阅读说明：本技术 一种波浪纹黑色TiO2微米管的制备方法 (Wavy black TiO2Preparation method of micron tube ) 是由 张艳华 黄竞 江艺萱 杨宏涛 肖巍 于 2021-09-22 设计创作，主要内容包括：一种波浪纹黑色TiO-(2)微米管的制备方法,包括波浪纹TiO-(2)微米管的制备和TiO-(2)的还原,所述波浪纹TiO-(2)微米管的制备是将聚乙二醇和异丙醇混合后加入盐酸,边搅拌边加入钛酸丁酯,持续搅拌2-6h,搅拌速率为40～60rpm,停止搅拌后,加入棉纤维,进行分段超声搅拌,然后依次洗涤和烘干棉纤维,最后将棉纤维在空气中煅烧得波浪纹TiO-(2)微米管。本发明制备的波浪纹黑色TiO-(2)微米管表面形貌规则,结构致密,Ti～(3+)和Ov随微米管的波浪形呈特定分布,具有优异的催化降解性能,在可见光下对亚甲基蓝的降解效率达到83.7%,催化稳定性优异。(Wavy black TiO 2 Preparation method of micron tube comprising raised grain TiO 2 Preparation of microtubes and TiO 2 By reduction of said wavy TiO 2 The preparation method of the micron tube comprises the steps of mixing polyethylene glycol and isopropanol, adding hydrochloric acid, adding butyl titanate while stirring, continuously stirring for 2-6 hours at the stirring speed of 40-60 rpm, adding cotton fibers after stopping stirring, carrying out sectional ultrasonic stirring, then sequentially washing and drying the cotton fibers, and finally calcining the cotton fibers in the air to obtain the wavy TiO (titanium dioxide) fiber 2 A micron tube. The wavy black TiO prepared by the invention 2 The micron tube has regular surface appearance, compact structure and Ti 3+ And Ov appears along with the wave shape of the micron tubeThe catalyst has the advantages of definite distribution, excellent catalytic degradation performance, degradation efficiency of methylene blue under visible light reaching 83.7%, and excellent catalytic stability.)

1. Wavy black TiO₂The preparation method of the micron tube is characterized by comprising the following steps: comprising raised grain TiO₂Preparation of microtubes and TiO₂By reduction of said wavy TiO₂The preparation method of the micron tube comprises the steps of mixing polyethylene glycol and isopropanol, adding hydrochloric acid, adding butyl titanate while stirring, continuously stirring for 2-6 hours at a stirring speed of 40-60 rpm, adding cotton fibers after stirring is stopped, carrying out ultrasonic and stirring alternating segmented ultrasonic stirring treatment, washing and drying the cotton fibers in sequence, and finally calcining the cotton fibers in air to obtain the wavy TiO (titanium dioxide) fiber₂A micron tube.

2. The wavy black TiO of claim 1₂The preparation method of the micron tube is characterized by comprising the following steps: the step of the segmented ultrasonic stirring treatment is to sequentially perform ultrasonic treatment on the mixed solution added with the cotton fibers for 20-30 min at room temperature, slowly stir the mixed solution for 20-30 min, then perform ultrasonic treatment for 20-30 min, and then perform ultrasonic treatment for 20-30 min.

3. A raised black TiO of claim 1 or 2₂The preparation method of the micron tube is characterized by comprising the following steps: the volume ratio of the polyethylene glycol to the isopropanol is 1: 1-5, and the volume ratio of the sum of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2.

4. A raised grain black TiO according to any one of claims 1 to 3₂The preparation method of the micron tube is characterized by comprising the following steps: the calcining temperature in the air is 600-700 ℃, and the calcining time is 3.5-5 h.

5. A raised grain black TiO as claimed in any one of claims 1 to 4₂Method for producing microtubesCharacterized in that: the TiO is₂The reduction is to make the wavy TiO₂Microtubes and NaHB₄Mixing and grinding the raw materials according to a molar ratio of 3:1-1:2, and then calcining the mixture in an Ar atmosphere.

6. The wavy black TiO of claim 5₂The preparation method of the micron tube is characterized by comprising the following steps: and calcining at 350-380 ℃ in the Ar atmosphere for 1.5-2 h.

