Preparation method and application of bismuth tungstate nanosheet composite material
By preparing a composite material of bismuth tungstate nanosheets and bismuth oxybromide nanoflowers, the problems of small light response range, fast photogenerated carrier recombination rate, low carrier mobility and poor redox ability of single semiconductor photocatalysts were solved, achieving efficient photocatalytic performance and large-scale production.
Patent Information
- Application Number
- CN202510850760.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-24
- Publication Date
- 2025-09-23
AI Technical Summary
Existing single semiconductor photocatalysts such as Bi2WO6 and BiOBr have deficiencies in light response range, photogenerated carrier recombination rate, carrier mobility and redox ability, which limit their catalytic activity and application.
By preparing a composite material of bismuth tungstate nanosheets and bismuth oxybromide nanoflowers, the bismuth tungstate nanosheet powder and bismuth oxybromide nanoflower powder were mixed using a hydrothermal method to form a composite material rich in bismuth vacancies, which optimized light absorption and redox ability and effectively separated photogenerated electron-hole pairs.
It improves the photogenerated carrier separation efficiency of the photocatalyst, reduces the photogenerated carrier recombination rate, enhances the redox ability, and has a simple preparation process, can be used for large-scale production, and exhibits excellent photocatalytic activity.
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Figure CN120679568A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of photocatalysts, and in particular to a preparation method and application of a bismuth tungstate nanosheet composite material. Background Art
[0002] In the problem of water pollution threatening the health of life and the ecological environment, photocatalytic technology can completely decompose pollutant macromolecules into green small molecules by utilizing solar energy, effectively solving the water pollution problem and improving energy utilization.
[0003] In recent years, researchers have developed a variety of semiconductor photocatalysts, which have found widespread application in environmental remediation and clean energy conversion. Metal oxide semiconductors, such as TiO2, ZnO, and WO3, have been the most studied, achieving some success in pollution control. Currently, new bismuth-based photocatalytic semiconductors, such as Bi2WO6, BiOBr, and BiVO4, are being used to address environmental challenges due to their excellent chemical stability, well-defined energy band positions, and outstanding photocatalytic activity.
[0004] Among them, Bi2WO6 and BiOBr have the advantages of unique stable layered structure, suitable band gap width, environmental friendliness and affordability, which give them excellent photocatalytic stability and overcome the shortcomings of low stability of traditional photocatalysts.
[0005] However, single semiconductor materials still have many limitations, such as a small light response range, a fast recombination rate of photogenerated carriers, a low carrier mobility, and a poor redox ability, which greatly limit the catalytic activity and application of semiconductor photocatalysts. Therefore, it is necessary to design a preparation method and application of bismuth tungstate nanosheet composite materials. Summary of the Invention
[0006] The purpose of the present invention is to provide a preparation method of a bismuth tungstate nanosheet composite material and its application, so as to solve the problems in the prior art.
[0007] The purpose of the present invention can be achieved through the following technical solutions:
[0008] A method for preparing a bismuth tungstate nanosheet composite material, the preparation method comprising:
[0009] The bismuth tungstate nanosheet powder and bismuth oxybromide nanoflower powder were prepared in advance, and then the two were mixed and stirred, and then centrifuged and dried to obtain B δ B finished product.
[0010] Preferably, the preparation method comprises:
[0011] S1. 0.48 g of bismuth nitrate, 0.40 g of polyethylene glycol, and 0.55 g of sorbitol were stirred in 40 mL of aqueous solution until transparent, and then 0.11 g of sodium bromide solution was added and stirred to obtain turbid liquid A. The turbid liquid A was transferred to a hydrothermal reactor for heating and insulation, and then mixed with pure water and centrifuged three times. After drying at 60 ° C for 8 h, Bi2WO6 nanosheet precursor powder was obtained;
[0012] S2. Place 0.37 g of nanosheet precursor powder in a beaker containing 40 mL of pure water and disperse it evenly by ultrasonication. Add 0.80 g of sodium tungstate to the beaker and stir. Then transfer the mixture to a hydrothermal reactor for heating and insulation. Centrifuge the mixture alternately with pure water and ethanol for 6 times, and dry it at 80°C for 6 h to obtain bismuth tungstate nanosheet powder rich in bismuth vacancies.
