Preparation method and application of two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film
By preparing a composite membrane of two-dimensional graphene oxide intercalated with one-dimensional cobalt-modified carbon nanotubes, the problems of long mass transfer distance and low catalyst utilization were solved, achieving efficient removal of organic pollutants and improvement of effluent water quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2023-12-28
- Publication Date
- 2026-06-02
AI Technical Summary
Existing carbon nanotube catalytic membranes suffer from problems such as long mass transfer distance, low catalyst utilization, and poor effluent quality in short-process water treatment.
A method for preparing a two-dimensional graphene oxide intercalation one-dimensional cobalt-modified carbon nanotube composite membrane was adopted. Through steps such as ultrasonic mixing and vacuum filtration, graphene oxide was intercalated onto a hydrophilic polyvinylidene fluoride membrane to construct an internal curved flow channel structure, which shortened the mass transfer distance and improved the catalyst utilization rate.
It achieves efficient utilization of catalyst and improvement of effluent quality, and can remove more than 90% of organic pollutants in a short time. The membrane pore size and flow channel structure are optimized, which improves the reaction rate and effluent quality.
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Figure CN117547973B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of two-dimensional material film preparation technology, specifically relating to a method for preparing and applying a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film. Background Technology
[0002] A range of organic pollutants, such as antibiotics, endocrine disruptors, and personal care products, can harm human health even at low concentrations when they enter water bodies. Advanced oxidation (AEO) can efficiently treat these recalcitrant organic pollutants; however, it is unsuitable for short-process water treatment projects, such as rural drinking water treatment, emergency water pollution control, and hiking trips, due to its large footprint and poor portability. Catalytic membranes, on the other hand, have great potential for application in short-process water treatment due to their small footprint, high portability, and good effluent quality. The combination of AEO and membranes offers unique advantages. The membrane, as a catalyst carrier, functions to recover the catalyst and perform filtration, uniformly fixing the catalyst on its surface. AEO, in turn, improves effluent quality and mitigates membrane fouling.
[0003] Carbon nanotubes can serve as carriers for metal active sites, and their internal cavities provide a nano-confined catalytic environment for chemical reactions, thereby increasing the reaction rate. However, the catalytic membrane obtained by direct filtration of carbon nanotubes has a loose porous structure, and the short and coarse flow channels result in a long mass transfer distance, which cannot guarantee effective contact between the metal active sites and the raw water, leading to low catalyst utilization and poor effluent quality. Summary of the Invention
[0004] The purpose of this invention is to solve the above-mentioned technical problems by providing a method for preparing and applying a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film.
[0005] A method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film, comprising the following steps:
[0006] I. Preparation of one-dimensional cobalt-modified carbon nanotubes: Cobalt nitrate hexahydrate and carboxylated multi-walled carbon nanotubes were mixed in an ethanol solution by ultrasonication. The resulting mixture was dried at room temperature after the ethanol evaporated, and then heat-treated in a tube furnace. After cooling to room temperature, it was washed and dried to obtain Co@CNTs.
[0007] II. Preparation of composite membrane: Graphene oxide and Co@CNTs were ultrasonically dispersed into deionized water, then vacuum filtered onto a hydrophilic polyvinylidene fluoride membrane, and after thermal fixation, a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane was obtained, thus completing the preparation method described above.
[0008] Furthermore, in step one, the mass-to-volume ratio of cobalt nitrate hexahydrate, carboxylated multi-walled carbon nanotubes, and ethanol in the mixture is 40 mg: 200 mg: 50 mL; the ethanol used is anhydrous ethanol.
[0009] Furthermore, the carboxylated multi-walled carbon nanotubes are obtained by centrifuging commercially available carboxylated multi-walled carbon nanotubes at 3000 rpm for 20 min, collecting the supernatant, vacuum filtering, and then drying.
[0010] Furthermore, the drying process described in step one involves drying at 60°C for 12 hours.
[0011] Furthermore, the heat treatment described in step one involves heating to 400°C at a rate of 3°C / min and holding for 2 hours.
[0012] Furthermore, the washing and drying described in step one involves washing with ultrapure water 5 to 6 times and drying at 60°C for 12 hours.
[0013] Furthermore, in step two, the mass ratio of graphene oxide to Co@CNT is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, or 1:16; and the mass ratio of the total mass of graphene oxide and Co@CNT to the mass of deionized water is 1:100000.
[0014] Furthermore, the ultrasonic mixing described in steps one and two involves ultrasonic disruption for 5 minutes using an ultrasonic cell disruptor.
