A ternary nanocomposite material of polyaniline / titanium carbide / graphene oxide, its preparation method and application

Abstract

This invention relates to the field of heavy metal pollution control, specifically to a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, its preparation method, and its application. A titanium carbide colloidal solution is added to a graphene oxide dispersion and mixed thoroughly. Under stirring, aniline is added to the graphene oxide-titanium carbide mixed solution, and the reaction is carried out at room temperature. After the reaction is complete, the resulting solid is soaked and dried to obtain the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material. In this invention, polyaniline is used to modify titanium carbide and graphene oxide, and the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material is prepared by electrostatic self-assembly. The polyaniline-modified nanocomposite material, under defined pH conditions, has a positively charged surface, enhancing its adsorption capacity for hexavalent chromium anions, thereby achieving the removal of hexavalent chromium anions.

Description

Technical Field

[0001] This invention relates to the field of heavy metal pollution control, specifically to a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, its preparation method, and its application. Background Technology

[0002] Heavy metal pollution primarily originates from industrial sources, such as electroplating, mining, and the smelting of steel and non-ferrous metals. Industrial pollution is mostly discharged into the environment through waste residue, wastewater, and exhaust gases. Heavy metals cannot be biodegraded into harmless substances and can accumulate in humans, animals, and plants, posing a significant threat to the environment and human health. Chromium is a highly toxic heavy metal, generally existing in the natural environment as trivalent and hexavalent chromium. Hexavalent chromium possesses high solubility, high fluidity, and high oxidizing power, and is more easily absorbed by the human body, accumulating in the body. It is a strong mutagen that can induce lung cancer and nasopharyngeal carcinoma. Trivalent chromium, on the other hand, has almost no fluidity in soil and water and plays a vital role in regulating the growth and development of plants and animals; it is an essential trace element. Therefore, directly removing hexavalent chromium or converting it into the less toxic trivalent chromium and immobilizing it is one direction for the treatment of hexavalent chromium pollution in water bodies.

[0003] Currently, wastewater remediation technologies such as chemical precipitation, ion exchange, membrane filtration, electrochemical treatment, and adsorption have been adopted and developed to some extent. Among these different treatment technologies, adsorption-reduction has become a key method for remediating hexavalent chromium anion pollution due to its advantages such as low cost, high removal rate, ease of operation, and wide applicability. Mineral adsorbents such as zeolite, silica, and montmorillonite, natural polysaccharide adsorbents such as chitosan and carboxymethyl cellulose, and carbon-based materials such as activated carbon, carbon nanotubes, and graphene-based materials are widely used for the removal of heavy metals. Among these, graphene oxide is widely used for the adsorption of hexavalent chromium due to its high specific surface area and abundant active oxygen-containing groups (hydroxyl, carboxyl, and epoxy groups). MXene, a rising star among layered two-dimensional materials, shares similar properties with graphene oxide. It boasts a larger specific surface area, better hydrophilicity, and surface-containing -O / -F and -OH groups. These groups can efficiently transfer electrons and undergo redox reactions with hexavalent chromium, reducing it to trivalent chromium. However, the excessive negative charge on the surfaces of both graphene oxide and MXene, along with the tendency of graphene oxide to self-assemble, limit their adsorption capacity for hexavalent chromium anions. Summary of the Invention

[0004] To overcome the above problems, this invention provides a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, its preparation method, and its application. In this invention, polyaniline is used to modify titanium carbide and graphene oxide, and the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material is prepared via electrostatic self-assembly. Under specific pH conditions, the polyaniline-modified nanocomposite material exhibits a positively charged surface, enhancing its adsorption capacity for hexavalent chromium anions, thereby achieving the removal of hexavalent chromium anions.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, comprising:

[0007] Add titanium carbide colloidal solution to graphene oxide dispersion and mix well. Under stirring, add aniline to graphene oxide-titanium carbide mixed solution and react at room temperature. After the reaction is complete, soak and dry the resulting solid to obtain polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0008] Both the graphene oxide in the graphene oxide dispersion and the titanium carbide in the titanium carbide colloidal solution possess oxygen-containing functional groups on their surfaces. Aniline is oxidized to cationic free radicals by the -OH and -O groups on the titanium carbide surface, forming dimers, which are then oxidized to quinones. The quinones further polymerize with aniline monomers to form trimers, subsequently forming short-chain polyaniline. Both the graphene oxide in the graphene oxide dispersion and the titanium carbide in the titanium carbide colloidal solution carry negative charges, while the polyaniline formed by the oxidative polymerization of aniline carries a positive charge. Therefore, polyaniline, titanium carbide, and graphene oxide form a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material through electrostatic self-assembly.

