Full-spectrum response BiOBr / Bi2O3-x / WO3-x double-S heterojunction rich in oxygen vacancies and preparation method and application of full-spectrum response BiOBr / Bi2O3-x / WO3-x double-S heterojunction

Abstract

The invention discloses a full-spectrum response BiOBr / Bi2O3-x / WO3-x double-S heterojunction material rich in oxygen vacancy as well as a preparation method and application of the full-spectrum response BiOBr / Bi2O3-x / WO3-x double-S heterojunction material. The heterojunction is prepared by taking bismuth nitrate pentahydrate, potassium bromide and WO3-x microspheres containing oxygen vacancies as main raw materials through a wet impregnation method, and the value range of x in Bi2O3-x and WO3-x is 0 < = xlt; 1 represents that the two have oxygen vacancies with certain concentration. Due to the introduction of the wide-spectrum response semiconductor materials WO3-x and Bi2O3-x, the double-S-type heterojunction shows a remarkable full-spectrum absorption capability. Meanwhile, oxygen vacancies in the material can serve as effective electron capture centers and transmission channels, and separation of photo-induced electron-hole pairs is effectively promoted. Based on the synergistic coupling effect among BiOBr, Bi2O3-x and WO3-x, the heterojunction can degrade ciprofloxacin (CIP) and reduce Cr (VI) (85% and 74% respectively) at the same time. The heterojunction material provided by the invention is simple in preparation process and good in repeatability, and has important application potential in the field of environmental governance.

Description

Technical Field

[0001] This application belongs to the field of photocatalytic materials technology, and particularly relates to an oxygen-rich, vacancy-rich, full-spectrum responsive BiOBr / Bi2O 3-x / WO 3-x Preparation of double S-type heterojunctions and their application in the synergistic removal of antibiotic and hexavalent chromium complex pollutants in water. Background Technology

[0002] Antibiotics and heavy metal pollutants often coexist in wastewater. Due to the limited conditions of redox reactions (such as the difficulty in spontaneous reactions in strongly alkaline environments), achieving the simultaneous and efficient removal of antibiotics and Cr(VI) and their conversion into low-toxicity products remains a significant technological challenge. Therefore, there is an urgent practical need to develop novel treatment technologies capable of synergistically removing multiple pollutants from water.

[0003] Photocatalysis can couple the oxidation of antibiotics and the reduction of Cr(VI) into the same reaction system, making full use of photogenerated electrons and holes, and is considered a low-cost and environmentally sustainable water treatment solution. BiOBr, as a typical visible light responsive material, has shown some potential in antibiotic degradation and hexavalent chromium reduction. However, it has inherent defects such as fast photogenerated carrier recombination rate, low quantum efficiency, and weak utilization of near-infrared light, which seriously restrict its practical application performance. Although constructing S-type heterojunctions is considered one of the effective strategies to enhance its photocatalytic performance, the traditional single S-type heterojunction structure still has obvious shortcomings, such as: i) weak interaction between components and unsatisfactory multiphase integration effect; ii) the main response range is limited to the visible light region.

[0004] To overcome the aforementioned bottlenecks, a feasible strategy is to select semiconductor materials with photoresponse in the near-infrared region to construct a double S-type heterojunction with higher space charge separation efficiency and stronger redox potential. Based on this, this invention innovatively introduces WO3, a broadband responsive semiconductor material rich in oxygen vacancies. 3-X With Bi2O 3-x It is then combined with BiOBr to construct BiOBr / Bi2O 3-x / WO 3-xA double S-shaped heterojunction. The oxygen vacancies in this material system not only significantly enhance the capture ability of visible-near-infrared light, but also serve as effective electron traps and transport channels, promoting the separation and migration of photogenerated carriers. Through the synergistic coupling of these three elements, this heterojunction is expected to achieve efficient separation and maximized utilization of photogenerated electron-hole pairs in space: the heterojunction structure itself inhibits carrier recombination, while the abundant oxygen vacancies further regulate charge behavior and broaden the photoresponse range, thereby jointly driving a comprehensive improvement in full-spectrum photocatalytic performance. However, to date, for this type of oxygen-vacancy-rich BiOBr / Bi2O... 3-x / WO 3-x There are no publicly available reports on the systematic study of double S-shaped heterojunctions in the synergistic removal of combined antibiotic and hexavalent chromium pollution in water bodies. Summary of the Invention

