A titanium-based perovskite material with different microstructures, a preparation method thereof, and application in photocatalytic antibiotic degradation

Abstract

The present invention provides a titanium-based perovskite material with different microstructures, a preparation method thereof, and an application in photocatalytic degradation of antibiotic pollutants. The microstructure of the titanium-based perovskite material is effectively regulated by adjusting the type of mineralizing agent in the hydrothermal reaction, and nanoparticles, nanosheets, and nanoflower structures with hierarchical structures are obtained. The titanium-based perovskite material with different microstructures of the present invention can quickly achieve enhanced separation of carriers due to its good microstructure and enhanced surface and interface reactions; at the same time, due to the effective regulation of the microscopic surface, it has more active reaction sites and thus exhibits good physicochemical activity, which not only enhances the surface and interface reactions, but also promotes effective adsorption of the surface of antibiotic pollutants. The titanium-based perovskite material with different microstructures of the present invention is used as a catalyst to exhibit high-end photocatalytic activity under visible light irradiation, and shows potential application effects on the removal of highly toxic and low-concentration antibiotic pollutants.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental nanomaterial photocatalysis, and specifically relates to a titanium-based perovskite material with different microstructures, a preparation method thereof, and application of the material in photocatalytic antibiotic degradation. Background Art

[0002] In recent years, the potential hazards and treatment methods of chemical substances with stable chemical structures, long-lasting existence in the environment, and easy accumulation in the biological food chain, such as persistent organic pollutants (POPs), environmental endocrine disruptors (EEDs), drugs and personal care products (PPCPs), plastics and microorganisms, which exist in water and air, have attracted great attention and widespread concern from the international academic, industrial and environmental sectors. Among the many types of new organic difficult-to-decompose environmental pollutants, PPCPs, especially antibiotics, are widely used and therefore widely exist in various environmental media. However, the chemical structure of antibiotics is stable, so they are easily enriched by organisms during long-distance migration and become potential sources of water pollution. Even at very low concentrations, they can cause great harm to biological organisms, resulting in serious ecological and health effects.

[0003] Antibiotics are widely used in medicine, animal husbandry and aquaculture as effective drugs for treating diseases. However, the discharge of domestic sewage, medical wastewater, animal feed and aquaculture wastewater will cause stable antibiotics to be excreted into the environment, and the residual antibiotics in these wastes can stably exist for a long time, thus causing drug residues in the environment. These antibiotics in the environment have a long half-life and good chemical stability in nature. Therefore, these antibiotics remaining in the environment will return to the human body through the food chain / ecological cycle, thereby causing various pathogens to develop serious drug resistance, and long-term trace intake also causes the human body to have similar drug resistance, thus causing serious harm to the natural environment and destroying the ecological balance, thus becoming one of the key issues to be solved in the field of environment. Existing methods for removing antibiotic residues have defects such as high cost, long cycle and secondary pollution, thus becoming a key technical bottleneck restricting antibiotic pollution control. Therefore, it is urgent to develop an efficient, accurate, convenient, green and reliable method for detecting and degrading trace antibiotics to quickly remove or reduce the impact of antibiotic pollutants in the environment, which has become one of the most urgent hot issues to be solved in the international environmental field today.

[0004] As a clean and renewable energy, solar energy is the most ideal, direct and effective way for mankind to fundamentally solve the problems of environmental pollution and energy depletion. Photocatalytic degradation of organic pollutants has become the forefront of research in the field of international environmental science and technology with its advantages of fast speed, no secondary pollution and effective use of solar energy. Materials with good microstructures (morphology / active crystal surfaces) have a large specific surface area, so they can make full use of sunlight. What is important is that the surface structure is an important factor affecting the physical and chemical properties of solid materials. The use of photocatalytic technology and the differences in the effects, adsorption modes and chemical environments of catalyst materials with different microstructures on antibiotics is expected to achieve effective removal of antibiotic pollutants. Among them, the surface interface structure is the key factor that determines the performance of nanomaterials, but how to regulate this active interface is extremely challenging. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a titanium-based perovskite material with different microstructures, a preparation method thereof, and an application thereof in the field of photocatalytic antibiotic degradation.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a titanium-based perovskite material comprises taking a precursor titanium source, a strontium source, a solvent source and an alkali source as raw materials, and preparing the titanium-based perovskite material through a hydrothermal reaction under the action of a mineralizing agent.