[0015] Furthermore, the vacuum filtration pressure in step two is 0.1 MPa; the pore size of the hydrophilic polyvinylidene fluoride membrane is 0.22 μm.
[0016] Furthermore, the heat fixation described in step two involves heat fixing at 60°C for 12 hours.
[0017] The above-prepared two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane is used to remove organic pollutants from water under a pressure of 0.01-0.1 MPa; the organic pollutants are micro-pollutants in the water body; the micro-pollutants in the water body are atrazine, phenol, sulfamethoxazole, carbamazepine, bisphenol A or p-chlorobenzoic acid.
[0018] Advantages of this invention:
[0019] 1. This invention employs a simple method to control the internal flow channel structure and pore size of the catalytic membrane, and the catalytic membrane fabrication steps are relatively simple. In this invention, the internal cavity of the one-dimensional carbon nanotubes provides the possibility for nano-confined catalysis, and the loading of metals inside the carbon nanotubes also helps reduce metal dissolution and improve the quality of the effluent. The addition of graphene oxide helps stabilize the carbon nanotubes and reduce their aggregation. The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane has a longer flow channel structure and a smaller mass transfer distance compared to previously reported modified carbon nanotube membranes.
[0020] 2. In this invention, two-dimensional graphene oxide intercalated with one-dimensional carbon nanotubes is used to adjust the membrane pore size and construct an internally curved flow channel structure, which is beneficial for shortening the mass transfer distance, extending the flow channel, and improving the reaction rate. The construction of the internal curved flow channel structure of the membrane is of vital importance for improving the utilization rate of the catalyst and ensuring the safety of the effluent water quality.
[0021] 3. This invention uses a vacuum-assisted self-assembly method to intercalate one-dimensional carbon nanotubes with two-dimensional graphene oxide to obtain a catalytic membrane, which reduces the membrane pore size, shortens the mass transfer distance, and constructs a curved flow channel structure inside the membrane, greatly improving the utilization rate of the catalyst and ensuring the safety of the effluent water quality.
[0022] 4. The total thickness of the two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared by this invention is 6–9.4 μm, and the water flux is 90 L·m⁻¹. -2 ·h -1 When running continuously for 72 hours, it can remove more than 90% of organic pollutants. In this invention, the two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film can remove 100% of organic pollutants within 175ms.
[0023] This invention is applicable to the preparation of two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite films. Attached Figure Description
[0024] Figure 1 These are surface and cross-sectional SEM images of the products in Examples 1-7 and Comparative Example 1.
[0025] Figure 2 These are pore size distribution diagrams of the catalytic films (i.e., catalytic membranes) composed of different proportions of graphene oxide and cobalt-supported carbon nanotubes in Examples 2-7 and Comparative Example 1, where ■ represents Example 2, ● represents Example 3, ▲ represents Example 4, ▼ represents Example 5, and ◆ represents Example 6. Example 7 is shown. This represents Comparative Example 1;
[0026] Figure 3 This is a schematic diagram of the experimental setup used in Examples 2-8 to test the removal performance of the catalytic membrane for the micro-pollutant atrazine (ATZ).
[0027] Figure 4 The bar chart shows the removal performance of atrazine (ATZ) micropollutants by catalytic films composed of different proportions of graphene oxide and cobalt-supported carbon nanotubes in Examples 2-8. Detailed Implementation
[0028] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.
[0029] Specific Implementation Method 1: This implementation method provides a method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film, which is carried out according to the following steps:
[0030] I. Preparation of one-dimensional cobalt-modified carbon nanotubes: Cobalt nitrate hexahydrate and carboxylated multi-walled carbon nanotubes were mixed in an ethanol solution by ultrasonication. The resulting mixture was dried at room temperature after the ethanol evaporated, and then heat-treated in a tube furnace. After cooling to room temperature, it was washed and dried to obtain Co@CNTs.
[0031] II. Preparation of composite membrane: Graphene oxide and Co@CNTs were ultrasonically dispersed into deionized water, then vacuum filtered onto a hydrophilic polyvinylidene fluoride membrane, and after thermal fixation, a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane was obtained, thus completing the preparation method described above.
[0032] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the mass-to-volume ratio of cobalt nitrate hexahydrate, carboxylated multi-walled carbon nanotubes, and ethanol in the mixture in step one is 40 mg:200 mg:50 mL; and anhydrous ethanol is used. Other steps and parameters are the same as in Specific Implementation Method One.