7. Wavy black TiO₂The preparation method of the micron tube is characterized by comprising the following steps of:

(1) mixing polyethylene glycol and isopropanol according to a volume ratio of 1: 1-5, adding hydrochloric acid with a mass concentration of 37%, stirring while adding butyl titanate at 40-60 rpm, and continuously stirring for 2-6h, wherein the volume ratio of the total of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2;

(2) sequentially carrying out ultrasonic treatment on the mixed solution prepared in the step (1) at room temperature for 20-30 min, slowly stirring for 20-30 min, then carrying out ultrasonic treatment for 20-30 min, carrying out ultrasonic treatment for 20-30 min at normal temperature, standing for 10min, carrying out ultrasonic treatment for 20-30 min, washing the cotton fiber subjected to ultrasonic treatment with deionized water, and then drying at 40-100 ℃;

(3) placing the dried cotton fiber in an air atmosphere, and calcining for 3.5-5 h at 600-700 ℃ to obtain the wavy TiO₂A micron tube;

(4) forming raised grain TiO₂Microtubes and NaBH₄Mixing and grinding the materials according to a molar ratio of 3:1-1:2, calcining the materials for 1.5-2 hours at 350-380 ℃ in an Ar atmosphere, then cooling the materials to room temperature, and carrying out calcination on the wavy TiO₂The microtube was washed with deionized water and dried.

Technical Field

The invention belongs to the technical field of catalysis, and particularly relates to a wavy black TiO₂A preparation method of a micron tube.

Background

Photocatalysis is considered to be one of the best solutions for hydrogen generation from water by sunlight and organic pollutant removal from the environment, and at present, the commonly used photocatalyst is traditional anatase type TiO₂Material (white in appearance, hereinafter referred to as white titanium dioxide). However, their large band gap limits their activity in the visible region of the solar spectrum to a large extent, absorbing less than 5% of the ultraviolet light of sunlight, so that conventional white TiO materials₂Generally, the photocatalyst has good catalytic activity only under ultraviolet light, has almost no catalytic effect under visible light, has a fast electron hole recombination rate, and has a great limitation on the photocatalytic performance. Improvement of TiO₂The optical property of the material is improved, the absorption of the material in a visible light region is improved, and TiO is improved₂The photocatalytic activity of the material is of great significance. Defective TiO reported in recent years₂Nanomaterial (black in appearance, hereinafter referred to as black titanium dioxide, expressed as TiO)_2-x) The crystal structure is improved by introducing the lattice defect, so that the electronic energy level structure is optimized, the forbidden bandwidth is shortened, the absorption performance of visible light can be obviously improved, the utilization rate of sunlight is greatly improved, and the catalyst has an excellent catalytic effect in a visible light area, so that the catalyst attracts extensive attention of researchers.

With people to TiO₂The intensive research also synthesizes TiO with different morphologies₂Catalysts, e.g. spherical, wire, flake, tubular, rod, etc., due to TiO₂The different appearance characteristics of the TiO material show different properties, and the TiO materials with different appearance structures are determined₂The catalytic performance of (a) is also different. Therefore, TiO with the morphology promoting the catalytic performance under visible light is prepared₂Has great significance.

Disclosure of Invention

The invention aims to provide a wavy black TiO₂A preparation method of a micron tube. The methodThe TiO2 micron tube prepared by the method is in a regular wave-shaped structure and has excellent catalytic performance and catalytic stability under visible light.

The purpose of the invention is realized by the following technical scheme:

wavy black TiO₂The preparation method of the micron tube is characterized by comprising the following steps: comprising raised grain TiO₂Preparation of microtubes and TiO₂By reduction of said wavy TiO₂The preparation method of the micron tube comprises the steps of mixing polyethylene glycol and isopropanol, adding hydrochloric acid, adding butyl titanate while stirring, continuously stirring for 2-6 hours at a stirring speed of 40-60 rpm, adding cotton fibers after stopping stirring, carrying out ultrasonic and stirring alternating segmented ultrasonic stirring treatment, washing and drying the cotton fibers in sequence, and finally calcining the cotton fibers in air to obtain the wavy TiO₂A micron tube.

TiO with wavy texture structure prepared by adopting cotton ball fiber as template₂In the process of the micron tube, because the cotton fiber can not form a regular wavy pattern but a random wrinkle shape, TiO is caused₂Can not form regular wavy patterns, resulting in Ti in the subsequent reduction process³⁺And the introduction of Ov (oxygen vacancy) is hindered. Secondly, the hydrolysis degree of the butyl titanate is not easy to control, so that the adsorption uniformity of the cotton fiber to the hydrolysis product is poor, the finally formed micron tube structure is incomplete, and the structure is not completely formed in TiO₂In the gaps between, irregular TiO is formed₂The number and distribution of subsequently formed defects are influenced, and reduced TiO is caused₂The catalytic degradation efficiency of the micron tube is not high.

