WO3-x, preparation method thereof, 3D printing self-supporting membrane and membrane reactor

Abstract

The invention relates to WO3-x, a preparation method thereof, a 3D printing self-supporting membrane and a membrane reactor. The WO3-x nano material with abundant W < 5 + > active sites and ordered oxygen vacancy defects is successfully prepared by accurately regulating and controlling solvothermal reaction conditions and an innovative OA / OLA mixed ligand system. According to the invention, a direct writing (DIW) 3D printing technology is innovatively adopted, and the three-dimensional self-supporting film is successfully constructed. An efficient, stable and economical solution is provided for water environment antibiotic pollution treatment, and a new thought is opened up for design and manufacturing of novel functional materials. The comprehensive performance index and the application potential are obviously superior to those of the prior art, and industrial application can be carried out. Furthermore, the technology can be applied to the fields of sewage treatment, medical wastewater treatment and the like, and is beneficial to environmental protection and public health.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection technologies, and particularly relates to a WO 3-x and its preparation method, a 3D printed self-supporting membrane, and a membrane reactor. Background Art

[0002] In recent years, fluoroquinolone antibiotics (such as ciprofloxacin, CIP) have been widely used in the medical and livestock industries due to their broad-spectrum antibacterial properties. However, the problem of their environmental residues has become increasingly severe. Therefore, the development of efficient and economical CIP removal technologies has become an urgent need for environmental governance. Among various treatment technologies, the adsorption method has attracted much attention due to its advantages such as simple operation and significant cost-effectiveness. However, existing adsorption materials still have obvious limitations. Traditional adsorbents (such as activated carbon, AC) have the problem of low regeneration efficiency (the desorption rate is only 16.9%); although nanocomposites (such as Fe3O4 / GO) have the advantage of magnetic recovery, their synthesis cost is relatively high. More critically, existing adsorption mechanisms mainly rely on physical interactions (such as van der Waals forces, π-π interactions), which are easily interfered by environmental pH and ionic strength. Although chemical adsorption (such as covalent bonding) has high stability, its practical application is limited by high activation energy. Therefore, the development of new adsorption materials with high adsorption capacity, excellent selectivity, and environmental adaptability is the key challenge in current research.

[0003] In recent years, tungsten oxide (WO 3-x ) nanomaterials have shown significant advantages in the field of pollutant treatment due to their unique physical and chemical properties: (1) Abundant surface hydroxyl groups and adjustable electronic structures provide active sites for pollutant adsorption; (2) The multivalent properties of tungsten elements (W4 + / W6 + ) can enhance the specific binding with organic pollutants through coordination; (3) Compared with traditional nanomaterials, WO 3- x has better cost-effectiveness and environmental compatibility. However, powdered WO 3-x faces two major challenges in practical applications: (1) Suspended catalysts are difficult to recover efficiently; (2) There is a potential environmental leakage risk of nanoparticles. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the deficiencies in the prior art. The three-dimensional self-supporting membrane material constructed by 3D printing technology can effectively overcome the limitations of traditional materials, providing a new strategy for realizing efficient and customizable water treatment membrane materials. Further combined with relevant structural characterizations, the key role of surface coordination groups of the material is systematically revealed, providing theoretical guidance for the design of high-performance adsorption materials.

[0005] To achieve the above object, The present invention first provides a WO 3-xNanomaterials, WO 3-x The nanomaterials are linear nanomaterials.

[0006] Preferably, the linear nanomaterials have a length of 7 nm to 15 nm and a width of 1 nm to 3 nm.

[0007] The present invention provides a preparation method of defective WO 3-x which includes the following steps: S1: Measure oleic acid and oleylamine respectively, and mix them to obtain solution A; the volume ratio of oleic acid to oleylamine is 20:5 to 20:1; S2: Weigh tungsten chloride and add it to solution A, and add absolute ethanol thereto, and ultrasonically stir to obtain solution B; the proportion of absolute ethanol is controlled at 10% - 50% of the total volume; S3: Add absolute ethanol to solution B again to obtain solution C; the proportion of absolute ethanol is controlled at 10% - 50% of the total volume; S4: React solution C under the condition of 150 °C to 240 °C, and obtain a specific type of product according to the reaction time, and cool to obtain a reaction solution; S5: Wash and dry to obtain a sample, named WO 3-x nanomaterials.

