Photocatalyst CAU-17-at-Bi2MoO6 as well as preparation method and application thereof

Abstract

The invention discloses a photocatalyst CAU-17 (at) Bi2MoO6 as well as a preparation method and application of the photocatalyst CAU-17 (at) Bi2MoO6. The invention belongs to the technical field of synthesis of CAU-17-coated Bi2MoO6 photocatalysts, degradation of organic pollutants in water and the like, and the CAU-17-coated Bi2MoO6 composite material provided by the invention has excellent photocatalytic performance, can efficiently degrade the organic pollutants in water, provides a new solution for water pollution treatment, and has wide application prospects.

Description

TECHNICAL FIELD

[0001] The application relates to the synthesis of a CAU-17@Bi2MoO6 photocatalyst and degradation of organic pollutants in water bodies and the like technical field, and particularly relates to a photocatalyst CAU-17@Bi2MoO6 and a preparation method and application thereof. BACKGROUND

[0002] Water pollution refers to the phenomenon that the concentration of harmful substances in water bodies exceeds the normal level, affecting the ecological environment of water bodies and the quality of human life. With the acceleration of urbanization and the expansion of industrial production, the amount of sewage discharged has increased dramatically, bringing great pressure to the global water environment. The sources of water pollution mainly include industrial wastewater, agricultural wastewater, domestic sewage and chemical drugs. These pollutants not only pollute the drinking water source, but also pose a great threat to the survival of aquatic organisms. Harmful substances such as heavy metal ions, organic pollutants and pathogenic microorganisms in water bodies can accumulate through the food chain and ultimately affect human health. Heavy metals such as lead, mercury and cadmium have strong toxic effects on the nervous system, liver and kidneys and even cause cancer. Pesticides and organic chemical pollutants can cause endocrine disorders, immune system damage and other problems, and even lead to the extinction of biological populations. In addition, water pollution also directly affects the development of agricultural irrigation, fishery production and tourism, hindering the sustainable development of society and economy. Therefore, solving the problem of water pollution has become a major task that needs to be addressed globally, and efficient and economical water pollution treatment technologies are urgently needed.

[0003] At present, traditional wastewater treatment methods mainly include physical methods, chemical methods and biological methods. Physical methods such as filtration and adsorption are simple to operate, but have low treatment efficiency and may cause secondary pollution, which cannot meet the treatment needs of high-concentration pollutants. Chemical methods such as oxidation-reduction reaction and electrolysis can remove some pollutants in water, but have limited effect on complex organic pollutants and some refractory substances. In addition, the use of chemical agents in the treatment process is costly and may cause secondary pollution. Biological methods can degrade pollutants through microbial metabolism, but are sensitive to environmental temperature and pH, and have problems such as microbial death and excessive sludge in the biological treatment process. Therefore, traditional methods have problems such as low efficiency, high cost and secondary pollution in treating complex water pollutants, and new alternative technologies are urgently needed.

[0004] Photocatalysis is a process driven by light energy that can degrade organic pollutants, heavy metal ions and other harmful substances in water. Photocatalytic degradation technology has the following advantages: ① Green and environmentally friendly: photocatalytic reactions do not require additional chemicals and use sunlight or other light sources as energy, thus avoiding secondary pollution and meeting environmental protection requirements. ② High efficiency: photocatalysts can work at room temperature and atmospheric pressure, and have strong degradation ability for various organic pollutants, enabling efficient treatment of trace harmful substances in water. ③ Sustainability: photocatalytic processes do not consume catalysts, and catalysts can be reused in multiple reaction cycles, reducing treatment costs. ④ Wide spectral absorption capacity: some photocatalytic materials can absorb light of various wavelengths, including ultraviolet and visible light, enabling efficient operation under sunlight. Therefore, photocatalytic degradation technology, as a new water pollution treatment technology, has broad application prospects, especially for the treatment of complex water bodies and refractory pollutants.