[0013] S3. Add a mixed solution of 5 mL of ethylene glycol and 35 mL of isopropanol to 0.12 g of bismuth nitrate and 0.18 g of dodecyltrimethylammonium bromide, stir evenly to obtain a flocculent solution B, transfer solution B to a hydrothermal reactor, heat and keep warm, centrifuge alternately with pure water and ethanol for 6 times, and dry at 60° C. for 10 h to obtain bismuth oxybromide nanoflower powder;
[0014] S4, take 1.00g B δ WO powder was mixed with 0.50-3.00 g of BOB powder, and pure water was added and stirred to obtain a turbid solution C. The solution C was then transferred to a hydrothermal reactor for heating and insulation. After alternating centrifugation with pure water and ethanol for 6 times, the solution was dried at 60°C for 8 h to obtain a bismuth tungstate / bismuth oxybromide composite material.
[0015] Preferably, S1 comprises heating to a temperature of 160° C. in a hydrothermal reactor and keeping the temperature for 3 hours.
[0016] Preferably, S2 comprises heating to 140° C. in a hydrothermal reactor and keeping the temperature for 3 hours.
[0017] Preferably, S3 comprises heating to 160° C. in a hydrothermal reactor and keeping the temperature therefor for 12 hours.
[0018] Preferably, S4 comprises heating to 100° C. in a hydrothermal reactor and keeping the temperature for 1 hour.
[0019] Preferably, the preparation method produces a bismuth tungstate / bismuth oxybromide composite material B δ BX;
[0020] The value range of X is 0.50-3.00.
[0021] A bismuth tungstate nanosheet composite material is disclosed. According to the preparation method of the bismuth tungstate nanosheet composite material, the bismuth tungstate nanosheet composite material is rich in bismuth vacancies.
[0022] Preferably, the bismuth tungstate nanosheet composite material is used in the photocatalytic degradation of antibiotic pollutants.
[0023] Beneficial effects of the present invention:
[0024] Among them, bismuth tungstate nanosheet powder and bismuth oxybromide nanoflower powder are used to prepare bismuth vacancy-rich bismuth tungstate nanosheet-loaded bismuth oxybromide nanoflower composite materials. Compared with monomers, the composite materials optimize both light absorption and redox capabilities, effectively separate photogenerated electron-hole pairs, and effectively reduce the recombination rate of photogenerated carriers of Bi2WO6 and BiOBr. Moreover, the preparation process is relatively simple and can be used for large-scale mass production. The composite materials have excellent photocatalytic activity and show great application possibilities. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention will be further described below with reference to the accompanying drawings.
[0026] Figure 1 Composite material sample B prepared in Example 6 of the present invention δ SEM image of B-3;
[0027] Figure 2 The composite material samples in Examples 1, 2, and 6 of the present invention and B δ XRD patterns of WO and BOB;
[0028] Figure 3 For B δ Comparison of the photocatalytic degradation performance of antibiotics OTC among WO, BOB and the composite materials of Examples 1, 2 and 6 of the present invention;
[0029] Figure 4 B δ PL comparison chart of WO, BOB and the composite material sample of Example 6 of the present invention. DETAILED DESCRIPTION
[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.
[0031] A bismuth tungstate nanosheet composite material is prepared by pre-preparing B δ WO powder, BOB powder, and then mix and stir to prepare B δ B finished product, such as Figure 1 As shown, bismuth tungstate nanosheets and bismuth oxybromide nanoflowers are assembled together to form composite material B δ B.
