Preparation method of copper-doped bismuth oxybromide microsphere photocatalyst
By doping copper and polyvinylpyrrolidone in bismuth bromine oxide, adjusting the electronic structure and morphology of the material, the problem of low photocatalytic activity of existing bismuth bromine oxide photocatalysts is solved, and its photocatalytic performance and wastewater treatment efficiency are significantly improved.
Patent Information
- Application Number
- CN202510053508.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-14
- Publication Date
- 2025-04-08
AI Technical Summary
The existing bismuth bromine oxide photocatalyst has low photocatalytic activity, which limits its practical application value in organic dye wastewater treatment.
By doping appropriate amounts of copper and polyvinylpyrrolidone in bismuth bromine oxide, the electronic structure and morphology of the material are adjusted, thereby improving the photocatalytic performance of the photocatalyst.
The activity of photocatalytic degradation of the copper-doped bismuth oxide microsphere photocatalyst is significantly improved, and its efficiency in organic dye wastewater treatment is improved.
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Abstract
Description
Technical Field
[0001] The invention relates to a method for preparing a copper-doped bismuth oxybromide microsphere photocatalyst, belonging to the technical field of semiconductor photocatalysis preparation. Background Art
[0002] With the rapid economic development and the acceleration of industrialization, organic dye industrial wastewater has become one of the major environmental pollution problems facing the world. Especially in areas where water resources are scarce and pollution is serious, how to achieve efficient and low-cost wastewater treatment is particularly important. Although traditional wastewater treatment technologies such as physical precipitation, chemical flocculation, biodegradation and membrane separation have achieved certain results, they generally have disadvantages such as high treatment costs, low efficiency, and easy secondary pollution, which cannot meet the increasingly stringent environmental protection requirements and sustainable development goals. In this context, the development of new and efficient photocatalytic materials for organic dye wastewater treatment has become the focus of attention in this field.
[0003] In recent years, photocatalytic technology has gradually attracted widespread attention due to its high efficiency, safety and environmental protection. Under light, photocatalysts can produce highly active free radicals, decompose organic pollutants into harmless small molecules, and achieve harmless treatment of pollutants. Among them, bismuth oxybromide has become a popular candidate material in the field of photocatalysis due to its unique photoelectric properties, stable chemical properties and wide spectral response range. However, the photocatalytic efficiency of single bismuth oxybromide is low, which limits its practical value. Therefore, finding an effective modification method has become the key to improving its photocatalytic performance.
[0004] Studies have found that the photocatalytic activity of bismuth oxybromide can be effectively improved by doping with metal ions. Copper has good electron transport capabilities, which can optimize the electronic structure of semiconductor materials, enhance light absorption and carrier separation efficiency, and thus improve the photocatalytic performance of the material. Surveys have shown that doping with an appropriate amount of copper can adjust the valence band position of bismuth oxybromide, expand the light absorption range to the visible light region, and promote the separation of electron-hole pairs, thereby improving photocatalytic activity. In addition, polyvinyl pyrrolidone, as a commonly used surfactant, can regulate the material morphology and particle size during the preparation process, which helps to improve the dispersibility and stability of the photocatalyst.
[0005] Based on this, the present invention proposes a method for preparing copper-doped bismuth oxybromide microsphere photocatalyst. The material exhibits excellent photocatalytic performance, thanks to the introduction of copper and polyvinyl pyrrolidone modification, which effectively promotes the migration of photogenerated carriers and improves the microstructure and light absorption capacity of the material. More importantly, the preparation method is simple, convenient, and low-cost, which greatly enhances the market competitiveness of the new material. Summary of the invention
[0006] Problem to be solved
[0007] In view of the problems existing in existing bismuth oxybromide photocatalysts, such as low photocatalytic activity, the present invention introduces copper and polyvinyl pyrrolidone to effectively improve the structure of bismuth oxybromide microspheres, etc., and significantly improves its photocatalytic activity in degrading pollutants.
[0008] Furthermore, the present invention also provides a method for preparing copper-doped bismuth oxybromide microsphere photocatalyst. The preparation method has a simple process, and the raw materials are easy to obtain, and can realize industrial mass production.