[0008] Preferably, the reaction time in S4 is 6 h, that is, WO 3-x - 6 h is obtained.

[0009] Preferably, in S1: Measure 20 mL of oleic acid and 2 mL of oleylamine and put them into a 100 mL beaker, and mix evenly to obtain solution A; S2: Weigh 0.397 g of tungsten chloride and add it to solution A, and add 5 mL of absolute ethanol thereto, and ultrasonically stir for 15 - 30 min to obtain solution B; S3: Add 5 mL of absolute ethanol to solution B again to obtain solution C; S4: Transfer solution C to a 50 mL polytetrafluoroethylene-lined bottle, then transfer it to a 50 mL reaction kettle, place it in a blast drying oven, react at 180 °C for 1 h, 6 h or 12 h, and then naturally cool to room temperature to obtain a reaction solution; S5: Centrifuge and wash the reaction solution with absolute ethanol for 3 - 5 times, discard the supernatant, and dry it overnight at 60 °C in a vacuum drying oven to obtain a sample, named WO 3-x .

[0010] The present invention also provides a 3D printed nanoscale defective WO 3-x self-supporting film, which includes based on WO 3-xA membrane structure formed by 3D printing, where the WO 3-x is prepared by the above method.

[0011] Preferably, the material for printing further includes an auxiliary binder, such as attapulgite powder and cellulose powder. The mass ratio of the WO 3-x to the auxiliary binder is 1:1 to 1:10. The WO 3-x is mixed with attapulgite powder and then used for 3D printing.

[0012] The present invention also provides a method for preparing a 3D printed nano-defective WO 3-x self-supporting membrane, which includes the following steps: S1: Dissolve WO 3-x in water under stirring to obtain solution A; S2: Add the auxiliary binder to solution A and stir until a uniform slurry state is obtained; S3: Construct and form by a 3D printing strategy; S4: After printing, cure the overall structure; S5: Heat the cured overall structure in a muffle furnace at 300 to 500 °C to obtain a 3D printed three-dimensional self-supporting membrane.

[0013] Preferably, it includes the following steps: S1: Weigh 5.0 g of WO 3-x , dissolve it in 50 mL of deionized water under stirring, and sonicate for 1.5 - 2.0 h to obtain solution A; S2: Weigh 45 g of attapulgite powder, gradually add it to solution A under mechanical stirring, and gradually stir until a uniform slurry state is obtained; S3: Use an integral adsorbent to construct and form by a direct writing printing strategy; S4: After printing, cure the overall structure at 25 °C for 24 h; S5: Heat the cured overall structure in a muffle furnace at a heating rate of 5 °C / min to 400 °C, and hold for 240 min to obtain a 3D printed three-dimensional self-supporting membrane.

[0014] The 3D printed nano-defective WO 3-x self-supporting membrane is used for the selective removal of fluoroquinolone antibiotics.

[0015] The present invention also provides a membrane reactor, which includes: A reaction vessel, divided into an upper space and a lower space, and the above 3D printed three-dimensional self-supporting membrane is between the upper space and the lower space; A back pressure valve, connected to the upper space; A liquid inlet is arranged on one side of the upper space, and the liquid inlet is used for inputting a liquid to be treated to remove fluoroquinolone antibiotics. A liquid outlet is arranged on one side of the lower space, and the liquid outlet is used for discharging the purified liquid.

[0016] Preferably, the top of the upper space is a quartz glass window, one side of the lower space has an observation window, and one side of the lower space has an air outlet; the air outlet is used to connect to a vacuum pump externally.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: In terms of material design and preparation, by precisely controlling the solvothermal reaction conditions and the innovative OA / OLA mixed ligand system, the present invention successfully prepares WO 5+ nanomaterials with abundant W 3-x active sites and ordered oxygen vacancy defects. XPS analysis confirms that in the optimized WO 3-x material, the proportion of W 5+ sites is relatively high, enabling it to exhibit excellent adsorption performance for fluoroquinolone antibiotics such as ciprofloxacin, with a removal rate of over 95%. Through systematic TEM, XRD, and FTIR characterization and analysis, it is found that the oxygen vacancy defects and specific surface functional groups formed in the material are the key structural features for achieving efficient adsorption.

