Composite photocatalytic material as well as preparation method and application thereof
By preparing metal-doped composite photocatalytic materials, the problem of low antibiotic degradation efficiency of existing bismuth-based photocatalytic materials is solved, and higher photocatalytic performance and environmental pollutant degradation effect are achieved.
Patent Information
- Application Number
- CN202510109568.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-05-06
AI Technical Summary
The existing bismuth-based photocatalytic materials are inefficient in degrading antibiotics, and have the problem of high recombination rates of electrons and hole pairs.
After mixing the metal salt, quaternary ammonium halide salt and solvent, and carrying out hydrothermal reaction, Fe0/Fe2O3 is introduced by potassium borohydride reduction method to prepare metal-doped composite photocatalytic materials, such as Fe0/Fe2O3/Bi4O5Br2.
The photocatalytic performance and the degradation efficiency of environmental pollutants (such as antibiotics) were improved, which was specifically manifested as the removal rates of norfloxacin and tetracycline under light conditions reached 93% and 98.7%, respectively.
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Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of photocatalytic materials and environmental pollutant treatment, for example, to a composite photocatalytic material and a preparation method and application thereof. Background Art
[0002] In recent years, due to the large-scale production and use of antibiotics around the world, people have continuously detected residual antibiotics in drinking water, domestic and industrial wastewater. Antibiotics are listed as one of the "new environmental pollutants that are difficult to degrade", and their main hazards to human health include: allergic reactions, drug toxicity, damage to the immune system, and the development of antibiotic resistance. China is a major user of antibiotics, mainly using antibiotics in human medicine and livestock and poultry breeding. Every year, about 54,000 tons of antibiotics are excreted in urine and feces in their original form or metabolites and enter the environment. At present, many large-scale farms separate livestock and poultry manure into solid-liquid separation, so that the manure enters the biogas system for anaerobic fermentation, and then returns it to the field for utilization, so as to achieve resource utilization. However, a considerable number of antibiotics cannot be absorbed and degraded after anaerobic digestion (i.e., biogas fermentation), and thus remain in the biogas slurry. With the widespread application of biogas slurry in farmland, residual antibiotics accumulate in soil and water, posing a potential threat to the ecosystem and human health. Therefore, from the perspective of ecological environment and human health, removing antibiotics from biogas slurry is crucial to the safe use of biogas slurry.
[0003] At present, the main treatment methods for antibiotic wastewater include adsorption, membrane separation, biological methods and advanced oxidation processes (AOPs). However, some methods have disadvantages such as high cost, long time consumption and large footprint, which greatly limits their practical application value. In recent years, AOPs have attracted much attention from researchers due to their ability to efficiently degrade organic pollutants. This method can directly convert organic pollutants into carbon dioxide, water and mineral acids or improve the biodegradability of pollutants through oxidation, which is conducive to further treatment. Therefore, AOPs have great development prospects in the future treatment of antibiotic wastewater.
[0004] Photocatalytic technology is one of the advanced oxidation technologies, which has the characteristics of strong oxidation ability and no secondary pollution. Among them, bismuth-based photocatalytic materials are becoming more and more attractive in the fields of energy conversion and environmental remediation due to their good chemical stability, unique layered structure and excellent photoelectric properties. However, bismuth-based photocatalytic materials still have shortcomings such as high recombination rate of electron-hole pairs and limited photocatalytic efficiency. Therefore, although bismuth-based photocatalytic materials have been widely used in the field of photocatalytic degradation of antibiotics, they still have disadvantages such as low degradation efficiency.
[0005] In summary, the design and preparation of bismuth-based photocatalytic materials with excellent degradation performance and their application in the removal of environmental pollutants (e.g., antibiotics) will continue to be a research hotspot in the field of water environment management in the future. Summary of the invention
[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a composite photocatalytic material and a preparation method and application thereof, so that the composite photocatalytic material can at least improve the photocatalytic performance and thus improve the degradation effect on environmental pollutants.