[0008] According to the present invention, the molar ratio of the titanium source to the strontium source should satisfy the following: 3 The molar ratio of Sr and Ti, for example, the molar ratio of the strontium source and the titanium source is (1-5):1, exemplified by 1:1, 3:1, and 5:1.

[0009] According to the present invention, the titanium source, alkali source and strontium source are mixed in the form of solutions before the reaction. For example, solutions of the titanium source, alkali source and strontium source are prepared separately, and then the three solutions are mixed to obtain a mixed solution.

[0010] According to the present invention, the solutions of the titanium source, alkali source and strontium source are prepared by stirring. For example, the stirring time of the three solutions is controlled to be at least 30 minutes during the preparation process.

[0011] According to the present invention, the titanium source and the alkali source may be ground into powder before mixing.

[0012] According to the present invention, the titanium source can be selected from at least one of titanium dioxide, titanium trichloride, tetrabutyl titanate and titanium tetrachloride, and is preferably selected from titanium dioxide.

[0013] Preferably, the solvent used to prepare the titanium source solution may be an organic solvent. For example, the organic solvent may be glyoxal.

[0014] According to the present invention, the molar volume (mmol:mL) ratio of the titanium source to glyoxal is 1:(0.02-0.05), exemplarily 1:0.02.

[0015] According to the present invention, the alkali source can be selected from at least one of lithium hydroxide, potassium hydroxide and sodium hydroxide, and is preferably selected from sodium hydroxide.

[0016] According to the present invention, the solvent used in preparing the alkaline source solution is water. Preferably, the concentration of the alkaline source is 1.0 mol·L -1 ~5.0moL·L -1 , exemplified by 3.0 mol·L -1 .

[0017] According to the present invention, the strontium source can be selected from at least one of strontium carbonate, strontium nitrate, strontium chloride and strontium hydroxide, and is preferably selected from strontium hydroxide.

[0018] According to the present invention, the molar ratio of the mineralizing agent to the titanium source is (5-10):1, exemplarily 9:1.

[0019] Preferably, the mineralizing agent is an alkali metal nitrate, for example, at least one of lithium nitrate, sodium nitrate and potassium nitrate, preferably lithium nitrate, sodium nitrate and potassium nitrate molten salt.

[0020] According to the present invention, the mineralization reagent can be added to the reaction system in the form of a solution.

[0021] According to the present invention, the preparation method further comprises adjusting the mixed solution to an alkaline environment, for example, adjusting the pH value of the mixed solution to 13-14, exemplarily 13.5.

[0022] According to an exemplary embodiment of the present invention, the mixing of the titanium source, the alkali source and the strontium source comprises the following steps:

[0023] a. Grind the titanium source, add to water and stir, and gradually add glyoxal, and continue to stir vigorously;

[0024] b. gradually add the alkali source solution to the solution obtained in step a and continue stirring;

[0025] c. Under vigorous stirring, gradually add the strontium source solution to the solution obtained in step b, and continue stirring;

[0026] d. Add the mineralizing reagent to the solution obtained in step c, and continue stirring again;

[0027] e. The pH value of the solution obtained in step d was adjusted to 13-14 and stirring was continued again.

[0028] According to the present invention, the temperature of the hydrothermal reaction is 120-180° C., exemplarily 180° C.; the time of the hydrothermal reaction is 12-48 hours, exemplarily 15 hours.

[0029] According to the present invention, the preparation method further comprises a post-treatment step of the reaction system after the reaction is completed. For example, the post-treatment step is: washing the reaction mixture with a mixed solvent of water and anhydrous ethanol. For example, the washing is performed at least three times.

[0030] According to an exemplary embodiment of the present invention, in the mixed solvent, the volume ratio of water to ethanol is 8:2.

[0031] According to the present invention, the preparation method further comprises performing solid-liquid separation on the washed product. For example, the solid-liquid separation can be performed by means known in the art, such as centrifugation.

[0032] According to the present invention, the preparation method further comprises drying the product obtained by solid-liquid separation. For example, the drying temperature is 60-80°C, exemplarily 60°C.

[0033] According to the present invention, the preparation method further comprises grinding the product obtained after drying to obtain titanium-based perovskite materials with different microstructures.