[0018] In terms of material structure design and manufacturing process, the present invention innovatively adopts the direct ink writing (DIW) 3D printing technology to successfully construct a three-dimensional self-supporting membrane. This breakthrough design not only fully retains the active sites of the nanomaterials but also effectively solves the industry problem of the difficult recovery of nano-powder materials in practical applications. This unique structural design enables the material to simultaneously meet the dual requirements of efficient adsorption and easy engineering application.

[0019] The successful development of this technology not only provides an efficient, stable, and economical solution for the treatment of antibiotic pollution in water environments but also opens up new ideas for the design and manufacturing of new functional materials. Its comprehensive performance indicators and application potential are significantly superior to the prior art and can be applied industrially. Further, this technology can be applied in fields such as sewage treatment and medical wastewater treatment, which is beneficial to environmental protection and public health. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 Schematic diagram of the synthesis steps of the samples of Examples 1-3 of the present invention; Figure 2 TEM images of the samples of Examples 1-3 of the present invention; Figure 3 XRD patterns of the samples of Examples 1-3 of the present invention; Figure 4 FTIR spectra of the samples of Examples 1-3 of the present invention; Figure 5 XPS spectra of the samples of Examples 1-3 of the present invention; Figure 6 Adsorption performance diagrams of the samples of Examples 1-3 of the present invention; Figure 7 Schematic diagram of the membrane reactor of the sample of Example 4 of the present invention; Figure 8 is Figure 7 Schematic diagram of the internal structure after cross-section in Figure 9 Structure of the sample of Example 4 of the present invention and its membrane reactor's CIP removal performance diagram. Detailed implementation manners

[0022] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] Reagents and instruments Reagents: Cyclohexane (C6H 12 ) and absolute ethanol (C2H6O) were purchased from Sinopharm Chemical Reagent Co., Ltd. (China). Tungsten chloride (WCl6), oleic acid (OA), oleylamine (OLA), and ciprofloxacin (CIP) were purchased from Aladdin (Shanghai, China). Attapulgite was purchased from Xuyi Xingchen Molecular Sieve Co., Ltd. All chemical reagents used in the experiments were of analytical grade and were not further purified. Deionized water was used in all experimental processes.

[0024] Instruments: Transmission electron microscope (TEM, Talos F200X G2), X-ray diffractometer (XRD, Bruker Vertex 80V), Fourier transform infrared spectroscopy (FTIR, Thermo Fisher Scientific), X-ray photoelectron spectroscopy (XPS, Thermo Scientific Escalab OXi), scanning electron microscope (SEM, JEOL JSM-7800F).

[0025] Example 1

[0026] Defective WO for selective removal of fluoroquinolone antibiotics 3-x (1h)'s preparation method includes the following steps: S1. Measure 20 mL of oleic acid (OA) and 2 mL of oleylamine (OLA) respectively and put them into a 100 mL beaker, mix evenly to obtain solution A; S2. Weigh 0.397 g of tungsten chloride (WCl6) and add it to solution A, and add 5 mL of absolute ethanol to it, stir ultrasonically for 15 - 30 min to obtain solution B; S3. Add another 5 mL of absolute ethanol to solution B to obtain solution C; S4. Transfer solution C to a 50 mL polytetrafluoroethylene - lined bottle, then transfer it to a 50 mL reaction kettle, place it in a forced - air drying oven, react at 180 °C for 1 h, and then naturally cool to room temperature to obtain a reaction solution; S5. Centrifuge and wash the reaction solution with absolute ethanol 3 - 5 times, discard the supernatant, and then dry it overnight at 60 °C in a vacuum drying oven to obtain a sample, named WO 3-x (1 h).

[0027] Example 2

[0028] The defective WO for selective removal of fluoroquinolone antibiotics in this example 3-x (6 h)'s preparation method is basically the same as that of Example 1, and the difference is that: the reaction heat time described in S4 is 6 h.

[0029] Example 3

[0030] The defective WO for selective removal of fluoroquinolone antibiotics in this example 3-x (12 h)'s preparation method is basically the same as that of Example 1, and the difference is that: the reaction heat time described in S4 is 12 h.

