Oxygen-deficient tungsten oxide WO with photodegradation and adsorption properties 2.72 Preparation method of nanospheres

Abstract

The present invention discloses oxygen-deficient tungsten oxide WO with photodegradation adsorption performance 2.72 The preparation method of nanospheres first uses urea to provide cations, which are embedded in tungsten oxide to form a non-stoichiometric compound ammonium tungsten bronze (NH4). 0.33 WO 3， The deionized water in the mixed solution provides OH ‑ roots, the cations NH4 in the pores + Capture precipitation, causing the valence of W to change from W 6+ Revert to W 5+ At the same time, during the synthesis process, alcohols are used as solvents, which provide 2.72 The required reaction medium, on the other hand, controls the growth and morphology of the product through its interaction with urea and deionized water to synthesize the final product WO 2.72 WO synthesized by the above method 2.72 It not only solves the problem of traditional synthetic WO 2.72 The agglomeration problem of the product can be solved, and by precisely controlling the synthesis conditions, the product morphology and size can be precisely regulated, thereby improving the adsorption and photodegradation properties of the product.

Description

Technical Field

[0001] The present invention belongs to the field of photocatalysis technology, and specifically relates to oxygen-deficient tungsten oxide (WO) with photodegradation and adsorption properties. 2.72 Preparation method of nanospheres. Background Art

[0002] Purple tungsten (oxygen-deficient tungsten oxide), (chemical formula WO 2.72 ) has excellent electrochemical properties, making it suitable for use as a negative electrode material in lithium batteries. Its high theoretical specific capacity, rapid ion transport rate, and large porosity allow it to extend battery range while also improving charge and discharge performance.

[0003] In addition, due to its excellent electrochromic and photochromic effects, as well as its strong absorption of electromagnetic waves, purple tungsten has become an important raw material for the preparation of dimming glass, which can give glass the ability to change color. At the same time, due to its excellent optical properties and strong absorption capacity in the near-infrared light region, purple tungsten can be used to prepare near-infrared photothermal diagnostic and therapeutic drugs, which has great application value in cancer treatment. In addition, purple tungsten also has excellent gas sensitivity and catalytic properties, which can accelerate the rate of chemical reactions and can be used to degrade related fuels. In general, purple tungsten oxide has many unique properties and broad application prospects, playing an important role in many fields.

[0004] Currently, there are related violet tungsten materials used for dye degradation. For example, patent publication number CN 102985178A discloses a method for preparing a copper-modified violet tungsten photocatalyst. This method involves mechanically grinding copper-ion-modified tungsten oxide particles using a solvent (preferably an organic solvent such as an alcohol). The resulting dispersion of ground particles is then exposed to oxygen or ozone to produce the catalyst. This method aims to improve photocatalytic activity, particularly under visible light. Drying the dispersion yields a photocatalyst powder with a diffuse reflectance of 75% or higher measured at a wavelength of 700 nm, demonstrating enhanced catalytic activity under visible light conditions. However, the copper-modified violet tungsten photocatalyst prepared by this method is difficult to achieve uniform mixing at the molecular level, potentially leading to localized excessively high or low copper concentrations, affecting overall catalytic performance and stability. The additional oxidation treatment required not only increases process complexity and production costs, but also may introduce additional impurities or cause unnecessary damage to the product structure. Furthermore, excessive grinding can lead to lattice distortion or amorphization, reducing the material's photocatalytic activity and selectivity.

[0005] In addition, patent number CN 104785275 A discloses a method for preparing a dispersion of copper-ion-modified tungsten oxide photocatalyst. This method uses a solution method to synthesize copper-doped violet tungsten powder in a single step. This method aims to introduce defect sites by doping with an appropriate concentration of copper, affecting the recombination of electrons and holes, thereby improving the photocatalytic effect. However, this method requires a high reaction temperature of 200°C, which is not only energy-intensive but can also lead to runaway reactions or unstable product structures. The resulting needle-like structures also have a small specific surface area and are prone to agglomeration, hindering the catalytic reaction. Furthermore, the resulting catalyst dispersion has a diameter of 30-200 nm, and this wide distribution of diameters can lead to unstable performance.

[0006] In addition, in the prior art, for WO 2.72 It is usually prepared by hydrothermal method, which involves using tungsten source and ethanol (or alcohols) to react at a specific time and temperature. However, this method has a major problem: the synthesized WO 2.72 The product is prone to agglomeration, which severely limits the performance of its physical functional properties, such as adsorption, photodegradation and photocatalysis. In order to overcome this limitation, it is usually necessary to convert WO 2.72 It can only play a specific functional property by being combined with other substances to form a composite material. 2.72 There are still flaws.