[0005] In view of this, the first objective of the present invention is to provide an oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x The preparation and synergistic purification application of full-spectrum responsive double S-type heterojunctions are used to solve the technical problems of the need to improve the photocatalytic performance and narrow light response range of BiOBr photocatalysts in the existing technology.

[0006] A second objective of this invention is to provide an oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x A method for preparing a full-spectrum responsive double S-type heterojunction.

[0007] The third objective of this invention is to provide an oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x Synergistic purification applications of full-spectrum responsive double S-shaped heterojunctions.

[0008] Therefore, the first technical solution provided by this invention is as follows:

[0009] An oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction, the oxygen-vacancy-rich BiOBr / Bi2O 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction is composed of bismuth nitrate pentahydrate, potassium bromide, and WO3. 3-x Prepared from granules;

[0010] Among them: Bi2O 3-x with WO 3-x The range of values ​​for x is 0 ≤ x < 1.

[0011] The above-mentioned oxygen-rich vacancy BiOBr / Bi2O 3-x / WO3-x Full-spectrum response dual S-type heterojunction, the aforementioned bismuth nitrate pentahydrate, potassium bromide, WO3 3-x The mass ratio of the particles is 972:238:100.

[0012] Furthermore, the aforementioned oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction, the WO 3-x The particles were prepared by dispersing WCl6 in methanol and stirring until homogeneous, then transferring it to a hydrothermal reactor and carrying out a solvothermal reaction in a muffle furnace.

[0013] The stirring time is 0.5 to 1 hour, and the temperature is room temperature;

[0014] The solvothermal reaction time is 12-24 hours, and the temperature is 180 ℃;

[0015] The methanol-WCl6 solution has a concentration of 1.0~2.0 mg / mL.

[0016] The second technical solution of the present invention is the above-mentioned oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x Full-spectrum response dual The preparation method of S-type heterojunction includes the following steps in sequence:

[0017] 1) Place bismuth nitrate pentahydrate in ethylene glycol and stir at a constant temperature of 80 ℃~100 ℃ for 1.5 hours until it is completely dissolved to obtain a clear solution;

[0018] 2) Dissolve potassium bromide in deionized water to obtain an aqueous solution of potassium bromide; under constant temperature and stirring conditions of 80 ℃~100 ℃, slowly inject the obtained aqueous solution of potassium bromide into the clear solution obtained in step 1) at a constant flow rate using an injection pump to obtain a milky white turbid liquid; then stir the milky white turbid liquid at constant temperature of 80 ℃~100 ℃ for 1 hour, and then transfer it to a hydrothermal reactor and carry out a solvothermal reaction at 140~180 ℃ in a muffle furnace for 10~20 hours, and then perform post-processing to obtain the BiOBr photocatalyst;

[0019] 3) Dissolve sodium borohydride in deionized water to obtain an aqueous solution of sodium borohydride; add the BiOBr photocatalyst from step 2) to the aqueous solution of sodium borohydride, stir at room temperature for 0.5 hours, centrifuge to collect the product, wash alternately with anhydrous ethanol and deionized water and dry, then transfer the product to a crucible and calcine in a muffle furnace at 160 °C for 1 hour to obtain BiOBr / Bi2O 3-x S-shaped heterojunction;

[0020] 4) Take the BiOBr / Bi2O from step 3) 3-x S-shaped heterojunction and WO 3-x The particles were co-suspended in an ethanol-water mixture and uniformly dispersed by stirring and sonication at room temperature to obtain a mixed dispersion. The mixed dispersion was then stirred at a constant temperature of 50 ℃~70 ℃ until the dispersion medium completely evaporated. Post-treatment yielded oxygen-rich vacancy BiOBr / Bi2O. 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction.