[0034] According to the present invention, the method for preparing the titanium-based perovskite material comprises the following steps:

[0035] (1) mixing and stirring the precursor strontium source, titanium source, and alkali source in sequence, adding a mineralizing agent and stirring, and then adjusting the solution to alkalinity;

[0036] (2) subjecting the mixed system of step (1) to a hydrothermal reaction to prepare titanium-based perovskite materials with different microstructures.

[0037] According to an exemplary embodiment of the present invention, the method for preparing the titanium-based perovskite material comprises the following steps:

[0038] (1) mixing and stirring the precursor strontium source, titanium source, and alkali source in sequence, adding and stirring the mineralizing reagent lithium nitrate solution, and then adjusting the solution to alkalinity;

[0039] (2) subjecting the mixed system of step (1) to a hydrothermal reaction to prepare a nano-granular titanium-based perovskite material.

[0040] According to an exemplary embodiment of the present invention, the method for preparing the titanium-based perovskite material comprises the following steps:

[0041] (1) mixing and stirring the precursor strontium source, titanium source, and alkali source in sequence, adding and stirring the mineralizing reagent sodium nitrate solution, and then adjusting the solution to alkalinity;

[0042] (2) subjecting the mixed system of step (1) to a hydrothermal reaction to prepare a titanium-based perovskite material with a nanosheet structure.

[0043] According to an exemplary embodiment of the present invention, the method for preparing the titanium-based perovskite material comprises the following steps:

[0044] (1) Precursors strontium source, titanium source, and alkali source are sequentially mixed and stirred, a mineralizing reagent potassium nitrate solution is added and stirred, and then the solution is adjusted to alkalinity;

[0045] (2) subjecting the mixed system of step (1) to a hydrothermal reaction to prepare a hierarchical nanoflower-shaped titanium-based perovskite material.

[0046] The present invention also provides a titanium-based perovskite material prepared by the above preparation method.

[0047] According to the present invention, the titanium-based perovskite material is strontium titanate SrTiO 3 , the strontium titanate SrTiO 3 The microstructure is nanoparticles, nanosheets or hierarchical nanoflowers.

[0048] According to the present invention, in the titanium-based perovskite material, the yields of nanoparticles, nanosheets and hierarchical nanoflowers are 95%, 98% and 100% respectively.

[0049] According to the present invention, in the titanium-based perovskite material, the particle size of the nanoparticles is 20-40nm; the length of the nanosheets is 150nm-200nm, and the thickness is 5-15nm (eg, 10nm); and the particle size of the hierarchical nanoflowers is 5-10μm.

[0050] The present invention also provides the use of the titanium-based perovskite material as a photocatalytic material. Preferably, the titanium-based perovskite material is used as a photocatalytic material in the field of environmental governance. For example, it is used in the photocatalytic degradation of antibiotic pollutants. Preferably, the titanium-based perovskite material is a hierarchical nanoflower-shaped titanium-based perovskite material.

[0051] According to the present invention, the antibiotic pollutant is preferably selected from tetracycline or ibuprofen.

[0052] The present invention also provides a photocatalyst comprising the above-mentioned titanium-based perovskite material, preferably comprising the above-mentioned hierarchical nanoflower-shaped titanium-based perovskite material.

[0053] The present invention also provides a method for catalytically degrading antibiotic pollutants using the above-mentioned titanium-based perovskite material or photocatalyst, comprising mixing the titanium-based perovskite material or photocatalyst with an aqueous solution containing antibiotic pollutants; for example, adding the titanium-based perovskite material or photocatalyst to the aqueous solution containing antibiotic pollutants and stirring to achieve adsorption-desorption equilibrium.

[0054] According to the present invention, the input amount of the titanium-based perovskite material or photocatalyst is 50-150 mg, and the antibiotic concentration is 5×10 -2 moL·L -1 For example, the input amount of titanium-based perovskite material or photocatalyst is 60.0 mg, and the concentration of antibiotic pollutants is 1.0×10 -5 mol.

[0055] According to the present invention, the stirring time is more than 20 minutes, for example, stirring for 20 to 120 minutes.

[0056] For example, in 100 mL, 1.0×10 -5 mol·L -1 60.0 mg of titanium-based perovskite material or photocatalyst was added to the aqueous solution containing antibiotic pollutants, and stirred in the dark to reach adsorption-desorption equilibrium. Then, the solution was illuminated with visible light. Samples were taken every 20 minutes and the light absorption spectrum at the maximum absorption wavelength was measured by UV-visible spectrophotometry and compared with the standard curve to determine the photocatalytic degradation performance of the titanium-based perovskite material.

