A supported ternary heterojunction photocatalytic material, its preparation method and application

Abstract

This application discloses a supported ternary heterojunction photocatalytic material, its preparation method, and its application, relating to the field of photocatalytic materials technology. The supported ternary heterojunction photocatalytic material includes an attapulgite support; titanium dioxide and bismuth sulfide supported on the surface of the attapulgite support; and the bismuth sulfide and titanium dioxide forming a heterojunction structure on the attapulgite surface. The supported ternary heterojunction photocatalytic material proposed in this application can generate a large number of highly oxidizing active species during photocatalysis. Under visible light and neutral conditions, it can achieve efficient mineralization of recalcitrant antibiotics such as tetracycline, exhibiting a significant purification effect.

Description

Technical Field

[0001] This application relates to the field of photocatalytic materials technology, and in particular to a supported ternary heterojunction photocatalytic material, its preparation method and application. Background Technology

[0002] With industrialization and the widespread use of antibiotics, dye and antibiotic pollutants in water bodies are difficult to remove completely using traditional treatment methods, becoming a significant challenge in water environment management. Photocatalysis technology has attracted widespread attention because it can mineralize organic pollutants into harmless small molecules under ambient temperature and pressure. While titanium dioxide (TiO2) exhibits high stability, it has a large band gap, responds only to ultraviolet light, and experiences rapid electron-hole recombination. Bismuth sulfide (Bi2S3), although active in visible light, is prone to photocorrosion. Although existing technologies have reported the construction of Bi2S3 / TiO2 composite materials, they still suffer from the following drawbacks: firstly, nanoparticles are prone to severe aggregation during preparation and reaction, leading to a significant reduction in effective active sites; secondly, the composite interface is not sufficiently tight, resulting in low photogenerated carrier migration efficiency and difficulties in material recovery. Therefore, constructing a ternary composite system that can both inhibit component aggregation and improve stability, while simultaneously generating highly oxidizing active species (such as ·OH) through efficient interfacial synergy, is a key challenge for improving the efficiency of antibiotic wastewater treatment. Summary of the Invention

[0003] The main purpose of this application is to propose a supported ternary heterojunction photocatalytic material, its preparation method and application, aiming to solve or at least partially alleviate the problems of low visible light utilization, easy agglomeration of nanoparticles and low efficiency of active species generation in existing photocatalytic materials.

[0004] To achieve the above objectives, in a first aspect, this application proposes a supported ternary heterojunction photocatalytic material, comprising:

[0005] attapulgite soil carrier; Titanium dioxide and bismuth sulfide loaded on the surface of the attapulgite carrier; The bismuth sulfide and titanium dioxide form a heterojunction structure on the surface of attapulgite.

[0006] In some embodiments, the mass ratio of bismuth sulfide, titanium dioxide and attapulgite carrier is (0.5~2):(0.5~2):(1~4).

[0007] In some embodiments, the attapulgite is acid-activated attapulgite with a one-dimensional rod-shaped or fibrous structure.

[0008] Secondly, this application proposes a method for preparing the supported ternary heterojunction photocatalytic material proposed in the first aspect of this application, comprising: The pretreated attapulgite was dispersed in a solvent, a titanium source was added, and the mixture was stirred to obtain a precursor solution. The bismuth source and sulfur source are dissolved in the precursor solution to obtain the precursor solution; The precursor solution was subjected to a hydrothermal reaction, and the product was then washed, dried, and calcined to obtain the supported ternary heterojunction photocatalytic material.

[0009] In some embodiments, the titanium source includes at least one of tetrabutyl titanate, titanium sulfate, and titanium chloride; The solvent includes at least one of deionized water and ethylene glycol.

[0010] In some embodiments, the bismuth source includes at least one of bismuth nitrate, bismuth chloride, or bismuth acetate; The sulfur source includes at least one of thiourea, sodium sulfide, or thioamide.

[0011] In some embodiments, the hydrothermal reaction is carried out at a temperature of 120-180°C for 6-18 hours, and the pH of the reaction system is 1.0-4.0.

[0012] In some embodiments, the calcination treatment is carried out at a temperature of 300-500°C for 1-4 hours.