[0021] The aforementioned bismuth nitrate pentahydrate, potassium bromide, and WO3 3-x The mass ratio of the particles is 972:238:100;

[0022] The volume ratio of ethanol to water in the ethanol-water mixture is 3:1.

[0023] Furthermore, the above-mentioned oxygen-enriched vacancy BiOBr / Bi2O 3-x / WO 3-x A method for preparing a full-spectrum responsive double S-type heterojunction, wherein the mass ratio of bismuth nitrate pentahydrate, ethylene glycol, potassium bromide, and sodium borohydride is 972:77700:238:28.

[0024] Furthermore, the above-mentioned oxygen-enriched vacancy BiOBr / Bi2O 3-x / WO 3-x Application of full-spectrum responsive double S-type heterojunctions as catalysts for the synergistic degradation of antibiotics and the reduction of hexavalent chromium.

[0025] Another technical solution of this invention is an oxygen-rich vacancy BiOBr / Bi2O 3-x / WO 3-x A method for the synergistic degradation of antibiotics and reduction of hexavalent chromium via photocatalysis using a full-spectrum responsive double S-type heterojunction, utilizing BiOBr / Bi2O 3-x / WO 3-x When added to a system containing antibiotics and hexavalent chromium, the antibiotics are photocatalytically degraded and the hexavalent chromium is reduced under full-spectrum light irradiation.

[0026] The system containing antibiotics and hexavalent chromium contains antibiotics, hexavalent chromium, and BiOBr / Bi2O. 3-x / WO 3-x The concentration ratio is 1:1:200.

[0027] Compared with the prior art, the technical solution provided by the present invention has the following advantages and beneficial effects:

[0028] 1) The oxygen-rich vacancy BiOBr / Bi2O provided by this invention 3-x / WO 3-xFull-spectrum responsive double S-type heterojunctions are achieved by introducing Bi2O, which is responsive in the near-infrared region. 3-x with WO 3-x The composition successfully broadened the light response range to the full spectrum, significantly improving the utilization efficiency of sunlight.

[0029] 2) The oxygen-rich vacancy BiOBr / Bi2O provided by this invention 3-x / WO 3-x The introduction of oxygen vacancies into the full-spectrum responsive double S-shaped heterojunction modulates the band structure and electronic properties of the material, promotes efficient charge separation and migration, and greatly improves the photocatalytic quantum efficiency.

[0030] 3) The oxygen-rich vacancy BiOBr / Bi2O provided by this invention 3-x / WO 3-x The full-spectrum responsive double S-type heterojunction has high photogenerated carrier separation efficiency and strong redox capability, and exhibits excellent photocatalytic synergistic degradation of antibiotics and reduction of hexavalent chromium under full-spectrum irradiation.

[0031] 4) The heterojunction preparation method provided by this invention is simple, low-cost, and highly productive, and is easy to scale up for production, making it suitable for widespread application. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x Transmission electron microscope image of a heterojunction;

[0034] Figure 2 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x X-ray diffraction pattern of a heterojunction;

[0035] Figure 3 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x X-ray photoelectron spectroscopy of heterojunctions;

[0036] Figure 4 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-xThe ultraviolet-visible diffuse reflectance spectrum of a heterojunction;

[0037] Figure 5 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x Band structure diagram of a heterojunction;

[0038] Figure 6 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x Graph showing the effect of simultaneous degradation of CIP and reduction of Cr(VI) in heterojunction under full-spectrum irradiation;

[0039] Figure 7 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x The effect of CIP degradation on a heterojunction under full-spectrum illumination; Detailed Implementation

[0040] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a BiOBr / Bi2O 3-x / WO 3-x The double S-shaped heterojunction is prepared sequentially through the following steps:

[0043] 1) Add 972 mg of bismuth nitrate pentahydrate to 70 mL of ethylene glycol aqueous solution (98% by volume) and stir in an oil bath at 90 °C for 1.5 hours. Dissolve 238 mg of potassium bromide completely in 10 mL of deionized water to obtain a KBr solution.

