Preparation method and application of a composite pollutant treatment agent
A carbon fiber-supported Bi2O2.33/Bi2O3 composite pollutant treatment agent was prepared by electrospinning and hydrothermal methods, which solved the problems of difficult recycling of powder treatment agents and slow photocatalytic degradation, and achieved efficient and convenient removal of organic pollutants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SICHUAN RUIOULAIZI TECH CO LTD
- Filing Date
- 2023-06-16
- Publication Date
- 2026-07-21
AI Technical Summary
Existing powder pollutant treatment agents are difficult to recycle, and the photocatalytic degradation process is slow, making it difficult to quickly treat high-concentration wastewater.
A carbon fiber-supported Bi2O2.33/Bi2O3 composite pollutant treatment agent was prepared by electrospinning and by hydrothermal method. The conductivity of carbon fiber was used to promote the separation of photogenerated electron-hole pairs, and the organic pollutants were rapidly removed through adsorption-degradation combination.
It achieves rapid removal of organic pollutants, has excellent surface charge distribution, improves photocatalytic degradation activity, uniform loading of the treatment agent, facilitates recycling, reduces treatment costs, and is green and efficient.
Smart Images
Figure CN117960115B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmental material preparation technology, and specifically relates to a method for preparing and applying a composite pollutant treatment agent. Background Technology
[0002] With the accelerating pace of industrialization, the generation of large amounts of industrial wastewater has severely damaged the Earth's ecosystem. Adsorption is a conventional method for treating industrial wastewater, but it essentially only collects pollutants from the liquid phase to the solid phase, and secondary pollution is easily generated during the treatment and recovery of the adsorbent. Photocatalytic degradation utilizes semiconductor materials to convert solar energy into chemical energy, allowing organic pollutants to be directly degraded, making it more environmentally friendly. However, its kinetic process is slow and it is difficult to quickly treat high-concentration wastewater.
[0003] Combining adsorption and photocatalytic degradation is a convenient approach to solving the aforementioned problems. Adsorption can rapidly remove organic pollutants from water, while photocatalysis can degrade the adsorbed organic pollutants. This method achieves rapid removal of pollutants without causing secondary pollution.
[0004] Existing pollutant treatment agents are typically powder materials. These powders are difficult to recover from water bodies, increasing water treatment costs and hindering practical applications. Loading the treatment agent onto a carbon fiber substrate effectively solves this problem. On one hand, carbon fibers restrict the free dispersion of the treatment agent in water, facilitating recovery; on the other hand, carbon fibers possess excellent electrical conductivity, promoting the separation of photogenerated electron-hole pairs in the photocatalytic material, thus improving photocatalytic degradation performance. Summary of the Invention
[0005] This invention provides a method for preparing and applying a composite pollutant treatment agent with dual adsorption and degradation effects, which is used to efficiently remove organic pollutants from water bodies and solves the technical problem that existing powder treatment agents are difficult to recycle after use.
[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:
[0007] On one hand, the present invention provides a method for preparing a composite pollutant treatment agent, comprising the following steps:
[0008] Step 1: Dissolve polyacrylonitrile in N,N-dimethylformamide, stir thoroughly to obtain spinning solution, perform electrospinning, and obtain electrospinned polyacrylonitrile film.
[0009] Step 2: Pre-oxidize the polyacrylonitrile film obtained by electrospinning in an air atmosphere to obtain a pre-oxidized polyacrylonitrile film;
[0010] Step 3: Carbonize the pre-oxidized polyacrylonitrile film under nitrogen protection to obtain electrospun carbon fibers;
[0011] Step 4: Dissolve bismuth nitrate in ethylene glycol and obtain a bismuth nitrate / ethylene glycol solution by magnetic stirring;
[0012] Step 5: Use 3A molecular sieve to purify anhydrous ethanol by removing water;
[0013] Step 6: The bismuth nitrate / ethylene glycol solution obtained in Step 4 is mixed with the anhydrous ethanol obtained in Step 5 and added to a hydrothermal reactor. The electrospun carbon fibers obtained in Step 3 are then added to carry out the hydrothermal reaction. After washing and drying, the reaction product yields Bi₂O supported on carbon fibers with both adsorption and degradation effects. 2.33 / Bi2O3 composite pollutant treatment agent.
[0014] In some embodiments, in step 1, the molecular weight of polyacrylonitrile is 85,000, and the mass fraction of the polyacrylonitrile / N,N-dimethylformamide solution is 10-12%.
