A substructure-controllable pen container grass template titanium-based composite material and a preparation method and application thereof

Abstract

The application belongs to the technical field of photocatalysis, and particularly relates to a substructure-controllable penicillium crustosum template titanium-based composite material and a preparation method and application thereof. The application uses cheap and easily obtained penicillium crustosum with high silicon content as a biological template, and uses potassium fluoride and glycerol as a regulator to realize multi-element step-by-step complex regulation of the substructure of the composite material. The addition of potassium fluoride makes K 1.28 Ti8O 16 , K2Ti6O 13 appear, and form a ternary heterojunction with anatase TiO2, so as to realize the substructure regulation of the penicillium crustosum template titanium-based composite material. The application first proposes the ternary heterojunction, and introduces the penicillium crustosum biological template with high silicon content, so that the adsorption performance and visible light catalytic performance are both optimized, and the complex structure is achieved. The composite material is used as a catalyst to degrade tetracycline under visible light, the method used is simple and convenient, is suitable for expanding the production scale, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of photocatalysis technology, specifically relating to a titanium-based composite material with tunable substructure based on *Pendula officinalis* template, its preparation method, and its application. Background Technology

[0002] Titanium dioxide (TiO2) has been widely used in fields such as organic pollutant degradation, dye-sensitized batteries, and sensors due to its advantages of high photocatalytic activity, chemical stability, non-toxicity, and low cost. The biotemplate method is an effective and universal approach for synthesizing hierarchical mesoporous materials with multi-level structures. The main advantage of this method is that various low-cost and environmentally friendly natural materials can be used as templates. However, existing research on the preparation of TiO2 using biotemplates mainly focuses on "replicating" the original biological microstructure, with limited control dimensions. Various TiO2-based catalysts exist in different dimensions, such as 0D (nanoparticles), 1D (nanorobars / tubes / belts and fibers), 2D (nanofalves), and 3D (connected, hierarchical structures, etc.). Few studies explore and utilize the inherent properties of the biotemplate itself, or combine it with titanium dioxide to achieve multi-dimensional and complex control of substructural units.

[0003] With the acceleration of industrialization, large amounts of industrial wastewater and domestic sewage are discharged into natural water bodies, causing harm to the ecology and environment. For example, antibiotics such as tetracycline and ciprofloxacin are excreted. Tetracycline hydrochloride is a broad-spectrum antibiotic that inhibits most Gram-positive and Gram-negative bacteria, has bactericidal effects at high concentrations, and can inhibit rickettsiae and trachoma viruses, showing good activity against Gram-negative bacilli. Ciprofloxacin also has broad-spectrum antibacterial activity and good bactericidal effects. However, these antibiotics are not completely consumed by the human body; a certain amount is excreted and enters water bodies, causing pollution and harm. Simultaneously, it can also enhance the drug resistance of bacteria in aquatic environments. Therefore, researching high-performance photocatalytic materials to degrade pollutant molecules in water bodies is of great research significance and promising development prospects. Summary of the Invention

[0004] The purpose of this invention is to provide a titanium-based composite material with substructure controllable penholder grass template, its preparation method, and its application.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for preparing a titanium-based composite material with substructure tunable penholder grass template, comprising the following steps: A titanium source, an alcohol solvent, penneading grass, and additives are mixed and subjected to a solvothermal reaction to obtain a precursor; the additives include potassium fluoride or a mixture of potassium fluoride and glycerol. The precursor is calcined to obtain the titanium-based composite material of the pen holder grass template; The titanium-based composite material of the pen holder grass template has a three-dimensional tubular structure. The material forming the three-dimensional tubular structure includes a silica substrate and a titanium-based material loaded on the surface of the silica substrate, which has a closely packed particle structure. The titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 ; The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

[0006] Preferably, the titanium source includes at least one of tetrabutyl titanate and tetraisopropyl titanate; The alcohol solvent includes at least one of isopropanol and polyethylene glycol; The length of the grass in the pen holder is 3-4 cm.

