A manganese-cobalt bimetallic modified bismuth vanadate catalyst, its preparation method and application
By preparing BiVO4 catalytic material modified with manganese and cobalt bimetals, the problem of unsatisfactory antibiotic degradation effect of cobalt-based catalysts activated PMS was solved, achieving efficient and stable antibiotic degradation effect with good stability and reusability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EAST CHINA UNIV OF SCI & TECH
- Filing Date
- 2026-03-23
- Publication Date
- 2026-06-02
AI Technical Summary
Existing cobalt-based catalysts for activating peroxymonosulfate (PMS) to degrade antibiotics are not very effective and have few active sites, making it difficult to effectively remove antibiotic pollution from water bodies.
BiVO4 catalyst material modified with manganese and cobalt bimetals was prepared by a specific ratio and process to form a rich pore structure and high specific surface area, thereby improving the electron and hole separation efficiency and synergistically activating PMS to degrade antibiotics.
It achieves efficient and stable degradation of antibiotics, exhibits excellent PMS activation efficiency and good stability, can be reused, and is suitable for the degradation of common antibiotics.
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Abstract
Description
Technical Field
[0001] This invention relates to a method for preparing a catalytic material modified with manganese-cobalt bimetals, bismuth vanadate (BiVO4), and its application in the degradation of antibiotics by activated peroxymonosulfate (PMS), belonging to the field of functional technical materials. Background Technology
[0002] Antibiotics are widely used due to their promising medical prospects, but most of them end up in the natural environment through wastewater from sewage treatment plants, causing water pollution. Therefore, removing these pollutants is urgent and important.
[0003] Currently, antibiotics are degraded primarily through physical, chemical, and biochemical methods. Physical methods utilize ultraviolet light and ultrasound, while biochemical methods employ microorganisms, but these methods have limitations in decomposing high-molecular-weight organisms. Chemical methods include the Fenton advanced oxidation process, which removes recalcitrant organic pollutants from various environmental media by generating highly oxidizing reactive species. Among these, photo-assisted Fenton PMS activation reactions, which couple ultraviolet-visible light radiation with the Fenton reaction, are widely used due to their green nature and low energy cost.
[0004] Transition metals are widely used to activate PMS due to their good structural tunability. Among them, cobalt-based materials have a wide pH range, exhibiting excellent stability and conductivity, but have few active sites. Therefore, there is an urgent need for a method to improve cobalt-based catalysts to activate PMS for antibiotic degradation.
[0005] Some research results in this area have been published. For example, Chinese patent application CN121402085A discloses a single-atom cobalt-based composite catalyst, its preparation method, and its application in activating peroxymonosulfate (PMS) to degrade antibiotics. This invention involves mixing biomass powder and water to obtain a biochar suspension, adding cobalt nitrate hexahydrate to the biochar suspension, centrifuging the mixture, collecting the residue, and then drying and pyrolyzing it to obtain the cobalt-based composite catalyst. This catalyst can be applied to activate PMS to degrade tetracycline. However, the degradation effect is not ideal, and the problem of the limited number of active sites in cobalt-based catalysts remains unresolved. Therefore, the cobalt-based catalysts disclosed in the literature cannot effectively activate PMS to degrade antibiotics. Summary of the Invention
[0006] This invention provides a method for preparing a catalytic material modified with manganese-cobalt bimetals, BiVO4, and the resulting catalyst can effectively degrade antibiotics.
[0007] The first aspect of this invention is to provide a method for preparing a bimetallic modified BiVO4 catalytic material, the specific preparation steps of which are as follows:
[0008] Step 1: Pour a certain amount of deionized water, anhydrous ethanol, and nitric acid into a beaker in sequence, and stir well at room temperature.
[0009] Step 2: Then add a certain amount of bismuth nitrate pentahydrate and ammonium metavanadate to the solution. A precipitate will appear in the solution. Stir until the precipitate is completely dissolved.
[0010] Step 3: Add a certain amount of manganese chloride tetrahydrate and cobalt nitrate hexahydrate, and stir until the solution is evenly mixed.
[0011] Step 4: Place a certain amount of the solution obtained above into an oven to dry, take out the solid from the beaker and grind it, pour the ground powder into a porcelain boat and calcine it in a muffle furnace to obtain BiVO4 modified with manganese and cobalt bimetals.
[0012] Furthermore, in the first step, the amount of deionized water added is 4-6 mL, the amount of anhydrous ethanol added is 5-15 mL, and the amount of nitric acid added is 2-7 mL.
