A woolen ball-shaped BaTiO3 / Bi4Ti3O 12 Preparation methods of catalyst materials and the products obtained therefrom

Abstract

This invention discloses a yarn-like ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material and the product obtained are described. An ethanol solution of flake-shaped bismuth titanate and tetrabutyl titanate, along with a barium salt solution, are stirred and mixed with an alkaline conditioning solution to obtain an alkaline suspension. After hydrothermal reaction, the suspension is acid-washed, washed, filtered, and dried to obtain yarn-like spherical BaTiO3 / Bi4Ti3O3. 12 Catalyst powder. The catalyst of this invention has a structure of hollow, woolen spheres assembled from nanowires, with nanoparticles embedded on the surface of the spheres. This effectively increases the contact area between the catalyst and the reactants, thereby improving the carrier separation efficiency in piezoelectric catalysis and greatly enhancing catalytic activity. The raw materials of this invention are inexpensive and the operation is simple, solving the problems of complex processes and high costs associated with the synthesis of one-dimensional catalysts or the need for templates and morphology modifications in existing technologies. The product can be applied in photocatalysis and piezoelectric catalysis, and has high application value.

Description

Technical Field

[0001] This invention relates to the field of ceramic nanocatalytic materials preparation technology, and particularly to a yarn-shaped BaTiO3 / Bi4Ti3O3 nanofiber assembled from nanowires. 12 Preparation methods of catalyst materials and the products obtained therefrom. Background Technology

[0002] Environmental pollution and energy shortages have become key bottlenecks restricting human development. Piezoelectric catalysis utilizes readily available but often overlooked mechanical energy to initiate catalytic reactions, thereby treating pollutants and holds promise as an effective solution to the energy crisis and environmental pollution. Barium titanate (BaTiO3) and bismuth titanate (Bi4Ti3O3) are examples of such solutions. 12 BaTiO3 and Bi4Ti3O3, respectively, are typical ferroelectric semiconductors and layered piezoelectric materials. They exhibit piezoelectric catalytic effects by spontaneously polarizing under pressure, and are considered ideal candidate piezoelectric catalysts. However, one of the main problems faced by single catalysts is that the rapid recombination of charge carriers during catalysis limits high catalytic activity. Constructing heterojunction materials is often considered an effective way to synthesize highly active catalysts because it can effectively adjust the transport behavior of charge carriers and thus improve catalytic efficiency. Therefore, constructing BaTiO3 / Bi4Ti3O3... 12 Heterojunction catalysts can both preserve their respective characteristics and further improve catalytic activity, making them an effective solution for obtaining high-performance catalysts.

[0003] Existing technologies demonstrate that preparing porous spherical catalyst materials is an effective way to enhance catalytic activity. Porous spherical catalysts, due to their large specific surface area and numerous exposed surface active sites, effectively improve catalytic efficiency. Furthermore, the one-dimensional structure in the monomers constructing porous spherical catalysts provides a rapid channel for charge carrier transfer, significantly reducing charge loss caused by electronic transitions in nanoparticles. Simultaneously, their strong deformation capability and long-term stable cycling performance endow them with excellent piezoelectric catalytic performance induced by mechanical vibration. Porous spherical catalysts assembled from these monomers can further exhibit high catalytic activity. Therefore, a porous spherical BaTiO3 / Bi4Ti3O3 catalyst woven from a one-dimensional structure was synthesized. 12 Composite materials are a key approach to obtaining high-performance catalysts. However, due to their intrinsic structure, their morphology will intrinsically transform into a particulate form during growth, making it difficult to obtain one-dimensional BaTiO3 / Bi4Ti3O3. 12 Powders, such as BaTiO3 / Bi4Ti3O prepared by the solvothermal method in the prior art. 12 The composite material exhibits a cubic morphology; Bi4Ti3O with good catalytic performance was prepared using a solid-state synthesis process. 12The BaTiO3 composite material exhibits an irregular granular morphology. To date, no nanowire spherical BaTiO3 / Bi4Ti3O3 composites assembled from one-dimensional structures have been observed. 12 Reports related to catalysts. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a yarn-like ball-shaped BaTiO3 / Bi4Ti3O 12 The method for preparing catalyst materials involves forming a hollow, woolen sphere structure assembled from woven nanowires, with nanoparticles embedded on the spherical surface. This effectively increases the contact area between the catalyst and the reactants, thereby improving the carrier separation efficiency and enhancing catalytic activity during piezoelectric catalysis. Another objective of this invention is to provide a product prepared using the above-described method.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] This invention provides a woolen ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material includes the following steps:

[0007] (1) According to the mass ratio of bismuth titanate: tetrabutyl titanate: anhydrous ethanol = 0.4~0.5: 3.3~3.5: 50~60, bismuth titanate and tetrabutyl titanate are dissolved in anhydrous ethanol and stirred continuously for 10~30 minutes to mix evenly, so as to obtain a light yellow suspension A.

[0008] (2) According to the mass ratio of barium hydroxide octahydrate: potassium hydroxide: deionized water = 3.36~6.72: 3~3.3: 10~20, dissolve barium hydroxide octahydrate and potassium hydroxide in deionized water, heat and stir until completely dissolved to obtain solution B;

[0009] (3) According to the mass ratio of suspension A: solution B: regulator = 3~2:1:0.05~0.2, add solution B to suspension A, and continue to add regulator, and stir continuously for 1~3 hours to obtain a suspension mixture; place the suspension mixture in a reaction vessel and react at 150~170℃ for 12~30 hours. After removing the supernatant from the reaction product system, a grayish-white powder is obtained.

[0010] (4) After acid washing, the grayish-white powder is washed, filtered, and dried to obtain yarn-like spherical BaTiO3 / Bi4Ti3O 12 Catalyst powder.

[0011] Further, in step (1) of the present invention, the stirring time is 10-30 min; in step (2), the heating temperature is 50-70℃ and the stirring time is 4-8 h; in step (3), the regulator is sodium dodecyl sulfonate; in step (4), acid washing is performed with dilute hydrochloric acid or dilute nitric acid at pH=1, and washing is performed with deionized water until neutral, the drying temperature is 65-85℃ and the drying time is 8-12 h.

[0012] This invention utilizes the above-mentioned wool-like spherical BaTiO3 / Bi4Ti3O 12 The product obtained by the catalyst material preparation method, wherein the yarn-like spherical BaTiO3 / Bi4Ti3O 12 The catalyst powder is composed of nanowires that are wound and interwoven. The diameter of the nanowires is 10-20 nm and the aspect ratio is 10-100:1. The particle size of the yarn-shaped catalyst powder formed by weaving is 400-500 nm.

[0013] The present invention has the following beneficial effects:

[0014] (1) This invention intentionally introduces a regulator that can selectively bond with the substrate surface, thereby achieving selective protection of the substrate, reducing the surface tension of the liquid in the reaction system and changing the surface activity of the substrate; at the same time, based on the difference in the binding force between different elements, and by utilizing the shearing effect of potassium hydroxide, the substrate is precisely "cut", and a one-dimensional nanostructure self-assembled yarn ball catalyst material is obtained without the use of a template.

[0015] (2) The BaTiO3 / Bi4Ti3O provided by this invention 12 The heterojunction catalyst is a yarn ball structure assembled from nanowires. The entangled nanowires provide more active sites for the reaction, while the interwoven nanosphere cages form a porous morphology, exposing more edges per unit volume, providing higher adsorption characteristics, and providing a higher contact area between reactants and catalyst, which greatly improves catalytic efficiency.