[0009] In a second aspect, the present invention provides a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared by a method thereof.

[0010] A third aspect of the present invention provides the application of the above-mentioned polyaniline / titanium carbide / graphene oxide ternary nanocomposite material in the adsorption of heavy metal ions in wastewater.

[0011] A fourth aspect of the present invention provides a method for adsorbing heavy metal ions from wastewater, comprising:

[0012] By adjusting the pH value of wastewater containing heavy metal ions and adding the above-mentioned polyaniline / titanium carbide / graphene oxide ternary nanocomposite material to the wastewater, and after thorough mixing and contact, the adsorption and removal of heavy metal ions in the wastewater can be achieved.

[0013] The beneficial effects of this invention are as follows:

[0014] (1) Graphene oxide and titanium carbide have similar negative potentials. Excessive negative potential is not conducive to the adsorption of hexavalent chromium anions. After modification with polyaniline, the introduction of N-containing functional groups increases the potential of the graphene oxide and titanium carbide-based composite material to a positive value under pH=2 conditions, which can effectively attract hexavalent chromium anions electrostatically. At the same time, the amino groups in polyaniline have a reducing effect, which can reduce some hexavalent chromium anions to trivalent chromium, and the N in polyaniline can chelate and fix trivalent chromium. In addition, the -OH, -O functional groups on titanium carbide and Ti can also provide electrons and promote electron transfer in the redox process of hexavalent chromium anions. Therefore, the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material provided by this invention achieves the adsorption and removal of hexavalent chromium anions through electrostatic adsorption, redox reaction and surface coordination. At the same time, experimental verification shows that the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material provided by this invention has a certain anti-interference ability for various anions and cations and has a certain adsorption selectivity.

[0015] (2) The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material provided by the present invention has excellent selective adsorption of hexavalent chromium anions of heavy metals, and the removal rate of hexavalent chromium anions of heavy metals reaches 84.5%, and the maximum adsorption capacity of Langmuir can reach 153.8 mg / g.

[0016] (3) In this invention, polyaniline is used to modify titanium carbide and graphene oxide, which improves the hydrophobicity of graphene oxide and titanium carbide-based materials and facilitates separation after adsorption. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a scanning electron microscope image of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1;

[0019] Figure 2 Optical images of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1;

[0020] Figure 3 The N2 adsorption-desorption isotherm of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1;

[0021] Figure 4The Freundlich and Langmuir adsorption isotherms are for the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0024] A first typical embodiment of the present invention provides a method for preparing a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, comprising:

[0025] Add titanium carbide colloidal solution to graphene oxide dispersion and mix well. Under stirring, add aniline to graphene oxide-titanium carbide mixed solution and react at room temperature. After the reaction is complete, soak and dry the resulting solid to obtain polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0026] In one or more embodiments, the concentration of the graphene oxide dispersion is 6-7 mg / mL, preferably 6.4 mg / mL.

[0027] In one or more embodiments, the concentration of the titanium carbide colloidal solution is 3-4 mg / mL, preferably 3.6 mg / mL.

[0028] In one or more embodiments, the mass ratio of titanium carbide to graphene oxide is 0 to 4:1.

[0029] In one or more embodiments, the total concentration of graphene oxide and titanium carbide in the graphene oxide-titanium carbide mixed solution is 7-9 mg / mL, preferably 8 mg / mL.

[0030] In one or more embodiments, the volume ratio of aniline and graphene oxide-titanium carbide mixed solution is 1:5 to 25, preferably 1:10 to 20, and more preferably 1:15.

[0031] In one or more embodiments, the reaction is carried out at room temperature for 20 to 30 hours, preferably 24 hours.

[0032] In one or more embodiments, the soaking method is: soaking in ultrapure water.

[0033] In one or more embodiments, the drying is freeze-drying.

[0034] A second typical embodiment of the present invention provides a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared by a method for preparing a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0035] A third typical embodiment of the present invention provides the application of the above-mentioned polyaniline / titanium carbide / graphene oxide ternary nanocomposite material in the adsorption of heavy metal ions in wastewater.