[0009] Solutions for solving problems
[0010] [1] A method for preparing copper-doped bismuth oxybromide microsphere photocatalyst, characterized in that the preparation of copper-doped bismuth oxybromide microsphere photocatalyst comprises the following steps:
[0011] 4 mmol of bismuth nitrate pentahydrate was dissolved in 40 mL of a mixed solution containing a certain amount of copper acetate monohydrate, 20 mL of ethylene glycol and 20 mL of deionized water, and the molar ratio of copper acetate monohydrate / bismuth nitrate pentahydrate was 0.5%, 1%, 2%, 3%, 4% and 5%. The above solution was stirred continuously for 30 min and was marked as solution S1. 4 mmol of hexadecyltrimethylammonium bromide was dissolved in 40 mL of a mixed solution containing 20 mL of ethylene glycol and 20 mL of deionized water and stirred continuously for 30 min, which was marked as solution S2. Then, solution S2 was slowly added to solution S1 under continuous stirring for 30 min to form a transparent mixed solution. Subsequently, 6.95 mmol of polyvinyl pyrrolidone was added to the mixed solution under vigorous stirring for 30 min, and then it was transferred to a 100 mL polytetrafluoroethylene-lined stainless steel autoclave and kept at 160 °C for 12 h. After naturally cooling to room temperature, the product was centrifuged and washed with deionized water and anhydrous ethanol several times, and finally dried at 80 °C for 10 h.
[0012] A bismuth oxybromide modified microsphere product is characterized in that the copper-doped bismuth oxybromide microsphere photocatalyst is prepared by using the above-mentioned preparation method and has high photocatalytic properties. Effects of the Invention
[0013] First, the present invention adds an appropriate amount of copper and polyvinyl pyrrolidone to bismuth oxybromide, which can effectively improve the catalytic activity of the photocatalyst, as follows:
[0014] (1) By Figure 1 It can be seen that the solvothermal method is beneficial to controlling the particle size distribution of the product and obtaining a uniform morphology and a relatively high degree of crystallinity.
[0015] (2) It can be seen from the X-ray diffraction pattern in Figure 2 that the addition of copper can weaken the characteristic diffraction peak intensity of Vo-BiOBr to a certain extent.
[0016] (3) Through Figure 3 It can be seen from the performance diagram that doping a certain amount of copper can significantly improve the photocatalytic efficiency of the material.
[0017] Finally, the present invention effectively improves the activity of copper-doped bismuth oxybromide microsphere photocatalyst in degrading pollutants by controlling a suitable heating rate and setting a suitable reaction and drying temperature and drying time. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a transmission electron microscope image of the copper-doped bismuth oxybromide microsphere photocatalyst prepared in Example 1 of the present invention.
[0019] Figure 2 It is the X-ray diffraction diagram of Example 1 of the present invention and Comparative Examples 1-6.
[0020] Figure 3 It is a performance diagram of the degradation of methyl orange by Example 1 of the present invention and Comparative Examples 1-6. DETAILED DESCRIPTION
[0021] The technical features described below are described based on representative embodiments of the present invention, but are not limited to these embodiments. Example
[0022] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.
[0023] The performance testing methods of Example 1 and Comparative Examples 1-6 of the present invention are as follows:
[0024] 1. Photocatalytic performance and degradation rate: The photocatalytic performance of the bismuth oxybromide modified microsphere powder was tested using a liquid ultraviolet tester, and the degradation rate was calculated according to a pseudo-first-order kinetic model. Example 1
[0025] The preparation method of the copper-doped bismuth oxybromide microsphere photocatalyst comprises the following steps:
[0026] (1) Preparation: Weigh 4.00 mmol of bismuth nitrate pentahydrate, 4.00 mmol of hexadecyltrimethylammonium bromide, 6.95 mmol of polyvinylpyrrolidone, and copper acetate monohydrate with a molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate of 2% using an electronic balance, and prepare a mixed solution of 20 mL of ethylene glycol and 20 mL of deionized water;
[0027] (2) Stirring: There are three stages. In the first stage, 4.00 mmol of bismuth nitrate pentahydrate was dissolved in 40 mL of a mixed solution containing copper acetate monohydrate / bismuth nitrate pentahydrate with a molar ratio of 2% copper acetate monohydrate / bismuth nitrate pentahydrate, 20 mL of ethylene glycol, and 20 mL of deionized water. The above solution was stirred continuously for 30 min and was marked as solution S1; in the second stage, 4.00 mmol of hexadecyltrimethylammonium bromide was dissolved in 40 mL of a mixed solution containing 20 mL of ethylene glycol and 20 mL of deionized water and stirred continuously for 30 min, which was marked as solution S2; in the third stage, solution S2 was slowly added to solution S1 to form a transparent mixed solution, and 6.95 mmol of polyvinyl pyrrolidone was added to the mixed solution and stirred vigorously for 30 min.