[0007] Preferably, the mass ratio of the grass in the pen holder to the amount of the titanium source is 0.1~100g:0.1~6mL; The potassium fluoride is added in the form of a potassium fluoride solution, and the mass concentration of the potassium fluoride solution is 1~100g / L; When the additive is potassium fluoride, the mass ratio of the penholder grass to potassium fluoride is 0.1~100:0.005~0.08; When the additive is a mixture of potassium fluoride and glycerin, the mass ratio of the herb to potassium fluoride is 0.1~100:0.005~0.08; the dosage ratio of the herb to glycerin is 0.1~100g:1~6mL.

[0008] Preferably, the mixture is further pretreated before mixing; The pretreatment includes: washing the grass with water, soaking it in glutaraldehyde solution and hydrochloric acid solution in sequence, washing it with water again, dehydrating it with ethanol, and drying it. The mass concentration of the glutaraldehyde solution is 20-80%, and the soaking time in the glutaraldehyde solution is 6-36 hours. The mass concentration of the hydrochloric acid solution is 1-30%, and the soaking time in the hydrochloric acid solution is 6-36 hours.

[0009] Preferably, when the additive is potassium fluoride, the mixing process includes: stirring and premixing the titanium source and alcohol solvent, adding potassium fluoride and stirring, then adding penholder grass and sonicating, and letting it stand; the stirring and premixing time is 1~60 min; the stirring time is 1~60 min; the sonication time is 0.5~3 h; and the standing time is 6~48 h.

[0010] Preferably, when the additive is a mixture of potassium fluoride and glycerin, the mixing process includes: stirring and premixing the titanium source and the alcohol solvent, first adding glycerin and stirring, adding *Pendula officinalis* for a first sonication, allowing it to stand, and then adding potassium fluoride for a second sonication; the stirring and premixing time is 1~60 min; the stirring time is 1~60 min; the first sonication time is 0.5~3 h; the standing time is 6~48 h; and the second sonication time is 0.5~3 h.

[0011] Preferably, the temperature of the solvothermal reaction is 100~200℃ and the time is 6~36h.

[0012] Preferably, the calcination temperature is 300~600℃ and the holding time is 6~15h.

[0013] The present invention also provides a titanium-based composite material for a penholder grass template prepared by the preparation method described above. The titanium-based composite material for a penholder grass template has a three-dimensional tubular structure. The material forming the three-dimensional tubular structure includes a silica substrate and a titanium-based material loaded on the surface of the silica substrate in the form of a closely packed particle structure. The titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 ; The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

[0014] The present invention also provides the application of the titanium-based composite material of the grass template described in the above technical solution as a catalyst in the visible light catalytic degradation of organic matter.

[0015] This invention provides a method for preparing a substructure-tunable titanium-based composite material templated with *Pterocarya stenoptera*, comprising the following steps: mixing a titanium source, an alcohol solvent, *Pterocarya stenoptera*, and additives, and performing a solvothermal reaction to obtain a precursor; the additives include potassium fluoride or a mixture of potassium fluoride and glycerol; calcining the precursor to obtain the *Pterocarya stenoptera* templated titanium-based composite material; the *Pterocarya stenoptera* templated titanium-based composite material has a three-dimensional tubular structure, the material forming the three-dimensional tubular structure including a silica substrate and a titanium-based material loaded on the surface of the silica substrate in a closely packed particle structure; the titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

[0016] Compared with the prior art, the beneficial effects of the present invention include: This invention uses readily available and inexpensive high-silica *Plectranthus praecox* as a biological template and potassium fluoride and glycerol as regulators to achieve multi-level, progressively complex control of the composite material. The addition of potassium fluoride enhances K... 1.28 Ti8O 16 K2Ti6O 13 The appearance of K 1.28 Ti8O 16 K2Ti6O 13 A ternary heterojunction formed with anatase TiO2.

