A method for preparing graphene-carbon nanotube hybrid oil-absorbing material

Abstract

The application relates to a preparation method of a graphene-carbon nanotube hybrid oil absorption material, which comprises the following steps: S1, preparing graphene oxide foam; S2, preparing modified graphene oxide foam by using the graphene oxide foam; S3, preparing graphene-carbon nanotube hybrid foam material: placing the prepared modified graphene oxide foam in a tube furnace for heating, meanwhile, argon is introduced into the tube furnace, hydrogen is introduced into the tube furnace, a catalyst is introduced into the tube furnace through a syringe pump, acetylene is introduced into the tube furnace, the acetylene channel and the syringe pump are closed, meanwhile, the temperature control system of the tube furnace is closed, the sample is taken out after cooling to room temperature, and the graphene-carbon nanotube hybrid foam material is obtained; and S4, grafting octadecylamine: preparing an octadecylamine grafting preparation solution, immersing the prepared graphene-carbon nanotube hybrid foam material in the octadecylamine grafting preparation solution, and obtaining the graphene-carbon nanotube hybrid oil absorption material grafted with octadecylamine after freeze drying.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of surface treatment of graphene oxide and chemical vapor deposition, and particularly relates to a preparation method of graphene-carbon nanotube hybrid oil absorption material. BACKGROUND

[0002] There is a risk of leakage in the process of exploitation, refining, storage and transportation of oil and its products, and oil pollution can cause great damage to freshwater and marine ecological environment, so it is urgent to develop an oil absorption material that can quickly and efficiently remove oil stains and can be recycled after treatment.

[0003] The physical adsorption oil removal method is widely used due to its low cost, small pollution, recyclability and simple operation. Traditional adsorption materials often have amphiphilic properties, poor selectivity and need to be hydrophobically treated. Graphene has a large specific surface area and lipophilic and hydrophobic properties. At the same time, graphene can produce strong van der Waals forces between organic pollutants such as oil, and has strong adsorption capacity for organic pollutants and is easy to recycle and reuse. Graphene can be used as a modified material or a base material for oil absorption materials, and has broad application prospects in oil absorption and oil-water separation. Due to the inherent rigidity of carbon-based materials, graphene-based foams often introduce flexible organic molecule cross-linking agents to improve their compressibility and oil absorption performance, but the preparation process is complicated and difficult to achieve large-scale application. In addition, the introduction of organic molecules will also reduce the content of graphene in the material, which will also affect the final oil absorption effect. In addition, although graphene foam materials have made certain achievements and progress as oil absorption materials, graphene foam still faces great challenges in molding and oil absorption efficiency. SUMMARY

[0004] The present application provides a preparation method of graphene-carbon nanotube hybrid oil absorption material to solve one or several technical problems existing in the prior art.

[0005] The technical solution of the present application to solve the above technical problems is as follows: a preparation method of graphene-carbon nanotube hybrid oil absorption material, comprising the following steps:

[0006] S1, preparing graphene oxide foam;

[0007] S2, preparing modified graphene oxide foam using the graphene oxide foam;

[0008] S3, preparing a graphene-carbon nanotube hybrid foam material: placing the prepared modified graphene oxide foam in a tubular furnace for heating, and simultaneously introducing argon into the tubular furnace, when the tubular furnace is heated to a first preset temperature, introducing hydrogen into the tubular furnace, after the tubular furnace is heated to a second preset temperature and stabilized for a first preset time, introducing ferrocene / xylene solution (obtained by mixing ferrocene and xylene) as a catalyst into the tubular furnace through an injection pump, when aerosol appears in the tubular furnace, introducing acetylene into the tubular furnace, after introducing acetylene for a second preset time, closing the acetylene channel and the injection pump, and simultaneously closing the temperature control system of the tubular furnace, closing the hydrogen channel when the tubular furnace naturally cools to a third preset temperature, closing the argon channel when the tubular furnace naturally cools to a fourth preset temperature, and taking out the sample after the tubular furnace naturally cools to room temperature, thereby obtaining a graphene-carbon nanotube hybrid foam material;

[0009] S4, grafting octadecylamine: preparing an octadecylamine grafting preparatory solution, immersing the prepared graphene-carbon nanotube hybrid foam material in the octadecylamine grafting preparatory solution, heating for a third preset time, and freeze-drying to obtain an octadecylamine grafted graphene-carbon nanotube hybrid oil-absorbing material.