According to the invention, polyethylene glycol and isopropanol are mixed as an organic solvent, hydrochloric acid is adopted to adjust pH to slow down hydrolysis of butyl titanate, and simultaneously, isopropanol quickly swells cotton fibers in an acid environment, so that the cotton fibers are used as a template to form a regular wavy stripe shape, and hydrolysis products Ti (OH) are promoted under sectional ultrasonic stirring treatment₄Uniformly adsorbed on the surface of the template to form complete repeated engraving, and tightly and uniformly arranged, so that irregular TiO generated in gaps is reduced in the process of removing the template by calcination₂Structure, anaphase and NaHB₄Mixed reduction and introduction of Ti³⁺And Ov, compared to smooth, straight TiO₂TiO with regular wavy-grain structure for microtubes₂The specific surface knot of the micron tube is obviously improved, and Ti is enabled to be in the reduction process through the unfolded special wavy texture structure³⁺And Ov is unhindered and is Ti³⁺And introduction of Ov provides different sites of distribution, different positions of Ti³⁺And Ov, so that TiO₂In the crystal Ti⁴⁺And O^2-The arrangement of the catalyst is changed in different degrees, and finally the catalytic activity of the catalyst is improved.

Further, the step-by-step ultrasonic stirring treatment specifically comprises the steps of sequentially carrying out ultrasonic treatment on the mixed solution added with the cotton fibers at room temperature for 20-30 min, slowly stirring for 20-30 min, then carrying out ultrasonic treatment for 20-30 min, slowly stirring for 20-30 min, and then carrying out ultrasonic treatment for 20-30 min.

Further, the volume ratio of the polyethylene glycol to the isopropanol is 1: 1-5, and the volume ratio of the sum of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2.

The polyethylene glycol is preferably polyethylene glycol 400, and the mass concentration of the hydrochloric acid is 37%.

Further, the calcination temperature in the air is 600-700 ℃, and the calcination time is 3.5-5 h.

Further, the above TiO compound₂The reduction is to make the wavy TiO₂The micron tube and the NaHB4 are mixed and ground according to the molar ratio of 3:1-1:2, and then are calcined in an Ar atmosphere.

Further, the calcination temperature under the Ar atmosphere is 350-380 ℃, and the calcination time is 1.5-2 h.

Most specifically, the black TiO with wavy lines₂The preparation method of the micron tube is characterized by comprising the following steps of:

(1) mixing polyethylene glycol and isopropanol according to a volume ratio of 1: 1-5, adding hydrochloric acid with a mass concentration of 37%, stirring while adding butyl titanate at 40-60 rpm, and continuously stirring for 2-6h, wherein the volume ratio of the total of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2;

(2) carrying out ultrasonic treatment on the mixed liquid prepared in the step (1) at normal temperature for 20-30 min, then slowly stirring for 20-30 min, then carrying out ultrasonic treatment for 20-30 min, washing the cotton fibers subjected to ultrasonic treatment with deionized water, and then drying at 40-100 ℃;

(3) placing the dried cotton fiber in an air atmosphere, and calcining for 3.5-5 h at 600-700 ℃ to obtain the wavy TiO₂A micron tube;

(4) forming raised grain TiO₂Microtubes and NaBH₄Mixing and grinding the materials according to a molar ratio of 3:1-1:2, calcining the materials for 1.5-2 hours at 350-380 ℃ in an Ar atmosphere, then cooling the materials to room temperature, and carrying out calcination on the wavy TiO₂The microtube was washed with deionized water and dried.

The invention has the following technical effects:

the wavy black TiO prepared by the invention₂The micron tube has regular surface appearance, compact structure and Ti³⁺And the Ov is specifically distributed along with the wave shape of the micron tube, so that the catalyst has excellent catalytic degradation performance, the degradation efficiency of the catalyst on methylene blue under visible light reaches 83.7%, and the catalytic stability is excellent.

Drawings

FIG. 1: the invention prepares the wavy black TiO₂A preparation flow chart of the micron tube.

FIG. 2: the wavy black TiO prepared by the invention₂X-ray diffraction pattern of microtubes.