[0031] Example 4

[0032] The method for 3D printing to construct a three - dimensional self - supporting membrane includes the following steps: S1. Weigh 5.0 g of WO 3-x (6 h), dissolve it in 50 mL of deionized water under stirring, and ultrasonicate for 1.5 - 2.0 h to obtain solution A; S2. Weigh 45 g of attapulgite powder, and gradually add it to solution A under mechanical stirring, and gradually stir until it becomes a uniform slurry state; S3. Use a monolithic adsorbent and adopt a direct writing (DIW) printing strategy for construction and molding; S4. After printing, cure the monolithic structure at 25 °C for 24 h; S5. Heat the cured monolithic structure in a muffle furnace to 400 °C at a heating rate of 5 °C / min and hold for 240 min to obtain a 3D-printed three-dimensional self-supporting membrane.

[0033] Attapulgite powder is used as an auxiliary binder. In other embodiments, the auxiliary binder can also be cellulose powder or other suitable materials.

[0034] 1. Analyze the synthesis of WO 3-x (1 h), WO 3-x (6 h) and WO 3-x (12 h) materials prepared in Examples 1 to 3: Figure 1 Outlined are the synthesis routes of i.) WO 3-x (1 h); ii.) WO 3-x (6 h) and iii.) WO 3-x (12 h). The synthesis process uses a solvothermal method and successfully prepares WO with oxygen vacancies through multi-step coordinated regulation 3-x nanomaterials. First, the mixed system of OA and OLA not only acts as a non-polar solvent and surfactant, and the synergistic coordination of its carboxyl and amino groups can effectively regulate the nucleation of nanocrystals. At the same time, the reducibility of OLA promotes the partial reduction of W 6+ to low-valent tungsten. Subsequently, the added WCl6 precursor undergoes a coordination exchange with the ligand to form a tungsten-carboxylate complex, laying a structural foundation for the subsequent crystal phase formation. The experiment innovatively adopts an ethanol stepwise addition strategy: the first addition initiates the reduction reaction and promotes the dissolution of the precursor, and vigorous stirring is used to ensure the uniformity of the reaction; when the system shows a characteristic dark blue color (indicating the local surface plasmon resonance effect caused by oxygen vacancies), ethanol is added for the second time to further regulate the polarity of the reaction system and the surface passivation of nanocrystals. The final solvothermal process realizes the controllable growth of crystals in a closed high-pressure environment. The high-temperature condition not only promotes the desorption of lattice oxygen to form oxygen vacancies but also regulates the reaction kinetics to make the defect structure orderly distributed, thereby obtaining WO with a stable non-stoichiometric ratio 3-x nanomaterials.

[0035] 2. Characterize the WO 3-x (1 h), WO 3-x (6 h) and WO 3-x (12 h) materials prepared in Examples 1 to 3: 2.1 Material Characterization: Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were used to characterize the materials. Among them, TEM was used to analyze the morphology and microstructure of the samples; XRD was used to analyze the chemical structure of the samples; FTIR was used to analyze the surface groups of the samples, and XPS spectra were further used to analyze and confirm the component elements and element states.

[0036] 2.2 Results and Discussion (1) Transmission Electron Microscopy (TEM) From Figure 2 the TEM images, it was found that the growth process of WO 3−x was from points to lines, and there was a situation of ablation after reaching a certain length. The length of WO 3−x (6 h) ( Figure 2 b) was significantly longer than that of WO 3−x (1 h) ( Figure 2 a) and WO 3−x (12 h) ( Figure 2 c), which may affect the adsorption performance of the material. In terms of diameter, with the extension of time, the diameter of the nanowires became shorter, indicating that there might be a quantum confinement effect. And with the extension of time, the variation range of the particle diameter of WO 3−x gradually became smaller, indicating a more uniform distribution of nanowires. These particle size differences have an important impact on the specific surface area and pore structure of the material, and thus affect its adsorption performance. The larger length and better dispersion of WO 3−x (6 h) may provide more adsorption sites, which is beneficial to improving the adsorption efficiency and stability. Therefore, WO 3−x (6 h) is a more preferred scheme. Specifically, the range of this preferred scheme is WO 3−x (6 h ± 1h).

[0037] From the TEM results, the WO 3-x nanomaterials obtained in this invention are linear nanomaterials. And preferably, the length of the linear nanomaterials is 7 nm to 15 nm, and the width is 1 nm to 3 nm.