[0010] The present invention has the following beneficial effects: The preparation method of the present invention comprises centrifuging and washing a commercially available graphene oxide solution to prepare graphene oxide foam. The washed graphene oxide foam is then dissolved in water and ethanol, and ethyl orthosilicate is dropwise added under alkaline conditions to deposit a layer of silicon dioxide on the surface of the graphene oxide. The presence of silicon dioxide enables uniform growth of carbon nanotubes on the surface of the graphene oxide. Subsequently, carbon nanotubes are grown on the surface of the graphene oxide using acetylene as a carbon source by chemical vapor deposition to increase the specific surface area of ​​the graphene foam. The graphene oxide is then subjected to high-temperature reduction to prepare a graphene / carbon nanotube hybrid material. Subsequently, the long-chain alkane octadecylamine is grafted onto the surface of the graphene / carbon nanotube hybrid material using polydopamine as a medium, thereby obtaining a carbon-based material with high oil absorption and excellent recycling performance.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, in S3, the introduction rate of the argon gas is 200-600 ml / min, the introduction rate of the hydrogen gas is 80-120 ml / min, the introduction rate of the acetylene is 5-20 ml / min, the propulsion rate of the injection pump is 0.1-0.5 ml / min, and the concentration of the catalyst is 0.01-0.1 g / mL.

[0013] Furthermore, the introduction rate of the argon gas was 400 ml / min, the introduction rate of the hydrogen gas was 90 ml / min, the introduction rate of the acetylene was 10 ml / min, the propulsion rate of the syringe pump was 0.2 ml / min, and the concentration of the catalyst was 0.05 g / mL.

[0014] Further, in S3, the heating rate of the temperature control system of the tube furnace is 10~25℃ / min; the first preset temperature is 200℃, the second preset temperature is 750℃, the first preset time is 5min, the second preset time is 5~20min, the third preset temperature is 500℃, and the fourth preset temperature is 100℃.

[0015] Furthermore, the heating rate of the temperature control system of the tube furnace is 20° C. / min, and the second preset time is 15 minutes.

[0016] The beneficial effect of this further approach is that after 15 minutes of acetylene addition, nearly all of the graphene oxide sheets were covered with carbon nanotubes. The carbon nanotubes grew denser and longer, reaching approximately 40 μm. The graphene oxide grew vertically on the surface, and the carbon nanotube coverage made the edges of the graphene oxide difficult to observe.

[0017] Furthermore, in S4, the preparation method of the octadecylamine grafting preparatory solution is: dissolving octadecylamine in anhydrous ethanol to prepare an octadecylamine solution of 1 to 5 mg / ml, adding Tris solution, stirring, and then adding dopamine hydrochloride to obtain an octadecylamine grafting preparatory solution with a dopamine hydrochloride concentration of 1 to 5 mg / ml after stirring.

[0018] Furthermore, the configuration ratio of the octadecylamine solution and the Tris solution is 1:4, which is the mass ratio of octadecylamine to Tris.

[0019] Furthermore, in S4, the prepared graphene-carbon nanotube hybrid foam material is immersed in the octadecylamine grafting preparatory solution and then heated in a 50° C. water bath for 4 to 12 hours.

[0020] Furthermore, in S3, the prepared modified graphene oxide foam is spread on the quartz glass. The paving is done naturally, and there is no requirement for the paving thickness, for example, about 1 cm is sufficient. The quartz glass is placed in the middle position of the tube furnace for heating.

[0021] Furthermore, in S2, the preparation process of modified graphene oxide foam using the graphene oxide foam is as follows: ultrasonically disperse the graphene oxide foam in a mixture of anhydrous ethanol and deionized water (the volume ratio of anhydrous ethanol to deionized water is 8:1), and after complete dispersion, adjust the pH value to 9-10, then add ethyl orthosilicate, seal the cup mouth with a plastic film, and react at room temperature for 12-24 hours; after the reaction is completed, add anhydrous ethanol, wash and centrifuge 2-3 times, mix the obtained precipitate with deionized water, ultrasonically disperse it at room temperature for 30 minutes, then ultrasonically crush it for 20 minutes, and freeze-dry to obtain modified graphene oxide foam.