[0007] The purpose of this disclosure is achieved through the following technical solutions:
[0008] On the one hand, a method for preparing a composite photocatalytic material is provided. The preparation method comprises: mixing a metal salt, a quaternary ammonium halide and a solvent to obtain a mixed solution, wherein the metal salt comprises a bismuth salt; cooling the mixed solution after a hydrothermal reaction, washing and solid-liquid separation to obtain a precipitate; drying the precipitate to obtain a bismuth-based photocatalytic material; and dispersing the bismuth-based photocatalytic material in a solution of an iron salt, and preparing the composite photocatalytic material by a potassium borohydride reduction method.
[0009] It should be noted that the composite photocatalytic material provided in the embodiment of the present disclosure is a metal-doped bismuth-based photocatalytic material.
[0010] It should be understood that the metal-doped bismuth-based photocatalytic material may be, for example, a single-metal-doped bismuth-based photocatalytic material, or may be a double-metal-doped bismuth-based photocatalytic material.
[0011] In some embodiments, the metal salt includes only the bismuth salt.
[0012] At this time, the composite photocatalytic material is the single metal-doped bismuth-based photocatalytic material.
[0013] In this case, the preparation method is to use the bismuth salt and the quaternary ammonium halide salt to prepare the Bi4O5Br2 photocatalytic material (i.e., the bismuth-based photocatalytic material), and then use metal ion impregnation and potassium borohydride reduction method to introduce Fe 0 / Fe2O3, and finally Fe 0 / Fe2O3 / Bi4O5Br2 composite photocatalytic material (ie, the composite photocatalytic material).
[0014] In other embodiments, the metal salt further comprises a manganese salt.
[0015] At this time, the composite photocatalytic material is the bimetallic doped bismuth-based photocatalytic material.
[0016] In this case, the preparation method is to use the bismuth salt, the manganese salt and the quaternary ammonium halide to prepare the Mn / Bi4O5Br2 photocatalytic material (i.e., the bismuth-based photocatalytic material), and then introduce Fe by metal ion impregnation and potassium borohydride reduction method. 0 / Fe2O3, and finally prepare the Fe / Mn / Bi4O5Br2 composite photocatalytic material (ie, the composite photocatalytic material).
[0017] In some embodiments, the manganese salt comprises MnCl2·4H2O.
[0018] In some examples, in the mixed solution, the concentration of the manganese salt is 0.1 to 1.5 mol / L.
[0019] In some embodiments, the bismuth salt comprises Bi(NO3)3·5H2O.
[0020] In some examples, in the mixed solution, the concentration of the bismuth salt is 0.05-0.5 mol / L.
[0021] In some embodiments, the quaternary ammonium halide salt includes cetyltrimethylammonium bromide (CTAB).
[0022] In some examples, in the mixed solution, the concentration of the quaternary ammonium halide salt is 0.05 to 0.5 mol / L.
[0023] In some examples, the mass ratio of the quaternary ammonium halide salt to the bismuth salt is approximately 4:3.
[0024] It should be noted that the above-mentioned method of "mixing the metal salt, the quaternary ammonium halide and the solvent" includes a variety of methods. Any method that can uniformly mix the metal salt, the quaternary ammonium halide and the solvent is included in the protection scope of the present disclosure. Those skilled in the art can make adaptive selections as needed, and the present disclosure does not limit this.
[0025] In some examples, the metal salt includes only the bismuth salt, or the metal salt includes the bismuth salt and the manganese salt; the mixing of the metal salt, the quaternary ammonium halide salt and the solvent includes: adding the metal salt and the quaternary ammonium halide salt to the solvent, stirring vigorously to disperse them evenly to form a white emulsion, and then performing ultrasonic treatment.
[0026] Illustratively, the solvent includes water.
[0027] Exemplarily, the ultrasonic treatment time is 30 to 60 minutes.