[0013] Furthermore, in the second step, the dosage of bismuth nitrate pentahydrate is 0.8-1.2 g, and the dosage of ammonium metavanadate is 0.2-0.3 g.
[0014] Furthermore, in the third step, the dosage of manganese chloride tetrahydrate is 0.01-0.03 g, and the dosage of cobalt nitrate hexahydrate is 0.02-0.04 g.
[0015] Furthermore, in the fourth step, the oven temperature is 70 ℃, and the drying time is 24 h. The calcination temperature of the muffle furnace is 450-550 ℃, the heating rate is 1-3 ℃ / min, and the holding time is 2 h.
[0016] Furthermore, in the fourth step, after calcination, the temperature is lowered to room temperature by natural cooling.
[0017] A second aspect of the present invention discloses a manganese-cobalt bimetallic modified BiVO4 catalytic material.
[0018] A third aspect of the present invention discloses a method for applying the above-mentioned manganese-cobalt bimetallic modified BiVO4, specifically, applying the material to the degradation of antibiotics, such as for the degradation of levofloxacin (LVX).
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0020] 1. Compared with BiVO4 materials without the introduction of manganese-cobalt bimetals, the introduction of cobalt in this invention gives the catalyst a high specific surface area and abundant pore structure. The further introduction of manganese serves as an active site for PMS activation during the catalytic process, improving the separation efficiency of electrons and holes, which is conducive to the activation of PMS and the degradation of pollutants.
[0021] 2. The manganese-cobalt bimetallic modified catalyst prepared in this invention has good charge migration efficiency, excellent PMS activation efficiency, high pollutant degradation ability, good stability and reusability, and can be widely used in the degradation of common antibiotics. Attached Figure Description
[0022] Figure 1 SEM and TEM images of the sample prepared in Example 1;
[0023] Figure 2 The XRD patterns of the samples prepared in Examples 1-5 and Comparative Examples 1-2 are shown.
[0024] Figure 3 These are magnified XRD patterns of the samples prepared in Examples 1-5 and Comparative Examples 1-2;
[0025] Figure 4 The degradation kinetics of LVX by the samples prepared in Examples 1-5 are shown. Detailed Implementation
[0026] To better explain the present invention, the following specific embodiments are provided for explanation and description.
[0027] Example 1
[0028] A method for preparing manganese-cobalt bimetallic modified BiVO4 includes the following steps:
[0029] Step 1: Pour 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid into a beaker in sequence, and stir well at room temperature.
[0030] Step 2: Then add 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate to the solution. An orange-red precipitate will appear in the solution. Stir until the precipitate is completely dissolved.
[0031] Step 3: Add 0.0198 g of manganese chloride tetrahydrate and 0.0291 g of cobalt nitrate hexahydrate, and stir until the solution is evenly mixed.
[0032] Step 4: Place a certain amount of the solution obtained above into a 70 ℃ oven and dry for 24 h. Take out the solid in the beaker and grind it. Pour the ground powder into a porcelain boat and calcine it in a muffle furnace at 500 ℃ for 2 h to obtain manganese-cobalt bimetallic modified BiVO4, named MCB.
[0033] Figure 1 The images shown are SEM and TEM images from Example 1. Figure 1 'a' is the SEM image. Figure 1Image b is a TEM image, which shows that MCB is composed of irregularly stacked nanosheets. Manganese and cobalt elements are combined with BiVO4 in two forms: doping and metal oxide loading. The above results indicate that a BiVO4 catalyst modified with manganese and cobalt bimetals was successfully synthesized.
[0034] Example 2
[0035] A method for preparing manganese-cobalt bimetallic modified BiVO4 includes the following steps.
[0036] 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid were sequentially added to a beaker and stirred thoroughly at room temperature. Then, 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate were added to the solution, resulting in an orange-red precipitate. The mixture was stirred until the precipitate was completely dissolved, and then 0.0198 g of manganese chloride tetrahydrate and 0.0582 g of cobalt nitrate hexahydrate were added. The mixture was stirred for 1 hour until homogeneous. The solution was then dried in a 70 °C oven for 24 hours. The solid in the beaker was removed and ground. The ground powder was poured into a ceramic boat and calcined in a muffle furnace. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 hours. This yielded manganese-cobalt bimetallic modified BiVO4, named 1 / 2MCB.
[0037] Example 3
[0038] A method for preparing manganese-cobalt bimetallic modified BiVO4 includes the following steps.