[0015] In some embodiments, in step 1, the electrospinning voltage is 20 kV, the feed flow rate is 0.5-0.6 mL / h, the distance between the needle and the receiver is 15 cm, and the spinning time is 6-8 h.
[0016] In some embodiments, in step 2, the pre-oxidation temperature is 230-250 ºC and the pre-oxidation time is 60-90 min.
[0017] In some embodiments, in step 3, the carbonization heating rate is 5 ºC / min, the carbonization temperature is 700-900 ºC, and the carbonization time is 60-120 min.
[0018] In some embodiments, in step 4, the concentration of the bismuth nitrate / ethylene glycol solution is 0.125-0.15 mol / L, and the stirring rate is 800 rpm.
[0019] In some embodiments, the purification time for anhydrous ethanol in step 5 is 12 h.
[0020] In some embodiments, in step 6, the volume ratio of bismuth nitrate / ethylene glycol solution to anhydrous ethanol is 1:2, the carbon fiber size used is 1 cm × 1.5 cm, the hydrothermal reaction temperature is 160 ºC, and the reaction time is 300 min.
[0021] On the other hand, the present invention also provides an application of the composite pollutant treatment agent prepared by the above preparation method in the removal of organic pollutants in wastewater.
[0022] The method for preparing the composite pollutant treatment agent proposed in this invention uses polyacrylonitrile as a carbon source, and forms electrospun carbon fibers by electrospinning, pre-oxidation, and carbonization; then, it obtains Bi2O supported on the carbon fibers through a one-step hydrothermal method. 2.33 / Bi2O3 composite pollutant treatment agent.
[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The material is rich in Bi2O 2.33 (1) The phase makes the surface charge of the material positive, thus producing excellent adsorption effect on anionic organic pollutant molecules; (2) The presence of oxygen vacancies reduces the conduction band potential and increases the valence band potential of the material, improving the redox ability of electron-hole pairs in the material and obtaining photocatalytic degradation activity superior to that of a single Bi2O3 phase; (3) The treatment agent is uniformly loaded on the surface of carbon fiber, which can provide a support framework for the system, which is conducive to the cycle stability of the system, and also makes the treatment agent easy to recycle, solving the problem that traditional powder treatment agents are difficult to recycle; (4) The preparation method is simple, low-cost, and will not cause pollution to the environment. It is a green and efficient treatment technology. Attached Figure Description
[0024] Figure 1 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33 SEM image of a Bi2O3 composite pollutant treatment agent;
[0025] Figure 2 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33 / Bi2O3 composite pollutant treatment agent, Bi2O prepared in Example 3 2.33 XRD patterns of the / Bi2O3 powder treatment agent and the β-Bi2O3 powder treatment agent prepared in Example 4;
[0026] Figure 3 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33 Adsorption curve of Bi2O3 composite pollutant treatment agent on 100 mg / L methyl orange;
[0027] Figure 4 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33 / Bi2O3 composite pollutant treatment agent and carbon fiber supported Bi2O prepared in Example 2 2.33 Removal curve of 50 mg / L tetracycline hydrochloride by / Bi2O3 composite pollutant treatment agent;
[0028] Figure 5 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33Cyclic removal curve of 50 mg / L tetracycline hydrochloride by / Bi2O3 composite pollutant treatment agent.
[0029] Figure 6 It is the Bi2O prepared in Example 3 2.33 Adsorption curves of / Bi2O3 powder and β-Bi2O3 powder prepared in Example 4 for 100 mg / L methyl orange;
[0030] Figure 7 It is the Bi2O prepared in Example 3 2.33 Removal curves of 10 mg / L Rhodamine B by / Bi2O3 powder and β-Bi2O3 powder prepared in Example 4;
[0031] Figure 8 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33 / Bi2O3 composite pollutant treatment agent and Bi2O prepared in Example 3 2.33 / Comparison of Bi2O3 powder catalyst before and after removal of 10 mg / L Rhodamine B. Detailed Implementation
[0032] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.
[0033] Example 1
[0034] This embodiment provides a carbon fiber-supported Bi2O 2.33 The preparation method of the Bi2O3 composite pollutant treatment agent is as follows:
[0035] Step 1: Dissolve 1.2 g of polyacrylonitrile in 8.8 g of N,N-dimethylformamide and stir thoroughly at 60 ºC to obtain the spinning solution. During the electrospinning process, the distance between the needle and the receiver is 15 cm, the spinning voltage is 20 kV, the feed flow rate is 0.5 mL / h, and the spinning time is 6 h.