[0044] 2) The KBr solution dissolved in step 1) was added dropwise to the ethylene glycol solution of bismuth nitrate pentahydrate using a syringe pump. After the addition was complete, the mixture was stirred at 90 °C for 1 hour to obtain a mixture. The mixture was then transferred to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor and reacted at 160 °C for 16 hours. After cooling, the product was washed alternately with anhydrous ethanol and deionized water and dried to obtain BiOBr.

[0045] 3) Dissolve 28.4 mg of sodium borohydride in 50 mL of deionized water to obtain an aqueous solution of sodium borohydride; add 500 mg of BiOBr prepared in step 2) to the aqueous solution of sodium borohydride, stir at room temperature for 0.5 hours, centrifuge to collect the product, wash with anhydrous ethanol and deionized water alternately, and dry. Then transfer the product to a crucible and calcine it in a muffle furnace at 160 °C for 1 hour to obtain BiOBr / Bi2O. 3-x .

[0046] 4) Take 80 mg of the BiOBr / Bi2O prepared in step 3). 3-x With 20 mg WO 3-x The particles were suspended in an ethanol-water mixture and then sonicated for 30 min followed by stirring for 30 min at room temperature to obtain a uniform dispersion. The dispersion was then stirred at 60 °C until the dispersion medium completely evaporated. The product was collected, washed, and dried to obtain oxygen-rich vacancy BiOBr / Bi2O. 3-x / WO 3-x Full-spectrum response dual S-shaped heterojunction.

[0047] The volume ratio of ethanol to water in the ethanol-water mixture is 3:1.

[0048] Among them WO 3-x The particles were prepared by dispersing 50 mg WCl6 in 50 mL of methanol and stirring at room temperature for 30 minutes. The mixture was then transferred to a hydrothermal reactor and reacted solvothermically at 180 °C for 12 hours.

[0049] Among them: Bi2O 3-x with WO 3-x In particles, 0 ≤ x < 1.

[0050] Example 2

[0051] This embodiment provides a BiOBr / Bi2O 3-x / WO 3-x pair The preparation process and parameters of the S-type heterojunction are basically the same as those in Example 1. The only difference is that the amount of sodium borohydride added in step 3 is adjusted to 18.9 mg, instead of the 28.4 mg added in Example 1.

[0052] Example 3

[0053] This embodiment provides a BiOBr / Bi2O 3-x / WO 3-xThe preparation process and parameters of the double S-type heterojunction are basically the same as those in Example 1. The only difference is that the amount of sodium borohydride added in step 3 is adjusted to 37.8 mg, instead of the 28.4 mg added in Example 1.

[0054] Example 4

[0055] This embodiment provides a BiOBr / Bi2O 3-x / WO 3-x The preparation process and parameters of the double S-type heterojunction are basically the same as those in Example 1, the only difference being: in step 4, BiOBr / Bi2O 3-x with WO 3-x The amount of granules added was adjusted to 90 mg and 10 mg, respectively, to replace the ratio of 80 mg and 20 mg in Example 1.

[0056] Example 5

[0057] This embodiment provides a BiOBr / Bi2O 3-x / WO 3-x The preparation process and parameters of the double S-type heterojunction are basically the same as those in Example 1, the only difference being: in step 4, BiOBr / Bi2O 3-x with WO 3-x The amount of granules added was adjusted to 70 mg and 30 mg, respectively, to replace the ratio of 80 mg and 20 mg in Example 1.

