proposed in Comparative Example 3 is as follows: molybdenum dithiophosphate, sorbitan monooleate, polymethacrylate, boronated polyisobutylene succinimide, dialkyl diphenylamine and polydimethylsiloxane are stirred at 60°C for 2 hours according to the ratio described in Comparative Example 3, and cooled to room temperature to obtain the finished product of Comparative Example 3.

[0116] Test example

[0117] The finished lubricating oil additives of Examples 1 to 7 and Comparative Examples 1 to 3 were added to the same lubricating oil base oil, respectively, with the added mass accounting for 5% of the base oil, and the mixture was uniformly mixed by stirring at 60° C. for 40 minutes. The performance tests of the evenly dispersed lubricating oil were carried out, where the kinematic viscosity was tested using the GB / T 265 "Method for determination of kinematic viscosity and calculation of dynamic viscosity of petroleum products", the viscosity index was calculated using the GB / T 1995 "Method for calculation of viscosity index of petroleum products", the foam characteristics were tested using the GB / T 12579 "Determination of foam characteristics of lubricating oils", the antioxidant performance was reflected by the SH / T 0123 "Determination of oxidation performance of extreme pressure lubricating oils" and SH / T0024 "Determination of sedimentation value of lubricating oils" methods, the extreme pressure anti-wear performance was characterized by the GB / T3142-2019 "Determination of load-bearing capacity of lubricants - four-ball method" and NB / SH / T 0189-2017 "Determination of anti-wear performance of lubricating oils", the anti-corrosion performance was reflected by the GB / T 5096 "Petroleum products copper sheet corrosion test method" and GB / T 11143 "Test method for anti-rust performance of mineral oil with inhibitor in the presence of water", and the test results are shown in Table 1.

[0118] Table 1

[0119]

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lubricating oil additive containing non-metallic elements doped with graphyne, characterized in that: The composition comprises the following components in parts by weight: The non-metallic element is selected from one or more of phosphorus, sulfur and boron.

2. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1, characterized in that: The composition comprises the following components in parts by weight:

3. A lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: In the non-metallic element-doped graphyne, the doping amount of the non-metallic element is 5wt%-15wt%.

4. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The non-metallic element-doped graphyne has a macromolecular structure formed by introducing non-metallic atoms into the graphyne skeleton and edge to replace the original carbon atoms of graphyne.

5. The lubricating oil additive containing non-metallic element doped graphyne according to claim 1 or 2, characterized in that: The base oil is 150BS base oil.

6. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The friction modifier is selected from one or more of molybdenum dithiophosphate, dithiocarbamate, and salicylate.

7. A lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The friction modifier is molybdenum dithiophosphate.

8. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The extreme pressure anti-wear agent is selected from one or more of di-n-butyl phosphite, isobutylene sulfide, and thiophosphate.

9. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The extreme pressure anti-wear agent is sulfurized phosphate ester.

10. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The rust inhibitor is selected from one or more of sulfonate, stearic acid, and sorbitan monooleate.

11. A lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The rust inhibitor is sorbitan monooleate.

12. The lubricating oil additive containing non-metallic elements doped with graphyne according to claim 1 or 2, characterized in that: The viscosity index improver is selected from one or more of polymethacrylate, hydrogenated styrene diene copolymer, and polyisobutylene; and / or, the dispersant is selected from boronated polyisobutylene succinimide and / or boronated succinate; and / or, the antioxidant is selected from dialkyldiphenylamine and / or phenyl-α-naphthylamine; And / or, the anti-foaming agent is selected from polydimethylsiloxane and / or acrylate.

13. The lubricating oil additive containing non-metallic element doped graphyne according to claim 1 or 2, characterized in that: The viscosity index improver is polymethacrylate; And / or, the anti-foaming agent is polydimethylsiloxane.

14. A method for preparing a lubricating oil additive containing non-metallic element-doped graphyne according to any one of claims 1 to 12, characterized in that: The following steps are involved: (1) Mixing a friction modifier, a rust inhibitor, a viscosity index improver, an antioxidant and a base oil according to a mass ratio at 40 to 80° C. and stirring for 1 to 5 hours to obtain a mixture A; (2) treating the dispersant, non-metallic element doped graphyne and extreme pressure anti-wear agent according to the mass ratio at 40-100° C. using a homogenizer at a speed of 15000-25000 rpm for 1-5 h to obtain a mixture B; (3) Mix mixture A, mixture B and antifoaming agent at 50-90°C and stir for 0.5-1h, then cool to room temperature to obtain the product.

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