[0007] How to prepare WO that is not prone to agglomeration and has excellent adsorption and photodegradation properties for fuels 2.72 It is still an urgent problem to be solved. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention discloses oxygen-deficient tungsten oxide WO with photodegradation adsorption performance. 2.72 The preparation method of nanospheres is to prepare WO by precisely controlling the synthesis conditions. 2.72 , synthesized WO 2.72 The degree of agglomeration of the product can be significantly reduced, thereby effectively exploring its physical functional properties. The WO prepared by the present invention 2.72 It can be directly applied to environmental governance and energy conversion without relying on composite materials, thereby simplifying the production process, reducing costs, and improving the application efficiency of materials; in particular, the WO synthesized by the present invention 2.72 It exhibits excellent adsorption and photodegradation properties for dyes.

[0009] In order to achieve the above technical effects, the present invention is realized by the following technical solutions: oxygen-deficient tungsten oxide WO with photodegradation adsorption performance 2.72 The preparation method of nanospheres comprises the following steps:

[0010] S1: Dissolve the raw materials urea and tungsten chloride in anhydrous ethanol at a ratio of 0.08-0.1:0.8-1, and magnetically stir the mixed solution at 10°C-40°C until the raw materials are completely dissolved in the anhydrous ethanol. Then, titrate the dissolved solution with deionized water and continue magnetically stirring until the mixed solution becomes colorless and transparent.

[0011] S2: The mixed solution obtained in S1 is quickly poured into a polytetrafluoroethylene liner and then transferred into a hydrothermal reactor. The sealed reactor is placed in a drying oven and dried and kept warm for a period of time to perform a hydrothermal reaction to synthesize the product;

[0012] S3: After natural cooling, the precipitate is ultrasonically dispersed and centrifuged with deionized water. The washed product is dispersed in deionized water to form a dispersion. The dispersion is placed in a freeze dryer to remove the deionized water to directly obtain WO with high dispersibility. 2.72 ;

[0013] Furthermore, during the magnetic stirring in S1, the magnetic stirring rate is 100-500 rpm, the stirring time is 2-6 hours, the amount of deionized water added dropwise is 0.5-1.5 parts, and the amount of ethanol is 60-100 parts;

[0014] Furthermore, during the magnetic stirring in S1, the magnetic stirring rate was 300 rpm, the stirring time was 3 hours, the amount of deionized water added dropwise was 0.9 parts, and the amount of ethanol added dropwise was 80 parts;

[0015] Furthermore, during the drying in S2, the drying temperature is 100-250° C. and the holding time is 8-30 hours;

[0016] Furthermore, during the drying in S2, the drying temperature is 180° C. and the holding time is 18 hours;

[0017] Furthermore, in S3, the ultrasonic dispersion time is 5-20 min, the number of ultrasonications is 5-10 times, the centrifuge speed is 6000-10000 rpm, the number of centrifugations is 5-10 times, the temperature of the freeze dryer is -60°C-0°C, the air pressure in the freeze dryer is 0.1-5 Pa, and the freeze drying time is 10-48 hours.

[0018] The beneficial effects of the present invention are:

[0019] In the preparation process of the present invention, urea is first used to provide ammonium cations, which are embedded in tungsten oxide to form a non-stoichiometric compound ammonium tungsten bronze (NH4). 0.33 WO 3， The deionized water in the mixed solution provides OH - The root captures the ammonia cation and precipitates it, causing the valence of W to change from W 6+ Revert to W 5+At the same time, during the synthesis process, alcohols are used as solvents, which provide 2.72 The required reaction medium, on the other hand, controls the growth and morphology of the product through its interaction with urea and deionized water to synthesize the final product WO 2.72 WO synthesized by the above method 2.72 It not only solves the problem of traditional synthetic WO 2.72 The agglomeration problem of the product is solved, and by precisely controlling the synthesis conditions, the morphology and size of the product are precisely regulated, and the adsorption and photodegradation properties of the product are improved. The degradation rate of methylene blue dye is over 99%;

[0020] In addition, the WO prepared by the present invention 2.72 It can be directly applied to environmental governance and energy conversion without relying on composite materials, and the WO 2.72 It can be prepared again as WO before use 2.72， It can be recycled. This method not only simplifies the production process, but also effectively reduces costs through recycling under simple conditions and improves the application efficiency of materials. It has important scientific significance and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0022] Figure 1 The present invention synthesizes WO 2.72 Flowchart of nanospheres;

[0023] Figure 2 is the XRD pattern of the sample prepared by the preparation method of the present invention;

[0024] Figure 3 It is a SEM image of the sample prepared by the preparation method of the present invention.

[0025] Figure 4 It is a TEM image of the sample prepared by the preparation method of the present invention.

[0026] Figure 5 This is the XPS graph of the sample prepared by the preparation method of the present invention, in which a is oxygen-deficient tungsten oxide WO 2.72 Full spectrum, b is oxygen-deficient tungsten oxide WO 2.72 Oxygen element spectrum, c is oxygen-deficient tungsten oxide WO 2.72 Elemental spectrum of tungsten in tungsten.