FIG. 3: the wavy black TiO prepared by the invention₂Raman spectrum of the microtube.

FIG. 4: the wavy black TiO prepared by the invention₂Scanning electron micrographs of microtubes.

FIG. 5: the wavy black TiO prepared by the invention₂Microtube absorbance and band gap width plots.

FIG. 6: the wavy black TiO prepared by the invention₂Micron tube catalytic efficiency graph.

Detailed Description

The present invention is described in detail below by way of examples, it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make some insubstantial modifications and adaptations of the present invention based on the above-mentioned disclosure.

Example 1

Wavy black TiO₂The preparation method of the micron tube comprises the following steps:

(1) mixing polyethylene glycol 400 and isopropanol according to a volume ratio of 1:1, adding hydrochloric acid with a mass concentration of 37%, stirring and adding butyl titanate at 50rpm, and continuously stirring for 6h, wherein the volume ratio of the total of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2;

(2) sequentially carrying out ultrasonic treatment on the mixed solution prepared in the step (1) at normal temperature for 20min, stirring at 40rpm for 20min, then carrying out ultrasonic treatment for 30min, stirring at 40rpm for 20min, then carrying out ultrasonic treatment for 20min, then washing with deionized water for 3 times, and drying at 40 ℃;

(3) placing the dried cotton fiber in an air atmosphere, and calcining at 700 ℃ for 4h to obtain the wavy TiO₂A micron tube;

(4) forming raised grain TiO₂Microtubes and NaBH₄Mixing and grinding according to the molar ratio of 1:2, calcining for 2 hours at 350 ℃ in Ar atmosphere, then cooling to room temperature, and calcining the wavy TiO₂The microtube was washed with deionized water and dried.

Example 2

Wavy black TiO₂The preparation method of the micron tube comprises the following steps:

(1) mixing polyethylene glycol 400 and isopropanol according to a volume ratio of 1:5, adding hydrochloric acid with a mass concentration of 37%, stirring and adding butyl titanate at 60rpm, and continuously stirring for 2h, wherein the volume ratio of the total of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2;

(2) sequentially carrying out ultrasonic treatment on the mixed solution prepared in the step (1) at normal temperature for 30min, stirring at 40rpm for 30min, then carrying out ultrasonic treatment for 20min, washing the cotton fibers subjected to ultrasonic treatment with deionized water, and then drying at 100 ℃;

(3) placing the dried cotton fiber in an air atmosphere, and calcining for 5 hours at 650 ℃ to obtain the wavy TiO₂A micron tube;

(4) forming raised grain TiO₂Microtubes and NaBH₄Mixing and grinding according to the molar ratio of 3:1, calcining for 1.5h at 380 ℃ in Ar atmosphere, then cooling to room temperature, and mixing the calcined wavy TiO₂The microtube was washed with deionized water and dried.

Example 3

Wavy black TiO₂The preparation method of the micron tube comprises the following steps:

(1) mixing polyethylene glycol 400 and isopropanol according to a volume ratio of 1:3, adding hydrochloric acid with a mass concentration of 37%, stirring and adding butyl titanate at 40rpm, and continuously stirring for 3h, wherein the volume ratio of the total of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2;

(2) sequentially carrying out ultrasonic treatment on the mixed liquid prepared in the step (1) at normal temperature for 25min, stirring at 40rpm for 20min, then carrying out ultrasonic treatment for 25min, stirring at 40rpm for 25min, then carrying out ultrasonic treatment for 25min, washing the cotton fibers subjected to ultrasonic treatment with deionized water, and then drying at 60 ℃;

(3) placing the dried cotton fiber in an air atmosphere, and calcining at 600 ℃ for 3.5h to obtain the wavy TiO₂A micron tube;

(4) forming raised grain TiO₂Microtubes and NaBH₄Mixing and grinding according to the molar ratio of 2:1, calcining for 2 hours at 360 ℃ in Ar atmosphere, then cooling to room temperature, and calcining the wavy TiO₂The microtube was washed with deionized water and dried.