[0033] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the carboxylated multi-walled carbon nanotubes are obtained by centrifuging commercially available carboxylated multi-walled carbon nanotubes at 3000 rpm for 20 min, collecting the supernatant, vacuum filtering, and then drying. Other steps and parameters are the same as in Specific Implementation Method 2.
[0034] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the drying in step one is performed at 60°C for 12 hours. All other steps and parameters are the same as in Specific Implementation Method One.
[0035] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the heat treatment in step one involves heating to 400°C at a rate of 3°C / min and holding for 2 hours. Other steps and parameters are the same as in Specific Implementation Method One.
[0036] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that the washing and drying in step one involves washing with ultrapure water 5-6 times and drying at 60°C for 12 hours. Other steps and parameters are the same as in Specific Implementation Method One.
[0037] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that the mass ratio of graphene oxide to Co@CNT in step two is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, or 1:16; and the mass ratio of the total mass of graphene oxide and Co@CNT to the mass of deionized water is 1:100000. Other steps and parameters are the same as in Specific Implementation Method One.
[0038] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the ultrasonic mixing described in steps one and two involves ultrasonic disruption using an ultrasonic cell disruptor for 5 minutes. Other steps and parameters are the same as in Specific Implementation Method One.
[0039] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that the vacuum filtration pressure in step two is 0.1 MPa; and the pore size of the hydrophilic polyvinylidene fluoride membrane is 0.22 μm. Other steps and parameters are the same as in Specific Implementation Method One.
[0040] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that the heat fixation in step two involves heat fixation at 60°C for 12 hours. Other steps and parameters are the same as in Specific Implementation Method One.
[0041] Specific Implementation Method Eleven: This implementation method describes the application of a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane, which is used to remove organic pollutants from water under a pressure of 0.01 to 0.1 MPa; the organic pollutants are micro-pollutants in the water body; the micro-pollutants in the water body are atrazine, phenol, sulfamethoxazole, carbamazepine, bisphenol A or p-chlorobenzoic acid.
[0042] The beneficial effects of the present invention are verified through the following embodiments:
[0043] Example 1:
[0044] A method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film, comprising the following steps:
[0045] I. Preparation of one-dimensional cobalt-modified carbon nanotubes: Cobalt nitrate hexahydrate and carboxylated multi-walled carbon nanotubes were mixed in an ethanol solution by ultrasonication. The resulting mixture was dried at room temperature after the ethanol evaporated, and then heat-treated in a tube furnace. After cooling to room temperature, it was washed and dried to obtain Co@CNTs.
[0046] II. Preparation of composite membrane: Graphene oxide and Co@CNTs were ultrasonically dispersed into deionized water, then vacuum filtered onto a hydrophilic polyvinylidene fluoride membrane, and after thermal fixation, a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane was obtained, thus completing the preparation method described above.
[0047] In step one of this embodiment, the mass-to-volume ratio of cobalt nitrate hexahydrate, carboxylated multi-walled carbon nanotubes, and ethanol in the mixture is 40 mg: 200 mg: 50 mL; the ethanol used is anhydrous ethanol.
[0048] The carboxylated multi-walled carbon nanotubes described in this embodiment are obtained by centrifuging commercially available carboxylated multi-walled carbon nanotubes at 3000 rpm for 20 min, collecting the supernatant, vacuum filtering, and then drying.
[0049] The drying process described in step one of this embodiment involves drying at 60°C for 12 hours.
[0050] The heat treatment described in step one of this embodiment is as follows: the temperature is increased to 400°C at a rate of 3°C / min and held for 2 hours.
[0051] The washing and drying process described in step one of this embodiment involves washing with ultrapure water 5 to 6 times and drying at 60°C for 12 hours.
[0052] In step two of this embodiment, the total mass ratio of graphene oxide and Co@CNT to deionized water is 1:100000.
[0053] In this embodiment, the ultrasonic mixing in steps one and two involves ultrasonic disruption for 5 minutes using an ultrasonic cell disruptor.
[0054] In step two of this embodiment, the vacuum filtration pressure is 0.1 MPa; the pore size of the hydrophilic polyvinylidene fluoride membrane is 0.22 μm.
[0055] The heat fixation described in step two of this embodiment is performed at 60°C for 12 hours.
[0056] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:0, thus a two-dimensional graphene oxide film is prepared as a control.
[0057] Example 2:
[0058] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:3; the rest is the same as in embodiment 1.
[0059] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-2.