[0038] (2) The XRD was used to analyze the phase structure of the samples, with Cu target Kα radiation, a scanning speed of 7° min −1 , a scanning angle of 10° - 60°, and a scanning step of 0.07°.

[0039] Figure 3 The XRD patterns of the samples in Examples 1 to 3 of this invention are shown. All samples have two typical characteristic peaks of W 18 O 49 , and well maintain the W 18 O 49The basic crystal structure. The original W 18 O 49 There are diffraction peaks at 23.5° and 48.2° in WO which correspond to the (010) and (020) crystal planes respectively. The (010) crystal plane reflects the layered arrangement characteristics of the crystal along the b-axis direction, and the (020) crystal plane is the second-order diffraction peak of the (010) crystal plane, further confirming the layered characteristics of the crystal structure. It can be seen from the spectrum that the diffraction peak intensity of WO 3−x (6 h) is the highest, indicating that at this reaction time, the crystallinity of the material is the best, the crystal structure is complete and the orderliness is strong, which provides the possibility for better adsorption performance. At the same time, compared with the original diffraction angle, the diffraction angles of the synthesized materials are all smaller, indicating that the oxygen vacancies in the materials increase, resulting in lattice expansion and an increase in the crystal plane spacing.

[0040] (3) Fourier transform infrared spectroscopy FTIR Figure 4 This is the FTIR spectrum of the samples in Examples 1 to 3 of the present invention. The peaks in the spectral region of 1000 - 400 cm −1 are all typical vibrations of WO 3−x including the bending vibration of O−W−O at 726 cm −1 and the stretching vibration of W−O−W at 819 cm −1 as well as the bending vibration of O=W at 925 cm −1 These results confirm the formation of the WO 3−x nanostructure. The absorption peak at 1605 cm −1 belongs to the bending vibration of −OH, which can prove the existence of W−OH. The absorption at 1605 and 1465 cm −1 can also be attributed to the stretching vibration of C=O and the bending vibration of C−O. The broad peak at 3676 cm −1 is caused by the stretching vibrations of O−H and N−H bonds and may be related to the oleic acid and oleylamine remaining on the catalyst surface. These results indicate that there are oxygen-containing functional groups attached to the surface of the prepared WO 3−x nanostructure, which is beneficial to the dispersion of the nanostructure in water or ethanol media.

[0041] (4) X-ray photoelectron spectroscopy XPS By Figure 5 This is the XPS spectrum of the samples in Examples 1 to 3 of the present invention. The O 1s and W 4f spectra are as shown in Figure 5 a, 5b. Figure 5 In a, the peaks at binding energies (BE) of 530.53, 530.00, and 529.77 eV are attributed to WO 3−x (1 h), WO 3−x (6 h), and WO 3−x(12 h) of lattice oxygen, the peaks at 531.12, 530.68, and 529.51 eV are attributed to chemisorbed oxygen species. Among them, the adsorbed oxygen of WO 3−x (6 h) has the highest proportion, which provides the possibility for improving the adsorption performance of the catalyst. In the W 4f spectrum ( Figure 5 b), the four curve peaks correspond to the core levels of W 6+ and W 5+ cations, W(4f 5 / 2) and W(4f 7 / 2). Taking WO 3−x (6h) as an example, the binding energy peaks observed at 37.35 and 35.42 eV are consistent with the binding energy peaks of W 6+ , while the peaks at 36.27 and 34.16 eV are attributed to the presence of W 5+ . As the reaction time prolongs, the peak positions of the W(4f 5 / 2) and W(4f 7 / 2) photoelectron lines shift to lower binding energies. Among them, the proportion of W 3−x in WO 5+ (6 h) is the highest, which provides the possibility for the catalyst to have more sites for adsorption. However, it can be calculated that the energy separation between the W 3−x peak and the W 6+ peak of WO 5+ has no obvious difference, which indicates that WO 3−x does not have a phase shift due to different reaction times. This characterization also shows that WO 3−x (6 h) and ±1h are the preferred options.