[0016] (3) The wool-like ball-shaped BaTiO3 / Bi4Ti3O provided by the present invention 12 The heterojunction catalyst exhibits uniform and controllable morphology, with its monomer nanowires having a diameter of 10–20 nm and an aspect ratio of 10–100:1. Nanospheres assembled from this high aspect ratio nanowire texture demonstrate higher stability compared to nanospheres assembled from conventional low aspect ratio nanowires. Therefore, for nanospheres of the same specifications, the catalyst material of this invention exhibits higher cycle durability in practical use.

[0017] (4) Compared with traditional template methods or morphology modification methods, special morphology BaTiO3 / Bi4Ti3O3 was prepared. 12Compared to other materials, this invention uses a simple one-step hydrothermal method to prepare a yarn ball structure BaTiO3 / Bi4Ti3O assembled from nanowire textures. 12 The synthesis process is simple, rapid, easy to control, low in cost, and short in cycle. This invention solves the problems of complex processes and high costs caused by the difficulty in synthesizing one-dimensional catalysts or the need to introduce templates and morphology modifications during the synthesis process in existing technologies. The product can be applied in the fields of photocatalysis and piezoelectric catalysis and has high application value. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings:

[0019] Figure 1 This is a SEM image of the catalyst powder prepared in Example 1 of this invention;

[0020] Figure 2 This is the X-ray diffraction pattern of the catalyst powder prepared in Example 1 of this invention;

[0021] Figure 3 This is a graph showing the relationship between the efficiency and time of the catalyst powder prepared in Example 1 of this invention in degrading 5 mg / L Rhodamine B under ultrasonic and light irradiation conditions.

[0022] Figure 4 This is a SEM image of the catalyst powder prepared in Example 2 of this invention;

[0023] Figure 5 This is the X-ray diffraction pattern of the catalyst powder prepared in Example 2 of this invention;

[0024] Figure 6 This is a SEM image of the catalyst powder prepared in Example 3 of this invention;

[0025] Figure 7 This is the X-ray diffraction pattern of the catalyst powder prepared in Example 3 of this invention;

[0026] Figure 8 This is a SEM image of the catalyst powder prepared in Example 4 of this invention;

[0027] Figure 9 This is the X-ray diffraction pattern of the catalyst powder prepared in Example 4 of this invention;

[0028] Figure 10 This is a graph showing the relationship between the efficiency of the catalyst powder prepared in Example 4 of this invention in degrading a typical dye under ultrasonic conditions and time.

[0029] Figure 11 This is a SEM image of the catalyst powder prepared in Example 5 of this invention;

[0030] Figure 12 This is the X-ray diffraction pattern of the catalyst powder prepared in Example 5 of the present invention. Detailed Implementation

[0031] Example 1:

[0032] This embodiment describes a woolen ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material includes the following steps:

[0033] (1) Weigh 0.45g of bismuth titanate and 3.4g of tetrabutyl titanate respectively, and gradually add them to 50g of anhydrous ethanol. Stir continuously for 30min to mix evenly and obtain a pale yellow suspension A.

[0034] (2) Weigh out 3.36g of barium hydroxide octahydrate and 3.15g of potassium hydroxide respectively, dissolve them in 20g of deionized water, place them on a heated magnetic stirrer and stir at 70℃ for 6h until completely dissolved to obtain solution B;

[0035] (3) Weigh 48g of suspension A and 16g of solution B respectively, add solution B to suspension A, add 1.5g of sodium dodecyl sulfonate, and stir continuously for 2h to obtain a suspension mixture; place the suspension mixture in a reaction vessel and react at 160℃ for 30h. After removing the supernatant from the reaction product system, a grayish-white powder is obtained.

[0036] (4) The above-mentioned grayish-white powder was washed with dilute nitric acid at pH=1, and then washed with deionized water until neutral. The resulting wet powder was filtered and dried at 80℃ for 8 hours to obtain spherical BaTiO3 / Bi4Ti3O3 woven from nanowires. 12 Catalyst powder.

[0037] like Figure 1 As shown, the catalyst powder prepared in this embodiment generally consists of multiple near-spherical particles under a scanning electron microscope. Each sphere is composed of nanowires with a diameter of about 10 nm, and the surface is covered with nanoparticles and accompanied by a porous structure.