[0060] Example 3:
[0061] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:4; the rest is the same as in embodiment 1.
[0062] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-3.
[0063] Example 4:
[0064] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:5; the rest is the same as in embodiment 1.
[0065] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-4.
[0066] Example 5:
[0067] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:6; the rest is the same as in embodiment 1.
[0068] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-5.
[0069] Example 6:
[0070] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:7; the rest is the same as in embodiment 1.
[0071] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-6.
[0072] Example 7:
[0073] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:8; the rest is the same as in embodiment 1.
[0074] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-7.
[0075] Example 8:
[0076] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 1:16; the rest is the same as in embodiment 1.
[0077] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-8.
[0078] Comparative Example 1:
[0079] In step two of this embodiment, the mass ratio of graphene oxide to Co@CNT is 0:1; the rest is the same as in embodiment 1.
[0080] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film obtained in this embodiment is denoted as Co@CNT-GO-9.
[0081] result:
[0082] Figure 1 The images show surface and cross-sectional SEM images of the products in Examples 1-7 and Comparative Example 1. The two-dimensional graphene oxide film prepared in Example 1 has many wrinkles on its surface, which are stacked one layer at a time to form a film with a thickness of about 3.9 μm.
[0083] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 2 has a thickness of approximately 6.0 μm.
[0084] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 3 has a thickness of approximately 6.5 μm.
[0085] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 4 has a film thickness of approximately 7.5 μm.
[0086] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 5 has a thickness of approximately 8.3 μm.
[0087] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 6 has a film thickness of approximately 8.4 μm.
[0088] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 7 has a thickness of approximately 9.4 μm.
[0089] Examples 2-7 show that carbon nanotubes and graphene oxide have good compatibility. Under the constraint of graphene oxide, the carbon nanotubes are arranged in a regular and almost parallel manner. The higher the proportion of graphene oxide, the smaller the membrane pores and the smaller the membrane thickness.
[0090] The cobalt-modified carbon nanotube membrane prepared in Comparative Example 1 has a thickness of approximately 12.8 μm.
[0091] Figure 2The figures show the pore size distribution of catalytic films (i.e., catalytic membranes) composed of different proportions of graphene oxide and cobalt-supported carbon nanotubes in Examples 2-7 and Comparative Example 1. The catalytic membrane without graphene oxide (Comparative Example 1) has a pore size distribution in the range of 210 nm to 1890 nm, with an average pore size of 1050 nm. After adding graphene oxide, the average pore size shrinks to 8 nm to 190 nm, and the distribution range also narrows. The more uniform pore size is beneficial for the occurrence of confined catalytic reactions.
[0092] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite membrane prepared in Example 2 has a pore size distribution range of 4–14.33 nm and an average pore size of 7.30 nm.
[0093] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 3 has a pore size distribution range of 10-17 nm and an average pore size of 13.61 nm.
[0094] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite membrane prepared in Example 4 has a pore size distribution range of 6.5–34.14 nm and an average pore size of 20.11 nm.
[0095] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite membrane prepared in Example 5 has a pore size distribution range of 12.34–59.9 nm and an average pore size of 34.82 nm.
[0096] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite membrane prepared in Example 6 has a pore size distribution range of 18.54–135.48 nm and an average pore size of 71.75 nm.
[0097] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite membrane prepared in Example 7 has a pore size distribution range of 53.99–210.21 nm and an average pore size of 133.09 nm.
[0098] The cobalt-modified carbon nanotube membrane prepared in Comparative Example 1 has a pore size distribution range of 210–1890 nm and an average pore size of 807.96 nm.
[0099] To test the removal performance of the catalytic membrane for the micro-pollutant atrazine (ATZ), a dead-end filtration method was used in the membrane filtration experiment, with an effective filtration area of 10.17 cm². 2 Experimental setup such as Figure 3 As shown, the catalytic membrane was placed in the membrane module and pressed tightly with a rubber ring. A solution containing 2 mg / LATZ and 0.5 mM MPMS at pH 7 was placed in the buffer bottle.
[0100] Figure 4Examples 2-8 illustrate the removal performance of catalytic films composed of different ratios of graphene oxide and cobalt-supported carbon nanotubes for the micropollutant atrazine (ATZ). Examples 2-5 (graphene oxide to Co@CNT ratio in the range of 1:3 to 1:6) were tested at 90 L·m⁻¹. -2 ·h -1 At a certain water flux, 100% of atrazine could be removed within 60 minutes. When the ratio was further increased to 1:7 (Example 6), 1:8 (Example 7), and 1:16 (Example 8), the ATZ removal rate decreased to 98.36%, 96.11%, and 70.41%, respectively. The addition of graphene oxide can effectively reduce membrane pores, shorten the mass transfer distance, construct a tortuous flow channel structure inside the membrane, and improve the availability of active sites.