[0058] To verify the BiOBr / Bi2O provided in this application 3-x / WO 3-x The properties of the double S-type heterojunction are described below for the BiOBr / Bi2O prepared in Example 1. 3-x / WO 3-x Performance test data of double S-shaped heterojunctions, and BiOBr / Bi2O prepared in other examples. 3-x / WO 3-x The performance test of the double S-type heterojunction is basically the same as that in Example 1, so it is omitted.

[0059] Test Example 1

[0060] This test example uses the BiOBr / Bi2O prepared in Example 1. 3-x / WO 3-x The photocatalytic simultaneous purification performance of CIP and hexavalent chromium by the double S-type heterojunction under full-spectrum light source conditions was tested using the following steps:

[0061] Prepare a 50 mL mixed solution of CIP and hexavalent chromium, wherein the concentration of both CIP and hexavalent chromium is 10 mg / L. Add 10 mg of BiOBr / Bi2O to the above solution. 3-x / WO3-x A double-S heterojunction was used, with its concentration in the reaction system set at 0.2 mg / mL. A 300 W xenon lamp (equipped with a full-spectrum reflector) was employed as the light source. The mixture was first stirred in darkness for 30 minutes to allow the photocatalyst and pollutants to reach adsorption-desorption equilibrium. The light source was then turned on for 120 minutes of illumination. Samples (3 mL) were taken at different time points and filtered through a 0.22 μm aqueous filter to remove photocatalyst particles. The absorbance of CIP was measured at 271 nm using UV spectrophotometry, and its degradation rate was calculated by comparing it with the initial absorbance. Simultaneously, the concentration change of hexavalent chromium was measured using diphenylcarbazide spectrophotometry. By monitoring the changes in the removal rates of CIP and hexavalent chromium over time, the simultaneous photocatalytic purification performance of the double-S heterojunction for both pollutants was evaluated.

[0062] The simultaneous removal efficiencies of the blank control group and each catalyst group for CIP and hexavalent chromium under full-spectrum conditions are as follows: Figure 6 As shown, compared with the blank group without photocatalyst and single or binary materials, BiOBr / Bi2O 3-x / WO 3-x The double S-type heterojunction exhibits significantly enhanced photocatalytic activity within 120 minutes of full-spectrum irradiation: its degradation rate of CIP can reach 85%, and its reduction and removal rate of Cr(VI) can reach 74%.

[0063] Test Example 2

[0064] This test example uses the BiOBr / Bi2O prepared in Example 1. 3-x / WO 3-x The photocatalytic degradation performance of CIP by the double S-type heterojunction under full-spectrum light source conditions was tested using the following steps:

[0065] Prepare a 50 mL CIP solution with a CIP concentration of 10 mg / L, and add 10 mg BiOBr / Bi2O to the above solution. 3-x / WO 3-x A double-S heterojunction was used, with its concentration in the reaction system set at 0.2 mg / mL. A 300 W xenon lamp (equipped with a full-spectrum reflector) was used as the light source. The mixture was first stirred in the dark for 30 minutes to allow the photocatalyst and pollutants to reach adsorption-desorption equilibrium, followed by 120 minutes of illumination. Samples (3 mL) were taken at different time points and filtered through a 0.22 μm aqueous filter to remove photocatalyst particles. The absorbance of CIP was measured at 271 nm using ultraviolet spectrophotometry, and its degradation rate was calculated by comparing it with the initial absorbance; thus evaluating the photocatalytic degradation performance of the double-S heterojunction on CIP.

[0066] The removal efficiency of CIP by the blank control group and each catalyst group under full-spectrum conditions is as follows: Figure 7 As shown, compared with the blank group without photocatalyst and single or binary materials, BiOBr / Bi2O 3-x / WO 3-x The double S-type heterojunction exhibits significantly enhanced photocatalytic activity within 120 minutes of full-spectrum irradiation: its degradation rate of CIP can reach 97%.