[0028] In other examples, the metal salt includes only the bismuth salt; and the mixing of the metal salt, the quaternary ammonium halide salt and the solvent includes: dispersing the quaternary ammonium halide salt in the solvent to obtain a bismuth-based precursor solution, and then adding the bismuth salt and stirring.
[0029] Exemplarily, the solvent includes ethylene glycol and NaOH solution.
[0030] Exemplarily, the stirring time is 60 to 120 minutes.
[0031] In some other examples, the metal salt includes the bismuth salt and the manganese salt; the mixing of the metal salt, the quaternary ammonium halide salt and the solvent includes: dispersing the quaternary ammonium halide salt in the solvent to obtain a bismuth-based precursor solution, adding the bismuth salt and performing initial stirring, and then adding the manganese salt and re-stirring.
[0032] Exemplarily, the solvent includes ethylene glycol and NaOH solution.
[0033] Exemplarily, the initial stirring time is 10 to 20 minutes.
[0034] Exemplarily, the further stirring time is 10 to 60 minutes.
[0035] It should be noted that the metal salt may include, for example, at least one of sulfate, nitrate, halide, citrate, carbonate, phosphate and amide.
[0036] In some embodiments, the temperature of the hydrothermal reaction is 100-200° C., and the time of the hydrothermal reaction is 6-24 hours.
[0037] In some examples, the cooling includes cooling to room temperature.
[0038] In some examples, the washing includes washing with ethanol and deionized water, respectively.
[0039] In some examples, the solid-liquid separation includes: performing centrifugation.
[0040] In some examples, the drying temperature is 60 to 105° C., and the drying time is 5 to 10 hours.
[0041] It should be noted that the iron salt may include, for example, at least one of ferric chloride, ferrous chloride, ferric sulfate and ferrous sulfate.
[0042] In some embodiments, the iron salt comprises FeSO4·7H2O.
[0043] In some examples, in the iron salt solution, the concentration of the iron salt is 0.1 to 0.8 mol / L.
[0044] In some examples, the composite photocatalytic material is prepared by potassium borohydride reduction method, including: adding a solution of potassium borohydride (KBH4), stirring and filtering, collecting a reaction precipitate; and re-washing and re-drying the reaction precipitate to obtain the composite photocatalytic material.
[0045] Exemplarily, in the potassium borohydride solution, the concentration of potassium borohydride is 1.2 to 4.8 mol / L.
[0046] Exemplarily, the re-washing includes: washing with ultrapure water and anhydrous ethanol respectively.
[0047] Exemplarily, the re-drying temperature is room temperature, and the re-drying time is 36 to 48 hours.
[0048] On the other hand, a composite photocatalytic material prepared by the preparation method described in any one of the above embodiments is provided.
[0049] In yet another aspect, there is provided a use of the composite photocatalytic material according to any one of the above embodiments in the degradation of environmental pollutants.
[0050] In some embodiments, the application includes: directly using the composite photocatalytic material to degrade environmental pollutants.
[0051] In other embodiments, the application includes: coupling the composite photocatalytic material with an oxidant for synergistic degradation of environmental pollutants.
[0052] It should be noted that the above-mentioned method of "coupling the composite photocatalytic material with the oxidant" includes multiple methods. Any method that can mix the composite photocatalytic material with the oxidant to treat the environmental pollutants is included in the protection scope of the present disclosure. Those skilled in the art can make adaptive choices as needed, and the present disclosure does not limit this.
[0053] In some examples, coupling the composite photocatalytic material with an oxidant for synergistic degradation of environmental pollutants includes: adding the composite photocatalytic material and the oxidant to a solution of the environmental pollutant.
[0054] In some examples, the oxidant includes at least one of persulfate, inorganic peroxide, perchlorate, chlorate, permanganate, and ozone.
[0055] Exemplarily, the persulfate salt includes potassium persulfate (PMS).
[0056] In some examples, the environmental contaminant includes at least one of an antibiotic and a dye.