[0027] Figure 6The present invention is a graph showing the degradation rate of methylene blue photodegradation and adsorption by a sample prepared by the preparation method of the present invention under different concentrations and lighting conditions. Graph d in the graph shows the degradation rate when the methylene blue solution concentration is 10 ml / L under darkroom, laboratory lighting, and xenon lamp lighting conditions; graph e shows the degradation rate when the methylene blue solution concentration is 30 ml / L under darkroom, laboratory lighting, and xenon lamp lighting conditions; and graph f shows the degradation rate when the methylene blue solution concentration is 50 ml / L under darkroom, laboratory lighting, and xenon lamp lighting conditions.

[0028] Figure 7 The sample prepared by the preparation method of the present invention is subjected to photodegradation and adsorption of methylene blue, and the solution after photodegradation and adsorption is obtained at different times, and then centrifuged to obtain UV-Vis-IR images of the transparent clear solution; the darkroom is shown in Figure g, the laboratory lighting is shown in Figure h, and the xenon lamp lighting is shown in Figure i.

[0029] Figure 8 It is an SEM picture of the sample prepared by the preparation method of the present invention and the sample obtained by titrating different amounts of deionized water.

[0030] Figure 9 The UV-Vis-IR graph is obtained by dispersing equal amounts of samples obtained by titrating different amounts of deionized water and measuring the optical properties of the samples.

[0031] Figure 10 The present invention is a preparation method of the sample obtained by titrating different amounts of deionized water, 100 ml of 50 mg / L methylene blue solution in a 2-hour photodegradation adsorption experiment showing the methylene blue removal rate bar graph.

[0032] Figure 11 The following is a graph showing the degradation rates of samples prepared by other preparation methods on 100 ml of 10 mg / L, 30 mg / L and 50 mg / L methylene blue solutions, respectively, under xenon lamp irradiation, and a 2-hour photodegradation adsorption tracking experiment.

[0033] Figure 12 50 mg of the sample prepared by the preparation method of the present invention is respectively used for 100 ml of 10 mg / L, 30 mg / L and 50 mg / L methylene blue solutions, and a removal rate graph of a methylene blue removal tracking experiment is performed for 2 hours under dark room conditions.

[0034] Figure 13 FTIR graph of the sample prepared by the preparation method of the present invention. DETAILED DESCRIPTION

[0035] Example 1

[0036] Oxygen-deficient tungsten oxide WO with photodegradation and adsorption properties 2.72The preparation method of nanospheres specifically comprises the following steps according to mass:

[0037] S1: Weigh 0.095 g of urea and 0.95 g of tungsten chloride into a 100 ml beaker, add 0.5-1.5 ml of deionized water, add 80 ml of anhydrous ethanol, and stir with a magnetic stirrer at a stirring rate of 300 rpm and a stirring temperature of 25°C for 3 hours until the solution becomes a transparent colorless liquid;

[0038] S2: Pour the mixed solution obtained in S1 into a 100 ml polytetrafluoroethylene liner, place the liner in a reactor, and perform a hydrothermal reaction in a drying oven at a reaction temperature of 180°C for 18 hours;

[0039] S3: After the reaction in S2 is complete, the temperature is naturally cooled to room temperature, the supernatant is extracted, and the blue-gray nano-product WO on the inner substrate is rinsed with 50 ml of deionized water. 2.72 Place the mixture in a 100 ml beaker and perform ultrasonic dispersion for 10 minutes. Centrifuge the dispersed solution for 3 minutes at a rate of 8000 rpm. Disperse the centrifuged product in 50 ml of deionized water and repeat the ultrasonic and centrifugal cycles for 3 times. The collected product is freeze-dried at a temperature of -45°C, a pressure of 0.5 Pa, and a time of 36 hours.

[0040] After the above experimental process, Figure 1 As shown, blue-grey oxygen-deficient tungsten oxide WO is finally obtained. 2.72 ; Figure 2 is the XRD pattern of the prepared sample, Figure 2 It can be seen that the WO synthesized by this patent 2.72 It is a single phase without other substance peaks; Figure 3 and Figure 4 It is the SEM image of the sample, showing the morphology, degree of agglomeration and size of the sample. Figure 3 and Figure 4 It can be seen that the blue-grey oxygen-deficient tungsten oxide WO prepared by this method 2.72 It is not agglomerated together, but in the form of dispersed particles. The specific surface area of ​​the dispersed particles will be significantly increased. The dispersed particles are not prone to precipitation or stratification during storage and use, and can maintain the uniformity and stability of the material, excellent catalytic performance, higher electrochromic performance, better optical properties, and higher theoretical specific capacity and ion transport rate.