[0032] Example 1
[0033] A method for preparing a bismuth tungstate nanosheet composite material, the preparation method comprising the following steps:
[0034] S1. 0.48 g of bismuth nitrate, 0.40 g of polyethylene glycol, and 0.55 g of sorbitol were stirred in 40 mL of aqueous solution until transparent, and then 0.11 g of sodium bromide solution was added and stirred to obtain a white turbid liquid A. The turbid liquid A was transferred to a hydrothermal reactor, heated at 160° C. and kept warm for 3 h, then mixed with pure water and centrifuged three times, and dried at 60° C. for 8 h to obtain Bi2WO6 nanosheet precursor powder;
[0035] S2. Subsequently, 0.37 g of the precursor powder was placed in a beaker containing 40 mL of pure water and ultrasonically dispersed uniformly. 0.80 g of sodium tungstate was added to the beaker and stirred. The mixture was then transferred to a hydrothermal reactor and heated at 140°C and kept warm for 3 h. After alternating centrifugation with pure water and ethanol for 6 times, the mixture was dried at 80°C for 6 h to obtain a white bismuth tungstate nanosheet powder rich in bismuth vacancies, which was recorded as B. δ WO;
[0036] S3. Add a mixed solution of 5 mL of ethylene glycol and 35 mL of isopropanol to 0.12 g of bismuth nitrate and 0.18 g of dodecyltrimethylammonium bromide, stir evenly to obtain a white flocculent solution B, transfer solution B to a hydrothermal reactor, heat at 160° C. and keep warm for 12 h, centrifuge alternately with pure water and ethanol 6 times, and dry at 60° C. for 10 h to obtain yellow bromide bismuth nanoflower powder, recorded as BOB;
[0037] S4, 1.00g B δ WO powder was mixed with 0.50 g of BOB powder, and pure water was added and stirred to obtain a white turbid solution C. The solution C was then transferred to a hydrothermal reactor and heated at 100 ° C for 1 h. After alternating centrifugation with pure water and ethanol for 6 times, it was dried at 60 ° C for 8 h to obtain a light yellow bismuth tungstate / bismuth oxybromide composite material rich in bismuth vacancies, which was recorded as B δ B-0.5.
[0038] Example 2
[0039] Based on Example 1, 1.00 g of B δ WO powder was mixed with 1.00 g of BOB powder, and pure water was added and stirred to obtain a white turbid solution C. The solution C was then transferred to a hydrothermal reactor and heated at 100 ° C for 1 h. After alternating centrifugation with pure water and ethanol for 6 times, it was dried at 60 ° C for 8 h to obtain a light yellow bismuth tungstate / bismuth oxybromide composite material rich in bismuth vacancies, which was recorded as B δ B-1.
[0040] Example 3
[0041] Based on Example 1, 1.00 g of B δ WO powder was mixed with 1.50 g of BOB powder, and pure water was added and stirred to obtain a white turbid solution C. The solution C was then transferred to a hydrothermal reactor and heated at 100 ° C for 1 h. After alternating centrifugation with pure water and ethanol for 6 times, it was dried at 60 ° C for 8 h to obtain a light yellow bismuth tungstate / bismuth oxybromide composite material rich in bismuth vacancies, which was recorded as B δ B-1.5.
[0042] Example 4
[0043] Based on Example 1, 1.00 g of B δ WO powder was mixed with 2.00 g of BOB powder, and pure water was added and stirred to obtain a white turbid solution C. The solution C was then transferred to a hydrothermal reactor and heated at 100 ° C for 1 h. After alternating centrifugation with pure water and ethanol for 6 times, it was dried at 60 ° C for 8 h to obtain a light yellow bismuth tungstate / bismuth oxybromide composite material rich in bismuth vacancies, which was recorded as B δ B-2.
[0044] Example 5
[0045] Based on Example 1, 1.00 g of B δ WO powder was mixed with 2.50 g of BOB powder, and pure water was added and stirred to obtain a white turbid solution C. The solution C was then transferred to a hydrothermal reactor and heated at 100 ° C for 1 h. After alternating centrifugation with pure water and ethanol for 6 times, it was dried at 60 ° C for 8 h to obtain a light yellow bismuth tungstate / bismuth oxybromide composite material rich in bismuth vacancies, which was recorded as B δ B-2.5.
[0046] Example 6
[0047] Based on Example 1, 1.00 g of B δ WO powder was mixed with 3.00 g of BOB powder, and pure water was added and stirred to obtain a white turbid solution C. The solution C was then transferred to a hydrothermal reactor and heated at 100 ° C for 1 h. After alternating centrifugation with pure water and ethanol for 6 times, it was dried at 60 ° C for 8 h to obtain a light yellow bismuth tungstate / bismuth oxybromide composite material rich in bismuth vacancies, which was recorded as B δ B-3.
[0048] In the instruction manual Figure 2 It can be seen intuitively that B δ BX appears B δ The diffraction peaks of WO and BOB, and with the δ As the content of BOB used in BX increases, the diffraction peak intensity of BOB becomes higher and higher.
[0049] like Figure 3 As shown, when the composite materials samples in Examples 1, 2 and 6 degrade pollutants, after the same time, the BOB system is better than the V Bi -The antibiotic concentration of the BWO system is lower, reflecting that the prepared BOB system composite material has better photocatalytic degradation performance of organic pollutants.