Example 4

Wavy black TiO₂The preparation method of the micron tube comprises the following steps:

(1) mixing polyethylene glycol 400 and isopropanol according to a volume ratio of 1:3, adding hydrochloric acid with a mass concentration of 37%, stirring and adding butyl titanate at 40rpm, and continuously stirring for 3h, wherein the volume ratio of the total of the polyethylene glycol and the isopropanol to the hydrochloric acid to the butyl titanate is 20:1: 2;

(2) sequentially carrying out ultrasonic treatment on the mixed liquid prepared in the step (1) at normal temperature for 25min, stirring at 40rpm for 25min, then carrying out ultrasonic treatment for 25min, washing the cotton fibers subjected to ultrasonic treatment with deionized water, and then drying at 60 ℃;

(3) placing the dried cotton fiber in an air atmosphere, and calcining at 600 ℃ for 3.5h to obtain the wavy TiO₂A micron tube;

(4) forming raised grain TiO₂Microtubes and NaBH₄Mixing and grinding according to the molar ratio of 1:1, calcining for 2 hours at 360 ℃ in Ar atmosphere, then cooling to room temperature, and calcining the wavy TiO₂The microtube was washed with deionized water and dried.

From the XRD pattern, it can be seen that the crystal is NaHB₄After reduction, TiO₂The diffraction peak intensity of the compound (A) is reduced to different degrees, which indicates that the TiO is₂In the channel of NaHB₄After reduction, the crystallinity is reduced, and the reduced TiO_2-xThe half-width peak of (A) becomes broad, indicating that Ti is responsible for the reduction after the reduction³⁺And Ov, which causes a change in the grain size and thus a change in the crystal density. Using TiO in all figures_2-xIndicating the defective titanium dioxide after reduction treatment, the unreduced titanium dioxide is directly used as TiO₂Expressed by taking this as a distinction, wherein TiO_2-x-3:1 represents TiO₂With NaBH₄The molar ratio is 3:1, and so on.

It can be seen from the Raman plots that the peaks are at 146, 200, 400, 519, and 644 cm^–1Characteristic peaks at the position respectively correspond to anatase phase TiO₂Is/are as follows, , , Andvibration mode whereinTypical anatase titanium dioxide Ti-O-Ti bonds; TiO2_2-xIs/are as followsThe characteristic peak appears blue shift and the half-width peak is widened because the TiO with the wavy texture structure is reduced₂Ti of different positions on the surface³⁺And Ov, influence TiO₂In the crystal Ti⁴⁺And O^2-Varying the arrangement of (A) and (B) to varying degrees, and also Ti⁴⁺And O^2-The arrangement becomes compact.

FIG. 4 is a scanning electron micrograph, in which (a) shows a surface of a TiO with a wavy texture morphology prepared according to the present invention₂Microtubes, TiO₂A tubular structure with a diameter of 3-5 μm, wherein (b), (c) and (d) are TiO respectively₂With NaBH₄Reducing the mixture according to the ratio of 2:1-1:2 to obtain TiO_2-x。

The TiO can be calculated by integrating the oxygen vacancy curve_2-xIn (3:1-1:2), TiO₂With NaHB₄The molar ratios of 3:1, 2:1, 1:1 and 1:2, respectively, correspond to oxygen vacancy ratios of 31.8%, 44.7%, 45.9% and 56.2%, respectively, which indicates that the amount of oxygen vacancies increases with increasing ratio of the reducing agent. Ti 2p orbital presents Ti³⁺Peak of (2), proving TiO_2-xMiddle Ti³⁺By the presence of Ti³⁺The curve is integrated to calculate Ti³⁺Content, TiO_2-x(3:1-1:2) of Ti³⁺The proportions are 29.9%, 34.3%, 41.2% and 46.9%, respectively, indicating Ti³⁺The ratio of (a) increases with increasing ratio of reducing agent consistent with changes in oxygen vacancies.

As shown in FIG. 5, FIG. a shows the wavy patterns of TiO prepared according to the present invention₂Microtubes and nanotubes of NaHB₄The wavy black TiO prepared after reduction₂The ultraviolet-visible absorption spectrum of the microtube shows that the microtube is unreducedRaised grain TiO₂The microtube has a strong absorption of ultraviolet light, but hardly absorbs ultraviolet light in the visible light region and near infrared region. TiO2_2-x-3:1 vs. TiO₂The light absorption in visible light and near infrared region is obviously improved, and TiO is obviously improved along with the increase of the proportion of the reducing agent_2-xThe absorption intensity of the (3:1-1:2) to visible light is further improved, and TiO_2-xThe highest 1:1, and the decrease in the absorption intensity for visible light, not Ti, which is observed, occurs after a continuously increasing proportion of reducing agent³⁺And the higher the amount of Ov introduced, the better.