[0017] To achieve step-by-step control, firstly, since the *Pencilwood* template is rich in silicon, its addition introduces a large amount of amorphous silicon onto the material surface, thereby enhancing the adsorption performance of the composite material and increasing the specific surface area; however, the Ti / Si ratio decreases. Secondly, due to the strong viscosity of glycerol, the movement of titanium dioxide particles is reduced, promoting their growth. Therefore, the subsequent addition of glycerol increases the amount of titanium dioxide, further increasing the Ti / Si ratio, and achieving a balance between the TiO2 and SiO2 ratio. This balance allows for improved adsorption performance through SiO2 while ensuring the visible light photocatalytic activity of TiO2, thus achieving the optimal synergistic effect between adsorption and photocatalytic performance. This invention is the first to propose K... 1.28 Ti8O 16 K2Ti6O 13A ternary heterojunction formed by potassium titanate and anatase TiO2, along with the introduction of a high-silicon-content *Pterocarya stenoptera* biotemplate, ensures optimal adsorption and visible-light photocatalytic performance, thus achieving a complex structure. This composite material, used as a catalyst for the degradation of tetracycline under visible light, employs a simple and convenient method suitable for large-scale production and shows great application potential. The study of the photocatalytic properties of potassium titanate and anatase heterojunctions provides new insights. Attached Figure Description

[0018] Figure 1 XRD patterns of the composite materials obtained in Comparative Examples 1, 2, and 6; Figure 2 This is a TEM image of the titanium-based composite material with a grass template obtained in Example 2; Figure 3 TEM image of the titanium-based composite material with penholder grass template obtained in Example 6. Figure 4 TEM image of the composite material obtained in Example 2; Figure 5 XPS spectra of the composite materials obtained in Comparative Examples 1, 2, and 6; Figure 6 The BET specific surface area, pore volume, and pore size of the composite materials obtained in the examples and comparative examples are shown in the following data. Figure 7 The results of photocatalytic degradation of tetracycline by the composite materials obtained in Examples 1-4 and Comparative Example 2 under 10W LED white light; Figure 8 The results of photocatalytic degradation of tetracycline by the composite materials obtained in Example 2 and Comparative Examples 1, 3, and 4 under 10W LED white light; Figure 9 The results of photocatalytic degradation of tetracycline by the composite materials obtained in Examples 5-8 under 10W LED white light; Figure 10 The results of the acute toxicity test of the composite material obtained in Example 6 are shown. Detailed Implementation

[0019] This invention provides a method for preparing a titanium-based composite material with substructure tunable penholder grass template, comprising the following steps: A titanium source, an alcohol solvent, penneading grass, and additives are mixed and subjected to a solvothermal reaction to obtain a precursor; the additives include potassium fluoride or a mixture of potassium fluoride and glycerol. The precursor is calcined to obtain the titanium-based composite material of the pen holder grass template; The titanium-based composite material of the pen holder grass template has a three-dimensional tubular structure. The material forming the three-dimensional tubular structure includes a silica substrate and a titanium-based material loaded on the surface of the silica substrate, which has a closely packed particle structure. The titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 ; The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

[0020] This invention involves mixing a titanium source, an alcohol solvent, a type of grass, and additives, and then performing a solvothermal reaction to obtain a precursor.

[0021] In this invention, the titanium source preferably includes at least one of tetrabutyl titanate and tetraisopropyl titanate; the alcohol solvent preferably includes at least one of isopropanol and polyethylene glycol.

[0022] In this invention, the length of the grass in the pen holder is preferably 3-4 cm.

[0023] In this invention, the mixing process preferably includes pretreatment of the *Pencilia fuciformis*. The pretreatment preferably includes: washing the *Pencilia fuciformis* with water, soaking it in glutaraldehyde solution and hydrochloric acid solution in sequence, washing it with water again, dehydrating it with ethanol, and drying it.