[0022] The present invention directly tests the oil absorption rates of graphene oxide and graphene-carbon nanotube hybrid oil-absorbing materials. The graphene-carbon nanotube hybrid foam material has an oil absorption rate of about 12 g / g for hydroxyl silicone oil, the graphene oxide foam has an adsorption rate of about 7 g / g for hydroxyl silicone oil, and the graphene / carbon nanotube hybrid oil-absorbing material grafted with ODA has an oil absorption rate of 49.7 g / g. It can be seen that the adsorption rate of the graphene-carbon nanotube hybrid foam material for hydroxyl silicone oil is higher than that of graphene oxide, almost twice that of the latter, and the introduction of ODA significantly improves the oil absorption rate of the foam material. This is mainly because the growth of carbon nanotubes (CNTs) constructs a hydrophobic nano-multilevel structure, and the introduction of ODA increases the hydrophobic surface. The two synergistically give the foam material significantly improved oil absorption performance. The test results of the cyclic adsorption rate of the graphene-carbon nanotube hybrid oil-absorbing material show that even after three cycles, the cyclic adsorption rate of the graphene-carbon nanotube hybrid oil-absorbing material remains above 75%, so it has good recycling performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the SEM image of graphene oxide foam in Example 1;

[0024] Figure 2 is the XRD pattern of graphene oxide foam in Example 1;

[0025] Figure 3 This is an SEM image of the modified graphene oxide foam with silicon dioxide deposited on the surface of Example 2;

[0026] Figure 4 This is the SEM image of the graphene-carbon nanotube hybrid foam material in Example 3;

[0027] Figure 5 is the XRD pattern of the graphene-carbon nanotube hybrid foam material in Example 4;

[0028] Figure 6 This is the SEM image of the graphene-carbon nanotube hybrid foam material in Example 4. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] Example 1

[0031] Commercially available graphene oxide was freeze-dried to prepare graphene oxide foam, serving as a control material. Specifically, a graphene oxide solution (prepared using conventional methods) was poured into a centrifuge tube, shaken evenly, and placed in a centrifuge set to 8000 rpm for 30 minutes. The supernatant was then aspirated with a rubber-tipped pipette and centrifuged with deionized water until the pH reached between 5 and 6. The tube was then frozen at -85°C for 24 hours and then dried in a freeze dryer for 48 hours to obtain the graphene oxide foam.

[0032] The obtained graphene oxide foam was ultrasonically dispersed in anhydrous ethanol and then dropwise added to a silicon wafer. After evaporation of the ethanol, a scanning electron microscope (SEM) image of the graphene oxide foam was taken (scanning electron microscope observation (TESCANMIRALMS, Czech Republic)). XRD patterns were obtained directly from the graphene oxide foam using an X-ray diffractometer (X'Pert PRO MPD, PANalytical, the Netherlands) with a scan range of 5-90° and a scan rate of 5° / min.

[0033] Figure 1 This SEM image of graphene oxide foam shows irregular flakes less than 100 μm in size. The flakes are translucent, indicating their thinness. The graphene oxide surface is relatively clean, free of impurities. Figure 2 This is the XRD diagram of graphene oxide foam. From the figure, we can see that the characteristic diffraction peak of graphene oxide appears at 2θ=11.56°, and the peak is sharp.

[0034] Example 2

[0035] Pour the graphene oxide solution into a centrifuge tube, shake it evenly, and place it in a centrifuge at 8,000 rpm for 30 minutes. Then, use a rubber-tipped pipette to remove the supernatant and centrifuge it with deionized water until the pH reaches between 5 and 6. Place the tube in a -85°C freezer for 24 hours, then dry it in a freeze dryer for 48 hours to obtain graphene oxide foam.