[0036] In one or more embodiments, the heavy metal ions include hexavalent chromium anions.

[0037] A fourth typical embodiment of the present invention provides a method for adsorbing heavy metal ions in wastewater, comprising:

[0038] By adjusting the pH value of wastewater containing heavy metal ions and adding the above-mentioned polyaniline / titanium carbide / graphene oxide ternary nanocomposite material to the wastewater, and after thorough mixing and contact, the adsorption and removal of heavy metal ions in the wastewater can be achieved.

[0039] In one or more embodiments, the heavy metal ions include hexavalent chromium anions.

[0040] In one or more embodiments, the pH of the wastewater containing heavy metal ions is adjusted to 1 to 10, preferably to 2.

[0041] In one or more embodiments, the mass ratio of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material to the volume ratio of wastewater containing heavy metal ions is 0.2–2.4:1 g / L.

[0042] In one or more embodiments, adsorption is carried out under oscillation conditions at a oscillation rate of 200-250 rpm / min, preferably 220 rpm / min.

[0043] In one or more embodiments, the adsorption temperature is 30–60°C and the adsorption time is 120–360 min, preferably 300 min.

[0044] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0045] Preparation method of graphene oxide: 3g of graphite powder (325 mesh) was added to a mixed solution of concentrated sulfuric acid and phosphoric acid (volume ratio 9:1) and stirred for 10 min. Then, 18g of potassium permanganate was slowly added to the above mixed solution and stirred for another 10 min. The mixture was stirred at 50℃ for 12 h. After the reaction solution was cooled to room temperature, 400mL of deionized water was added, and the suspension was adjusted to a golden yellow color with hydrogen peroxide at 0℃. After centrifugation, the supernatant was removed, and the remaining solid material was washed three times successively with hydrochloric acid (solute mass dispersion of 9%) and deionized water. Graphene oxide was dispersed in deionized water, and impurities were removed by dialysis (ion exchange).

[0046] Titanium carbide colloidal solution was purchased from Foshan Xinxi Technology Co., Ltd.

[0047] In the following examples, after the adsorption separation process is completed, the concentration of metal ions in the solution after centrifugation is determined by ICP-OES (inductively coupled plasma optical emission spectrometry).

[0048] The formula for calculating the metal ion removal rate is as follows:

[0049]

[0050] Among them, C0 and C e (mg / L) represents the concentration of metal ions in the solution before and after adsorption.

[0051] The formula for calculating adsorption capacity is as follows:

[0052]

[0053] Where C0 and C e (mg / L) represents the concentration of metal ions in the solution before and after adsorption, respectively; V is the volume of the solution (mL), and m is the mass of the adsorbent added (mg).

[0054] Example 1

[0055] (1) A mixed dispersion of graphene oxide and titanium carbide colloidal solution was prepared by mixing 15 mL of graphene oxide-titanium carbide mixed dispersion with a total concentration of 8 mg / mL, wherein the mass ratio of titanium carbide to graphene oxide was 1:4. After ultrasonic treatment for 0.5 h, the mixture was transferred to a stirrer for stirring. Under stirring conditions, 1 mL of aniline was added to the graphene oxide-titanium carbide mixed solution, and the reaction was carried out at room temperature for 24 h. After the reaction was complete, the resulting solid was soaked in ultrapure water overnight and freeze-dried at -50 °C for 48 h to obtain a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0056] (2) The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared and synthesized in this embodiment was characterized:

[0057] in Figure 1 This is a scanning electron microscope (SEM) image of a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material. Figure 1 As can be seen, the microstructure of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material is a wrinkled, layered stacked structure.

[0058] Figure 2 Optical images of a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, from [source missing]. Figure 2 As can be seen, the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material exhibits an irregular spherical shape on a macroscopic scale.

[0059] Figure 3 The N2 adsorption-desorption isotherm for the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, from Figure 3 As can be seen from the data, the specific surface area of ​​the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment is 15 m². 2 / g. This indicates that the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment has a large specific surface area and many active sites.