[0038] like Figure 2 As shown, the characteristic peak positions and intensities of the catalyst powder prepared in this embodiment coincide with those of barium titanate (PDF06-0626) and bismuth titanate (PDF34-0079), respectively, and there are no other crystalline phase impurity peaks present, indicating that the product is composed of barium titanate and bismuth titanate and has good crystallinity.

[0039] like Figure 3As shown, the catalyst powder prepared in this embodiment was tested for degradation of 5 mg / L Rhodamine B under ultrasonic conditions (45 kHz, 360 W) and light irradiation. Under both conditions, the degradation rate exceeded 90%, indicating that the material has good application performance in the fields of piezoelectric catalysis and photocatalysis.

[0040] Example 2:

[0041] This embodiment describes a woolen ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material includes the following steps:

[0042] (1) Weigh 0.5g of bismuth titanate and 3.5g of tetrabutyl titanate respectively, and gradually add them to 50g of anhydrous ethanol. Stir continuously for 30min to mix evenly and obtain a light yellow suspension A.

[0043] (2) Weigh out 6.72g of barium hydroxide octahydrate and 3.3g of potassium hydroxide respectively, dissolve them in 20g of deionized water, place them on a heated magnetic stirrer and stir at 70℃ for 8h until completely dissolved to obtain solution B;

[0044] (3) Weigh 32g of suspension A and 16g of solution B respectively, add solution B to suspension A, add 2g of sodium dodecyl sulfonate, and stir continuously for 3h to obtain a suspension mixture; place the suspension mixture in a reaction vessel and react at 160℃ for 12h. After removing the supernatant from the reaction product system, a grayish-white powder is obtained.

[0045] (4) The above-mentioned grayish-white powder was washed with dilute nitric acid at pH=1, and then washed with deionized water until neutral. The resulting wet powder was filtered and dried at 80℃ for 8 hours to obtain spherical BaTiO3 / Bi4Ti3O3 woven from nanowires. 12 Catalyst powder.

[0046] like Figure 4 As shown, the catalyst powder prepared in this embodiment has the morphology of an assembly of high aspect ratio nanowires and nanoparticles under a scanning electron microscope. The nanowires are intertwined and entangled to form a porous structure, and the nanoparticles are loaded on top of the nanowires.

[0047] like Figure 5 As shown, the characteristic peak positions and intensities of the catalyst powder prepared in this embodiment coincide with those of barium titanate (PDF06-0626) and bismuth titanate (PDF34-0079), respectively, and there are no other crystalline phase impurity peaks present, indicating that the product is composed of barium titanate and bismuth titanate and has good crystallinity.

[0048] Example 3:

[0049] This embodiment describes a woolen ball-shaped BaTiO3 / Bi4Ti3O 12The preparation method of the catalyst material includes the following steps:

[0050] (1) Weigh 0.4g of bismuth titanate and 3.3g of tetrabutyl titanate respectively, and gradually add them to 60g of anhydrous ethanol. Stir continuously for 30min to mix evenly and obtain a pale yellow suspension A.

[0051] (2) Weigh 3.36g of barium hydroxide octahydrate and 3g of potassium hydroxide respectively, dissolve them in 10g of deionized water, place them on a heated magnetic stirrer and stir at 70℃ for 8h until completely dissolved to obtain solution B;

[0052] (3) Weigh 48g of suspension A and 16g of solution B respectively, add solution B to suspension A, add 1g of sodium dodecyl sulfonate, and stir continuously for 1h to obtain a suspension mixture; place the suspension mixture in a reaction vessel and react at 160℃ for 30h. After removing the supernatant from the reaction product system, a grayish-white powder is obtained.

[0053] (4) The above-mentioned grayish-white powder was washed with dilute nitric acid at pH=1, and then washed with deionized water until neutral. The resulting wet powder was filtered and dried at 80℃ for 8 hours to obtain spherical BaTiO3 / Bi4Ti3O3 woven from nanowires. 12 Catalyst powder.