[0013] Thirdly, this application proposes the application of the supported ternary heterojunction photocatalytic material prepared by the preparation method of the supported ternary heterojunction photocatalytic material proposed in the first aspect of this application and the supported ternary heterojunction photocatalytic material proposed in the second aspect of this application in the treatment of organic wastewater, wherein the organic wastewater contains antibiotics and / or dyes, and the treatment process is carried out under visible light irradiation.

[0014] In some embodiments, the antibiotic includes tetracycline or ciprofloxacin; the dye includes methylene blue or methyl orange.

[0015] The beneficial effects of this application are: The supported ternary heterojunction photocatalytic material proposed in this application utilizes the unique one-dimensional fibrous structure of attapulgite (ATP) as a supporting framework. Its large specific surface area effectively disperses Bi₂S₃ and TiO₂ nanoparticles, fundamentally solving the severe agglomeration problem of semiconductor particles during preparation and reaction. Simultaneously, the binding effect of ATP significantly inhibits the photocorrosion behavior of Bi₂S₃, improving the material's recyclability. Furthermore, experiments have confirmed that the proposed supported ternary heterojunction photocatalytic material generates a large number of highly oxidizing active species during photocatalysis, with hydroxyl radicals (·OH) playing a dominant role in the degradation reaction. This enables the material to achieve efficient mineralization of recalcitrant antibiotics such as tetracycline under visible light and neutral conditions, demonstrating a significant purification effect.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more easily understood, specific embodiments of the present invention are described below. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 Scanning electron microscope image of attapulgite soil provided in the embodiments of this application; Figure 2 Scanning electron microscope (SEM) image of the supported ternary heterojunction photocatalyst material provided in the embodiments of this application; Figure 3 Specific surface area diagram of the supported ternary heterojunction photocatalytic material provided in the embodiments of this application; Figure 4 A pore size distribution diagram of the supported ternary heterojunction photocatalyst material provided in the embodiments of this application; Figure 5 Fourier transform infrared spectra of attapulgite and supported ternary heterojunction photocatalytic materials provided in the embodiments of this application; Figure 6 X-ray diffraction pattern provided for embodiments of this application; Figure 7 This is a graph showing the relationship between the relative concentration of the solution and time during the photocatalytic degradation of tetracycline hydrochloride provided in the embodiments of this application; Figure 8 Fitted kinetic curves for the photocatalytic degradation process of tetracycline hydrochloride provided in the embodiments of this application.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] With the accelerated pace of industrialization and the widespread use of antibiotics, a large amount of recalcitrant organic pollutants have entered the aquatic environment. Among these, dye wastewater is complex in composition, highly chromatic, and toxic, while antibiotic pollutants possess strong biological activity and persistence, easily inducing microorganisms to develop drug-resistant genes, posing a potential threat to ecosystems and human health. Traditional water treatment methods, such as physical adsorption, biodegradation, and conventional chemical oxidation, are insufficient for the efficient and complete removal of these pollutants, especially for low-concentration, highly stable organic molecules, making them a prominent challenge in current water pollution control.

[0024] Photocatalysis, driven by light energy under ambient temperature and pressure, is considered a green and efficient emerging water treatment technology that can gradually degrade organic pollutants into carbon dioxide, water, and other inorganic small molecules through redox reactions. Among numerous photocatalytic materials, TiO2 has been widely studied due to its high chemical stability, non-toxicity, and low cost. However, its large band gap (approximately 3.2 eV) limits its absorption to ultraviolet light, resulting in low utilization of sunlight. Furthermore, the rapid recombination of photogenerated electrons and holes severely restricts its catalytic efficiency. On the other hand, the narrow-bandgap semiconductor Bi2S3 exhibits excellent visible light response, effectively expanding the range of light utilization. However, this material is prone to photocorrosion under light irradiation and has poor structural stability, limiting its practical applications.