[0024] In this invention, the first water wash removes impurities from the surface of the *Plectranthus praecox*. The preferred mass concentration of the glutaraldehyde solution is 20-80%, specifically 20%, 30%, 40%, 50%, 60%, 70%, or 80%. The preferred soaking time in the glutaraldehyde solution is 6-36 hours, specifically 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, or 36 hours. Soaking in the glutaraldehyde solution helps maintain the morphology of the *Plectranthus praecox* biotemplate. After soaking, a water wash is preferably performed to remove residual glutaraldehyde. In this invention, the preferred mass concentration of the hydrochloric acid solution is 1-30%, specifically 5%, 10%, 20%, or 30%. The preferred soaking time in the hydrochloric acid solution is 6-36 hours, specifically 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, or 36 hours. Soaking in the hydrochloric acid solution removes soluble impurities. After soaking, a water wash is preferably performed until the solution is neutral. In this invention, the dehydration treatment is preferably carried out using an ethanol solution with a gradient content, specifically: first soaking in an ethanol aqueous solution with a volume fraction of 50% for 12 hours, then soaking in an ethanol aqueous solution with a volume fraction of 100% for 12 hours, and then drying for later use.

[0025] In this invention, the additive comprises potassium fluoride or a mixture of potassium fluoride and glycerol.

[0026] In this invention, the preferred ratio of the mass of the *Pencilia fuciformis* to the amount of the titanium source is 0.1~100g:0.1~6mL, specifically 2g:1.2mL. In this invention, the potassium fluoride is preferably added in the form of a potassium fluoride solution, and the preferred mass concentration of the potassium fluoride solution is 1~100g / L, specifically 10g / L, 50g / L, or 100g / L.

[0027] In this invention, when the additive is potassium fluoride, the mass ratio of *Hedyotis diffusa* to potassium fluoride is preferably 0.1~100:0.005~0.08, specifically 2:0.005~0.08; the mixing process preferably includes: stirring and premixing the titanium source and alcohol solvent, adding potassium fluoride and stirring, then adding *Hedyotis diffusa* and sonicating, and letting it stand; the stirring and premixing time is preferably 1~60 min, specifically 5 min, 10 min, 20 min, 30 min, or 40 min. The stirring time is preferably 1 to 60 minutes, specifically 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, or 60 minutes; the ultrasonic time is preferably 0.5 to 3 hours, specifically 0.5 hours, 1 hour, 2 hours, or 3 hours; the settling time is preferably 6 to 48 hours, specifically 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 42 hours, or 48 hours.

[0028] In this invention, when the additive is a mixture of potassium fluoride and glycerin, the preferred mass ratio of *Hedyotis diffusa* to potassium fluoride is 0.1~100:0.005~0.08, specifically 2:0.005~0.08; the preferred dosage ratio of *Hedyotis diffusa* to glycerin is 0.1~100g:1~6mL, specifically 2g:1~6mL; the mixing process preferably includes: stirring and premixing the titanium source and alcohol solvent, first adding glycerin and stirring, adding *Hedyotis diffusa* for a first sonication, allowing it to stand, and then adding potassium fluoride for a second sonication; the stirring and premixing time is 1~60min, specifically 5min, 10min, 15min, etc. The stirring time is preferably 1 to 60 minutes, specifically 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, or 60 minutes; the first ultrasound time is preferably 0.5 to 3 hours, specifically 0.5 hours, 1 hour, 2 hours, or 3 hours; the settling time is preferably 6 to 48 hours, specifically 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 42 hours, or 48 hours; the second ultrasound time is preferably 0.5 to 3 hours, specifically 0.5 hours, 1 hour, 2 hours, or 3 hours.

[0029] In this invention, the temperature of the solvothermal reaction is preferably 100~200℃, specifically 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, or 200℃; the time is preferably 6~36h, specifically 6h, 12h, 18h, 24h, 30h, or 36h; the solvothermal reaction is preferably carried out in a stainless steel high-pressure reactor with a polytetrafluoroethylene liner. After the solvothermal reaction, this invention also preferably includes cooling, cleaning, and drying; the cleaning is preferably performed by alternating washing with deionized water and ethanol; the drying temperature is preferably 70℃, and the drying time is preferably 12h.

[0030] In this invention, the calcination temperature is preferably 300~600℃, specifically 300℃, 400℃, 450℃, 500℃, or 600℃; the holding time is preferably 6~15h, specifically 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, or 15h; the calcination atmosphere is preferably oxygen; and the calcination is preferably carried out in a muffle furnace.