[0028] (3) Reaction: The stirred solution was transferred into a 100 mL polytetrafluoroethylene-lined stainless steel autoclave and maintained at 160 °C for 12 h.
[0029] (4) Washing: The reaction product was centrifuged and washed three times with deionized water and anhydrous ethanol alternately.
[0030] (5) Drying: Place the washed samples in a drying oven at 80 °C for 10 h.
[0031] (6) Grinding: Grind the dried sample to obtain a powdery product.
[0032] The copper-doped bismuth oxybromide microsphere photocatalyst product was tested. The degradation rate of 15 mg / L methyl orange solution was 80.52% when illuminated by LED light for 60 min. Comparative Example 1
[0033] Without adding polyvinyl pyrrolidone and copper acetate monohydrate, the preparation method of the bismuth oxybromide microsphere photocatalyst comprises the following steps:
[0034] (1) Preparation: Use an electronic balance to weigh 4.00 mmol of bismuth nitrate pentahydrate and 4.00 mmol of hexadecyltrimethylammonium bromide, and prepare a mixed solution of 20 mL of ethylene glycol and 20 mL of deionized water;
[0035] (2) Stirring: There are three stages. In the first stage, 4.00 mmol of bismuth nitrate pentahydrate was dissolved in a mixed solution of 20 mL of ethylene glycol and 20 mL of deionized water. The above solution was stirred continuously for 30 min and was marked as solution S1; in the second stage, 4.00 mmol of hexadecyltrimethylammonium bromide was dissolved in 40 mL of a mixed solution containing 20 mL of ethylene glycol and 20 mL of deionized water and stirred continuously for 30 min, which was marked as solution S2; in the third stage, solution S2 was slowly added to solution S1 to form a transparent mixed solution, and the solution was stirred vigorously for 30 min.
[0036] (3) Reaction: The stirred solution was transferred into a 100 mL polytetrafluoroethylene-lined stainless steel autoclave and maintained at 160 °C for 12 h.
[0037] (4) Washing: The reaction product was centrifuged and washed three times with deionized water and anhydrous ethanol alternately.
[0038] (5) Drying: Place the washed samples in a drying oven at 80 °C for 10 h.
[0039] (6) Grinding: Grind the dried sample to obtain a powdery product.
[0040] The bismuth oxybromide microsphere photocatalyst product was tested. The degradation rate of 15 mg / L methyl orange solution was 27.40% when illuminated by LED light for 60 min. Comparative Example 2, Example 3, Example 4, Example 5, Example 6
[0041] Comparative Example 2: Excessive copper element is doped. The preparation method of the copper-doped bismuth oxybromide microsphere photocatalyst comprises the following steps:
[0042] (1) Preparation: Using an electronic balance, weigh 4.00 mmol of bismuth nitrate pentahydrate, 4.00 mmol of hexadecyltrimethylammonium bromide, polyvinylpyrrolidone, and copper acetate monohydrate with a molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate of 0.5%, 1%, 3%, 4%, and 5%, respectively, and prepare a mixed solution of 20 mL of ethylene glycol and 20 mL of deionized water;
[0043] (2) Stirring: There are three stages. In the first stage, 4.00 mmol of bismuth nitrate pentahydrate was dissolved in 40 mL of a mixed solution containing copper acetate monohydrate / bismuth nitrate pentahydrate with a molar ratio of 0.5%, 1%, 3%, 4% and 5%, 20 mL of ethylene glycol and 20 mL of deionized water. The above solution was stirred continuously for 30 min and was marked as solution S1; in the second stage, 4.00 mmol of hexadecyltrimethylammonium bromide was dissolved in 40 mL of a mixed solution containing 20 mL of ethylene glycol and 20 mL of deionized water and stirred continuously for 30 min, which was marked as solution S2; in the third stage, solution S2 was slowly added to solution S1 to form a transparent mixed solution, and 6.95 mmol of polyvinyl pyrrolidone was added to the mixed solution and stirred vigorously for 30 min.
[0044] (3) Reaction: The stirred solution was transferred into a 100 mL polytetrafluoroethylene-lined stainless steel autoclave and maintained at 160 °C for 12 h.
[0045] (4) Washing: The reaction product was centrifuged and washed three times with deionized water and anhydrous ethanol alternately.
[0046] (5) Drying: Place the washed samples in a drying oven at 80 °C for 10 h.
[0047] (6) Grinding: Grind the dried sample to obtain a powdery product.