[0036] The graphene oxide foam was ultrasonically dispersed in a mixture of anhydrous ethanol and deionized water (0.5 mg / mL). After complete dispersion, it was magnetically stirred at room temperature. Ammonia was added dropwise with a rubber pipette to adjust the pH to 9-10. Then, 2 mL of ethyl orthosilicate was added. The cup was sealed with plastic film and allowed to react at room temperature for 16 hours. After the reaction, the liquid was transferred to a centrifuge tube, added an appropriate amount of ethanol, and shaken evenly. The tube was centrifuged at 8000 rpm for 10 minutes. The supernatant was aspirated with a rubber pipette, washed with anhydrous ethanol, and centrifuged 2-3 times. The resulting precipitate was mixed with a certain amount of deionized water and ultrasonically dispersed at room temperature for 30 minutes. After ultrasonic crushing for 20 minutes, it was placed in a refrigerator for 24 hours and freeze-dried for 48 hours to obtain the modified graphene oxide foam.

[0037] Figure 3 This is the SEM image of graphene oxide with silicon dioxide deposited on the surface, Figure 3 As shown, after depositing a layer of silicon dioxide, the shape of the graphene oxide flakes hardly changes significantly and the graphene oxide layer appears translucent, indicating that the deposited silicon dioxide layer is very thin. The SEM images and XRD patterns obtained in this example were obtained using the same methods and instruments as in Example 1.

[0038] Example 3

[0039] Pour the graphene oxide solution into a centrifuge tube, shake it evenly, and place it in a centrifuge at 8,000 rpm for 30 minutes. Then, use a rubber-tipped pipette to remove the supernatant and centrifuge it with deionized water until the pH reaches between 5 and 6. Place the tube in a -85°C freezer for 24 hours, then dry it in a freeze dryer for 48 hours to obtain graphene oxide foam.

[0040] The graphene oxide foam was ultrasonically dispersed in a mixture of anhydrous ethanol and deionized water (0.5 mg / mL). After complete dispersion, it was magnetically stirred at room temperature. Ammonia was added dropwise with a rubber-tipped pipette to adjust the pH to 9-10. Subsequently, 2 mL of tetraethyl orthosilicate was added. The cup was sealed with plastic film and allowed to react at room temperature for 16 hours. After the reaction, the liquid was transferred to a centrifuge tube, and after adding an appropriate amount of ethanol, it was shaken evenly and centrifuged at 8000 rpm for 10 minutes. The supernatant was aspirated with a rubber-tipped pipette, and then washed with anhydrous ethanol and centrifuged 2-3 times. The resulting precipitate was mixed with a certain amount of deionized water and ultrasonically dispersed at room temperature for 30 minutes. After ultrasonic crushing for 20 minutes, it was placed in a refrigerator for 24 hours and freeze-dried for 48 hours to obtain the modified graphene oxide foam.

[0041] The prepared modified graphene oxide foam was spread on the quartz glass, and the introduction rates of argon (400 ml / min), hydrogen (90 ml / min), and acetylene (10 ml / min) were set at the same time. The pre-prepared ferrocene-xylene mixed solution (reaction catalyst, 0.05 g / mL) was installed on the syringe pump, and the advancement rate was set to 0.2 ml / min. The quartz glass with the modified graphene oxide foam was placed in the middle position of the tube furnace, and the temperature control program of the tube furnace was set and then heating was started. The heating rate was 20 ° C / min, and argon was introduced at the set rate at the same time. When the temperature was raised to 2 At 100℃, hydrogen is introduced at a set rate. When the temperature reaches 750℃, after the temperature stabilizes for 5 minutes, ferrocene / xylene solution is introduced as a catalyst (200μL) at a set rate. When the amount of catalyst introduced reaches a certain amount and aerosol appears in the tube, acetylene is introduced at a set rate for reaction and timing is started. After 5 minutes of acetylene introduction, the acetylene channel is closed, the injection pump is turned off, the temperature control program of the tubular furnace is turned off, and the hydrogen is turned off when it is naturally cooled to 500℃. The argon channel is closed when it is naturally cooled to 100℃. After cooling to room temperature, the sample can be taken out to obtain the graphene / carbon nanotube hybrid material.