[0054] like Figure 6 As shown, the catalyst powder prepared in this embodiment has the morphology of an assembly of high aspect ratio nanowires and nanoparticles under a scanning electron microscope. The nanowires are intertwined and entangled to form a porous structure, and the nanoparticles are loaded on top of the nanowires.

[0055] like Figure 7 As shown, the characteristic peak positions and intensities of the catalyst powder prepared in this embodiment coincide with those of barium titanate (PDF06-0626) and bismuth titanate (PDF34-0079), respectively, and there are no other crystalline phase impurity peaks present, indicating that the product is composed of barium titanate and bismuth titanate and has good crystallinity.

[0056] Example 4:

[0057] This embodiment describes a woolen ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material includes the following steps:

[0058] (1) Weigh 0.45g of bismuth titanate and 3.4g of tetrabutyl titanate respectively, and gradually add them to 50g of anhydrous ethanol. Stir continuously for 30min to mix evenly and obtain a pale yellow suspension A.

[0059] (2) Weigh out 5g of barium hydroxide octahydrate and 3.15g of potassium hydroxide respectively, dissolve them in 20g of deionized water, place them on a heated magnetic stirrer and stir at 70℃ for 6h until completely dissolved to obtain solution B;

[0060] (3) Weigh 48g of suspension A and 16g of solution B respectively, add solution B to suspension A, add 1.5g of sodium dodecyl sulfonate, and stir continuously for 1.5h to obtain a suspension mixture; place the suspension mixture in a reaction vessel and react at 150℃ for 24h. After removing the supernatant from the reaction product system, a grayish-white powder is obtained.

[0061] (4) The above-mentioned grayish-white powder was washed with dilute nitric acid at pH=1, and then washed with deionized water until neutral. The resulting wet powder was filtered and dried at 80℃ for 8 hours to obtain spherical BaTiO3 / Bi4Ti3O3 woven from nanowires. 12 Catalyst powder.

[0062] like Figure 8 As shown, the catalyst powder prepared in this embodiment exhibits an overall morphology of yarn-shaped spheres assembled from nanowires and nanoparticles under a scanning electron microscope. Each sphere is composed of nanowires intertwined and wrapped together to form a porous structure, with nanoparticles loaded above the nanowires.

[0063] like Figure 9 As shown, the characteristic peak positions and intensities of the catalyst powder prepared in this embodiment coincide with those of barium titanate (PDF06-0626) and bismuth titanate (PDF34-0079), respectively, and there are no other crystalline phase impurity peaks present, indicating that the product is composed of barium titanate and bismuth titanate and has good crystallinity.

[0064] like Figure 10 As shown, the catalyst powder prepared in this embodiment was tested under ultrasonic conditions (45KHz, 360W) to degrade 5mg / L Rhodamine B, methylene blue, methyl orange, and Congo red dyes. All dyes showed degradation rates, and the degradation effects of different dyes were as follows: Congo red > Rhodamine B > methylene blue > methyl orange. This indicates that the catalyst material has good universality and specificity in the field of piezoelectric catalytic degradation of dyes.

[0065] Example 5:

[0066] This embodiment describes a woolen ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material includes the following steps:

[0067] (1) Weigh 0.45g of bismuth titanate and 3.4g of tetrabutyl titanate respectively, and gradually add them to 50g of anhydrous ethanol. Stir continuously for 30min to mix evenly and obtain a pale yellow suspension A.

[0068] (2) Weigh out 5g of barium hydroxide octahydrate and 3.15g of potassium hydroxide respectively, dissolve them in 20g of deionized water, place them on a heated magnetic stirrer and stir at 70℃ for 6h until completely dissolved to obtain solution B;

[0069] (3) Weigh 48g of suspension A and 16g of solution B respectively, add solution B to suspension A, add 1.5g of sodium dodecyl sulfonate, and stir continuously for 2.5h to obtain a suspension mixture; place the suspension mixture in a reaction vessel and react at 170℃ for 18h. After removing the supernatant from the reaction product system, a grayish-white powder is obtained.