[0005] Currently, research on photocatalysts mainly focuses on semiconductor materials, metal-organic frameworks (MOFs), and carbon-based materials. Common photocatalysts include TiO2, ZnO, g-C3N4, and other semiconductor materials. These materials have good catalytic performance under ultraviolet light, resulting in low utilization under sunlight. Therefore, improving their visible light response has become a research hotspot. Bi-based photocatalysts, such as Bi2MoO6 and BiOCl, have gradually become the mainstream direction of photocatalytic research due to their wide light absorption range, high photocatalytic activity, and good stability. Bi2MoO6, as a typical Bi-based material, has a high specific surface area and strong photocatalytic performance, showing broad application potential in organic pollutant degradation and water splitting. CAU-17, as a new Bi-MOF, has good structural stability, a large specific surface area, and adjustable pore structure, making it have good application prospects in the field of photocatalysis. However, the performance of single CAU-17 material in photocatalytic degradation of organic pollutants is still limited, so it needs to be modified and combined with other photocatalytic materials to further improve its catalytic performance.

[0006] To address the shortcomings of traditional photocatalytic materials, researchers have proposed various methods to improve photocatalytic performance. Common strategies to improve photocatalyst performance include: ① Material compounding: combining different types of photocatalytic materials can effectively improve the light response range, carrier migration speed, and reaction activity of photocatalysts. For example, combining MOFs materials with Bi-based materials can enhance their electron transport performance and improve the efficiency of catalytic reactions. ② Surface modification: surface modification of photocatalysts, such as doping and introducing surface active sites, can effectively improve the light absorption performance and catalytic activity of photocatalysts. ③ Nanocrystallization: preparing photocatalysts into nanomaterials can help improve their specific surface area and light absorption capacity, thereby enhancing their photocatalytic performance.

[0007] The CAU-17@Bi2MoO6 composite material proposed in this patent combines the metal-organic framework structure of CAU-17 with the excellent photocatalytic performance of Bi2MoO6, and has the following advantages: ① Dual photocatalytic effect: By combining CAU-17 and Bi2MoO6, the composite material exhibits strong photocatalytic activity in the visible light range, which can efficiently degrade organic pollutants in water. ② Excellent structural stability: As a MOF material, CAU-17 has good structural stability and a large specific surface area, which can provide more active sites and enhance the catalytic reaction effect. ③ Simple preparation process: The process of synthesizing CAU-17@Bi2MoO6 material in this patent is relatively simple, which can not only improve the photocatalytic performance of the material, but also reduce the synthesis cost, and has good prospects for industrial application. ④ Environmentally friendly and efficient: The CAU-17@Bi2MoO6 composite material can use sunlight for photocatalytic reaction without adding chemical reagents, which meets the requirements of green environmental protection and is suitable for the field of water pollution control.

[0008] In summary, the CAU-17@Bi2MoO6 composite material provided by this patent has excellent photocatalytic performance and can efficiently degrade organic pollutants in water, providing a new solution for water pollution control and having broad application prospects. Summary of the Invention

[0009] To address the problem of organic pollution in water bodies, this invention provides a CAU-17@Bi2MoO6 photocatalyst and its preparation method. The aim is to utilize this photocatalytic material to efficiently remove pollutants from water bodies. The technical solution of this invention is achieved through the following steps:

[0010] 1. Preparation of CAU-17

[0011] First, 1 mmol Bi(NO3)3·5H2O was dissolved in 50 mL of anhydrous methanol and stirred until homogeneous. Then, 3 mmol H3BTC was added and stirred continuously for 1 h. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The product was then dried under vacuum at 60 °C for 12 h to obtain CAU-17.

[0012] 2. Preparation of CAU-17@Bi2MoO6

[0013] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to between 7 and 10 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 8-12 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C for 12 h.

[0014] To compare the performance of CAU-17@Bi2MoO6 with that of Bi2MoO6, Bi2MoO6 was also synthesized in this invention, and the experimental scheme is as follows:

[0015] 3. Preparation of Bi2MoO6

[0016] First, 1 mmol Bi(NO3)3·5H2O was dissolved in 50 mL of anhydrous methanol and stirred until homogeneous. Then, 0.5 mmol Na2MO4·2H2O was added and stirred continuously for 1 h. Next, a certain amount of NaOH solution was added to the above solution to adjust the pH to 9. Then, the above solution was transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed 5 times by centrifugation with deionized water and anhydrous ethanol, and the obtained product was dried under vacuum at 60 °C for 12 h.