[0036] Step 2: The polyacrylonitrile fiber membrane obtained by spinning is pre-oxidized in air at a temperature of 230 ºC for 90 min to obtain a pre-oxidized polyacrylonitrile fiber membrane.
[0037] Step 3: Place the pre-oxidized polyacrylonitrile fiber membrane in a high-temperature tube furnace and carbonize it at a rate of 5 ºC / min to 900 ºC for 90 min under nitrogen protection to obtain electrospun carbon fiber.
[0038] Step 4: Dissolve bismuth nitrate in ethylene glycol and stir magnetically at 60 °C to obtain a 0.125 mol / L bismuth nitrate / ethylene glycol solution;
[0039] Step 5: Use 3A molecular sieve to purify anhydrous ethanol by dehydration for 12 h;
[0040] Step 6: Add 4 mL of bismuth nitrate / ethylene glycol solution and 8 mL of anhydrous ethanol (after dehydration and purification) to a 25 mL Teflon-lined reactor, then add 1 cm × 1.5 cm electrospun carbon fiber. Place the reactor in a forced-air drying oven and perform a hydrothermal reaction at 160 ºC for 300 min. Wash the resulting fiber membrane five times with anhydrous ethanol and dry it in a forced-air drying oven at 60 ºC for 12 h to obtain a composite pollutant treatment agent.
[0041] Example 2
[0042] This embodiment provides a carbon fiber-supported Bi2O 2.33 The preparation method of the Bi2O3 composite pollutant treatment agent is as follows:
[0043] Step 1: Dissolve 1.0 g of polyacrylonitrile in 8.8 g of N,N-dimethylformamide and stir thoroughly at 60 ºC to obtain the spinning solution. During the electrospinning process, the distance between the needle and the receiver is 15 cm, the spinning voltage is 20 kV, the feed flow rate is 0.6 mL / h, and the spinning time is 6 h.
[0044] Step 2: The polyacrylonitrile fiber membrane obtained by spinning is pre-oxidized in air at a temperature of 250 ºC for 90 min to obtain a pre-oxidized polyacrylonitrile fiber membrane.
[0045] Step 3: Place the pre-oxidized polyacrylonitrile fiber membrane in a high-temperature tube furnace and carbonize it at a rate of 5 ºC / min to 900 ºC for 90 min under nitrogen protection to obtain electrospun carbon fiber.
[0046] Step 4: Dissolve bismuth nitrate in ethylene glycol and stir magnetically at 60 °C to obtain a 0.15 mol / L bismuth nitrate / ethylene glycol solution;
[0047] Step 5: Use 3A molecular sieve to purify anhydrous ethanol by dehydration for 12 h;
[0048] Step 6: Add 4 mL of bismuth nitrate / ethylene glycol solution and 8 mL of anhydrous ethanol (after dehydration and purification) to a 25 mL polytetrafluoroethylene-lined reactor, then add 1 cm × 1.5 cm electrospun carbon fiber. Place the reactor in a forced-air drying oven and perform a hydrothermal reaction at 160 ºC for 300 min. Wash the resulting fiber membrane five times with anhydrous ethanol and dry it in a forced-air drying oven at 60 ºC for 12 h to obtain a composite pollutant treatment agent.
[0049] Example 3
[0050] This embodiment provides Bi2O 2.33 The preparation method of the Bi2O3 powder treatment agent is as follows:
[0051] Step 1: Dissolve bismuth nitrate in ethylene glycol and stir magnetically at 60 °C to obtain a 0.125 mol / L bismuth nitrate / ethylene glycol solution;
[0052] Step 2: Use 3A molecular sieve to purify anhydrous ethanol by dehydration for 12 h;
[0053] Step 3: Add 4 mL of bismuth nitrate / ethylene glycol solution and 8 mL of anhydrous ethanol (after dehydration and purification) to 25 mL of polytetrafluoroethylene-lined reaction vessel. Place the reaction vessel in a forced-air drying oven and perform a hydrothermal reaction at 160 ºC for 300 min. After the reaction, centrifuge the product at 8000 rpm for 3 min to separate the powder. Wash the powder twice with anhydrous ethanol and centrifuge twice. Then, dry the powder in a forced-air drying oven at 60 ºC for 12 h to obtain Bi₂O. 2.33 / Bi2O3 powder treatment agent.