[0031] The present invention also provides a titanium-based composite material for a penholder grass template prepared by the preparation method described above. The titanium-based composite material for a penholder grass template has a three-dimensional tubular structure. The material forming the three-dimensional tubular structure includes a silica substrate and a titanium-based material loaded on the surface of the silica substrate in the form of a closely packed particle structure. The titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 ; The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

[0032] The present invention also provides the application of the titanium-based composite material of the grass template described in the above technical solution as a catalyst in the visible light catalytic degradation of organic matter.

[0033] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0034] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] Example 1 After washing 3-4 cm long *Plectranthus praecox* with water, it was soaked in a 50% glutaraldehyde solution for 24 hours to maintain the shape of the *Plectranthus praecox* template. After removal, it was washed with water to remove residual glutaraldehyde. Then, it was soaked in a 5% hydrochloric acid solution for 24 hours to remove soluble impurities. After removal, it was washed with water until neutral, and then dehydrated using a gradient concentration of ethanol solution and dried (specifically: first soaked in a 50% ethanol aqueous solution for 12 hours, then soaked in a 100% ethanol aqueous solution for 12 hours, and then dried for later use), to obtain pretreated *Plectranthus praecox*. After stirring and premixing 50 mL of isopropanol and 1.2 mL of tetrabutyl titanate for 5 min, add 1.584 mL of potassium fluoride solution with a mass concentration of 50 g / L. Stir the resulting solution for 15 min, add 2.0 g of the pretreated penholderia obtained above, sonicate for 60 min, and let stand for 24 h. The obtained mixture was transferred to a stainless steel high-pressure reactor with a polytetrafluoroethylene liner and reacted at 180°C for 24 hours. After cooling, the solid product was collected, washed alternately with deionized water and ethanol, and dried at 70°C for 12 hours. The dried material was placed in a muffle furnace and calcined at 450°C for 10 hours under an oxygen atmosphere to obtain a titanium-based composite material.

[0036] Example 2 The titanium-based composite material of the penholder grass template was prepared according to the method in Example 1, wherein the amount of potassium fluoride solution added was 1.045 mL.

[0037] Example 3 The titanium-based composite material of the penholder grass template was prepared according to the method in Example 1, wherein the amount of potassium fluoride solution added was 0.517 mL.

[0038] Example 4 The titanium-based composite material of the grass template was prepared according to the method in Example 1, wherein the amount of potassium fluoride solution added was 0.103 mL.

[0039] Example 5 50 mL of isopropanol and 1.2 mL of tetrabutyl titanate were stirred and premixed for 5 min. 1.0 mL of glycerol was added and stirred for 15 min. 2.0 g of the pretreated penholderia obtained in Example 1 was added, and the mixture was sonicated for 60 min and allowed to stand for 24 h. 1.045 mL of potassium fluoride solution with a mass concentration of 50 g / L was added and the mixture was sonicated for 30 min. The obtained mixture was transferred to a stainless steel high-pressure reactor with a polytetrafluoroethylene liner and reacted at 180°C for 24 hours. After cooling, the solid product was collected, washed alternately with deionized water and ethanol, and dried at 70°C for 12 hours. The dried material was placed in a muffle furnace and calcined at 450°C for 10 hours in an oxygen atmosphere to obtain the titanium-based composite material of the penholder grass template.

[0040] Example 6 The titanium-based composite material of the penholder grass template was prepared according to the method in Example 5, wherein the amount of glycerol added was 2 mL.

[0041] Example 7 The titanium-based composite material of the penholder grass template was prepared according to the method in Example 5, wherein the amount of glycerol added was 4 mL.

[0042] Example 8 The titanium-based composite material of the penholder grass template was prepared according to the method in Example 5, wherein the amount of glycerol added was 6 mL.

[0043] Comparative Example 1 The composite material was prepared according to the method of Example 2, without the addition of penholderia.

[0044] Comparative Example 2 The composite material was prepared according to the method of Example 1, wherein the amount of potassium fluoride solution added was 0.