[0039] 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid were sequentially added to a beaker and stirred thoroughly at room temperature. Then, 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate were added to the solution, resulting in an orange-red precipitate. The mixture was stirred until the precipitate was completely dissolved, and then 0.0396 g of manganese chloride tetrahydrate and 0.0291 g of cobalt nitrate hexahydrate were added. The mixture was stirred for 1 hour until homogeneous. The solution was then dried in a 70 °C oven for 24 hours. The solid in the beaker was removed and ground. The ground powder was poured into a ceramic boat and calcined in a muffle furnace. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 hours. This yielded BiVO4 bimetallic modified BiVO4, named 2 / 1MCB.
[0040] Example 4
[0041] A method for preparing manganese-cobalt bimetallic modified BiVO4 includes the following steps.
[0042] 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid were sequentially added to a beaker and stirred thoroughly at room temperature. Then, 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate were added to the solution, resulting in an orange-red precipitate. The mixture was stirred until the precipitate was completely dissolved, and then 0.0198 g of manganese chloride tetrahydrate and 0.1164 g of cobalt nitrate hexahydrate were added. The mixture was stirred for 1 hour until homogeneous. The solution was then dried in a 70 °C oven for 24 hours. The solid in the beaker was removed and ground. The ground powder was poured into a ceramic boat and calcined in a muffle furnace. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 hours. This yielded BiVO4 bimetallic modified BiVO4, named 1 / 4MCB.
[0043] Example 5
[0044] A method for preparing manganese-cobalt bimetallic modified BiVO4 includes the following steps:
[0045] 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid were sequentially added to a beaker and stirred thoroughly at room temperature. Then, 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate were added to the solution, resulting in an orange-red precipitate. The mixture was stirred until the precipitate was completely dissolved, and then 0.0792 g of manganese chloride tetrahydrate and 0.0291 g of cobalt nitrate hexahydrate were added. The mixture was stirred for 1 hour until homogeneous. The solution was then dried in a 70 °C oven for 24 hours. The solid in the beaker was removed and ground. The ground powder was poured into a ceramic boat and calcined in a muffle furnace. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 hours. This yielded BiVO4 bimetallic modified BiVO4, named 4 / 1MCB.
[0046] Comparative Example 1
[0047] A method for preparing BiVO4 modified with single-metal manganese includes the following steps:
[0048] 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid were sequentially added to a beaker and stirred thoroughly at room temperature. Then, 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate were added to the solution, resulting in an orange-red precipitate. The mixture was stirred until the precipitate was completely dissolved, and then 0.0198 g of manganese chloride tetrahydrate was added. The mixture was stirred for 1 hour until homogeneous. The solution was then dried in a 70 °C oven for 24 hours. The solid in the beaker was removed and ground. The ground powder was poured into a ceramic boat and calcined in a muffle furnace. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 hours. Manganese-modified BiVO4 was obtained and named MB.
[0049] Comparative Example 2
[0050] A method for preparing cobalt-modified BiVO4 by a single metal includes the following steps:
[0051] 5 mL of deionized water, 10 mL of anhydrous ethanol, and 5 mL of nitric acid were sequentially added to a beaker and stirred thoroughly at room temperature. Then, 0.97 g of bismuth nitrate pentahydrate and 0.234 g of ammonium metavanadate were added to the solution, resulting in an orange-red precipitate. The mixture was stirred until the precipitate was completely dissolved, and then 0.0291 g of cobalt nitrate hexahydrate was added. The mixture was stirred for 1 hour until homogeneous. The solution was then dried in a 70 °C oven for 24 hours. The solid in the beaker was removed and ground. The ground powder was poured into a ceramic boat and calcined in a muffle furnace. The temperature was increased to 500 °C at a rate of 2 °C / min and held for 2 hours. Cobalt-modified BiVO4 was obtained and named CB.
[0052] The method for evaluating the degradation performance of simulated pollutants provided by this invention is as follows:
[0053] 1 mg of the catalyst prepared in the above examples or comparative examples was mixed with 50 mL of LVX solution with a concentration of 20 mg / L in a 100 mL quartz glass tube and stirred magnetically until homogeneous. After adsorption equilibrium was reached, the oxidant PMS was added. A xenon lamp was turned on to simulate visible light. To obtain degradation kinetic data, samples were taken at specified times, and the LVX concentration was determined by high-performance liquid chromatography (HPLC).
[0054] from Figure 2 It can be seen that all materials with introduced metals (CB, MB, MCB series samples) have characteristic peaks of BiVO4, and the relative intensity of the characteristic peaks gradually decreases with the increase of Mn and Co content.