[0057] It should be noted that the antibiotics may include, for example, at least one of quinolones, tetracyclines, sulfonamides, macrolides and β-lactams.
[0058] Exemplarily, the antibiotic includes at least one of norfloxacin, tetracycline, ciprofloxacin and sulfamethoxazole, for example, may include at least one of norfloxacin and tetracycline.
[0059] Exemplarily, the dye includes at least one of an acid dye and a basic dye.
[0060] It is worth noting that bismuth bromide (BiOBr), as a relatively special photocatalytic material, is widely used in redox photocatalytic reactions. However, although pure BiOBr has certain photocatalytic properties, its bandgap is slightly larger, the visible light utilization rate is low, and photogenerated carriers are prone to recombination. Therefore, the efficiency of BiOBr in photocatalytic degradation of environmental pollutants (e.g., antibiotics) is not high.
[0061] In view of this, in the preparation method provided in the embodiment of the present disclosure, Bi4O5Br2 is first prepared using the bismuth salt and the quaternary ammonium halide salt. As a derivative of BiOBr, Bi4O5Br2 can increase the concentration of Bi and O, thereby reducing the bandgap and improving the utilization rate of visible light. At the same time, Bi4O5Br2, with its unique electronic structure, can not only accelerate the separation and transfer of photogenerated carriers, but also greatly improve the efficiency of photocatalytic degradation of the environmental pollutants (for example, the antibiotics). On this basis, metallic iron is then introduced by metal ion impregnation and potassium borohydride reduction method, which can promote the oxidant to produce free radicals, and then with the help of the photocatalytic effect of Bi4O5Br2, the time required for the degradation of the environmental pollutants (for example, the antibiotics) can be greatly shortened.
[0062] It is worth noting that in the preparation method provided in some of the above embodiments, the metal salt includes the manganese salt in addition to the bismuth salt, so that metallic iron and metallic manganese can be introduced at the same time, thereby further promoting the oxidant to produce free radicals, and then assisted by the photocatalytic effect of Bi4O5Br2, the time required for the degradation of the environmental pollutants (for example, the antibiotics) can be further shortened.
[0063] The beneficial effects of the present disclosure are:
[0064] The composite photocatalytic material provided by the present disclosure can not only improve the photocatalytic performance, but also promote the generation of free radicals when coupled with an oxidant, thereby improving the degradation effect of environmental pollutants; wherein, when the composite photocatalytic material is used to activate potassium persulfate to degrade antibiotics in water, under light conditions, the composite photocatalytic material has a removal rate of 93% for norfloxacin (NOR) and a removal rate of 98.7% for tetracycline (TC). BRIEF DESCRIPTION OF THE DRAWINGS
[0065] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required to be used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual process of the method involved in the embodiments of the present disclosure.
[0066] Figure 1 The Fe provided in Example 1 0 Scanning electron microscope image of / Fe2O3 / Bi4O5Br2 composite photocatalytic material;
[0067] Figure 2 The Fe provided in Example 1 0 Infrared spectrum of / Fe2O3 / Bi4O5Br2 composite photocatalytic material;
[0068] Figure 3 The Fe provided in Example 1 0 / Fe2O3 / Bi4O5Br2 composite photocatalytic material for the removal of norfloxacin;
[0069] Figure 4 The Fe provided in Example 1 0 / Fe2O3 / Bi4O5Br2 composite photocatalytic material activated PMS to remove norfloxacin;
[0070] Figure 5 This is a diagram showing the removal effect of tetracycline by activating PMS using the Fe / Mn / Bi4O5Br2 composite photocatalytic material provided in Example 2. DETAILED DESCRIPTION
[0071] The technical solutions in some embodiments of the present disclosure are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.
[0072] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.
[0073] As used herein, "approximately" includes the stated values and averages that are within an acceptable range of deviation from the particular value, where the acceptable range of deviation is determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).
[0074] When describing some embodiments, the expressions "at least one of A, B and C" and "at least one of A, B or C" may be used, both of which have the same meaning and include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.