[0050] like Figure 4 As shown, the PL peak intensity of the composite material sample is lower, indicating that the composite material sample in Example 6 has the strongest carrier separation ability.
[0051] Among them, in this embodiment, the prepared bismuth vacancy-rich bismuth tungstate nanosheets loaded with bismuth oxybromide nanoflower composite material has stronger carrier separation ability and redox ability, reduces the recombination rate of photogenerated carriers of Bi2WO6 and BiOBr, the preparation process of the present invention is simple and convenient, and can be used for large-scale mass production. The composite material has excellent photocatalytic activity, showing the application possibility of the composite material.
[0052] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.
Claims
1. A method for preparing a bismuth tungstate nanosheet composite material, characterized in that: The preparation method comprises: The bismuth tungstate nanosheet powder and bismuth oxybromide nanoflower powder were prepared in advance, and then the two were mixed and stirred, and then centrifuged and dried to obtain B δ B finished product.
2. The method for preparing the bismuth tungstate nanosheet composite material according to claim 1, wherein: The preparation method comprises: S1. 0.48 g of bismuth nitrate, 0.40 g of polyethylene glycol, and 0.55 g of sorbitol were stirred in 40 mL of aqueous solution until transparent, and then 0.11 g of sodium bromide solution was added and stirred to obtain turbid liquid A. The turbid liquid A was transferred to a hydrothermal reactor for heating and insulation, and then mixed with pure water and centrifuged three times. After drying at 60 ° C for 8 h, Bi2WO6 nanosheet precursor powder was obtained; S2. Place 0.37 g of nanosheet precursor powder in a beaker containing 40 mL of pure water and disperse it evenly by ultrasonication. Add 0.80 g of sodium tungstate to the beaker and stir. Then transfer the mixture to a hydrothermal reactor for heating and insulation. Centrifuge the mixture alternately with pure water and ethanol for 6 times, and dry it at 80°C for 6 h to obtain bismuth tungstate nanosheet powder rich in bismuth vacancies. S3. Add a mixed solution of 5 mL of ethylene glycol and 35 mL of isopropanol to 0.12 g of bismuth nitrate and 0.18 g of dodecyltrimethylammonium bromide, stir evenly to obtain a flocculent solution B, transfer solution B to a hydrothermal reactor, heat and keep warm, centrifuge alternately with pure water and ethanol for 6 times, and dry at 60° C. for 10 h to obtain bismuth oxybromide nanoflower powder; S4, take 1.00g B δ WO powder was mixed with 0.50-3.00 g of BOB powder, and pure water was added and stirred to obtain a turbid solution C. The solution C was then transferred to a hydrothermal reactor for heating and insulation. After alternating centrifugation with pure water and ethanol for 6 times, the solution was dried at 60°C for 8 h to obtain a bismuth tungstate / bismuth oxybromide composite material.
3. The method for preparing the bismuth tungstate nanosheet composite material according to claim 2, wherein: S1 includes heating to a temperature of 160° C. in a hydrothermal reactor and keeping the temperature for 3 h.
4. The method for preparing the bismuth tungstate nanosheet composite material according to claim 2, wherein: S2 includes heating to 140° C. in a hydrothermal reactor and maintaining the temperature for 3 h.
5. The method for preparing the bismuth tungstate nanosheet composite material according to claim 2, wherein: S3 includes heating to 160° C. in a hydrothermal reactor and maintaining the temperature for 12 h.
6. The method for preparing the bismuth tungstate nanosheet composite material according to claim 2, wherein: S4 includes heating to 100° C. in a hydrothermal reactor and keeping the temperature for 1 hour.
7. The method for preparing the bismuth tungstate nanosheet composite material according to claim 2, wherein: The preparation method prepares bismuth tungstate / bismuth oxybromide composite material B δ BX; The value range of X is 0.50-3.
00.
8. A bismuth tungstate nanosheet composite material, comprising the method for preparing the bismuth tungstate nanosheet composite material according to any one of claims 1 to 7, characterized in that: The bismuth tungstate nanosheet composite material is rich in bismuth vacancies.
9. Use of the bismuth tungstate nanosheet composite material according to claim 8 in photocatalytic degradation of antibiotic pollutants.