[0057] Beneficial effects of the present invention:

[0058] The present invention provides a titanium-based perovskite material with different microstructures, a preparation method thereof, and a study on the photocatalytic antibiotic degradation performance thereof, which has the following advantages:

[0059] 1. The method is to adjust the type of mineralizing reagent added in the hydrothermal reaction to achieve the regulation of the morphology of the titanium-based perovskite material, and obtain the titanium-based perovskite material with nanoparticles, nanosheets and hierarchical nanoflower structures. Compared with the reported strontium titanate prepared by inducing reagents, the titanium-based perovskite SrTiO 3 Due to its good microstructure and enhanced surface and interface reactions, it can quickly achieve enhanced separation of charge carriers, and has greater advantages and research value in improving catalytic activity;

[0060] 2. Due to the regulation of the surface interface, the titanium-based perovskite materials with different microstructures prepared by the present invention have rich surface atomic coordination, atomic steps, unsaturated atoms, dangling bonds, more active reaction sites, unique atomic arrangement and significantly regulated electronic structure. The micro-nano crystals show good physical and chemical activity, thereby providing a good surface interface reaction site for photocatalytic reaction, making full use of the absorption of sunlight, and promoting the efficient degradation process of antibiotic pollutants;

[0061] 3. The titanium-based perovskite materials with different microstructures of the present invention have excellent microscopic surface structures, which can make good use of the surface-interface synergy induced by the surface structure, which can not only achieve the expansion of light response and the enhancement of surface-interface reaction, but also promote the effective adsorption of antibiotic molecules, optimize the system reaction kinetics, and thus improve the quantum efficiency of photocatalytic degradation of antibiotic pollutants. The titanium-based perovskite materials with hierarchical nanoflower structures of the present invention show efficient photocatalytic degradation activity for highly toxic, low-concentration tetracycline and ibuprofen under visible light irradiation.

[0062] 4. The precursors required for the synthesis of titanium-based perovskite materials with different microstructures in the present invention are abundant and inexpensive, the preparation process is relatively simple, the purity and yield of the obtained titanium-based perovskite materials are relatively high, and the synthesis steps are simple and easy to control. It mainly utilizes a simple molten salt-like hydrothermal synthesis process. By changing the type of mineralizing reagent, the controllable preparation of classic perovskite-type catalyst materials with different microstructures and capable of absorbing visible light is achieved in a one-step molten salt-like hydrothermal synthesis.

[0063] 5. The titanium-based perovskite materials with different microstructures prepared by the present invention show differences in photoelectric properties due to their diverse surface characteristics. At the same time, such microstructural differences also directly affect the effective removal activity of titanium-based perovskite catalysts for highly toxic and low-concentration antibiotic pollutants, thus showing potential practical application value in environmental governance.

[0064] 6. The titanium-based perovskite materials with different microstructures prepared by the present invention can achieve effective degradation of antibiotic pollutants under visible light (emission wavelength 420nm-780nm) (the degradation rate of antibiotics within 120 minutes is as high as 87.03%), which shows that the titanium-based perovskite materials with different microstructures prepared by the present invention are potential environmental functional materials with visible light catalytic activity.

[0065] 7. The titanium-based perovskite material prepared by the present invention not only has a simple and feasible synthesis process, but also has differences in catalytic activity due to the different atomic arrangements on the surface interface, unsaturated sites, adsorption modes and even the mechanism of action with the target molecule. The visible light photocatalytic antibiotic degradation performance exhibited by the catalyst of the present invention is expected to make it an effective environmental purification material, which provides a strong theoretical basis for revealing the structure-activity relationship, exploring nanomaterials with excellent performance and their applications and functional mechanisms in solving environmental pollution, and developing new environmental nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a scanning electron microscope image of the titanium-based perovskite material prepared in Example 1 of the present invention.

[0067] Figure 2 This is a scanning electron microscope image of the titanium-based perovskite material prepared in Example 2 of the present invention.

[0068] Figure 3 This is a scanning electron microscope image of the titanium-based perovskite material prepared in Example 3 of the present invention.