[0067] To verify the effectiveness of the present invention, Figure 1 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x The transmission electron microscope (TEM) image of the heterojunction clearly shows that BiOBr forms the substrate with irregular nanosheet-like structures, while Bi2O... 3-x and WO 3-x The material is uniformly loaded onto the surface of BiOBr nanosheets, forming a tight interfacial contact between the three components. This distinct composite morphology and spatial distribution effectively confirms the BiOBr / Bi2O4 composite structure. 3-x / WO 3-x The successful construction of the heterojunction provides a structural basis for the subsequent analysis of photocatalytic performance.

[0068] Figure 2 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x The X-ray diffraction (XRD) pattern of the heterojunction clearly shows BiOBr and Bi2O. 3-x and WO 3-x The characteristic diffraction peaks of each component correspond to those on the standard card, indicating BiOBr / Bi2O. 3-x / WO 3-x The successful construction of heterojunctions provides ample evidence for crystal structure.

[0069] Figure 3 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x The full-spectrum X-ray photoelectron spectroscopy (XPS) of the heterojunction clearly shows characteristic photoelectron peaks from four elements: Bi, O, Br, and W, with significant signal intensities, perfectly consistent with the theoretical chemical composition of the heterojunction. Notably, no other obvious impurity element peaks were detected in the spectrum, indicating the high purity of the prepared material. This XPS full-spectrum analysis identifies it as BiOBr / Bi2O. 3-x / WO 3-x The successful construction of heterojunctions provides direct evidence for surface elemental composition.

[0070] Figure 4 BiOBr / Bi2O prepared in Example 13-x / WO 3-x Compared to pure BiOBr, the UV-Vis diffuse reflectance spectrum of the heterojunction shows a significant redshift in the absorption edge, with a marked increase in absorption intensity across the entire visible to near-infrared region. This enhancement is primarily attributed to the full-spectrum responsive material Bi₂O₃. 3-x with WO 3-x The introduction of these materials not only expands the photoresponse range but also promotes the separation and migration of photogenerated carriers by forming a heterojunction structure. The significantly enhanced light-harvesting ability indicates that this material has great potential for photocatalytic reactions utilizing the full spectrum.

[0071] Figure 5 BiOBr / Bi2O prepared in Example 1 3-x / WO 3-x Band structure analysis results of the heterojunction. BiOBr and Bi2O were calculated based on the Kubelka-Munk formula. 3-x with WO 3-x band gap value (E) g The values ​​were 2.68 eV, 3.01 eV, and 2.81 eV, respectively. Further XPS valence band analysis determined the peak positions of the three valence bands (E). VB The values ​​are 2.77 eV, 1.82 eV, and 2.88 eV, respectively. According to the band structure E... CB = E VB – E g It is estimated that the corresponding conduction band bottom position (E) CB The values ​​were 0.09 eV, -1.19 eV, and 0.07 eV, respectively. The final constructed band structure diagram clearly shows a typical double S-type heterojunction arrangement, which is consistent with the expected mechanism of directional migration and efficient separation of photogenerated carriers, providing a theoretical basis for explaining the enhanced photocatalytic performance of the material.

[0072] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An oxygen-enriched vacancy BiOBr / Bi2O 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction, the oxygen-vacancy-rich BiOBr / Bi2O 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction is composed of bismuth nitrate pentahydrate, potassium bromide, and WO3. 3-x Prepared from granules; in: Bi2O 3-x with WO 3-x The range of values ​​for x is 0 ≤ x < 1.

2. The oxygen-enriched vacancy BiOBr / Bi2O according to claim 1 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction, wherein the bismuth nitrate pentahydrate, potassium bromide, and WO3 are present. 3-x The mass ratio of the particles is 972: 238:

100.

3. The oxygen-enriched vacancy BiOBr / Bi2O according to claim 1 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction, the WO 3-x The particles were prepared by dispersing WCl6 in methanol and stirring until homogeneous, then transferring it to a hydrothermal reactor and carrying out a solvothermal reaction in a muffle furnace. in, The stirring time is 0.5 to 1 hour, and the temperature is room temperature; The solvothermal reaction time is 12-24 hours, and the temperature is 180 ℃; The methanol-WCl6 solution has a concentration of 1.0~2.0 mg / mL.