[0041] Example 2

[0042] The blue-grey oxygen-deficient tungsten oxide WO prepared by the preparation method in Example 1 2.72The photodegradation adsorption performance test was carried out to further verify its actual degradation situation. The specific process is as follows:

[0043] Weigh 50 mg of the blue-gray oxygen-deficient tungsten oxide WO obtained by the above preparation process 2.72 Participate in each photodegradation adsorption performance test. The test light environment is divided into dark room, laboratory lighting and xenon lamp lighting. 50mg of sample is weighed and added to 100ml of methylene blue solution of different concentrations (10mg / L, 30mg / L, 50mg / L). At different time points during the photodegradation process, 4ml of the dispersion is extracted and centrifuged at a centrifugal speed of 10000rpm for 2 minutes. After centrifugation, the transparent clear solution is taken for optical property detection to determine the residual amount of methylene blue. The specific test results are as follows: Figure 6 、 7 As shown in the test results, it can be seen from the analysis that for 100ml of 10mg / L and 30mg / L methylene blue aqueous solutions, no matter the lighting conditions are darkroom, laboratory lighting or xenon lamp lighting, the blue-gray oxygen-deficient tungsten oxide WO 2.72 The removal rate of methylene blue within 5 minutes reaches more than 99%. For a 50 mg / L methylene blue aqueous solution, the removal rates of methylene blue within 2 hours under darkroom and laboratory lighting conditions are 83% and 85% respectively. The removal rate of methylene blue within 1 hour under xenon lamp lighting reaches more than 99%. This further illustrates the blue-gray oxygen-deficient tungsten oxide WO prepared by the present invention. 2.72 , improves the adsorption and photodegradation adsorption performance of the product; In addition, the WO prepared by the present invention 2.72 It can be directly applied to environmental governance and energy conversion without relying on composite materials, thereby simplifying the production process, reducing costs, and improving the application efficiency of materials.

[0044] Example 3

[0045] Based on the preparation method in Example 1, it was found during the synthesis experiment that the amount of deionized water in the mixed solution is very sensitive to the control of the nano-characteristics (agglomeration degree, morphology, and particle size) of the nano-product, and the change of the nano-characteristics can directly affect the optical properties of the nano-product, thereby changing the photodegradation adsorption performance of the nano-product in removing methylene blue;

[0046] In order to further verify the above process, specifically: oxygen-deficient tungsten oxide WO with photodegradation adsorption performance 2.72 The preparation method of nanospheres includes the following steps according to mass: dropping different amounts of deionized water 0.7ml, 0.8ml, 0.9ml, 1.0ml to obtain oxygen-deficient tungsten oxide WO with different nano characteristics 2.72 sample):

[0047] S1: Weigh 0.095 g of urea and 0.95 g of tungsten chloride into a 100 ml beaker, add 0.7 ml of deionized water, add 80 ml of anhydrous ethanol, and stir with a magnetic stirrer at a stirring rate of 300 rpm and a stirring temperature of 25°C for 3 hours until the solution becomes a transparent colorless liquid;

[0048] S2: Pour the mixed solution obtained in S1 into a 100 ml polytetrafluoroethylene liner, place the liner in a reactor, and perform a hydrothermal reaction in a drying oven at a reaction temperature of 180°C for 18 hours;

[0049] S3: After the reaction in S2 is completed, the temperature is naturally cooled to room temperature, the supernatant is extracted, and the blue-gray nano-product WO on the inner substrate is rinsed with 50 ml of deionized water. 2.72 The mixture was placed in a 100 ml beaker and ultrasonically dispersed for 10 minutes. The dispersed solution was centrifuged for 3 minutes at a rate of 8000 rpm. The centrifuged product was dispersed in 50 ml of deionized water and the ultrasonic and centrifugal cycles were repeated three times. The collected product was freeze-dried at a temperature of -45°C, a pressure of 0.5 Pa, and a time of 36 hours to obtain the first sample.

[0050] Similarly, S1: Weigh 0.095 g of urea and 0.95 g of tungsten chloride into a 100 ml beaker, add 0.8 ml of deionized water, add 80 ml of anhydrous ethanol, and stir with a magnetic stirrer at a stirring rate of 300 rpm and a stirring temperature of 25°C for 3 hours until the solution becomes a transparent colorless liquid;

[0051] S2: Pour the mixed solution obtained in S1 into a 100 ml polytetrafluoroethylene liner, place the liner in a reactor, and perform a hydrothermal reaction in a drying oven at a reaction temperature of 180°C for 18 hours;

[0052] S3: After the reaction in S2 is completed, the temperature is naturally cooled to room temperature, the supernatant is extracted, and the blue-gray nano-product WO on the inner substrate is rinsed with 50 ml of deionized water. 2.72 The mixture was placed in a 100 ml beaker and ultrasonically dispersed for 10 min. The dispersed solution was centrifuged for 3 min at a rate of 8000 rpm. The centrifuged product was dispersed in 50 ml of deionized water and the ultrasonic and centrifugal cycles were repeated three times. The collected product was freeze-dried at a temperature of -45 ° C, a pressure of 0.5 Pa, and a time of 36 hours to obtain a second sample.