[0075] Among them, the device information used in some embodiments of the present disclosure is as follows:
[0076] The constant temperature heating magnetic stirrer used is the DF-101Z collector constant temperature heating magnetic stirrer produced by Shanghai Lichen Bangxi Instrument Technology Co., Ltd.; the electric heating blast drying oven used is the electric heating blast drying oven produced by Shanghai Yiheng Scientific Instrument Co., Ltd.; the ultraviolet visible spectrophotometer used is the UV-1800PC ultraviolet visible spectrophotometer produced by Shanghai Aoyi Instrument Co., Ltd.
[0077] Example 1
[0078] A method for preparing a composite photocatalytic material comprises the following steps:
[0079] S1. Weigh 1.093 g of CTAB and disperse it in a mixed solvent of 30 mL of ethylene glycol and 20 mL of 1 mol / L NaOH solution to obtain a bismuth-based precursor solution A;
[0080] S2. Weigh 1.455 g of Bi(NO3)3·5H2O and add it to the bismuth-based precursor solution A, place it in a constant temperature heated magnetic stirrer and stir for 60 min to obtain a mixed solution B;
[0081] S3. The mixed solution B was transferred to a 100 mL stainless steel autoclave with a polytetrafluoroethylene liner, placed in an electric blast drying oven for hydrothermal reaction at 150°C for 10 h, cooled to room temperature after the reaction, washed with ethanol and deionized water for multiple times, centrifuged and collected the precipitate, and then dried in an electric blast drying oven at 80°C for 6 h to obtain a Bi4O5Br2 photocatalytic material;
[0082] S4. Disperse the Bi4O5Br2 photocatalytic material in the FeSO4·7H2O solution, stir for 15 min, then slowly drop 1.2 mol / L KBH4 solution, continue stirring for 30 min, filter and collect the precipitate, wash the precipitate three times with ultrapure water and anhydrous ethanol respectively, put it into a beaker, seal it with plastic wrap, move it to a glass desiccator and store it at room temperature for 48 h to obtain Fe 0 / Fe2O3 / Bi4O5Br2 composite photocatalytic material.
[0083] In this regard, it should be noted that by dispersing the Bi4O5Br2 photocatalytic material in FeSO4·7H2O solutions of different concentrations, Fe and Bi4O5Br2 photocatalytic materials with different mass ratios can be prepared. 0 / Fe2O3 / Bi4O5Br2 composite photocatalytic material; wherein the mass ratio of Fe and Bi4O5Br2 photocatalytic material is 1:1, 2:1, 4:1, 8:1 respectively. 0 The scanning electron microscope images and infrared spectra of the / Fe2O3 / Bi4O5Br2 composite photocatalytic materials are shown in Figures 1-2 shown.
[0084] On this basis, Fe and Bi4O5Br2 photocatalytic materials with a mass ratio of 2:1 were added. 0 The / Fe2O3 / Bi4O5Br2 composite photocatalytic material was used in a 20 mg / L norfloxacin solution and treated for 60 min under light-proof conditions and photocatalytic conditions, respectively. After filtration, the concentration of norfloxacin was detected using a UV-visible spectrophotometer. The results are as follows: Figure 3 As shown, when other reaction conditions are the same, Fe 0 The degradation efficiency of norfloxacin by / Fe2O3 / Bi4O5Br2 composite photocatalytic material under photocatalytic conditions is higher than that under light-protected conditions.
[0085] In addition, the mass ratio of Fe to Bi4O5Br2 photocatalyst was 3:7. 0The / Fe2O3 / Bi4O5Br2 composite photocatalytic material was coupled with PMS and used in a 20 mg / L norfloxacin solution. It was treated for 30 min under light-proof conditions (i.e., dark reaction) and light conditions (i.e., light reaction), respectively. After filtration, the concentration of norfloxacin was detected using a UV-visible spectrophotometer. The results are as follows: Figure 4 As shown in the figure, the removal efficiency of norfloxacin reached 93% at 60 min.