[0060] (3) Adsorption and removal of hexavalent chromium anions:

[0061] To prepare a solution of hexavalent chromium anion: Weigh 0.2829 g of potassium dichromate that has been dried at 110℃ for 2 h, dissolve it in deionized water, and after the solution temperature has cooled to room temperature, transfer it to a 100 mL volumetric flask. Dilute it with deionized water to prepare a solution of hexavalent chromium anion at a concentration of 1000 mg / L, and adjust the pH to 2 with concentrated hydrochloric acid.

[0062] Take 0.8 mL of a 1000 mg / L hexavalent chromium anion solution and dilute it in a centrifuge tube to a 160 mg / L hexavalent chromium anion solution. During the above process, the pH of the resulting hexavalent chromium anion solution is controlled to be 2 by adding concentrated hydrochloric acid. Then add 5 mg of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this example. Adsorb the material for 5 h under mechanical shaking at 30 °C and 220 rpm to ensure that the adsorbent is in full contact with the aqueous phase. After the adsorption is completed, centrifuge to separate the adsorbent and test the remaining concentration of hexavalent chromium anions in the aqueous phase and calculate the adsorption capacity.

[0063] During the above adsorption and separation process, the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment achieved an adsorption capacity of 106.9 mg / g in the above solution of 160 mg / L hexavalent chromium anions.

[0064] Example 2

[0065] (1) A mixed dispersion of graphene oxide and titanium carbide colloidal solution was prepared by mixing 15 mL of graphene oxide-titanium carbide mixed dispersion with a total concentration of 8 mg / mL, wherein the mass ratio of titanium carbide to graphene oxide was 1:9. After ultrasonic treatment for 0.5 h, the mixture was transferred to a stirrer for stirring. Under stirring conditions, 1 mL of aniline was added to the graphene oxide-titanium carbide mixed solution, and the reaction was carried out at room temperature for 24 h. After the reaction was complete, the resulting solid was soaked in ultrapure water overnight and freeze-dried at -50 °C for 48 h to obtain a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0066] (2) The adsorption and removal method for hexavalent chromium anions is the same as in Example 1.

[0067] The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment has an adsorption capacity of 85.6 mg / g in the above-mentioned solution of 160 mg / L hexavalent chromium anions.

[0068] Example 3

[0069] (1) A mixed dispersion of graphene oxide and titanium carbide colloidal solution was prepared by mixing 15 mL of graphene oxide-titanium carbide mixed dispersion with a total concentration of 8 mg / mL, wherein the mass ratio of titanium carbide to graphene oxide was 2:3. After ultrasonic treatment for 0.5 h, the mixture was transferred to a stirrer for stirring. Under stirring conditions, 1 mL of aniline was added to the graphene oxide-titanium carbide mixed solution, and the reaction was carried out at room temperature for 24 h. After the reaction was complete, the resulting solid was soaked in ultrapure water overnight and freeze-dried at -50 °C for 48 h to obtain a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0070] (2) The adsorption and removal method for hexavalent chromium anions is the same as in Example 1.

[0071] The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment has an adsorption capacity of 122.2 mg / g in the above-mentioned solution of 160 mg / L hexavalent chromium anions.

[0072] Example 4

[0073] (1) A mixed dispersion of graphene oxide and titanium carbide colloidal solution was prepared by mixing 15 mL of graphene oxide-titanium carbide mixed dispersion with a total concentration of 8 mg / mL, wherein the mass ratio of titanium carbide to graphene oxide was 3:2. After ultrasonic treatment for 0.5 h, the mixture was transferred to a stirrer for stirring. Under stirring conditions, 1 mL of aniline was added to the graphene oxide-titanium carbide mixed solution, and the reaction was carried out at room temperature for 24 h. After the reaction was complete, the resulting solid was soaked in ultrapure water overnight and freeze-dried at -50 °C for 48 h to obtain a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0074] (2) The adsorption and removal method for hexavalent chromium anions is the same as in Example 1.

[0075] The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment has an adsorption capacity of 122.1 mg / g in the above-mentioned solution of 160 mg / L hexavalent chromium anions.