[0042] Figure 4 This is a SEM image of a graphene / carbon nanotube hybrid material. It shows that only a small portion of the graphene oxide surface is attached to carbon nanotubes, while the remaining surface remains smooth and free of attached carbon nanotubes. The carbon nanotubes attached to the graphene oxide surface are also less than 10 μm in length. This is because the acetylene was introduced for a short time, limiting the number and length of carbon nanotubes grown on the graphene oxide surface. These carbon nanotubes are not only small in length but also fail to fully cover the graphene oxide surface. The SEM images and XRD patterns in this example were obtained using the same methods and instruments as in Example 1.

[0043] Example 4

[0044] Pour the graphene oxide solution into a centrifuge tube, shake it evenly, and place it in a centrifuge at 8,000 rpm for 30 minutes. Then, use a rubber-tipped pipette to remove the supernatant and centrifuge it with deionized water until the pH reaches between 5 and 6. Place the tube in a -85°C freezer for 24 hours, then dry it in a freeze dryer for 48 hours to obtain graphene oxide foam.

[0045] The graphene oxide foam was ultrasonically dispersed in a mixture of anhydrous ethanol and deionized water (0.5 mg / mL). After complete dispersion, it was magnetically stirred at room temperature. Ammonia was added dropwise with a rubber pipette to adjust the pH to 9-10. Then, 2 mL of ethyl orthosilicate was added. The cup was sealed with plastic film and allowed to react at room temperature for 16 hours. After the reaction, the liquid was transferred to a centrifuge tube, added an appropriate amount of ethanol, and shaken evenly. The tube was centrifuged at 8000 rpm for 10 minutes. The supernatant was aspirated with a rubber pipette, washed with anhydrous ethanol, and centrifuged 2-3 times. The resulting precipitate was mixed with a certain amount of deionized water and ultrasonically dispersed at room temperature for 30 minutes. After ultrasonic crushing for 20 minutes, it was placed in a refrigerator for 24 hours and freeze-dried for 48 hours to obtain the modified graphene oxide foam.

[0046] The prepared modified graphene oxide foam was spread on the quartz glass, and the introduction rates of argon (400 ml / min), hydrogen (90 ml / min), and acetylene (10 ml / min) were set at the same time. The pre-prepared ferrocene-xylene mixed solution (reaction catalyst, 0.05 g / mL) was installed on the syringe pump, and the advancement rate was set to 0.2 ml / min. The quartz glass with the modified graphene oxide foam was placed in the middle position of the tube furnace, and the temperature control program of the tube furnace was set and heating was started. The heating rate was 20 ° C / min, and argon was introduced at the set rate at the same time. When the temperature reached 20 ° C / min, the quartz glass was heated. At 0°C, hydrogen is introduced at a set rate. When the temperature reaches 750°C, ferrocene / xylene solution is introduced as a catalyst (200 μL) at a set rate after the temperature stabilizes for 5 minutes. When the amount of catalyst introduced reaches a certain amount and aerosol appears in the tube, acetylene is introduced at a set rate for reaction and timing is performed. After 15 minutes of acetylene introduction, the acetylene channel is closed, the injection pump is turned off, the temperature control program of the tubular furnace is turned off, and the hydrogen is turned off when the temperature is naturally cooled to 500°C. The argon channel is closed when the temperature is naturally cooled to 100°C. After cooling to room temperature, the sample can be taken out to obtain a graphene-carbon nanotube hybrid foam material.

[0047] Figure 5 This is the XRD diagram of the graphene / carbon nanotube hybrid material. In addition to the characteristic diffraction peak of graphene oxide at 2θ=11.56°, the graphene / carbon nanotube hybrid material also has a sharp characteristic diffraction peak at 2θ=25.94°. Carbon nanotubes were successfully grown on the GO@SiO2 surface using the CVD process (under alkaline conditions, ethyl orthosilicate is hydrolyzed in a graphene oxide dispersion, and then the silicon-oxygen bonds in the hydrolysis product react with the oxygen-containing functional groups on the graphene oxide surface to deposit a layer of silicon dioxide on the graphene oxide surface. GO@SiO2 represents a layer of silicon dioxide deposited on the graphene oxide surface.), and the graphene / carbon nanotube hybrid material was successfully prepared. Figure 6This SEM image of the graphene / carbon nanotube hybrid shows that after 15 minutes of acetylene treatment, nearly all of the graphene oxide sheets are covered with carbon nanotubes. The carbon nanotubes grow denser and longer, reaching approximately 40 μm. The graphene oxide grows vertically on the surface, and the carbon nanotube coverage makes the edges of the graphene oxide difficult to observe.