[0042] 3. Adsorption performance tests were carried out on the WO 3-x (1 h), WO 3-x (6 h), and WO 3-x (12 h) materials prepared in Examples 1 to 4 and the 3D-printed three-dimensional self-supporting membrane. The specific experimental process is as follows: Weigh a certain mass of ciprofloxacin standard product and dissolve it in deionized water to prepare a ciprofloxacin aqueous solution with a concentration of 10 mg / L as the working solution; Weigh 30 mg of WO 3-x (1 h), WO 3-x (6 h), and WO 3-x(12 h) The material was placed in a 100 mL three-necked flask. 50 mL of a 10 mg / L ciprofloxacin aqueous solution was added thereto, and these solutions were respectively placed in a constant temperature water bath at 298 K, 308 K, and 318 K. After reaching equilibrium, the solution was centrifuged, and the residual concentration of CIP (ciprofloxacin) was analyzed using ultraviolet spectrophotometry. The batch kinetics study was similar to the adsorption experiment, and water samples were collected at predetermined time intervals. At each time point, 3 mL of the solution was sampled, centrifuged to remove adsorbent particles, and then the absorbance of the supernatant was measured using a Shimadzu UV-2600 spectrophotometer with a wavelength of 272 nm. The adsorption efficiency of CIP ( E ) is calculated by the following formula: ; where, C 0 and C are the concentrations of the CIP solution before and after adsorption respectively, A 0 and A are the absorbance values of CIP before and after adsorption respectively.

[0043] For the 3D printed three-dimensional self-supporting membrane in Example 4, the performance test method was the same, except that a suction filtration device was used to make the membrane contact with the ciprofloxacin aqueous solution.

[0044] In the present invention, the adsorption performances of Examples 1 to 3 were investigated at three temperatures (25 °C, 35 °C, and 45 °C). As shown in Figure 6 a-c, the adsorption removal rates of WO 3-x (1 h), WO 3-x (6 h), and WO 3-x (12 h) for CIP all reached over 95%. In addition, it was found that within 0 - 30 min, due to more collisions between adsorption sites and the CIP solution, the adsorption amount increased rapidly. However, with the increase of adsorption time and the decrease of adsorption sites, the adsorption amount increased slowly. After 60 min of adsorption, the adsorption amount basically remained unchanged, indicating that the surface CIP completely occupied the adsorption sites.

[0045] Figure 7 And Figure 8 are the schematic diagrams of the membrane reactor for the sample of Example 4 of the present invention.

[0046] The membrane reactor includes a reaction vessel 10, which is divided into an upper space 11 and a lower space 12. Between the upper space 11 and the lower space 12 is the 3D printed three-dimensional self-supporting membrane 13 in the above-mentioned example; The back pressure valve 14 is connected to the upper space 11; The liquid inlet 15 is arranged on one side of the upper space 11, and the liquid inlet 15 is used to input the liquid to be treated to remove fluoroquinolone antibiotics; The liquid outlet 16 is arranged on one side of the lower space 12, and the liquid outlet 16 is used to discharge the purified liquid.

[0047] Preferably, the top of the upper space 11 is a quartz glass window 17, one side of the lower space 12 has an observation window 18, and one side of the lower space 12 has an air outlet 19. The air outlet 19 is used to connect to a vacuum pump externally, for controlling the pressure difference between the upper and lower layers and controlling the fluid flow rate.

[0048] Integrate the prepared 3D membrane material into the membrane reactor, control the internal pressure of the container through the back pressure valve 14 to adjust the reactor fluid flow parameters (such as flow rate, residence time, etc.), optimize the contact efficiency between the pollutant and the membrane surface, and ensure efficient mass transfer and adsorption performance; the reactor has the following advantages: ① Hydrodynamic design of the reaction liquid: By regulating the liquid flow rate and membrane porosity, improve the mass transfer efficiency of the reactants on the membrane surface; ② Modular design of the reactor: Facilitate the replacement and reuse of the membrane material, and can be extended for large-scale water treatment applications.

[0049] Figure 9 It is the structure of the sample of Example 4 of the present invention and the performance graph of the membrane reactor for removing CIP. As Figure 9 shown in a-c, it is found that after adding WO 3-x (6 h), the pore space in the 3D membrane is occupied, and the thickness of the WO 3-x (6 h) membrane is 8 µm. The experimental results show that the removal rate of ciprofloxacin (CIP) by this material can reach more than 95% after the secondary adsorption cycle, and the adsorption efficiency remains stable during multiple recycling processes, without obvious desorption phenomenon. This characteristic fully demonstrates the significant application potential and industrial promotion value of this three-dimensional self-supporting membrane in the removal of water pollutants.