[0025] To address the limitations of single catalysts, existing research has attempted to construct Bi₂S₃ / TiO₂ heterojunction composites to promote the separation of photogenerated carriers through band matching. However, these composite systems still suffer from several key drawbacks in practical preparation and application: First, nanoscale TiO₂ and Bi₂S₃ particles are prone to severe aggregation during synthesis and catalysis, leading to a significant decrease in specific surface area and reduced exposure of active sites, thereby weakening catalytic performance; second, the interfacial contact between the two materials is often not tight enough and the structure is not sufficiently regulated, affecting the cross-interfacial migration efficiency of photogenerated electrons and holes, resulting in a still relatively high carrier recombination rate; furthermore, powdered nanocatalysts are difficult to separate and recover from water bodies after use, easily causing secondary pollution and increasing operating costs.

[0026] Based on the above problems, in a first aspect, embodiments of this application propose a supported ternary heterojunction photocatalytic material, comprising: an attapulgite support and titanium dioxide and bismuth sulfide supported on the surface of the attapulgite support. The bismuth sulfide and titanium dioxide form a heterojunction structure on the surface of the attapulgite.

[0027] The supported ternary heterojunction photocatalytic material proposed in this application utilizes the unique one-dimensional fibrous structure of attapulgite (ATP) as a supporting framework. Its large specific surface area effectively disperses Bi₂S₃ and TiO₂ nanoparticles, fundamentally solving the severe agglomeration problem of semiconductor particles during preparation and reaction. Simultaneously, the binding effect of ATP significantly inhibits the photocorrosion behavior of Bi₂S₃, improving the material's recyclability. Furthermore, experiments have confirmed that the supported ternary heterojunction photocatalytic material generates a large number of highly oxidizing active species during photocatalysis, with hydroxyl radicals (·OH) playing a dominant role in the degradation reaction. This enables the material to achieve efficient mineralization of recalcitrant antibiotics such as tetracycline under visible light and neutral conditions, demonstrating a significant purification effect.

[0028] In some embodiments, the mass ratio of bismuth sulfide, titanium dioxide, and attapulgite carrier is (0.5~2):(0.5~2):(1~4). For example, the mass ratio of bismuth sulfide, titanium dioxide, and attapulgite carrier is 1:1:2, 2:2:2, 0.5:0.5:4, 2:0.5:0.5, 0.5:2:3, or 0.5:0.5:1, etc.

[0029] If the Bi2S3 or TiO2 content is too high, it can easily lead to particle accumulation and aggregation; if the ATP ratio is too high, the active component loading will be insufficient, affecting light absorption and catalytic efficiency. This ratio ensures that the heterojunction interface is fully formed, while the ATP carrier provides sufficient dispersion and support, enabling the material to have excellent degradation performance and cycling stability under visible light.

[0030] In some embodiments, the attapulgite is acid-activated attapulgite with a one-dimensional rod-shaped or fibrous structure.

[0031] Acid activation treatment can remove impurities from the surface of ATP and increase its surface hydroxyl content, enhancing its hydrophilicity and surface activity, which is beneficial for the adsorption of titanium and bismuth sources and the subsequent in-situ growth of heterojunctions. The one-dimensional fibrous structure has a high specific surface area and good mechanical strength, which can not only effectively disperse active components, but also facilitate the sedimentation and recovery of materials after the reaction, making it suitable for continuous flow or batch wastewater treatment systems.

[0032] This application also proposes a method for preparing the supported ternary heterojunction photocatalytic material as described above, including: S101. Disperse the pretreated attapulgite in a solvent, add a titanium source, and stir to obtain a precursor solution. S102. Dissolve the bismuth source and sulfur source in the precursor solution to obtain the precursor solution; S103. The precursor solution is subjected to a hydrothermal reaction, and the product is washed, dried and calcined to obtain the supported ternary heterojunction photocatalytic material.

[0033] A dense Bi₂S₃ / TiO₂ heterojunction interface was constructed on the surface of ATP using an in-situ hydrothermal growth process. Bi₂S₃, acting as a visible light sensitizer, effectively broadened the material's photoresponse range and promoted spatial separation of photogenerated carriers through energy level matching, reducing recombination probability. Furthermore, the combination of hydrothermal and calcination methods resulted in a simple process route, easily controllable conditions, and good reproducibility. The ATP carrier is an inexpensive natural mineral, which not only reduces production costs but also facilitates the sedimentation and recycling of the composite material, making it suitable for large-scale application in the field of organic wastewater treatment.