[0069] Figure 4 (a), (b), and (c) are powder diffraction patterns of titanium-based perovskite materials with different microstructures prepared in Examples 1-3 of the present invention, respectively.

[0070] Figure 5 (a), (b), and (c) are respectively the photocatalytic removal activity diagrams of the antibiotic pollutant tetracycline prepared by the titanium-based perovskite materials of Examples 1-3 of the present invention under visible light irradiation:

[0071] Figure 6 (a), (b), and (c) are respectively the photocatalytic removal activity diagrams of the antibiotic pollutant ibuprofen by the titanium-based perovskite materials prepared in Examples 1-3 of the present invention under visible light irradiation. DETAILED DESCRIPTION

[0072] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies realized based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0073] Comparative Example 1

[0074] A method for preparing a titanium-based perovskite material comprises the following steps:

[0075] a. Accurately take 1.0mmol of titanium dioxide and grind it into a mortar; add it into a beaker containing 20.0mL of distilled water and stir; accurately measure 0.02mL of glyoxal and pour it into the beaker and stir for about 30 minutes; then add 5.0mL, 3mol·L -1 The lithium hydroxide solution was stirred continuously to obtain a white oily turbid liquid; after stirring for 30 min, 0.3 mol·L -1 10 mL of strontium hydroxide solution was added and stirred again; finally, the pH of the solution was adjusted to 13.5 with sodium hydroxide or hydrochloric acid solution, and stirring was continued for about 60 minutes;

[0076] b. The above solution was transferred to a hydrothermal reactor and placed in an oven and heated at 180°C for 15 h. After the reaction was completed, the temperature was adjusted to 2°C / min. -1 The sample was cooled to room temperature at a rate of 1000 ℃, and then slowly poured into a mixed solvent of anhydrous ethanol and double distilled water with a volume ratio of 2:8. The sample was repeatedly washed, dried and ground in an oven at 60 °C to obtain strontium titanate SrTiO 3 .

[0077] Example 1

[0078] A method for preparing a titanium-based perovskite material comprises the following steps:

[0079] a. Accurately take 1.0mmol of titanium dioxide and grind it into a mortar; add it into a beaker containing 20.0mL of distilled water and stir; accurately measure 0.02mL of glyoxal and pour it into the beaker and stir for about 30 minutes; then add 5.0mL, 3mol·L -1 The lithium hydroxide solution was stirred continuously to obtain a white oily turbid liquid; after stirring for 30 min, 0.3 mol·L -1 10 mL of strontium hydroxide solution was added and stirred again; then 3.0 mL of 3 mol·L -1 The lithium nitrate solution is stirred and mixed continuously; finally, the pH value of the solution is adjusted to 13.5 with sodium hydroxide or hydrochloric acid solution, and stirring is continued for about 60 minutes;

[0080] b. The above solution was transferred to a hydrothermal reactor and heated in an oven at 180°C for 15 h. After the reaction was completed, the temperature was adjusted to 2°C / min. -1 The sample was cooled to room temperature at a rate of 1000 ℃, and then slowly poured into a mixed solvent of anhydrous ethanol and double distilled water with a volume ratio of 2:8. The sample was repeatedly washed, dried and ground in an oven at 60 °C to obtain nano-granular strontium titanate SrTiO 3 .

[0081] Figure 1The perovskite SrTiO prepared in Example 1 of the present invention 3 SEM images show that strontium titanate SrTiO 3 It presents a uniformly distributed nanoparticle structure.

[0082] Example 2

[0083] A method for preparing a titanium-based perovskite material comprises the following steps:

[0084] a. Accurately take 1.0mmol of titanium dioxide and grind it into a mortar; add it into a beaker containing 20.0mL of distilled water and stir; accurately measure 0.02mL of glyoxal and pour it into the beaker and stir for about 30 minutes; then add 5.0mL, 3mol·L -1 The lithium hydroxide solution was stirred continuously to obtain a white oily turbid liquid; after stirring for 30 min, 0.3 mol·L -1 10 mL of strontium hydroxide solution was added and stirred again; then 3.0 mL of 3 mol·L -1 The sodium nitrate solution is stirred and mixed continuously; finally, the pH value of the solution is adjusted to 13.5 with sodium hydroxide or hydrochloric acid solution, and stirring is continued for about 60 minutes;

[0085] b. The above solution was transferred to a hydrothermal reactor and heated in an oven at 180°C for 15 h. After the reaction was completed, the temperature was adjusted to 2°C / min. -1 The sample was cooled to room temperature at a rate of 100 °C, and then slowly poured into a mixture of anhydrous ethanol and double distilled water to wash the sample repeatedly, dried in an oven at 60 °C, and ground to obtain strontium titanate SrTiO containing nanosheet structure. 3 .