[0050] Obviously, the above embodiments are merely examples given for clear illustration, and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A WO 3-x preparation method of a nanomaterial, characterized in that It includes the following steps: S1: Measure oleic acid and oleylamine respectively, and mix them to obtain solution A; the volume ratio of oleic acid to oleylamine is 20:5 to 20:1; S2: Weigh tungsten chloride and add it to solution A, and then add absolute ethanol thereto, and perform ultrasonic stirring to obtain solution B; the proportion of absolute ethanol is controlled at 10% - 50% of the total volume; S3: Add absolute ethanol to solution B again to obtain solution C; S4: React solution C under the condition of 150°C to 240°C to obtain a product, and obtain a reaction solution after cooling; S5: Dry after washing to obtain a sample, which is WO 3-x nanomaterials.

2. The WO according to claim 1 3-x The method for preparing the nanomaterial is characterized in that S1: Measure 20 mL of oleic acid and 2 mL of oleylamine respectively and put them into a 100 mL beaker, and mix them evenly to obtain solution A; S2: Weigh 0.397 g of tungsten chloride and add it to solution A, and then add 5 mL of absolute ethanol thereto, and perform ultrasonic stirring for 15 - 30 min to obtain solution B; S3: Add 5 mL of absolute ethanol to solution B again to obtain solution C; S4: Transfer solution C to a 50 mL polytetrafluoroethylene-lined bottle, then transfer it to a 50 mL reaction kettle, place it in a blast drying oven, react under the condition of 180°C for 1 h, 6 h or 12 h, and then naturally cool to room temperature to obtain a reaction solution; S5: Centrifuge and wash the reaction solution with absolute ethanol 3 - 5 times. After discarding the supernatant, dry it overnight at 60 °C in a vacuum drying oven to obtain a sample named WO 3-x .

3. A WO 3-x nanomaterial, characterized in that, Prepared by the method for preparing WO nanomaterials according to claim 1 or 2 3-x The WO nanomaterials are linear nanomaterials 3-x prepared by the method for preparing WO nanomaterials 4. The WO according to claim 3 3-x nanomaterial, characterized in that The length of the linear nanomaterial is 7 nm to 15 nm, and the width is 1 nm to 3 nm.

5. A 3D printed nano-scale defective WO 3-x self-supporting film, characterized in that, including a membrane structure formed by 3D printing based on WO 3-x The WO 3-x is the WO as described in any one of claims 3-4 3-x nanomaterials.

6. The 3D printed nano-defect type WO 3-x self-supporting film according to claim 5, characterized in that The material for printing further includes an auxiliary binder, and the mass ratio of the WO 3-x to the auxiliary binder is 1:1 to 1:

10.

7. The 3D printed nano-defect type WO 3-x self-supporting film according to claim 5 or 6, for use as a selective removal of fluoroquinolone antibiotics.

8. A method for preparing a 3D printed nano-defective WO 3-x self-supporting film, applicable to the 3D printed nano-defective WO as described in claim 5 or 6 3-x self-supporting film, characterized in that, It includes the following steps: S1: WO 3-x Dissolve it in water under stirring to obtain solution A by mixing; S2: Add an auxiliary binder to solution A and stir until it becomes a uniform slurry state; S3: Construct and form by a 3D printing strategy; S4: After printing, cure the overall structure; S5: Place the cured overall structure in a muffle furnace at 300 to 500°C to obtain a 3D printed three-dimensional self-supporting film.

9. A membrane reactor, characterized in that, It includes: The reaction vessel is divided into an upper space and a lower space, and between the upper space and the lower space is the 3D printed nano-defective WO described in claim 5 or 6 3-x self-supporting film; A back pressure valve, which is communicated with the upper space; An inlet, which is arranged on one side of the upper space, and the inlet is used to input the liquid to be treated to remove fluoroquinolone antibiotics; An outlet is arranged on one side of the lower space, and the outlet is used to export the purified liquid.

10. A membrane reactor according to claim 9, wherein The top of the upper space is a quartz glass window, one side of the lower space has an observation window, and one side of the lower space has an air outlet; the air outlet is used to connect an external vacuum pump.

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