[0054] Example 4
[0055] This embodiment provides a method for preparing β-Bi2O3 powder treatment agent as follows:
[0056] Step 1: Dissolve bismuth nitrate in ethylene glycol and stir magnetically at 60 °C to obtain a 0.125 mol / L bismuth nitrate / ethylene glycol solution;
[0057] Step 2: Use 3A molecular sieve to purify anhydrous ethanol by dehydration for 12 h;
[0058] Step 3: Add 4 mL of bismuth nitrate / ethylene glycol solution and 8 mL of anhydrous ethanol (after dehydration and purification) to 25 mL of polytetrafluoroethylene-lined reaction vessel. Place the reaction vessel in a forced-air drying oven and perform a hydrothermal reaction at 160 ºC for 300 min. After the reaction, centrifuge the product at 8000 rpm for 3 min to separate the powder. Wash the powder twice with anhydrous ethanol and centrifuge twice. Then, dry the powder in a forced-air drying oven at 60 ºC for 12 h to obtain Bi₂O. 2.33 / Bi2O3 powder treatment agent;
[0059] Step 4: Add Bi2O 2.33 β-Bi2O3 powder was loaded into a ceramic crucible and placed in a tube furnace. The crucible was heated to 450 °C for 1 hour in air at a heating rate of 5 °C / min. After annealing, the crucible was naturally cooled to room temperature to obtain β-Bi2O3 powder.
[0060] Figure 1 It is the carbon fiber-supported Bi2O prepared in Example 1. 2.33 The SEM image of the Bi2O3 composite pollutant treatment agent shows that the carbon fibers are uniformly coated with sheet-like bismuth oxide, exposing a large surface area, which is beneficial for adsorption and photocatalytic degradation.
[0061] Figure 2 It is the carbon fiber-supported Bi2O prepared in Example 1 2.33 / Bi2O3 composite pollutant treatment agent, Bi2O prepared in Example 3 2.33 XRD patterns of the Bi2O3 powder treatment agent and the β-Bi2O3 powder treatment agent prepared in Example 4. For Bi2O 2.33 Bi₂O₃ powder treatment agent and composite pollutant treatment agent, whose diffraction peaks at 10.2° and 20.5° correspond to Bi₂O₃ in the body-centered tetragonal crystal system, respectively. 2.33 The (004) and (008) crystal planes of the phase (JCPDS NO. 27-0051). The diffraction peaks at 27.91°, 31.03°, and 32.71° belong to the (201), (002), and (220) crystal planes of the tetragonal β-Bi₂O₃ phase (JCPDS NO. 27-0050), respectively, indicating that the composite pollutant treatment agent and Bi₂O₃... 2.33 Bi₂O₃ powder treatment agent consists of β-Bi₂O₃ phase and non-stoichiometric Bi₂O₃. 2.33The β-Bi2O3 powder treatment agent is composed of pure β-Bi2O3 phase. The 27.89°, 31.65°, 32.70°, 46.17°, 46.93°, 54.10°, 55.52° and 57.67° of the β-Bi2O3 powder treatment agent belong to the (201), (002), (220), (222), (400), (203), (421) and (402) crystal planes of the tetragonal β-Bi2O3 phase, respectively, indicating that the β-Bi2O3 powder treatment agent is composed of pure β-Bi2O3 phase.
[0062] Figure 3 It is the carbon fiber-supported Bi2O prepared in Example 1. 2.33 The adsorption curve of 100 mg / L methyl orange by the / Bi2O3 composite pollutant treatment agent shows that the catalyst can complete the adsorption of methyl orange within 120 min, demonstrating excellent adsorption performance.
[0063] Figure 4 It is the carbon fiber-supported Bi2O prepared in Example 1. 2.33 / Bi2O3 composite pollutant treatment agent and carbon fiber-supported Bi2O prepared in Example 2 2.33 The removal curve of 50 mg / L tetracycline hydrochloride by the / Bi2O3 composite pollutant treatment agent shows that the sample prepared in Example 1 has better pollutant removal ability. Through the combination of adsorption and degradation, the removal rate of 50 mg / L tetracycline hydrochloride reached 72.5% after 180 min.
[0064] Figure 5 It is the carbon fiber-supported Bi2O prepared in Example 1. 2.33 The cyclic removal curve of 50 mg / L tetracycline hydrochloride by the / Bi2O3 composite pollutant treatment agent showed a slight decrease in the adsorption performance of the sample after the first cycle, but the performance of the sample remained stable in the next three cycles.