[0086] Example 2
[0087] A method for preparing a composite photocatalytic material comprises the following steps:
[0088] S1. Weigh 0.396 g of MnCl2·4H2O, 0.8197 g of Bi(NO3)3·5H2O and 1.093 g of CTAB and add them to 50 mL of water. Stir vigorously to disperse them evenly to form a white emulsion, and then ultrasonicate for 30 min to form solution A.
[0089] S2. The solution A was transferred to a 100 mL stainless steel autoclave with a polytetrafluoroethylene liner, placed in an electric blast drying oven for hydrothermal reaction at 160°C for 12 h, cooled naturally to room temperature after the reaction, washed with ethanol and deionized water for multiple times, centrifuged and the precipitate was collected, and then dried in an electric blast drying oven at 80°C for 6 h to obtain a Mn-modified Bi4O5Br2 photocatalytic material (i.e., Mn / Bi4O5Br2 photocatalytic material);
[0090] S3. Disperse the Mn / Bi4O5Br2 photocatalytic material in a 0.18 mol / L FeSO4·7H2O solution, stir for 15 min, then slowly drop 1.2 mol / L KBH4 solution, continue stirring for 30 min after completion, collect the precipitate by filtration, wash the precipitate three times with ultrapure water and anhydrous ethanol respectively, after washing, put it into a beaker, seal it with plastic wrap, move it to a glass desiccator and store it at room temperature for 48 h to obtain a Fe / Mn / Bi4O5Br2 composite photocatalytic material.
[0091] The Fe / Mn / Bi4O5Br2 composite photocatalytic material prepared in this example was coupled with PMS and used in a 20 mg / L tetracycline solution, treated for 120 min under light conditions, and then filtered and the concentration of tetracycline was detected by a UV-visible spectrophotometer. The results were as follows: Figure 5 As shown, at 120 min, the removal efficiency of tetracycline reached 98.7%.
[0092] Therefore, the composite photocatalytic material and its preparation method and application provided by the present disclosure can not only improve the photocatalytic performance, but also promote the generation of free radicals when coupled with an oxidant, thereby improving the degradation effect of environmental pollutants (especially antibiotics).
[0093] The above is only a preferred embodiment of the present disclosure. It should be understood that the present disclosure is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present disclosure, and should be within the scope of protection of the claims attached to the present disclosure.
Claims
1. A method for preparing a composite photocatalytic material, characterized in that: include: Mixing a metal salt, a quaternary ammonium halide salt and a solvent to obtain a mixed solution; wherein the metal salt includes a bismuth salt; The mixed solution is cooled after hydrothermal reaction, and then washed and solid-liquid separated to obtain a precipitate; Drying the precipitate to obtain a bismuth-based photocatalytic material; and The bismuth-based photocatalytic material is dispersed in an iron salt solution, and the composite photocatalytic material is prepared by a potassium borohydride reduction method.
2. The preparation method according to claim 1, characterized in that: The metal salts also include manganese salts.
3. The preparation method according to claim 2, characterized in that: The manganese salt includes MnCl2·4H2O.
4. The preparation method according to claim 1, characterized in that: The bismuth salt includes Bi(NO3)3·5H2O.
5. The preparation method according to claim 1, characterized in that: The quaternary ammonium halide salt includes hexadecyltrimethylammonium bromide.
6. The preparation method according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 100 to 200° C., and the time of the hydrothermal reaction is 6 to 24 hours.
7. The preparation method according to claim 1, characterized in that: The iron salt includes FeSO4·7H2O.
8. The composite photocatalytic material prepared by the preparation method according to any one of claims 1 to 7.
9. Use of the composite photocatalytic material as claimed in claim 8 in the degradation of environmental pollutants.
10. The use according to claim 9, characterized in that: include: The composite photocatalytic material is coupled with an oxidant to synergistically degrade environmental pollutants.