[0048] The method and instrument for obtaining the SEM images and XRD patterns in this example are the same as those in Example 1.

[0049] Example 5

[0050] Pour the graphene oxide solution into a centrifuge tube, shake it evenly, and place it in a centrifuge at 8,000 rpm for 30 minutes. Then, use a rubber-tipped pipette to remove the supernatant and centrifuge it with deionized water until the pH reaches between 5 and 6. Place the tube in a -85°C freezer for 24 hours, then dry it in a freeze dryer for 48 hours to obtain graphene oxide foam.

[0051] The graphene oxide foam was ultrasonically dispersed in a mixture of anhydrous ethanol and deionized water (0.5 mg / mL). After complete dispersion, it was magnetically stirred at room temperature. Ammonia was added dropwise with a rubber pipette to adjust the pH to 9-10. Then, 2 mL of ethyl orthosilicate was added. The cup was sealed with plastic film and allowed to react at room temperature for 16 hours. After the reaction, the liquid was transferred to a centrifuge tube, added an appropriate amount of ethanol, and shaken evenly. The tube was centrifuged at 8000 rpm for 10 minutes. The supernatant was aspirated with a rubber pipette, washed with anhydrous ethanol, and centrifuged 2-3 times. The resulting precipitate was mixed with a certain amount of deionized water and ultrasonically dispersed at room temperature for 30 minutes. After ultrasonic crushing for 20 minutes, it was placed in a refrigerator for 24 hours and freeze-dried for 48 hours to obtain the modified graphene oxide foam.

[0052] The prepared modified graphene oxide foam was spread on the quartz glass, and the introduction rates of argon (400 ml / min), hydrogen (90 ml / min), and acetylene (10 ml / min) were set at the same time. The pre-prepared ferrocene-xylene mixed solution (reaction catalyst, 0.05 g / mL) was installed on the syringe pump, and the advancement rate was set to 0.2 ml / min. The quartz glass with the modified graphene oxide foam was placed in the middle position of the tube furnace, and the temperature control program of the tube furnace was set and then heating was started. The heating rate was 20 ° C / min, and argon was introduced at the set rate at the same time. When the temperature was raised to 2 At 100℃, hydrogen is introduced at a set rate. When the temperature reaches 750℃, after the temperature stabilizes for 5 minutes, ferrocene / xylene solution is introduced as a catalyst (200μL) at a set rate. When the amount of catalyst introduced reaches a certain amount and aerosol appears in the tube, acetylene is introduced at a set rate for reaction and timing is started. After 15 minutes of acetylene introduction, the acetylene channel is closed, the injection pump is turned off, the temperature control program of the tubular furnace is turned off, and the hydrogen is turned off when it is naturally cooled to 500℃. The argon channel is closed when it is naturally cooled to 100℃. After cooling to room temperature, the sample can be taken out to obtain the graphene-carbon nanotube hybrid material.

[0053] Octadecylamine (ODA) was dissolved in anhydrous ethanol (stirred for 30 minutes) to prepare a 2.5 mg / ml ODA solution. Tris solution was added at a ratio of 1:4 and stirred. Dopamine hydrochloride (DA) was then added to a concentration of 2 mg / ml and stirred for 30 minutes. The resulting graphene / carbon nanotube hybrid material was immersed in this solution and heated in a 50°C water bath for 6 hours. Freeze-dried for 48 hours, the octadecylamine-grafted graphene-carbon nanotube hybrid oil-absorbing material was obtained.