[0034] In some embodiments, the preparation method of the supported ternary heterojunction photocatalytic material as described above may further include the following steps: S201. Dissolve the bismuth source and sulfur source in a solvent to obtain a precursor solution; S202. Add titanium source and pretreated attapulgite to the precursor solution and stir to obtain composite material precursor; S203. The composite material precursor is subjected to a hydrothermal reaction, and the product is cleaned, dried and calcined to obtain the supported ternary heterojunction photocatalytic material.

[0035] In some embodiments, the titanium source includes at least one of tetrabutyl titanate, titanium sulfate, and titanium chloride. These titanium sources are readily soluble in common solvents, have controllable hydrolysis rates, and can uniformly adsorb onto the ATP surface to form a highly active, highly crystalline TiO2 layer, providing a good interfacial basis for subsequent in-situ growth of Bi2S3.

[0036] In some embodiments, the solvent includes at least one of deionized water and ethylene glycol.

[0037] In some embodiments, the bismuth source includes at least one of bismuth nitrate, bismuth chloride, or bismuth acetate. The sulfur source includes at least one of thiourea, sodium sulfide, or thioamide. The selected bismuth source and sulfur source exhibit moderate reactivity under hydrothermal conditions, making it easy to control the crystallization process of Bi2S3 and avoiding particle coarsening or uneven distribution caused by excessively rapid precipitation, thereby ensuring the uniformity of the heterojunction and the interface quality.

[0038] In some embodiments, the hydrothermal reaction temperature is 120–180°C, the reaction time is 6–18 hours, and the pH value of the reaction system is 1.0–4.0. For example, the hydrothermal reaction temperature is 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, or 180°C, etc. The hydrothermal reaction time is 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, or 18 hours, etc. The pH value of the hydrothermal reaction system is 1, 2, 3, or 4, etc.

[0039] At this temperature, the hydrothermal system provides sufficient driving force for the reaction, enabling the bismuth and sulfur source precursors to decompose and react effectively, ensuring stable nucleation and growth of Bi₂S₃ crystals. Simultaneously, the ample thermal energy promotes the diffusion of reactant ions in solution and their adsorption and migration on the TiO₂ / ATP support surface, facilitating the epitaxial or semi-epitaxy growth of Bi₂S₃ on a TiO₂ grain substrate, rather than random agglomeration. This is the physicochemical basis for the formation of a compact, low-defect heterojunction interface.

[0040] A time window of 6 to 18 hours provides the necessary time for the full growth and crystal face development of Bi2S3 crystals. If the time is too short (<6 hours), Bi2S3 crystallization may be incomplete, resulting in a large number of amorphous or microcrystalline particles with poor light absorption and charge conduction properties, and weak interfacial bonding with TiO2, making them easy to detach during subsequent processing.

[0041] Limiting the pH value to 1-4 helps to inhibit Bi³⁺. + Premature hydrolysis and precipitation of bismuth sources (such as Bi(NO3)3) are easily hydrolyzed under near-neutral or alkaline conditions to form basic salt precipitates such as BiOCl and BiONO3. These precipitates have different chemical properties from the target product Bi2S3 and consume the bismuth source, resulting in an impure final product and low Bi2S3 yield. Premature hydrolysis and precipitation of Bi3 can be effectively inhibited in strongly acidic to weakly acidic environments with a pH of 1–4. + The premature hydrolysis of ions allows them to exist in solution as soluble ions, creating conditions for a homogeneous reaction with the sulfur source. On the other hand, commonly used sulfur sources (such as thiourea) slowly decompose and release S² under acidic heating conditions. - or HS -Ions. Within this pH range, both an appropriate decomposition rate of the sulfur source and controlled reaction of released sulfur ions with Bi³⁺ are ensured. + Ions react on the ATP / TiO2 surface, achieving in-situ, slow, and uniform nucleation and growth of Bi2S3, avoiding explosive nucleation and particle aggregation caused by excessively high instantaneous concentrations of sulfide ions. More importantly, under acidic hydrothermal conditions, Bi³ + Ions react more readily with Ti-OH on the TiO2 surface, forming chemical bridges through dehydration condensation and other mechanisms, rather than simply physical adhesion. This significantly enhances the interfacial bonding between Bi2S3 and TiO2, reduces the interfacial resistance, and greatly promotes the migration and separation of photogenerated carriers between heterojunctions.