In the band gap width graph shown in the graph (b), TiO₂With NaHB₄Are 3:1, 2:1, 1:1 and 1:2, respectively, and the corresponding band gap widths are 2.8 eV, 2.3 eV, 2.4 eV and 2.5 eV, respectively, indicating that Ti is responsible for the difference in band gap width³⁺And Ov, an intermediate band is formed between the Valence Band (VB) and the Conduction Band (CB) to reduce the band gap width.

Testing the photocatalytic performance:

methylene Blue (MB) is used as a pollutant model, a 500W xenon lamp is used as a visible light source, ultraviolet light below 400 nm is filtered by a 400 nm optical filter, and a photocatalysis test is carried out in a photocatalysis instrument. 20 mg of catalyst was added to 50 mL of 60 mg/L methylene blue solution and dispersed by ultrasound to form a suspension, which was transferred to a quartz tube and placed in a reactor for dark adsorption. After adsorption and desorption balance for 30min, turning on a light source to perform photocatalytic reaction, taking out 3 mL of suspension every 30min, centrifuging, and testing the light absorption intensity of the degraded methylene blue solution in an ultraviolet-visible spectrophotometer.

Catalytic efficiency: TiO2_2-xThe degradation rates of (3:1-1:2) on Methylene Blue (MB) at 180min are respectively 48.5%, 50.6%, 83.7% and 49.2%, which are much higher than that of TiO before reduction in example 3₂Degradation rate of methylene blue (24.9%), as shown in FIG. 6, commercially available TiO was examined under the same conditions₂(P25), the degradation efficiency was only 9.2%.

Comparative example 1:

mixing 100mL of absolute ethyl alcohol and 5mL of hydrochloric acid, stirring uniformly, and adding absorbent cottonAdding 10mL of butyl titanate into the ball under continuous stirring, continuously stirring for 5h to fully hydrolyze the butyl titanate, continuously performing ultrasonic treatment for 1.5h, after complete hydrolysis, performing high-temperature calcination on the obtained gel at 600 ℃ for 3.5h, and then mixing with NaHB₄Mixing and grinding according to the molar ratio of 1:1, and calcining at 360 ℃ for 2 h.

Examination of the unreduced TiO prepared in comparative example 1 was carried out under the same conditions as described above₂Microtubes and nanotubes of NaHB₄TiO prepared after reduction treatment_2-xThe catalytic degradation efficiency of-1: 1 for methylene blue was 17.5% and 71.8%, respectively. TiO prepared by the method of comparative example 1₂The surface appearance of the prepared micron tube is in a corrugated state due to the fact that absolute ethyl alcohol is used as a solvent and continuous ultrasound is adopted for 1h in the ultrasound process, a completely unfolded regular wavy texture structure is not formed, the specific surface area is not obviously increased, and Ti in the reduction process of the micron tube is not obviously increased³⁺And a certain degree of hindrance by the introduction of Ov, which finally results in a less significant effect of improving the catalytic activity under visible light.

Comparative example 2

Different from the comparative example 1, the ultrasonic treatment adopts the step ultrasonic treatment of sequentially carrying out ultrasonic treatment for 25min at normal temperature, stirring for 25min at 40rpm, further carrying out ultrasonic treatment for 25min, stirring for 20min at 40rpm and further carrying out ultrasonic treatment for 20-30 min in the embodiment 3 instead of the continuous ultrasonic treatment for 1.5h in the comparative example 1, and the rest steps are consistent with the comparative example 1.

TiO prepared in comparative example 2_2-xThe degradation efficiency of methylene blue is 70.6% under the same conditions of the tube with the diameter of-1: 1 micron, and the influence on the final performance of the product is small by adopting continuous ultrasound and segmented ultrasound in the system of the comparative example.

Comparative example 3

Unlike example 3, the sonication process used continuous sonication for 1h, the remaining steps were consistent with example 3.

TiO prepared in comparative example 3_2-xThe degradation efficiency of methylene blue is 76.5% under the same conditions of the tube with the diameter of-1: 1 micron, and the final performance of the product is less influenced by using continuous ultrasound and segmented ultrasound in the system of the comparative example. Comparative example 3 degradation efficiency compared to example 3Obviously reduces, indicates that in the system of the invention, the cotton fiber forming the regular wave patterns is subjected to a step of sectional ultrasonic treatment, and the Ti (OH) on the surface of the template₄Has a significant impact on the adsorption, and the specific structure.