[0045] Comparative Example 3 1.2 mL of tetrabutyl titanate was dropped directly onto a petri dish, covered with plastic wrap, holes were poked in it, and the dish was placed on a table. After 24 hours, the material was scraped off and placed in a muffle furnace for calcination at 450°C for 10 hours to obtain the hydrolyzed titanium-based material.

[0046] Comparative Example 4 The composite material was prepared according to Example 1, wherein no penholderia was added and the amount of potassium fluoride solution added was 0.

[0047] Performance testing Figure 1 The images show the XRD patterns of the composite materials obtained in Comparative Examples 1, 2, and 6, where BKFG2 is from Example 6, BKF1.0 is from Example 2, and KF1.0 is from Comparative Example 1. This characterization indicates that when potassium fluoride is added, the composite material, in addition to anatase titanium dioxide, also exhibits K... 1.28 Ti8O 16 and K2Ti6O 13 Furthermore, the subsequent addition of penneadolite biotemplate and glycerol does not change the crystal form.

[0048] Figure 2 This is a TEM image of the titanium-based composite material with a grass-like template obtained in Example 2. This characterization shows that when potassium fluoride is added, anatase titanium dioxide and K2O are produced. 1.28 Ti8O 16 and K2Ti6O 13 The related lattice fringes can corroborate this. Figure 1 Crystal form results in XRD.

[0049] Figure 3 This is a TEM image of the titanium-based composite material with a grass-like template obtained in Example 6. This characterization shows that anatase and K+ appear when potassium fluoride and glycerol are added. 1.28 Ti8O 16 and K2Ti6O 13 The related lattice fringes can corroborate the attached... Figure 1 Crystal form results in XRD.

[0050] Figure 4 The image shown is a TEM image of the composite material obtained in Example 2. This characterization indicates that after the addition of the *Pentacarum cuspidatum* biotemplate, a large number of amorphous silicon regions appeared on the surface of the material. This can correspond to the significant increase in the specific surface area of ​​the catalyst on the one hand, and the enhanced adsorption performance of the catalyst on the other hand.

[0051] Figure 5 XPS spectra of the composite materials obtained in Comparative Examples 1, 2, and 6 are shown. BKFG2 is from Example 6, BKF1.0 is from Example 2, and KF1.0 is from Comparative Example 1. These spectra show that after adding the high-silicon-content *Plectranthus praecox* biotemplate, a large amount of Si element appeared in the material. The presence of SiO2 peaks can also be found in the O spectrum. The Ti / Si ratio of each catalyst was obtained by processing the XPS data. It can be seen that the ratio increased after the addition of glycerol, proving that glycerol effectively increased the proportion of TiO2 and further improved the degradation activity.

[0052] Figure 6 The following data represent the BET specific surface area, pore volume, and pore size of the composite materials obtained in the examples and comparative examples. In these examples, BKFG2 is Example 6, BKF1.0 is Example 2, BKF1.0 is Comparative Example 1, BKF1.5 is Example 1, BKF0.5 is Example 3, BKF0.1 is Example 4, BKF0 is Comparative Example 2, BKFG1 is Example 5, BKFG4 is Example 7, and BKFG6 is Example 8. It can be seen that the addition of the high-silica *Plectranthus praecox* biotemplate significantly increases the specific surface area of ​​the composite material. However, the addition of glycerol further reduces the specific surface area and pore size. This corresponds to the increased Ti / Si ratio in XPS, resulting in the formation of more titanium dioxide and a reduction in the area of ​​amorphous silicon.

[0053] Test Example 2 The composite materials obtained in the examples and comparative examples were used as catalysts to verify their degradation performance against tetracycline. Plotting the standard curve: Accurately weigh 0.0214 g of TCH standard into a 250.00 mL volumetric flask, and dilute to volume with ultrapure water to obtain a TCH stock solution with a concentration of 84.80 mg / L. Take 0.00, 1.00, 2.00, 4.00, 8.00, 16.00, 32.00, and 64.00 mL of the stock solution into 100.00 mL volumetric flasks, and dilute to volume with ultrapure water to obtain TCH solutions with concentrations of 0.00, 0.856, 1.712, 3.424, 6.848, 13.696, 27.392, and 54.784 mg / L, respectively. Plot a standard curve with the TCH standard concentration (mg / L) as the ordinate and the chromatographic peak area as the abscissa. Calculate the regression equation: y = 0.04001x + 0.24114, R0 2 The result was 0.99993, indicating that the TCH standard curve exhibited good linearity within the concentration range of 0.000–54.784 mg / L.