[0101] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 2 achieved a 100% removal rate of ATZ after 60 min.
[0102] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 3 had a 100% removal rate of ATZ after 60 min.
[0103] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 4 had a 100% removal rate of ATZ after 60 min.
[0104] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 5 had a 100% removal rate of ATZ after 60 min.
[0105] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 6 had an ATZ removal rate of 98.36% after 60 min.
[0106] The two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite film prepared in Example 7 had an ATZ removal rate of 96.11% after 60 min.
[0107] The two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared in Example 8 had an ATZ removal rate of 70.41% after 60 min.
[0108] In summary, the two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite membrane prepared by this invention exhibits high membrane flux. The pore size can be effectively controlled by adjusting the ratio of graphene oxide to Co@CNTs. When the ratio of graphene oxide to Co@CNTs is in the range of 1:3 to 1:6, the membrane flux reaches 90 L·m⁻¹. -2 ·h -1At that time, 100% of micro-contaminants can be removed within 60 minutes. The higher the proportion of graphene oxide, the smaller the membrane pores, and the higher the pressure required for the solution to pass through the membrane. Therefore, the overall membrane performance is optimal when the ratio of graphene oxide to Co@CNT is 1:6.
Claims
1. A method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film, characterized in that: Follow these steps: I. Preparation of one-dimensional cobalt-modified carbon nanotubes: Cobalt nitrate hexahydrate and carboxylated multi-walled carbon nanotubes were mixed in an ethanol solution by ultrasonication. The resulting mixture was dried at room temperature after the ethanol evaporated, and then heat-treated in a tube furnace. After cooling to room temperature, it was washed and dried to obtain Co@CNTs. II. Preparation of composite membrane: Graphene oxide and Co@CNTs were ultrasonically dispersed into deionized water, then vacuum filtered onto a hydrophilic polyvinylidene fluoride membrane, and after thermal fixation, a two-dimensional graphene oxide intercalated one-dimensional cobalt modified carbon nanotube composite membrane was obtained, thus completing the preparation method described above. In step one, the mass-to-volume ratio of cobalt nitrate hexahydrate, carboxylated multi-walled carbon nanotubes, and ethanol in the mixture is 40 mg: 200 mg: 50 mL; the ethanol used is anhydrous ethanol. In step two, the mass ratio of graphene oxide to Co@CNT is 1:3, 1:4, 1:5, 1:6, 1:7, or 1:8; the total mass ratio of graphene oxide and Co@CNT to deionized water is 1:100000.
2. The method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film according to claim 1, characterized in that: The carboxylated multi-walled carbon nanotubes were obtained by centrifuging commercially available carboxylated multi-walled carbon nanotubes at 3000 rpm for 20 min, collecting the supernatant, vacuum filtering, and then drying.
3. The method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film according to claim 1, characterized in that: The heat treatment described in step one: heat to 400℃ at a rate of 3℃ / min and hold for 2 hours.
4. The method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film according to claim 1, characterized in that: The washing and drying process described in step one involves washing with ultrapure water 5-6 times and drying at 60°C for 12 hours.
5. The method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film according to claim 1, characterized in that: The ultrasonic mixing described in steps one and two: use an ultrasonic cell disruptor to sonicate for 5 minutes.
6. The method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film according to claim 1, characterized in that: The vacuum filtration pressure in step two is 0.1 MPa; the pore size of the hydrophilic polyvinylidene fluoride membrane is 0.22 μm.
7. The method for preparing a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film according to claim 1, characterized in that: The heat fixation described in step two involves heat fixing at 60°C for 12 hours.
8. The application of a two-dimensional graphene oxide intercalated one-dimensional cobalt-modified carbon nanotube composite film prepared by the method described in claim 1, characterized in that: Two-dimensional graphene oxide intercalated with one-dimensional cobalt-modified carbon nanotube composite membranes is used to remove organic pollutants from water under a pressure of 0.01~0.1 MPa; the organic pollutants are micro-pollutants in the water body; the micro-pollutants in the water body are atrazine, phenol, sulfamethoxazole, carbamazepine, bisphenol A or p-chlorobenzoic acid.