[0070] (4) The above-mentioned grayish-white powder was washed with dilute nitric acid at pH=1, and then washed with deionized water until neutral. The resulting wet powder was filtered and dried at 80℃ for 8 hours to obtain spherical BaTiO3 / Bi4Ti3O3 woven from nanowires. 12 Catalyst powder.

[0071] like Figure 11 As shown, the catalyst powder prepared in this embodiment has an overall structure formed by the assembly of nanowires and nanoparticles under a scanning electron microscope. The nanowires are intertwined and entangled, and the nanoparticles are loaded on top of the nanowires, accompanied by a porous structure.

[0072] like Figure 12 As shown, the characteristic peak positions and intensities of the catalyst powder prepared in this embodiment coincide with those of barium titanate (PDF06-0626) and bismuth titanate (PDF 34-0079), respectively, and there are no other crystalline phase impurity peaks present, indicating that the product is composed of barium titanate and bismuth titanate and has good crystallinity.

Claims

1. A yarn ball-like BaTi03 / Bi4Ti30i 12 Process for the preparation of a catalyst material, characterized in that It comprises the following steps: (1) Dissolve bismuth titanate, tetrabutyl titanate in anhydrous ethanol according to the mass ratio of bismuth titanate:tetrabutyl titanate:anhydrous ethanol = 0.4-0.5:3.3-3.5:50-60, continuously stir and mix uniformly to obtain a light yellow suspension A; (2) Dissolve barium hydroxide octahydrate, potassium hydroxide in deionized water according to the mass ratio of barium hydroxide octahydrate:potassium hydroxide:deionized water = 3.36-6.72:3-3.3:10-20, heat and stir until completely dissolved to obtain solution B; (3) Add solution B to suspension A according to the mass ratio of suspension A:solution B:regulator = 3-2:1:0.1-0.2, continuously add the regulator and continuously stir for 1-3 h to obtain a suspension mixture; place the suspension mixture in a reaction kettle and react at a temperature of 150-170℃ for 12-30 h; after removing the supernatant from the reaction product system, a grayish white powder is obtained; the regulator is sodium dodecyl sulfonate; (4) After the ash-white powder is pickled, it is washed, filtered and dried to obtain a wool ball-like BaTiO3 / Bi4Ti3O 12 Catalyst powder.

2. The yarn ball-like BaTi03 / Bi4Ti30i of claim 1. 12 Process for the preparation of a catalyst material, characterized in that: The stirring time of step (1) is 10-30 min.

3. The yarn ball-like BaTi03 / Bi4Ti30i of claim 1, wherein the BaTi03 / Bi4Ti30i is a single crystal. 12 A method for producing a catalyst material, characterized by: The heating temperature in step (2) is 50-70℃ and the stirring time is 4-8 h.

4. The yarn ball-like BaTi03 / Bi4Ti30i of claim 1, wherein the BaTi03 / Bi4Ti30i is a single crystal. 12 A method for producing a catalyst material, characterized by: In step (4), dilute hydrochloric acid or dilute nitric acid with pH = 1 is used for acid pickling; deionized water is used for washing until neutral; the drying temperature is 65-85℃ and the drying time is 8-12 h.

5. A yarn ball-like BaTi03 / Bi4Ti30i core-shell particle according to any one of claims 1 to 4. 12 The product of the process for the preparation of a catalyst material.

6. The product of claim 5, wherein: The ball-shaped BaTiO3 / Bi4Ti3O 12 The catalyst powder is composed of interwoven nanowires with a diameter of 10-20 nm and a length-diameter ratio of 10-100:1, and the particle size of the ball-shaped catalyst powder formed by the interwoven nanowires is 400-500 nm.

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