[0054] High-performance liquid chromatography (HPLC) detection method; chromatographic column: Agilent ZORBAX SB-C18 reverse-phase column (4.6). 250 mm, 5 μm); (A) Mobile phase: phosphate buffer (NaH2PO4-H3PO4); (B) acetonitrile; Mobile phase ratio: 83:17, gradient elution, the mobile phase ratio changed to 68:12 after 15 min; Injection volume: 50.00 μL; Flow rate: 1.0 mL / min; Detection wavelength: 350 nm; Column temperature: 40 °C; 20 mg of catalyst was added to a quartz reactor containing 50 mL of tetracycline hydrochloride solution with a concentration of 40 ppm. After stirring and reacting in the dark for 60 min under light-protected conditions to reach adsorption equilibrium, the reactor was irradiated with a 10 W LED white light source. Samples were taken at regular intervals, and after filtering out the catalyst, the residual concentration of the pollutants was analyzed by high performance liquid chromatography. The ratio of the residual concentration to the initial concentration was the residual rate.

[0055] Figure 7 The composite materials obtained in Examples 1-4 and Comparative Example 2 were subjected to photocatalytic degradation of tetracycline under 10W LED white light. BKF1.5 was Example 1, BKF1.0 was Example 2, BKF0.5 was Example 3, BKF0.1 was Example 4, and BKF0 was Comparative Example 2. This series of composite materials has a certain adsorption effect. After 60 minutes of light exposure, the composite material obtained in Example 2 showed the best effect.

[0056] Table 1. Removal rate of tetracycline by the composite materials obtained in Examples 1-4 and Comparative Example 2

[0057] Figure 8 The composite materials obtained in Example 2 and Comparative Examples 1, 3, and 4 were used for photocatalytic degradation of tetracycline under 10W LED white light. KF1.0 was Comparative Example 1, BKF1.0 was Example 2, Hydrolysis was Comparative Example 3, and BT was Comparative Example 4. Compared with Example 2, this series of composite materials had poor adsorption effect. After 60 minutes of light exposure, the removal rate of tetracycline was generally low.

[0058] Table 2. Removal rate of tetracycline by the composite materials obtained in Example 2 and Comparative Examples 1, 3, and 4

[0059] Figure 9Examples 5-8 illustrate the photocatalytic degradation of tetracycline by the composite materials obtained under 10W LED white light. BKFG1 is from Example 5, BKFG2 from Example 6, BKFG4 from Example 7, and BKFG6 from Example 8. Due to the strong adsorption performance of the catalysts, control groups were set up for each material under complete dark reaction conditions, denoted as D, where L represents the catalyst undergoing normal light-induced reaction after the dark reaction. This series of composite materials exhibits stronger adsorption effects; after 30 minutes of light exposure, the composite material obtained in Example 6 showed the best results.

[0060] Table 3. Removal rate of tetracycline by the composite materials obtained in Examples 5-8

[0061] Test Example 3 20 mg of the composite material was added to a quartz reactor containing 50 mL of 40 ppm tetracycline hydrochloride solution. After stirring and reacting in the dark for 60 min under light-protected conditions until adsorption equilibrium was reached, the reactor was irradiated with a 10W LED white light source. Samples were taken periodically, and after filtering to remove the catalyst, the residual concentration of the pollutants was analyzed by high-performance liquid chromatography (HPLC). The ratio of the residual concentration to the initial concentration was taken as the residue rate. Acute toxicity tests for E. coli were conducted on degradation solutions collected at different reaction times. Figure 10 The results of the acute toxicity test of the composite material obtained in Example 6 for Escherichia coli show that, when using Escherichia coli as the test strain, the toxicity of the degradation solution gradually decreases with increasing degradation time.