[0065] Figure 6 Bi2O prepared in Example 3 2.33 The adsorption curves of 100 mg / L methyl orange by Bi₂O₃ powder and β-Bi₂O₃ powder prepared in Example 4 are shown. After 40 min of adsorption, the removal rate of methyl orange by β-Bi₂O₃ powder was only 11.4%, while that by Bi₂O₃ powder was much higher. 2.33 Bi₂O₃ powder achieved a methyl orange removal rate of up to 93.3%. This is due to the non-stoichiometric phase of Bi₂O₃. 2.33 Bi2O is rich in oxygen vacancies, which makes it suitable for use in oxygen-rich environments. 2.33 The surface of / Bi2O3 is positively charged, thus exhibiting excellent adsorption performance for anionic pollutants such as methyl orange and tetracycline hydrochloride.
[0066] Figure 7Bi2O prepared in Example 3 2.33 Removal curves of 10 mg / L Rhodamine B by Bi₂O₃ powder and β-Bi₂O₃ powder prepared in Example 4. After 150 min, the removal rate of Rhodamine B by β-Bi₂O₃ was only 28.1%, while the removal rate by Bi₂O₃ / Bi₂O₃ ratio was higher. 2.33 The removal rate of Rhodamine B was as high as 83%. (Bi₂O₃ / Bi₂O) 2.33 The presence of oxygen vacancies reduces the conduction band potential and increases the valence band potential of the material, thereby affecting the Bi2O3 / Bi2O ratio. 2.33 The photogenerated electron-hole pairs in it have stronger redox capabilities, exhibiting stronger photocatalytic degradation activity than single-phase β-Bi2O3.
[0067] Figure 8 It is the carbon fiber-supported Bi2O prepared in Example 1. 2.33 / Bi2O3 composite pollutant treatment agent and Bi2O prepared in Example 3 2.33 The image shows a comparison of the effects of Bi₂O₃ powder treatment agent on the removal of 10 mg / L Rhodamine B before and after the removal of pollutants. The powder sample remained suspended in the water after pollutant removal, requiring complex powder separation steps to clarify the solution. In contrast, the carbon fiber sample, after degradation, only required removal of the fiber membrane to directly obtain a colorless and clear solution, demonstrating excellent recyclability and overcoming the difficulty in recovering traditional powder treatment agents.
[0068] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for preparing a composite pollutant treatment agent, characterized in that, Includes the following steps: Step 1: Dissolve polyacrylonitrile in N,N-dimethylformamide, stir thoroughly to obtain spinning solution, perform electrospinning, and obtain electrospinned polyacrylonitrile film. Step 2: Pre-oxidize the polyacrylonitrile film obtained by electrospinning in an air atmosphere to obtain a pre-oxidized polyacrylonitrile film; Step 3: Carbonize the pre-oxidized polyacrylonitrile film under nitrogen protection to obtain electrospun carbon fibers; Step 4: Dissolve bismuth nitrate in ethylene glycol and obtain a bismuth nitrate / ethylene glycol solution by magnetic stirring; Step 5: Use 3A molecular sieve to purify anhydrous ethanol by removing water; Step 6: The bismuth nitrate / ethylene glycol solution obtained in Step 4 is mixed with the anhydrous ethanol obtained in Step 5 and added to a hydrothermal reactor. The electrospun carbon fibers obtained in Step 3 are then added to carry out the hydrothermal reaction. After washing and drying, the reaction product yields Bi₂O supported on carbon fibers with both adsorption and degradation effects. 2.33 / Bi2O3 composite pollutant treatment agent.
2. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: In step 1, the molecular weight of polyacrylonitrile is 85,000, and the mass fraction of the polyacrylonitrile / N,N-dimethylformamide solution is 10-12%.
3. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: In step 1, the electrospinning voltage is 20 kV, the feed flow rate is 0.5-0.6 mL / h, the distance between the needle and the receiver is 15 cm, and the spinning time is 6-8 h.
4. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: In step 2, the pre-oxidation temperature is 230-250ºC and the pre-oxidation time is 60-90 min.
5. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: In step 3, the carbonization process has a heating rate of 5 ºC / min, a carbonization temperature of 700-900 ºC, and a carbonization time of 60-120 min.
6. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: In step 4, the concentration of the bismuth nitrate / ethylene glycol solution is 0.125-0.15 mol / L, and the stirring rate is 800 rpm.
7. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: The purification time for anhydrous ethanol in step 5 is 12 hours.
8. The method for preparing a composite pollutant treatment agent according to claim 1, characterized in that: In step 6, the volume ratio of bismuth nitrate / ethylene glycol solution to anhydrous ethanol is 1:2, the hydrothermal reaction temperature is 160 ºC, and the reaction time is 300 min.
9. The application of a composite pollutant treatment agent obtained by the preparation method according to any one of claims 1 to 8 in the removal of organic pollutants from wastewater.