[0076] Example 5

[0077] (1) A mixed dispersion of graphene oxide and titanium carbide colloidal solution was prepared by mixing 15 mL of graphene oxide-titanium carbide mixed dispersion with a total concentration of 8 mg / mL, wherein the mass ratio of titanium carbide to graphene oxide was 4:1. After ultrasonic treatment for 0.5 h, the mixture was transferred to a stirrer for stirring. Under stirring conditions, 1 mL of aniline was added to the graphene oxide-titanium carbide mixed solution, and the reaction was carried out at room temperature for 24 h. After the reaction was complete, the resulting solid was soaked in ultrapure water overnight and freeze-dried at -50 °C for 48 h to obtain a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

[0078] (2) The adsorption and removal method for hexavalent chromium anions is the same as in Example 1.

[0079] The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in this embodiment has an adsorption capacity of 120.2 mg / g in the above-mentioned solution of 160 mg / L hexavalent chromium anions.

[0080] Example 6

[0081] Preparation of hexavalent chromium anion solutions: Weigh 0.2829 g of potassium dichromate dried at 110℃ for 2 h, dissolve it in deionized water, and after the solution temperature cools to room temperature, transfer it to a 100 mL volumetric flask. Dilute with deionized water to a 1000 mg / L hexavalent chromium anion solution, and adjust the pH to 2 with concentrated hydrochloric acid. Then, dilute with deionized water to obtain hexavalent chromium anion solutions of 40 mg / L, 80 mg / L, 120 mg / L, 160 mg / L, 200 mg / L, 240 mg / L, 280 mg / L, and 320 mg / L, respectively. During the above dilution process, the pH of the resulting hexavalent chromium anion solutions was controlled to 2 by adding concentrated hydrochloric acid.

[0082] Take 5 mL of solutions of hexavalent chromium anions at different concentrations into centrifuge tubes, and add 5 mg of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1. Adsorb the solutions for 5 h at 30 °C and 220 rpm to ensure sufficient contact between the adsorbent and the aqueous phase. After adsorption, centrifuge to separate the solutions, test the remaining concentration of hexavalent chromium anions in the aqueous phase, and calculate the adsorption capacity. Obtain the relationship between equilibrium concentration and adsorption capacity. Plot adsorption equilibrium and adsorption isotherms using the adsorption capacities and equilibrium concentrations obtained from solutions of different concentrations of hexavalent chromium anions, as shown below. Figure 4 As shown, R is obtained by fitting the Freundlich adsorption isotherm. 2 The value of 0.9907 further illustrates that this adsorption process is a multilayer adsorption process that occurs on a heterogeneous surface.

[0083] In the above adsorption and separation process, the adsorption process of hexavalent chromium anions by the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1 was fitted by Langmuir adsorption isotherm fitting, and the maximum adsorption capacity reached 153.8 mg / g.

[0084] Example 7

[0085] Preparation of a hexavalent chromium anion solution: Weigh 0.2829 g of potassium dichromate dried at 110℃ for 2 h, dissolve it in deionized water, and after the solution cools to room temperature, transfer it to a 100 mL volumetric flask. Dilute with deionized water to a concentration of 1000 mg / L for hexavalent chromium anions, and then further dilute with deionized water to a concentration of 80 mg / L for hexavalent chromium anions. During the above dilution process, the pH of the final hexavalent chromium anion solution is controlled from 1 to 10 using concentrated hydrochloric acid or sodium hydroxide aqueous solution.

[0086] The main forms of hexavalent chromium anion in aqueous solutions at different pH values ​​are as follows: at pH ≤ 7, hexavalent chromium anion exists primarily as HCrO4. - Cr2O7 2- It exists, in the form of HCrO4 - Primarily; at pH > 7, hexavalent chromium anions are mainly CrO4. 2- HCrO4 - It exists, in CrO4 2- Mainly.

[0087] Five mL of solutions of hexavalent chromium anions at different pH values ​​were taken into centrifuge tubes, and 5 mg of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1 was added. The solutions were adsorbed for 5 h at 30 °C and 220 rpm to ensure sufficient contact between the adsorbent and the aqueous phase. After adsorption, the solutions were centrifuged, and the remaining concentration of hexavalent chromium anions in the aqueous phase was measured. The adsorption capacity at different initial pH values ​​was calculated. The results are shown in Table 1.

[0088] Table 1. Adsorption capacity of polyaniline / titanium carbide / graphene oxide ternary nanocomposite materials for hexavalent chromium anions at different pH values.