[0055] from Figure 3 The (121) peak of BiVO4 can be observed to shift to a higher angle. This phenomenon can be attributed to the unit cell shrinkage of BiVO4 caused by the substitution of Bi by manganese and cobalt atoms, indicating that manganese and cobalt elements enter BiVO4 in a doping manner. Metal doping leads to more defects, reduces grain size, and thus increases specific surface area. The above results indicate that manganese and cobalt elements are combined with BiVO4 in two forms: doping and metal oxide loading.
[0056] from Figure 4It can be seen that the BiVO4 material modified with manganese-cobalt bimetals performs significantly better as a catalyst for activating PMS to degrade LVX than the monometallic modified material. Firstly, the bimetallic effect is superior to the monometallic effect due to the synergistic effect of Mn and Co. Co is the most active PMS activator among transition metals, and Mn is often considered a good hole trapping site and oxidation reaction center. Their introduction modifies the electronic properties and surface structure, forming a bimetallic material with superior performance compared to the monometallic material. Secondly, it can be seen that BiVO4 materials modified with different proportions of manganese-cobalt bimetals can all achieve the expected effect within 60 min. Among them, the 2 / 1MCB shows better degradation effect than the 1 / 2MCB before 25 min, but the result is reversed after 25 min, with the MCB degradation effect remaining in the middle. This may be due to the switching of the dominant reaction pathway and the dynamic changes on the catalyst surface. 2 / 1MCB initially promotes the generation of highly active but short-lived hydroxyl radicals, which rapidly attack high concentrations of pollutants; while 1 / 2MCB has weaker initial activity but promotes the oxidation pathway of superoxide radicals or holes with longer lifespans and more effective for reaction intermediates. There was no significant difference in degradation effect between 4 / 1MCB and 1 / 4MCB, except that the degradation rate was slightly improved when the manganese-cobalt ratio was 1:4.
[0057] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.
Claims
1. A method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material, characterized in that, The method includes the following steps: Step 1: Mix deionized water, anhydrous ethanol and nitric acid to obtain a precursor solution; Step 2: Add bismuth nitrate pentahydrate and ammonium metavanadate to the precursor solution and stir until the precipitate is completely dissolved to obtain a bismuth vanadate solution; Step 3: Add manganese chloride tetrahydrate and cobalt nitrate hexahydrate to the bismuth vanadate solution to obtain a bismuth vanadate solution rich in manganese and cobalt. Step 4: The bismuth vanadate solution rich in manganese and cobalt is dried, ground, and calcined to obtain a manganese-cobalt bimetallic modified bismuth vanadate material.
2. The method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material according to claim 1, characterized in that, In the first step, the mixing involves dispersing the anhydrous ethanol and nitric acid in deionized water, wherein the amount of deionized water added is 4-6 mL, the amount of anhydrous ethanol added is 5-15 mL, and the amount of nitric acid added is 2-7 mL.
3. The method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material according to claim 1, characterized in that, In the second step, the dosage of bismuth nitrate pentahydrate is 0.8-1.2 g, and the dosage of ammonium metavanadate is 0.2-0.3 g. The precipitation is a phenomenon produced by mixing bismuth nitrate pentahydrate and ammonium metavanadate.
4. The method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material according to claim 1, characterized in that, In the third step, the dosage of manganese chloride tetrahydrate is 0.01-0.03 g, and the dosage of cobalt nitrate hexahydrate is 0.02-0.04 g.
5. The method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material according to claim 1, characterized in that, In the fourth step, the drying temperature is 70 ℃ and the drying time is 24 h.
6. The method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material according to claim 1, characterized in that, In the fourth step, the calcination temperature is 450-550 ℃, the heating rate is 1-3 ℃ / min, and the holding time is 2 h.
7. A method for preparing a manganese-cobalt bimetallic modified bismuth vanadate material according to any one of claims 1 or 6, characterized in that, In the fourth step, the high-temperature calcination is completed and the material is naturally cooled to room temperature.
8. The manganese-cobalt bimetallic modified bismuth vanadate material obtained by the preparation method according to any one of claims 1-7, characterized in that, The manganese and cobalt elements in the manganese-cobalt bimetallic modified bismuth vanadate material are combined with bismuth vanadate in two forms: doping and metal oxide loading.
9. The application of the manganese-cobalt bimetallic modified bismuth vanadate material according to claim 8 in the degradation of antibiotics.