[0048] The copper-doped bismuth oxybromide microsphere photocatalyst product was tested. When the molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate was 0.5%, Comparative Example 2 was obtained: for 15 mg / L methyl orange solution, the degradation rate was 59.89% when LED illumination was applied for 60 min.
[0049] When the molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate is 1%, comparative example 3 is obtained: when the LED light is irradiated for 60 min, the degradation rate of methyl orange is 62.52%.
[0050] When the molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate is 3%, comparative example 4 is obtained: when the LED light is irradiated for 60 min, the degradation rate of methyl orange is 65.71%.
[0051] When the molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate is 4%, comparative example 5 is obtained: when the LED light is irradiated for 60 min, the degradation rate of methyl orange is 30.60%.
[0052] When the molar ratio of copper acetate monohydrate to bismuth nitrate pentahydrate is 5%, comparative example 6 is obtained: when the LED light is irradiated for 60 min, the degradation rate of methyl orange is 38.99%.
[0053] Excessive copper doping reduces the photocatalytic degradation efficiency because it forms particles with large grain size, reducing the specific surface area of the material.
[0054] It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.
[0055] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. A method for preparing copper-doped bismuth oxybromide microsphere photocatalyst, characterized in that: The preparation of copper-doped bismuth oxybromide microsphere photocatalyst comprises the following steps: (1) Preparation: Weigh a certain amount of bismuth nitrate pentahydrate, hexadecyltrimethylammonium bromide, polyvinyl pyrrolidone and copper acetate monohydrate, and prepare a mixed solution of ethylene glycol and deionized water; (2) stirring: adding the weighed raw materials to the mixed solution in sequence and stirring to obtain a reaction solution; (3) Reaction: The obtained reaction solution is transferred to a stainless steel autoclave and subjected to high temperature reaction; (4) Washing: The reaction product was centrifuged and washed several times with deionized water and anhydrous ethanol; (5) Drying: Dry the sample in a drying oven; (6) Grinding: Grind the dried sample to obtain the final product.
2. The method for preparing copper-doped bismuth oxybromide microsphere photocatalyst according to claim 1, characterized in that: The raw materials and amounts of step (1) are: 4.00 mmol bismuth nitrate pentahydrate, 4.00 mmol hexadecyltrimethylammonium bromide, 6.95 mmol polyvinylpyrrolidone, copper acetate monohydrate in different proportions, and the mixed solution is 20 mL ethylene glycol and 20 mL deionized water.
3. The copper acetate monohydrate in different proportions according to claim 2, characterized in that: The molar ratios of copper acetate monohydrate and bismuth nitrate pentahydrate are 0.5%, 1%, 2%, 3%, 4% and 5%, respectively.
4. The method for preparing the copper-doped bismuth oxybromide microsphere photocatalyst according to claim 1, characterized in that: The stirring in step (2) is divided into three stages. In the first stage, 4.00 mmol of bismuth nitrate pentahydrate is dissolved in 40 mL of a mixed solution of 20 mL of ethylene glycol and 20 mL of deionized water containing a certain amount of copper acetate monohydrate. The above solution is stirred continuously for 30 min and is marked as solution S1; in the second stage, 4.00 mmol of hexadecyltrimethylammonium bromide is dissolved in 40 mL of a mixed solution containing 20 mL of ethylene glycol and 20 mL of deionized water and stirred continuously for 30 min, which is marked as solution S2; in the third stage, solution S2 is slowly added to solution S1 to form a transparent mixed solution, and 6.95 mmol of polyvinyl pyrrolidone is added to the mixed solution and stirred continuously for 30 min.
5. The method for preparing copper-doped bismuth oxybromide microsphere photocatalyst according to claim 1, characterized in that: The stainless steel autoclave in step (3) is lined with polytetrafluoroethylene, has a capacity of 100 mL, a reaction temperature of 160 °C, and a reaction time of 12 h.
6. The method for preparing copper-doped bismuth oxybromide microsphere photocatalyst according to claim 1, characterized in that: The washing method of step (4) is to wash with deionized water and anhydrous ethanol alternately for 3 times.
7. The method for preparing copper-doped bismuth oxybromide microsphere photocatalyst according to claim 1, characterized in that: The drying process in step (5) is to place the washed sample in a drying oven at a temperature of 80°C for 10 h.
8. A copper-doped bismuth oxybromide microsphere photocatalyst product, characterized in that: The copper-doped bismuth oxybromide microsphere photocatalyst is prepared by using the preparation method described in claims 1-8 and has high photocatalytic properties.