[0053] In addition, in step 1 of the above steps, 0.9 ml and 1.0 ml of deionized water were titrated respectively, and the rest of the process was the same to obtain the third and fourth samples respectively;

[0054] The SEM images of the four samples mentioned above are as follows: Figure 8 As shown, Figure a shows that the amount of deionized water used in the synthesis of the sample is 0.7ml; Figure b shows that the amount of deionized water used in the synthesis of the sample is 0.8ml; Figure c shows that the amount of deionized water used in the synthesis is 0.9ml; and Figure d shows that the amount of deionized water used in the synthesis is 1.0ml. It can be seen from the figure that when the deionized water titration is 0.7ml and 0.8ml, the degree of agglomeration of the nanoparticles in the sample is very serious, the morphology of the nanoparticles is not obvious, and the particle size of the nanoparticles is in the range of 10nm to 80nm. When the deionized water titration is 0.9ml, the dispersion of the sample nanoparticles is significant, the morphology of the nanoparticles is nanospheres composed of nanoneedles, and the particle size of the nanoparticles is in the range of 50nm to 150nm. When the deionized water titration is 1.0ml, the dispersion of the sample nanoparticles is significant, and the morphology of the nanoparticles is nanospheres composed of nanoneedles. , the particle size of the nanoparticles is in the range of 150nm to 300nm; when the amount of deionized water is small (0.7ml and 0.8ml), although the particle size of the synthesized nanoparticle samples is small, the degree of agglomeration is serious and the morphology is not obvious. When the amount of deionized water is large (1.0ml), although the degree of agglomeration of the synthesized nanosamples is significantly reduced and they have a nanosphere morphology composed of nanoneedles, the particle size is too large. When the deionized water droplet is 0.9ml, the nano characteristics of the nanosamples in terms of dispersibility, morphology and particle size are more suitable without obvious defects.

[0055] In addition, if Figure 9 The optical properties of UV-Vis-IR graph show that the oxygen-deficient tungsten oxide WO synthesized by titrating 0.7ml, 0.8ml, and 1.0ml of deionized water during the synthesis process 2.72 The sample has no absorption peak in the visible light band (380nm~720nm), and the oxygen-deficient tungsten oxide WO synthesized by titrating 0.9ml of deionized water during the synthesis process 2.72 The sample has an absorption peak in the visible light band, which will increase the oxygen defect tungsten oxide WO 2.72 The sample's photodegradation adsorption performance on methylene blue; this comparison can further illustrate that it has a significant effect on the photodegradation adsorption performance of methylene blue when titrating 0.9 ml of deionized water.

[0056] Example 4

[0057] In this example, based on the titration of different amounts of deionized water in Example 3, the photodegradation adsorption performance of the sample was further tested. The specific steps and process of the test were the same as those described in Example 2, except that the content of deionized water used was different. The specific results are shown in FIG. Figure 10 As shown, oxygen-deficient tungsten oxide WO with different nano features and optical properties was synthesized by titrating different amounts of deionized water (0.7 ml, 0.8 ml, 0.9 ml, 1.0 ml). 2.72 50 mg of each sample was dispersed in 100 ml of 50 mg / L methylene blue solution. The dispersion was subjected to a photodegradation experiment for 1 hour under xenon lamp illumination. During this period, the dispersion was sampled at intervals to perform a photodegradation experiment on methylene blue. The photodegradation methylene blue removal rate bar graph shows (as shown in the figure). Figure 10 ), Figure 10 The lighting conditions in the figure are xenon lamp lighting. The purple column is a 0.7 ml deionized water volume for the synthesized sample, the green column is a 0.8 ml deionized water volume for the synthesized sample, the pink column is a 0.9 ml deionized water volume for the synthesized sample, and the blue column is a 1.0 ml deionized water volume for the synthesized sample. Oxygen-deficient tungsten oxide WO was synthesized by titrating 0.7 ml, 0.8 ml, and 1.0 ml deionized water during the synthesis process. 2.72 The removal rates of methylene blue by the samples within 1 hour were all less than 70%, namely 49%, 52% and 65% respectively. The oxygen-deficient tungsten oxide WO synthesized by titrating 0.9 ml of deionized water during the synthesis process was 2.72 The removal rate of methylene blue by the sample reached more than 99% within 1 hour.

[0058] In summary, in the synthesis of oxygen-deficient tungsten oxide WO 2.72 In the experiment, the tungsten oxide WO prepared by this method 2.72 It has very good photodegradation adsorption performance. When the content of deionized water is 0.9 ml, it has more excellent photodegradation adsorption performance. When used as a catalytic degradation agent, it is a better choice to titrate it with a volume of 0.9 ml.