[0089] pH 1 2 3 4 5 6 7 8 9 10 Adsorption capacity (mg / g) 35.3 67.6 65.7 64.9 63.7 63.0 61.9 59.4 56.5 46.9

[0090] As can be seen from Table 1, the adsorption capacity of the adsorbent for hexavalent chromium anions first increases and then decreases with increasing pH, and the optimal adsorption capacity is achieved at pH 2.

[0091] Example 8

[0092] Preparation of a hexavalent chromium anion solution: Weigh 0.2829 g of potassium dichromate dried at 110℃ for 2 h, dissolve it in deionized water, and after the solution temperature cools to room temperature, transfer it to a 100 mL volumetric flask. Dilute with deionized water to a concentration of 1000 mg / L for hexavalent chromium anions, and then further dilute with deionized water to a concentration of 120 mg / L for hexavalent chromium anions. During the above dilution process, adjust the pH of the final hexavalent chromium anion solution to 2 using concentrated hydrochloric acid.

[0093] Take 5 mL of the above-mentioned hexavalent chromium anion solution into centrifuge tubes, and then add 5 mg of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1. Adsorb for 5 h at different temperatures (30℃, 40℃, 50℃, 60℃) and mechanical shaking at 220 rpm to ensure sufficient contact between the adsorbent and the aqueous phase. After adsorption, centrifuge to separate the adsorbents, test the remaining concentration of hexavalent chromium anions in the aqueous phase, and calculate the adsorption capacity at different temperatures. The results are shown in Table 2.

[0094] Table 2 Adsorption capacity of polyaniline / titanium carbide / graphene oxide ternary nanocomposite materials for hexavalent chromium anions at different temperatures

[0095] Temperature (°C) 30 40 50 60 Adsorption capacity (mg / g) 90.9 93.0 95.4 96.3

[0096] As can be seen from Table 2, the adsorption capacity of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite for hexavalent chromium anions gradually increases with increasing temperature.

[0097] Example 9

[0098] Preparation of a hexavalent chromium anion solution: Weigh 0.2829 g of potassium dichromate dried at 110℃ for 2 h, dissolve it in deionized water, and after the solution temperature cools to room temperature, transfer it to a 100 mL volumetric flask. Dilute with deionized water to a concentration of 1000 mg / L for hexavalent chromium anions, and then further dilute with deionized water to a concentration of 80 mg / L for hexavalent chromium anions. During the above dilution process, adjust the pH of the final hexavalent chromium anion solution to 2 using concentrated hydrochloric acid.

[0099] Five mL of the above-mentioned hexavalent chromium anion solution was taken into centrifuge tubes, and then different masses of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1 (1 mg, 3 mg, 5 mg, 7 mg, 9 mg, 12 mg) were added. Adsorption was carried out at 30 °C and 220 rpm for 5 h to ensure sufficient contact between the adsorbent and the aqueous phase. After adsorption, the mixture was centrifuged, and the remaining concentration of hexavalent chromium anions in the aqueous phase was measured. The adsorption removal rate at different adsorbent dosages was calculated. The results are shown in Table 3.

[0100] Table 3. Removal rates of hexavalent chromium anions by polyaniline / titanium carbide / graphene oxide ternary nanocomposites of different masses.

[0101] Adsorption dose (mg) 1 3 5 7 9 12 Removal rate 24.5％ 62.7％ 84.5％ 85.6％ 86.0％ 89.4％

[0102] As can be seen from Table 3, the removal rate of hexavalent chromium anions increases with the addition of polyaniline / titanium carbide / graphene oxide ternary nanocomposite materials.

[0103] Example 10

[0104] Preparation of a hexavalent chromium anion solution: Weigh 0.2829 g of potassium dichromate dried at 110℃ for 2 h, dissolve it in deionized water, and after the solution temperature cools to room temperature, transfer it to a 100 mL volumetric flask. Dilute with deionized water to a concentration of 1000 mg / L hexavalent chromium anion, and then further dilute with deionized water to a concentration of 80 mg / L hexavalent chromium anion. Add different amounts of NaCl, Na₂SO₄, and NaNO₃ to the 80 mg / L hexavalent chromium anion solution, respectively, so that the final 80 mg / L hexavalent chromium anion solutions contain 0 mM, 5 mM, 10 mM, and 20 mM Cl₂, respectively. - SO4 2- NO3 - During the above dilution process, the pH of the final hexavalent chromium anion solution was adjusted to 2 using concentrated hydrochloric acid.