4. An oxygen-enriched vacancy BiOBr / Bi2O according to any one of claims 1 to 3 3-x / WO 3-x The method for preparing a full-spectrum responsive double S-type heterojunction includes the following steps: 1) Place bismuth nitrate pentahydrate in ethylene glycol and stir at a constant temperature of 80 ℃~100 ℃ for 1.5 hours until it is completely dissolved to obtain a clear solution; 2) Dissolve potassium bromide in deionized water to obtain an aqueous solution of potassium bromide; under constant temperature and stirring conditions of 80 ℃~100 ℃, slowly inject the obtained aqueous solution of potassium bromide into the clear solution obtained in step 1) at a constant flow rate using an injection pump to obtain a milky white turbid liquid; then stir the milky white turbid liquid at constant temperature of 80 ℃~100 ℃ for 1 hour, and then transfer it to a hydrothermal reactor and carry out a solvothermal reaction at 140~180 ℃ in a muffle furnace for 10~20 hours, and then perform post-processing to obtain the BiOBr photocatalyst; 3) Dissolve sodium borohydride in deionized water to obtain an aqueous solution of sodium borohydride; add the BiOBr photocatalyst from step 2) to the aqueous solution of sodium borohydride, stir at room temperature for 0.5 hours, centrifuge to collect the product, wash alternately with anhydrous ethanol and deionized water and dry, then transfer the product to a crucible and calcine in a muffle furnace at 160 °C for 1 hour to obtain BiOBr / Bi2O 3-x S-shaped heterojunction; 4) Take the BiOBr / Bi2O from step 3) 3-x S-shaped heterojunction and WO 3-x The particles were co-suspended in an ethanol-water mixture and uniformly dispersed by stirring and sonication at room temperature to obtain a mixed dispersion. The mixed dispersion was then stirred at a constant temperature of 50 ℃~70 ℃ until the dispersion medium was completely evaporated. Post-treatment yielded an oxygen-rich BiOBr / Bi2O3 ... 3-x / WO 3-x Full-spectrum responsive double S-type heterojunction. The aforementioned bismuth nitrate pentahydrate, potassium bromide, and WO3 3-x The mass ratio of the particles is 972:238:100; The volume ratio of ethanol to water in the ethanol-water mixture is 3:

1.

5. The oxygen-enriched vacancy BiOBr / Bi2O according to claim 4 3-x / WO 3-x A method for preparing a full-spectrum responsive double S-type heterojunction, wherein the mass ratio of bismuth nitrate pentahydrate, ethylene glycol, potassium bromide, and sodium borohydride is 972:77700:238:

28.

6. The oxygen-enriched vacancy BiOBr / Bi2O according to claim 1 3-x / WO 3-x Application of full-spectrum responsive double S-type heterojunctions as catalysts for the synergistic degradation of antibiotics and the reduction of hexavalent chromium.

7. An oxygen-enriched vacancy BiOBr / Bi2O 3-x / WO 3-x A method for the synergistic degradation of antibiotics and reduction of hexavalent chromium via photocatalysis using a full-spectrum responsive double S-type heterojunction, utilizing BiOBr / Bi2O 3-x / WO 3-x When added to a system containing antibiotics and hexavalent chromium, the antibiotics are photocatalytically degraded and the hexavalent chromium is reduced under full-spectrum light irradiation.

8. An oxygen-enriched vacancy BiOBr / Bi2O according to claim 7 3-x / WO 3-x A method for the synergistic degradation of antibiotics and reduction of hexavalent chromium by a full-spectrum responsive double S-type heterojunction photocatalysis, characterized in that... The system containing antibiotics and hexavalent chromium contains antibiotics, hexavalent chromium, and BiOBr / Bi2O. 3-x / WO 3-x The concentration ratio is 1:1:200.

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