[0059] In this embodiment, in order to highlight the oxygen deficiency of tungsten oxide WO 2.72 The superiority of the photodegradation adsorption performance of the nanospheres was compared with other materials in a 2-hour methylene blue solution photodegradation adsorption tracking experiment. The photodegradation adsorption experiments of other material samples were carried out under the illumination conditions of a xenon lamp. The oxygen-deficient tungsten oxide WO synthesized by this method 2.72The nanosphere samples were subjected to photodegradation adsorption. The illumination conditions used in the experiment were dark room (no light). Similarly, 50 mg of sample was taken, and photodegradation adsorption experiments were performed on 100 ml of 10 mg / L, 30 mg / L and 50 mg / L methylene blue, respectively. The dispersion, sampling and detection steps were consistent with Example 2 and will not be described in detail here.

[0060] For other material samples, the photodegradation adsorption methylene blue removal rate graph was obtained, such as Figure 11 As shown in the figure, the illumination conditions were xenon lamp irradiation. The dispersion was stirred for 2 hours, and the dispersion was continuously sampled at intervals to measure the methylene blue removal rate of the samples at different concentrations at different times. The yellow column corresponds to a 10 mg / L methylene blue solution, the sky blue column corresponds to a 30 mg / L methylene blue solution, and the pink column corresponds to a 50 mg / L methylene blue solution. As can be seen from the figure, the maximum methylene blue removal rates of the other material samples in solutions of different concentrations within 2 hours under xenon lamp irradiation were 63%, 52%, and 41%, respectively, corresponding to concentrations of 10 mg / L, 30 mg / L, and 50 mg / L.

[0061] Figure 12 This is a graph showing the removal rate of methylene blue by photodegradation of the samples prepared in the present invention. The lighting condition is a dark room (no light). The yellow column corresponds to a 10 mg / L methylene blue solution, the blue column corresponds to a 30 mg / L methylene blue solution, and the red column corresponds to a 50 mg / L methylene blue solution. 2.72 In a dark room (without light), the nanosphere sample can remove methylene blue by more than 99% (within 5 minutes), more than 99% (within 5 minutes) and 80% (within 1 hour) within 2 hours, respectively. The corresponding concentrations are 10 mg / L, 30 mg / L and 50 mg / L. From the three aspects of light conditions, removal rate and removal time, the oxygen-deficient tungsten oxide WO synthesized by this method is 2.72 The nanosphere samples have significant advantages in the photodegradation adsorption performance of removing methylene blue.

[0062] The reasons can be found based on the FIRT diagram analysis, specifically, Figure 13 As shown, at 605cm -1 and 803cm -1 The two correspond to WO 2.72 The bridge bond WOW vibration and oxygen vacancy-induced WO vibration are caused by freeze drying. 2.72 There are water molecules and hydroxyl groups (OH) on the surface, which appear at 1642 cm -1 and 3443cm -1 These water molecules and hydroxyl groups can provide more active sites, which will help to enhance the WO 2.72The photocatalytic activity of methylene blue can more efficiently generate free radicals with strong oxidizing ability (such as ·OH and ·O2 - ), these free radicals can effectively attack and decompose organic pollutants; at the same time, water molecules and hydroxyl groups are polar molecules, which can interact with the polar groups in the methylene blue molecules through hydrogen bonds, enhancing the WO 2.72 Adsorption capacity of methylene blue and photodegradation products.

[0063] Example 5

[0064] In this embodiment, the oxygen-deficient tungsten oxide WO with better performance obtained in Example 3 is specifically provided. 2.72 Treatment of water sources contaminated by methylene blue and treatment of used WO 2.72 The desorption recycling method specifically comprises the following steps:

[0065] S1: First determine the concentration of methylene blue in the contaminated water source by spectrophotometer. If it is less than 50ml / L, use WO 2.72 The concentration in the solution is 25mg / L. If it is higher than 50ml / L, use WO 2.72 The concentration in the solution is 50 mg / L. The corresponding WO is taken according to the amount of sewage to be treated. 2.72 amount.

[0066] S2: WO determined according to S1 2.72 The amount of the methylene blue was weighed, dispersed in deionized water, and the dispersion was poured into a nanofiltration membrane for sealing, and then put into a water source pool contaminated by methylene blue.

[0067] Generally, water samples are taken every 2.5 hours during the day (8:00-18:00) and every 5 hours at night (20:00-6:00). The sampling interval can be adjusted according to the concentration change of methylene blue. The absorbance corresponding to the characteristic wavelength is measured by spectrophotometer until the concentration of methylene blue in the water source drops to the level of the added WO 2.72 If the removal limit meets the discharge requirements, the adsorption and photodegradation of methylene blue will be stopped. If it does not meet the requirements, the WO2-containing solution will be added to the polluted water source. 2.72 Nanofiltration membranes for deionized water dispersions.