[0042] In some embodiments, the calcination treatment is carried out at a temperature of 300-500°C for 1-4 hours. For example, the calcination treatment temperature is 300°C, 350°C, 400°C, 450°C, or 500°C, etc., and the calcination treatment time is 1 hour, 2 hours, 3 hours, or 4 hours, etc.

[0043] Setting the calcination temperature to 300~500℃ helps remove organic residues on the material surface, enhances the chemical bond between Bi2S3 and TiO2, improves the thermal stability and photocatalytic activity of the material, and avoids the decomposition of Bi2S3 or the collapse of the ATP structure due to excessive temperature.

[0044] This application also provides an application of the supported ternary heterojunction photocatalyst material described above, and the method for preparing the supported ternary heterojunction photocatalyst material described above, in the treatment of organic wastewater. The organic wastewater contains antibiotics and / or dyes, and the treatment process is carried out under visible light irradiation.

[0045] In some implementations, the antibiotics include tetracycline or ciprofloxacin; the dyes include methylene blue or methyl orange.

[0046] Experiments have confirmed that the ternary composite material provided in this application can generate a large number of highly oxidizing active species during photocatalysis, and hydroxyl radicals (·OH) play a dominant role in the degradation reaction. This enables the material to achieve efficient mineralization of recalcitrant antibiotics such as tetracycline under visible light and neutral conditions, demonstrating a significant purification effect.

[0047] The following specific examples provide further details.

[0048] Example 1 (1) Pretreatment: Take natural attapulgite (ATP) and soak it in 1 mol / L HCl for 2 hours, wash it until neutral, and dry it at 80℃ for later use.

[0049] (2) Weigh 0.485 g Bi(NO3)3·5H2O (bismuth source) and 0.228 g thiourea (sulfur source) and dissolve them in 40 mL of a mixed solvent of ethylene glycol and water.

[0050] (3) Add 0.08 g TiO2 powder and 0.16 g pretreated ATP to the solution and stir for 30 minutes.

[0051] (4) Transfer the mixture from (3) to a high-pressure reactor and carry out a hydrothermal reaction at 160°C for 12 hours.

[0052] (5) After the reaction is complete, the product is taken out, cooled, centrifuged, washed and dried, and finally calcined at 400°C for 2 hours to obtain the supported ternary heterojunction photocatalytic material.

[0053] Example 2 (1) Pretreatment: Take natural attapulgite (ATP) and soak it in 1 mol / L HCl for 2 hours, wash it until neutral, and dry it at 80℃ for later use.

[0054] (2) Weigh 0.485 g Bi(NO3)3·5H2O (bismuth source) and 0.228 g thiourea (sulfur source) and dissolve them in 40 mL of a mixed solvent of ethylene glycol and water.

[0055] (3) Add 0.08 g TiO2 powder and 0.08 g pretreated ATP to the solution and stir for 30 minutes.

[0056] (4) Transfer the mixture from (3) to a high-pressure reactor and carry out a hydrothermal reaction at 180°C for 6 hours.

[0057] (5) After the reaction is complete, the product is taken out, cooled, centrifuged, washed and dried, and finally calcined at 300°C for 4 hours to obtain the supported ternary heterojunction photocatalytic material.

[0058] Example 3 (1) Pretreatment: Take natural attapulgite (ATP) and soak it in 1 mol / L HCl for 2 hours, wash it until neutral, and dry it at 80℃ for later use.

[0059] (2) Weigh 0.485 g Bi(NO3)3·5H2O (bismuth source) and 0.228 g thiourea (sulfur source) and dissolve them in 40 mL of a mixed solvent of ethylene glycol and water.