[0062] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a titanium-based composite material with substructure tunable penholder grass template, characterized in that, Includes the following steps: A titanium source, an alcohol solvent, penneading grass, and additives are mixed and subjected to a solvothermal reaction to obtain a precursor; the additives include potassium fluoride or a mixture of potassium fluoride and glycerol. The precursor is calcined to obtain the titanium-based composite material of the pen holder grass template; The titanium-based composite material of the pen holder grass template has a three-dimensional tubular structure. The material forming the three-dimensional tubular structure includes a silica substrate and a titanium-based material loaded on the surface of the silica substrate, which has a closely packed particle structure. The titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 ; The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

2. The preparation method according to claim 1, characterized in that, The titanium source includes at least one of tetrabutyl titanate and tetraisopropyl titanate; The alcohol solvent includes at least one of isopropanol and polyethylene glycol; The length of the grass in the pen holder is 3-4 cm.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the *Pencilia purpurea* to the amount of titanium source is 0.1~100g:0.1~6mL; The potassium fluoride is added in the form of a potassium fluoride solution, and the mass concentration of the potassium fluoride solution is 1~100g / L; When the additive is potassium fluoride, the mass ratio of the penholder grass to potassium fluoride is 0.1~100:0.005~0.08; When the additive is a mixture of potassium fluoride and glycerin, the mass ratio of the herb to potassium fluoride is 0.1~100:0.005~0.08; the dosage ratio of the herb to glycerin is 0.1~100g:1~6mL.

4. The preparation method according to claim 1, characterized in that, Before mixing, the grass in the pen holder is also pretreated; The pretreatment includes: washing the grass with water, soaking it in glutaraldehyde solution and hydrochloric acid solution in sequence, washing it with water again, dehydrating it with ethanol, and drying it. The mass concentration of the glutaraldehyde solution is 20-80%, and the soaking time in the glutaraldehyde solution is 6-36 hours. The mass concentration of the hydrochloric acid solution is 1-30%, and the soaking time in the hydrochloric acid solution is 6-36 hours.

5. The preparation method according to claim 1 or 3, characterized in that, When the additive is potassium fluoride, the mixing process includes: stirring and premixing the titanium source and alcohol solvent, adding potassium fluoride and stirring, then adding penholder grass and sonicating, and letting it stand; the stirring and premixing time is 1~60min; the stirring time is 1~60min; the sonication time is 0.5~3h; and the standing time is 6~48h.

6. The preparation method according to claim 1 or 3, characterized in that, When the additive is a mixture of potassium fluoride and glycerin, the mixing process includes: stirring and premixing the titanium source and the alcohol solvent, first adding glycerin and stirring, adding *Pendula officinalis* for a first sonication, letting it stand, and then adding potassium fluoride for a second sonication; the stirring and premixing time is 1~60 min; the stirring time is 1~60 min; the first sonication time is 0.5~3 h; the standing time is 6~48 h; and the second sonication time is 0.5~3 h.

7. The preparation method according to claim 1, characterized in that, The solvothermal reaction is carried out at a temperature of 100~200℃ for a time of 6~36h.

8. The preparation method according to claim 1, characterized in that, The calcination temperature is 300~600℃, and the holding time is 6~15h.

9. The titanium-based composite material with a grass template prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The titanium-based composite material of the pen holder grass template has a three-dimensional tubular structure. The material forming the three-dimensional tubular structure includes a silica substrate and a titanium-based material loaded on the surface of the silica substrate, which has a closely packed particle structure. The titanium-based material includes anatase titanium dioxide, K... 1.28 Ti8O 16 and K2Ti6O 13 ; The anatase titanium dioxide, K 1.28 Ti8O 16 and K2Ti6O 13 A ternary heterojunction is formed.

10. The application of the titanium-based composite material of the penholder grass template as described in claim 9 as a catalyst in the visible light catalytic degradation of organic matter.

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