[0054] The oil absorption rates of the graphene oxide foam obtained in Example 1, the graphene-carbon nanotube hybrid foam material obtained in Example 4, and the graphene-carbon nanotube hybrid oil-absorbing material grafted with octadecylamine obtained in Example 5 were tested as shown in Table 1.

[0055] The specific test method is to spread a certain mass m0 of graphene-carbon nanotube hybrid foam material (Example 4) with a CVD time of 15min and freeze-dried graphene oxide foam (Example 1) on laboratory gauze and fold it into a shape similar to a tea bag. At the same time, a clean laboratory gauze is also folded into a shape similar to a tea bag as a blank control. The three "tea bags" are weighed using an electronic balance, and the data m1, m2, and m3 are recorded. Take three clean beakers, put the three "tea bags" in respectively, and number the three beakers. The beaker with only gauze is marked as ①, the beaker with graphene oxide foam is marked as ②, and the beaker with graphene-carbon nanotube hybrid foam material is marked as ③. Pour an appropriate amount of hydroxy silicone oil into the three beakers until the hydroxy silicone oil can submerge the "tea bag", then weigh the three beakers on an electronic balance, and record the data m 11 、m 22 、m 33 After soaking for a certain period of time, use tweezers to pick up the three "tea bags" and separate them from the hydroxy silicone oil, then drain them above the beaker for the same period of time, then remove the three "tea bags" and place ①, ②, ③, and the beaker on an electronic balance for weighing and record the data. 111 、m 222 、m 333 The saturated oil absorption rate of laboratory gauze can be calculated using formula (1).

[0056]

[0057] Q1 is the saturated oil absorption rate of the laboratory gauze (since tea bags are folded from gauze, the saturated oil absorption rate of the gauze can be calculated to deduct the blank absorption of the carrier of the graphene-carbon nanotube hybrid foam material, deducting the influence of irrelevant variables on the test results). Then, the weight of the other two "tea bag" gauze can be calculated, and their oil absorption can be calculated. The oil absorption of the sample can be obtained by subtracting the oil absorption of the gauze from the oil absorption of the "tea bag". Finally, the oil absorption rate of the sample is calculated. The oil absorption rate calculation method of Example 5 is the same as above.

[0058] Graphene-carbon nanotube hybrid foam material recycling oil absorption test: The "tea bag" in beaker No. ③ was squeezed and the above test method was repeated to measure the recycling performance of the graphene-carbon nanotube hybrid material, as shown in Table 3.

[0059] Table 1

[0060] Sample Oil uptake (g / g) Example 1 6.691 Example 4 11.849 Example 5 49.700

[0061] Table 2

[0062] Sample Water contact Example 1 100° Example 4 112° Example 5 122°

[0063] Table 3

[0064] Number of cycles Cyclic oil uptake (%) 1 95 2 85 3 77

[0065] Table 1 shows the oil absorption rate data for Examples 1, 4, and 5. The results demonstrate that, after chemical vapor deposition and reduction of carbon nanotubes, the oil absorption of graphene foam is significantly improved compared to graphene oxide. Table 2 shows the contact angles of the materials in Examples 1, 4, and 5, demonstrating that the introduction of carbon nanotubes (CNTs) enhances the hydrophobicity of the graphene foam. This is because the presence of the silica deposit facilitates the uniform deposition of CNTs on the graphene oxide surface, and the hydrophobic nanostructure created by the graphene oxide and CNTs contributes to the improved oil absorption performance of the material. Table 3 shows the cyclic oil absorption efficiency of Example 4. The results demonstrate that even after three cycles, the cyclic adsorption rate of the graphene / carbon nanotube hybrid material remains above 75%, demonstrating excellent recyclability.

[0066] As shown in Table 1, the oil absorption of the composite foam material of Example 5 is significantly higher than that of Examples 4 and 1. Table 2 shows the contact angles of the materials of Examples 1, 4, and 5. These data indicate that the introduction of ODA further enhances the hydrophobicity of the materials. The introduction of ODA increases the surface hydrophobicity of the material compared to that of Example 4, further enhancing its oil adsorption capacity and demonstrating the successful grafting of ODA.