[0060] (3) Add 0.08 g TiO2 powder and 0.24 g pretreated ATP to the solution and stir for 30 minutes.

[0061] (4) Transfer the mixture from (3) to a high-pressure reactor and carry out a hydrothermal reaction at 120°C for 18 hours.

[0062] (5) After the reaction is complete, the product is taken out, cooled, centrifuged, washed and dried, and finally calcined at 500°C for 1 hour to obtain the supported ternary heterojunction photocatalytic material.

[0063] Comparative Example 1 (1) Weigh 0.485 g Bi(NO3)3·5H2O (bismuth source) and 0.228 g thiourea (sulfur source) and dissolve them in 40 mL of a mixed solvent of ethylene glycol and water.

[0064] (2) Add 0.08 g TiO2 powder to the solution and stir for 30 minutes.

[0065] (3) Transfer the mixture from (2) to a high-pressure reactor and carry out a hydrothermal reaction at 160°C for 12 hours.

[0066] (5) After the reaction is complete, the product is taken out, cooled, centrifuged, washed and dried, and finally calcined at 400°C for 2 hours to obtain the composite photocatalytic material.

[0067] The comprehensive characterization of the supported ternary heterojunction photocatalytic material prepared in Example 1 was tested.

[0068] (1) Morphology and dispersibility: Scanning electron microscopy observation showed (e.g.) Figure 1 and Figure 2 As shown, the supported ternary heterojunction photocatalytic material fully retains the unique one-dimensional fibrous rod-like cluster structure of attapulgite. Bi₂S₃ and TiO₂ nanoparticles are tightly anchored on the surface of ATP fibers in a highly dispersed state, with no obvious particle accumulation or large-area aggregation observed. This strongly confirms that ATP fibers, as a three-dimensional structural framework, achieve spatial confinement and uniform distribution of active components through their huge physical surface area, significantly increasing the effective contact sites for the degradation reaction.

[0069] (2) Pore structure and adsorption: Nitrogen adsorption-desorption test results show (e.g. Figure 3 and Figure 4 As shown in the figure, after introducing the ATP carrier, the supported ternary heterojunction photocatalytic material exhibits excellent specific surface area and pore size distribution characteristics. This porous structure not only enhances the physical adsorption and pre-enrichment of organic molecules such as tetracycline (TC), but also provides abundant transport channels for the migration of photogenerated charges from the bulk phase to the surface, thereby maintaining a high pollutant concentration at the interface and accelerating the heterogeneous catalytic reaction process.

[0070] (3) Active groups and mechanisms: such as Figure 5As shown, the infrared spectrum (FT-IR) at 3400 cm⁻¹ 1 A distinct -OH stretching vibration peak was observed nearby, indicating an abundance of hydroxyl groups on the material surface. Combined with the free radical trapping experiment results, the strong inhibition of the degradation reaction by the IPA group confirms that hydroxyl radicals (·OH) are the main active oxide species for tetracycline degradation. This further confirms the strong oxidizing holes (h0) generated by the energy level matching of the Bi2S3 / TiO2 heterojunction. + It can efficiently oxidize surface hydroxyl groups to produce ·OH.

[0071] (4) Crystal phase structure and heterostructure construction: X-ray diffraction analysis was performed on the supported ternary heterojunction photocatalytic material (e.g., Figure 6 The diffraction patterns clearly show the presence of characteristic diffraction peaks for anatase TiO2 (JCPDS No. 21-1272) and bismuthinite Bi2S3 (JCPDS No. 17-0320) in the sample, with no other impurity phases observed, demonstrating that each component maintains good crystallinity in the composite system. The correspondence of the diffraction peaks confirms the successful loading and in-situ growth of Bi2S3 and TiO2 on the attapulgite (ATP) surface, laying the crystalline phase foundation for constructing a stable ternary heterostructure.

[0072] The photocatalytic performance of the supported ternary heterojunction photocatalytic materials prepared in Examples 1-3 and those prepared in Comparative Examples 1 and 2 was tested.