[0086] Figure 2 The perovskite SrTiO prepared in Example 2 of the present invention 3 SEM images show that strontium titanate SrTiO 3 It presents a nanosheet structure.

[0087] Example 3

[0088] A method for preparing a titanium-based perovskite material comprises the following steps:

[0089] a. Accurately take 1.0mmol of titanium dioxide and grind it into a mortar; add it into a beaker containing 20.0mL of distilled water and stir; accurately measure 0.02mL of glyoxal and pour it into the beaker and stir for about 30 minutes; then add 5.0mL, 3mol·L -1The lithium hydroxide solution was stirred continuously to obtain a white oily turbid liquid; after stirring for 30 min, 0.3 mol·L -1 10 mL of strontium hydroxide solution was added and stirred again; then 3.0 mL of 3 mol·L -1 The potassium nitrate solution is stirred and mixed continuously; finally, the pH value of the solution is adjusted to 13.5 with sodium hydroxide or hydrochloric acid solution, and stirring is continued for about 60 minutes;

[0090] b. The above solution was transferred to a hydrothermal reactor and heated in an oven at 180°C for 15 h. After the reaction was completed, the temperature was adjusted to 2°C / min. -1 The sample was cooled to room temperature at a rate of 100 °C, and then slowly poured into a mixture of anhydrous ethanol and double distilled water to wash the sample repeatedly, dried in an oven at 60 °C, and ground to obtain strontium titanate SrTiO 3 .

[0091] Figure 3 The perovskite SrTiO prepared in Example 3 of the present invention 3 SEM images show that strontium titanate SrTiO 3 A flower structure showing a hierarchical structure.

[0092] Figure 4 (a), (b), and (c) are powder diffraction patterns of titanium-based perovskite materials with different microstructures prepared in Examples 1-3 of the present invention, respectively. Figure 4 (a) shows that the nano-particle structure of strontium titanate SrTiO was successfully prepared in Example 1. 3 ; Figure 4 (b) shows that the nanosheet-structured strontium titanate SrTiO was successfully prepared in Example 2. 3 ; Figure 4 (c) shows that the hierarchical nanoflower structure of strontium titanate SrTiO was successfully prepared in Example 3. 3 .

[0093] Test Example 1

[0094] The titanium-based perovskite materials prepared in Examples 1-3 were respectively used as catalysts in the photocatalytic degradation of antibiotic pollutants, and the specific operations were carried out according to the following steps:

[0095] In order to measure the photocatalytic activity, 1.0×10 -5 mol·L -160.0 mg of the titanium-based perovskite material prepared in Example 1-3 of the present invention was added to the tetracycline pollutant aqueous solution, and wrapped with tin foil and stirred with a magnetic stirrer in the dark to reach adsorption-desorption equilibrium and dispersed evenly. At room temperature, a 300W xenon lamp (PLS-SXE300, Perfectlight, 420nm filter) was used as the light source. (The total illumination time was 120 min, and a sample was taken every 20 min. Before each sampling, it was necessary to stand for 2 min to allow the titanium-based perovskite material to precipitate. A sample of about 10 mL of the mixture was taken from the upper clear night, and centrifuged at 9000 rpm for 20 min on a centrifuge to separate the titanium-based perovskite material from the suspension.) The pollutant solution used in the experiment was scanned throughout the ultraviolet and visible light bands by an ultraviolet-visible spectrophotometer (UV-1800, Shimadzu, Japan) to determine its maximum absorption characteristic peak. The absorbance of the degradation product is measured at this maximum absorption wavelength, and the light absorption spectrum of tetracycline pollutants at different time intervals is measured and compared with the standard curve to determine the accurate concentration changes of tetracycline pollutants.