[0068] S3: According to S2, the used WO 2.72 Desorption and recovery treatment was performed; the amount of used WO2.72 desorbed each time did not exceed 3 g, and the amount of all solvents used was 100 ml.

[0069] Desorption recovery is divided into 3 steps:

[0070] 1) First, use no more than 3g of used WO 2.72 Place in 100 ml of deionized water for 30 min ultrasonic dispersion, and then magnetically stir for 4 h to make WO 2.72 The attachments on WO were dissolved in deionized water. 2.72 Desorption was performed, and the above steps were repeated twice, followed by centrifugation at 8000 rpm, and the aqueous solution after centrifugation was collected, and WO was recovered at the same time. 2.72 ;

[0071] 2) Next, the WO recovered by centrifugation 2.72 Disperse it again in 100 ml of deionized water and add 50 times of sodium chloride to make the sodium ions react with WO 2.72 The attached substances on the WO are exchanged by ion exchange, and the displaced adsorbents are dissolved in deionized water to achieve the purpose of WO 2.72 Continuous desorption, wherein the desorption steps are: ultrasonic dispersion, magnetic stirring, centrifugal recovery. The specific parameters are the same as above, the number of cycles is 2, and the solution after centrifugation is continuously collected and WO is recovered. 2.72 ;

[0072] 3) Again, the WO recovered by centrifugation 2.72 Dispersed in 100 ml of organic solvent ethanol, make ethanol to WO 2.72 Dissolve the attachments on WO 2.72 Further desorption is performed, wherein the desorption steps are as above and will not be repeated here.

[0073] After the desorption step, the collected solution after centrifugation is finally heated to remove the solvent, and the obtained methylene blue and the photodegraded material are calcined to remove the adsorbent; the desorbed WO 2.72 Dispersed in deionized water and freeze-dried, the freeze-dried WO 2.72 It can be used again to treat water sources contaminated by methylene blue. It can not only adsorb and remove the contaminated water, but also remove it with high efficiency. Under normal test conditions, it can achieve high efficiency removal, up to 99% or more. At the same time, it can be recycled, which can greatly save resources and realize the recycling of resources.

[0074] Based on the above examples 1-4, the oxygen-deficient tungsten oxide WO synthesized by the present invention has photodegradation adsorption performance. 2.72 The oxygen-deficient tungsten oxide WO synthesized by the method of the present invention is prepared by controlling the growth and morphology of the product through the interaction of the raw material tungsten chloride with urea and deionized water by hydrothermal synthesis. 2.72 It not only solves the problem of traditionally synthesized oxygen-deficient tungsten oxide WO 2.72The agglomeration problem is solved, and by precisely controlling the synthesis conditions, the morphology and size of the product are precisely controlled, and the adsorption and photodegradation properties of the product are improved; in order to make the synthesized oxygen-deficient tungsten oxide WO 2.72 The excellent nano features of the synthesis are maintained in terms of agglomeration, morphology and dispersion, thereby maximizing the adsorption and photodegradation properties of the product. This method abandons the conventional drying and grinding method to collect WO 2.72 make wo 2.72 Agglomeration increased, and WO was collected by freeze-drying 2.72 Achieve WO 2.72 The retention and improvement of various excellent properties; the WO synthesized by this method with significant adsorption and photodegradation properties 2.72 The repeated recycling and thus reducing the cost of use are crucial to its practical application prospects. This method designs the desorption steps to remove WO in deionized water, sodium chloride solution and ethanol respectively. 2.72 The adsorbed methylene blue and photodegraded substances are desorbed layer by layer, and finally the desorbed WO 2.72 It maintains the original surface properties and nano features, thereby maintaining good adsorption and photodegradation properties, and can be directly applied to environmental governance and energy conversion without relying on composite materials, thereby simplifying the production process, reducing costs, and improving the application efficiency of the material. It has important scientific significance and application value.

[0075] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the invention to only the specific implementation methods described.

Claims

1. Oxygen-deficient tungsten oxide WO with photodegradation and adsorption properties 2 .72 The method for preparing nanospheres is characterized in that: The following steps are involved: S1: dissolving tungsten chloride and urea in anhydrous ethanol at a ratio of 0.08-0.1:0.8-1, and subjecting the mixed solution to magnetic stirring at 10°C-40°C until the raw materials are completely dissolved in the anhydrous ethanol. Then, the dissolved solution is titrated with deionized water and magnetic stirring is continued until the mixed solution becomes colorless and transparent. During the magnetic stirring, the magnetic stirring rate is 300 rpm, the stirring time is 3 hours, and the amount of deionized water added is 0.9 parts and the amount of ethanol added is 80 parts. S2: The mixed solution obtained in S1 is quickly poured into a polytetrafluoroethylene liner and then transferred into a hydrothermal reactor. The sealed reactor is placed in a drying oven and dried and kept warm for a period of time to perform a hydrothermal reaction to synthesize the product; S3: After natural cooling, the precipitate is ultrasonically dispersed and centrifuged with deionized water. The washed product is dispersed in deionized water to form a dispersion. The dispersion is placed in a freeze dryer to remove the deionized water to directly obtain WO with high dispersibility. 2 .72 .