[0073] (1) Degradation activity test: 50 mg of the supported ternary heterojunction photocatalyst material prepared in Example 1 and the composite photocatalyst material prepared in Comparative Example 1 were respectively added to 100 mL of tetracycline (TC) solution with an initial concentration of 20 mg / L. The mixture was stirred for 30 minutes under light-protected conditions to reach adsorption-desorption equilibrium. Then, a 300 W xenon lamp (equipped with a 420 nm cutoff filter to provide visible light irradiation) was turned on. The relative concentrations of the solutions in the reaction were tested, and the results are as follows: Figure 7 and Figure 8 As shown. Figure 7 and Figure 8 In the text, BT represents the composite photocatalytic material without ATP prepared in Comparative Example 1, and BTA represents the supported ternary heterojunction photocatalytic material prepared in Example 1.

[0074] from Figure 7 and Figure 8 As can be seen from this, the C of the two curves t The C0 values ​​of both materials (BT and BTA) decreased continuously with the duration of illumination, indicating that both materials can effectively degrade tetracycline (TC) under illumination. Under the same illumination conditions, the C0 values ​​of the BTA group... tThe degradation rate of CO was faster and greater: at 180 min, the degradation rate of BTA reached 85%, while the degradation rate of BT was only 44%. This indicates that the photocatalytic degradation performance of the supported ternary heterojunction photocatalytic material prepared in Example 1 is significantly better than that of the composite photocatalytic material without ATP prepared in Comparative Example 1, exhibiting a higher reaction rate and final degradation efficiency.

[0075] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A supported ternary heterojunction photocatalytic material, characterized in that, include: attapulgite soil carrier; Titanium dioxide and bismuth sulfide loaded on the surface of the attapulgite carrier; The bismuth sulfide and titanium dioxide form a heterojunction structure on the surface of attapulgite.

2. The supported ternary heterojunction photocatalytic material as described in claim 1, characterized in that, The mass ratio of bismuth sulfide, titanium dioxide and attapulgite carrier is (0.5~2):(0.5~2):(1~4).

3. The supported ternary heterojunction photocatalytic material as described in claim 1, characterized in that, The attapulgite is acid-activated attapulgite, and its morphology is a one-dimensional rod-shaped or fibrous structure.

4. A method for preparing a supported ternary heterojunction photocatalytic material according to any one of claims 1 to 3, characterized in that, include: The pretreated attapulgite was dispersed in a solvent, a titanium source was added, and the mixture was stirred to obtain a precursor solution. The bismuth source and sulfur source are dissolved in the precursor solution to obtain the precursor solution; The precursor solution was subjected to a hydrothermal reaction, and the product was then washed, dried, and calcined to obtain the supported ternary heterojunction photocatalytic material.

5. The preparation method of the supported ternary heterojunction photocatalytic material as described in claim 4, characterized in that, The titanium source includes at least one of tetrabutyl titanate, titanium sulfate, and titanium chloride. The solvent includes at least one of deionized water and ethylene glycol.

6. The method for preparing the supported ternary heterojunction photocatalytic material as described in claim 4, characterized in that, The bismuth source includes at least one of bismuth nitrate, bismuth chloride, or bismuth acetate. The sulfur source includes at least one of thiourea, sodium sulfide, or thioamide.

7. The preparation method of the supported ternary heterojunction photocatalytic material as described in claim 4, characterized in that, The hydrothermal reaction is carried out at a temperature of 120~180℃ for 6~18 hours, and the pH value of the reaction system is 1.0~4.

0.

8. The method for preparing the supported ternary heterojunction photocatalytic material as described in claim 4, characterized in that, The calcination treatment is carried out at a temperature of 300~500℃ for 1~4 hours.

9. The application of the supported ternary heterojunction photocatalytic material according to any one of claims 1 to 3, and the supported ternary heterojunction photocatalytic material prepared by the preparation method according to any one of claims 4 to 8, in the treatment of organic wastewater, characterized in that, The organic wastewater contains antibiotics or dyes, and the treatment process is carried out under visible light irradiation.

10. The application as described in claim 9, characterized in that, The antibiotics include tetracycline or ciprofloxacin; the dyes include methylene blue or methyl orange.

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