[0096] Figure 5 (a), (b), and (c) are respectively the photocatalytic removal activity diagrams of the titanium-based perovskite materials prepared in Examples 1-3 of the present invention for the antibiotic pollutant tetracycline under visible light irradiation. From the degradation results, it can be seen that the strontium titanate with nanoparticle structure achieved 59.56% degradation of tetracycline pollutants; the strontium titanate with nanosheet structure achieved 78.57% degradation of tetracycline pollutants, and the strontium titanate with hierarchical structure achieved 87.03% degradation of tetracycline pollutants.

[0097] Test Example 2

[0098] In order to measure the photocatalytic activity, 1.0×10 -5 mol·L -160.0mg of titanium-based perovskite material prepared by Example 1-3 of the present invention was added to the ibuprofen aqueous solution, and wrapped with tin foil and stirred with a magnetic stirrer in the dark to reach adsorption-desorption equilibrium and be evenly dispersed. At room temperature, a 300W xenon lamp (PLS-SXE300, Perfect light) with a 420nm filter was used as a light source. (Total illumination duration 120min, sample taken every 20min, each sampling before needing to stand for 2min to allow the titanium-based perovskite material to precipitate, about 10mL of the mixture sample was taken from the upper clear night, centrifuged at 9000rpm for 20min on a centrifuge, and the titanium-based perovskite material was separated from the suspension.) The pollutant solution used in the experiment was scanned throughout the ultraviolet and visible light bands by an ultraviolet-visible spectrophotometer (UV-1800, Shimadzu, Japan) to determine its maximum absorption characteristic peak. The absorbance of the degradation products is measured at this maximum absorption wavelength, and the light absorption spectra of the ibuprofen-like pollutants at different time intervals are measured and compared with the standard curve to determine the exact concentration changes of the ibuprofen-like pollutants.

[0099] Figure 6 (a), (b), and (c) are respectively the photocatalytic removal activity diagrams of the antibiotic pollutant ibuprofen by the titanium-based perovskite materials prepared in Examples 1-3 of the present invention under visible light irradiation. From the degradation results, it can be seen that: the strontium titanate with nanoparticle structure achieved 56.68% degradation of ibuprofen pollutants; the strontium titanate with nanosheet structure achieved 65.56% degradation of ibuprofen pollutants, and the strontium titanate with hierarchical structure achieved 83.11% degradation of ibuprofen pollutants.

[0100] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a titanium-based perovskite material, It is characterized in that The method comprises the following steps: The method comprises taking a precursor titanium source, a strontium source, a solvent source and an alkali source as raw materials, and subjecting the precursor to a hydrothermal reaction at 120-180 ° C for 12-48 h under the action of a mineralizing agent to prepare the titanium-based perovskite material SrTiO 3 ; The molar ratio of the mineralizing agent to the titanium source is (5-10):1; The alkali source is selected from lithium hydroxide; the concentration of the alkali source is 1.0 mol·L -1 ~5.0 mol·L -1 ; The strontium source is selected from strontium hydroxide; The mineralizing agent is at least one of sodium nitrate and potassium nitrate; The morphology of the titanium-based perovskite material is nanosheet or hierarchical nanoflower; The molar ratio of the strontium source to the titanium source is (1-5):

1.

2. The preparation method according to claim 1, It is characterized in that The titanium source is selected from at least one of titanium dioxide, titanium trichloride, tetrabutyl titanate and titanium tetrachloride.

3. The preparation method according to any one of claims 1 to 2, It is characterized in that The steps include: (1) Mixing the precursor strontium source, titanium source and alkali source, adding the mineralizing agent and stirring, and then adjusting the solution to alkalinity; (2) subjecting the mixed system of step (1) to a hydrothermal reaction to prepare titanium-based perovskite catalyst materials having different microstructures.

4. The preparation method according to claim 1, It is characterized in that In the titanium-based perovskite material, the length of the nanosheet is 150 nm-200 nm, and the thickness is 5-15 nm; the particle size of the nanoflower with a hierarchical structure is 5-10 μm.

5. The titanium-based perovskite material prepared by the preparation method according to any one of claims 1 to 4 is used as a photocatalyst.

6. The titanium-based perovskite material according to claim 5 is used as a photocatalyst, It is characterized in that The method for photocatalytically degrading antibiotic pollutants or ibuprofen comprises mixing a titanium-based perovskite material with an aqueous solution containing antibiotic pollutants or ibuprofen.

7. The titanium-based perovskite material according to claim 6 is used as a photocatalyst, It is characterized in that The antibiotic pollutants are selected from tetracycline.

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