2. The oxygen-deficient tungsten oxide WO having photodegradation adsorption performance according to claim 1 2 .72 The method for preparing nanospheres is characterized in that: During the drying in S2, the drying temperature is 100-250° C. and the heat preservation time is 8-30 hours.

3. The oxygen-deficient tungsten oxide WO having photodegradation adsorption performance according to claim 1 2 .72 The method for preparing nanospheres is characterized in that: During the drying in S2, the drying temperature is 180° C. and the heat preservation time is 18 hours.

4. The oxygen-deficient tungsten oxide WO having photodegradation adsorption performance according to claim 1 2 .72 The method for preparing nanospheres is characterized in that: In S3, the ultrasonic dispersion time is 5-20 min, the number of ultrasonications is 5-10 times, the centrifuge speed is 6000-10000 rpm, the number of centrifugations is 5-10 times, the temperature of the freeze dryer is -60°C-0°C, the air pressure in the freeze dryer is 0.1-5 Pa, and the freeze drying time is 10-48 hours.

5. The oxygen-deficient tungsten oxide (WO) having photodegradation adsorption performance according to any one of claims 1 to 4 2 .72 Preparation method of nanospheres to prepare oxygen-deficient tungsten oxide WO 2 .72 Application in environmental governance and energy conversion.

6. The use according to claim 5, characterized in that The following steps are involved: S1: First determine the concentration of methylene blue in the contaminated water source by spectrophotometer. If it is lower than 50 mg / L, the WO 2.72 The concentration in the solution is 25 mg / L; if it is higher than 50 mg / L, the WO 2.72 The concentration in the solution is 50 mg / L. The corresponding WO is taken according to the amount of sewage to be treated. 2.72 the amount; S2: WO determined according to S1 2.72 The amount of the product was weighed, dispersed in deionized water, and the dispersion was poured into a nanofiltration membrane for sealing, and then placed into a water source pool contaminated with methylene blue; S3: According to S2, the used WO 2.72 Desorption and recovery treatment is carried out; each time the used WO 2.72 The amount of desorption does not exceed 3g, and the amount of all solvents used is 100ml; the desorption recovery mainly includes the following steps: S3.1: Used WO 2.72 Place in 100 ml of deionized water for 30 min ultrasonic dispersion, and then magnetically stir for 4 h to make WO 2.72 The attachments on WO were dissolved in deionized water. 2.72 Desorption was performed, and the above steps were repeated twice, followed by centrifugation at 8000 rpm, and the aqueous solution after centrifugation was collected, and WO was recovered at the same time. 2.72 ; S3.2: WO recovered by centrifugation 2.72 Disperse it again in 100 ml of deionized water and add 50 times of sodium chloride to make the sodium ions react with WO 2.72 The attached substances on the WO are exchanged by ion exchange, and the displaced adsorbents are dissolved in deionized water to achieve the purpose of WO 2.72 Continuous desorption; S3.3: Centrifuge the recovered WO again 2.72 Dispersed in 100 ml of organic solvent ethanol, make ethanol to WO 2.72 Dissolve the attachments on WO 2.72 Further desorption is performed; S4: WO 2.72 Recycling; after 3 desorption, the WO 2.72 Dispersed in deionized water, freeze-dried, freeze-dried at -45 °C, 0.5 Pa pressure, freeze-dried for 36 hours, and collected after desorption. 2.72 , to be used again for photodegradation adsorption of the dye methylene blue.

7. The use according to claim 6, characterized in that In the S2, the water source is sampled every 2.5 hours during the day and every 5 hours at night. The sampling interval can be adjusted according to the concentration change of methylene blue; the absorbance corresponding to the characteristic wavelength is measured by a spectrophotometer until the concentration of methylene blue in the water source drops to the concentration of the added WO 2.72 If the removal limit meets the discharge requirements, the adsorption and photodegradation of methylene blue will be stopped; if it does not meet the requirements, the WO2-containing solution will be added to the polluted water source. 2.72 Nanofiltration membranes for deionized water dispersions.

8. The use according to claim 6, characterized in that In S3.2 and S3.3, the desorption steps are: ultrasonic dispersion, magnetic stirring, and centrifugal recovery. The specific parameters are the same as those in S3.1, and the number of cycles is 2. The solution after centrifugation is continuously collected and the used WO is recovered. 2.72 .

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