[0105] Take 5 mL of the above-mentioned hexavalent chromium anion solution into a centrifuge tube, and then add 5 mg of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared in Example 1. Adsorb the solution for 5 h under mechanical shaking at 30 °C and 220 rpm to ensure sufficient contact between the adsorbent and the aqueous phase. After adsorption, centrifuge to separate the solutions and test the remaining concentration of hexavalent chromium anions in the aqueous phase. The results are shown in Table 4.

[0106] Table 4. Adsorption capacity of polyaniline / titanium carbide / graphene oxide ternary nanocomposites at different concentrations of coexisting anions.

[0107] Concentration / Adsorption Capacity <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[NO3 - ]]> 0mM 71.9 mg / g 71.9 mg / g 71.9 mg / g 5mM 71.5mg / g 41.3 mg / g 71.2 mg / g 10mM 71.2 mg / g 40.5mg / g 70.7mg / g 20mM 70.1 mg / g 40.3 mg / g 69.3mg / g

[0108] As can be seen from Table 4, different concentrations of Cl - SO4 2- NO3 - All of these have a certain impact on the adsorption capacity of the adsorbent, especially SO4. 2- The most affected, NO3 - The impact is secondary, Cl - The impact is minimal.

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a polyaniline / titanium carbide / graphene oxide ternary nanocomposite material, characterized in that, include: Add titanium carbide colloidal solution to graphene oxide dispersion and mix well. Under stirring, add aniline to graphene oxide-titanium carbide mixed solution and react at room temperature. After the reaction is complete, soak and dry the resulting solid to obtain polyaniline / titanium carbide / graphene oxide ternary nanocomposite material.

2. The preparation method of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 1, characterized in that, The mass ratio of titanium carbide to graphene oxide is 0 to 4:1; wherein the mass of titanium carbide is not 0.

3. The preparation method of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 1, characterized in that, The total concentration of graphene oxide and titanium carbide in the graphene oxide-titanium carbide mixed solution is 7~9 mg / mL.

4. The preparation method of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 3, characterized in that, The total concentration of graphene oxide and titanium carbide in the graphene oxide-titanium carbide mixed solution is 8 mg / mL.

5. The method for preparing the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 1, characterized in that, The volume ratio of aniline and graphene oxide-titanium carbide mixed solution is 1:5~25.

6. The method for preparing the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 5, characterized in that, The volume ratio of the aniline and graphene oxide-titanium carbide mixed solution is 1:10~20.

7. The preparation method of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 6, characterized in that, The volume ratio of the aniline and graphene oxide-titanium carbide mixed solution is 1:

15.

8. The preparation method of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 1, characterized in that, The reaction time at room temperature is 20-30 h.

9. The method for preparing the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 8, characterized in that, The reaction was carried out at room temperature for 24 hours.

10. The method for preparing the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 1, characterized in that, The soaking method is as follows: soaking in ultrapure water.

11. The method for preparing the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 1, characterized in that, The drying process is freeze-drying.

12. The polyaniline / titanium carbide / graphene oxide ternary nanocomposite material prepared by the preparation method of any one of claims 1 to 11.

13. The application of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material according to claim 12 in the adsorption of heavy metal ions in wastewater.

14. The application as described in claim 13, characterized in that, The heavy metal ions include hexavalent chromium anions.

15. A method for adsorbing heavy metal ions from wastewater, characterized in that, include: Adjusting the pH value of wastewater containing heavy metal ions and adding the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material as described in claim 12 to the wastewater, and after thorough mixing and contact, can achieve the adsorption and removal of heavy metal ions in the wastewater.

16. The method for adsorbing heavy metal ions in wastewater as described in claim 15, characterized in that, The heavy metal ions include hexavalent chromium anions.

17. The method for adsorbing heavy metal ions in wastewater as described in claim 15, characterized in that, Adjust the pH of wastewater containing heavy metal ions to 1-10.

18. The method for adsorbing heavy metal ions in wastewater as described in claim 17, characterized in that, The pH value is 2.

19. The method for adsorbing heavy metal ions in wastewater as described in claim 15, characterized in that, The mass ratio of the polyaniline / titanium carbide / graphene oxide ternary nanocomposite material to the volume of wastewater containing heavy metal ions is 0.2~2.4 g:1 L.

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