[0067] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0068] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a graphene-carbon nanotube hybrid oil-absorbing material, characterized in that: The following steps are involved: S1, preparation of graphene oxide foam; S2, preparing modified graphene oxide foam using the graphene oxide foam; S3, preparing a graphene-carbon nanotube hybrid foam material: placing the prepared modified graphene oxide foam in a tubular furnace for heating, and simultaneously introducing argon into the tubular furnace; when the tubular furnace is heated to a first preset temperature, introducing hydrogen into the tubular furnace; after the tubular furnace is heated to a second preset temperature and stabilized for a first preset time, introducing a ferrocene / xylene solution as a catalyst into the tubular furnace through an injection pump; when aerosol appears in the tubular furnace, introducing acetylene into the tubular furnace; after introducing acetylene for a second preset time, closing the acetylene channel and the injection pump, and simultaneously closing the temperature control system of the tubular furnace; closing the hydrogen channel when the tubular furnace is naturally cooled to a third preset temperature; closing the argon channel when the tubular furnace is naturally cooled to a fourth preset temperature; and taking out the sample after the tubular furnace is naturally cooled to room temperature, thereby obtaining a graphene-carbon nanotube hybrid foam material; S4, grafting octadecylamine: preparing an octadecylamine grafting preparatory solution, immersing the prepared graphene-carbon nanotube hybrid foam material in the octadecylamine grafting preparatory solution, heating for a third preset time, and freeze-drying to obtain an octadecylamine grafted graphene-carbon nanotube hybrid oil-absorbing material; In S4, the preparation method of the octadecylamine grafting preparatory solution is as follows: octadecylamine is dissolved in anhydrous ethanol to prepare an octadecylamine solution with a concentration of 1-5 mg / ml, a Tris solution is added, and dopamine hydrochloride is added after stirring, and the octadecylamine grafting preparatory solution with a concentration of 1-5 mg / ml is obtained after stirring; In S2, the preparation process of modified graphene oxide foam using the graphene oxide foam is as follows: ultrasonically disperse the graphene oxide foam in a mixture of anhydrous ethanol and deionized water, and after it is completely dispersed, adjust the pH value to 9~10, then add ethyl orthosilicate, seal the cup mouth with a plastic film, and react at room temperature for 12~24h; after the reaction is completed, add anhydrous ethanol to wash and centrifuge 2~3 times, mix the obtained precipitate with deionized water, ultrasonically disperse it at room temperature for 30 min, then ultrasonically crush it for 20 min, and freeze-dry to obtain modified graphene oxide foam.

2. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 1, characterized in that: In S3, the introduction rate of the argon gas is 200-600 ml / min, the introduction rate of the hydrogen gas is 80-120 ml / min, the introduction rate of the acetylene is 5-20 ml / min, the propulsion rate of the syringe pump is 0.1-0.5 ml / min, and the concentration of the catalyst is 0.01-0.1 g / mL.

3. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 2, characterized in that: The introduction rate of the argon gas was 400 ml / min, the introduction rate of the hydrogen gas was 90 ml / min, the introduction rate of the acetylene was 10 ml / min, the propulsion rate of the injection pump was 0.2 ml / min, and the concentration of the catalyst was 0.05 g / mL.

4. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 1, characterized in that: In S3, the heating rate of the temperature control system of the tube furnace is 10~25℃ / min; the first preset temperature is 200℃, the second preset temperature is 750℃, the first preset time is 5min, the second preset time is 5~20min, the third preset temperature is 500℃, and the fourth preset temperature is 100℃.

5. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 4, characterized in that: The heating rate of the temperature control system of the tube furnace is 20° C. / min, and the second preset time is 15 minutes.

6. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 1, characterized in that: The configuration ratio of the octadecylamine solution to the Tris solution is 1:

4.

7. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 1, characterized in that: In S4, the prepared graphene-carbon nanotube hybrid foam material is immersed in an octadecylamine grafting preparatory solution and then heated in a 50° C. water bath for 4 to 12 hours.

8. The method for preparing a graphene-carbon nanotube hybrid oil-absorbing material according to claim 1, characterized in that: In S3, the prepared modified graphene oxide foam is spread on quartz glass, and the quartz glass is placed in the middle position of a tube furnace for heating.

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