[0017] The features and beneficial effects of this invention are as follows:

[0018] (1) Dual photocatalytic effect

[0019] This invention prepares CAU-17@Bi2MoO6 composite material through a two-step method, which fully leverages the synergistic effect of the two components in the composite material. CAU-17 provides a large specific surface area and porous structure, while Bi2MoO6 improves the photocatalytic activity of the material. This composite material has a strong photocatalytic degradation ability under visible light, which can effectively treat organic pollutants in water and improve photocatalytic efficiency.

[0020] (2) Simple preparation process

[0021] The preparation process of CAU-17@Bi2MoO6 composite material is simple, easy to operate and has low energy consumption, which effectively reduces production costs.

[0022] (3) Good recyclability

[0023] The CAU-17@Bi2MoO6 composite material maintains high photocatalytic degradation efficiency even after multiple uses, exhibiting good stability and durability. This reduces the frequency of catalyst replacement, thereby lowering long-term operating costs and demonstrating high economic and environmental benefits. Attached Figure Description

[0024] Figure 1 The images show the physical images of the CAU-17, Bi2MoO6 and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention.

[0025] Figure 2 The XRD patterns of the CAU-17, Bi2MoO6 and CAU-17@Bi2MoO6 photocatalysts prepared in Example 31 of this invention are shown below.

[0026] Figure 3 SEM images of the CAU-17, Bi2MoO6 and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention;

[0027] Figure 4 The photoresponse diagrams are for the CAU-17, Bi2MoO6 and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention. Detailed Implementation

[0028] The instruments and characterization methods used in this invention are as follows:

[0029] (1) The X-ray diffractometer (XRD) used was a German Bruker D8 ADVANCE wide-angle X-ray diffractometer with a Cu target. Scanning range: 0–10°.

[0030] (2) Scanning electron microscope (SEM) was used to record the images of the scanned samples using a JEM2100PLUS.

[0031] (3) The electrochemical workstation is Chenhua CHI760E.

[0032] The testing process is as follows:

[0033] To test the photocatalyst's photoelectric response, 10 mg of CAU-17@Bi2MoO6 photocatalyst was added to 1 mL of ethanol and sonicated for 1 h. The completely ultrasonically dispersed solution was then dropped onto a 1×3 cm FTO sheet. Under a 300 W xenon lamp light source and NaSO4 electrolyte, a three-electrode system was used, with a Pt sheet electrode as the counter electrode and an Ag / AgCl electrode as the reference electrode. The photoresponse current of the photocatalyst was then measured.

[0034] The chemical reagents used in the embodiments of this invention were provided by Sinopharm Chemical Reagent Co., Ltd.

[0035] The present invention will now be described in detail with reference to specific embodiments. These embodiments are only for illustrating the present invention and are not intended to limit the scope of application of the present invention. Various modifications or alterations to the present invention and other equivalent forms are also within the scope limited by the appended claims.

[0036] Example 1:

[0037] (1) Preparation of CAU-17

[0038] First, 1 mmol Bi(NO3)3·5H2O was dissolved in 50 mL of anhydrous methanol and stirred until homogeneous. Then, 3 mmol H3BTC was added and stirred continuously for 1 h. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The product was then dried under vacuum at 60 °C for 12 h to obtain CAU-17.

[0039] (2) Preparation of CAU-17@Bi2MoO6

[0040] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 9 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 8 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0041] Example 2:

[0042] (1) Preparation of CAU-17

[0043] The preparation process of CAU-17 is described in step (1) of Example 1.

[0044] (2) Preparation of CAU-17@Bi2MoO6

[0045] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 9 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 9 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0046] Example 3:

[0047] (1) Preparation of CAU-17

[0048] The preparation process of CAU-17 is described in step (1) of Example 1.

[0049] (2) Preparation of CAU-17@Bi2MoO6

[0050] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 9 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0051] Example 4:

[0052] (1) Preparation of CAU-17

[0053] The preparation process of CAU-17 is described in step (1) of Example 1.

[0054] (2) Preparation of CAU-17@Bi2MoO6

[0055] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 9 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 11 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0056] Example 5:

[0057] (1) Preparation of CAU-17

[0058] The preparation process of CAU-17 is described in step (1) of Example 1.

[0059] (2) Preparation of CAU-17@Bi2MoO6

[0060] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 9 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 12 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0061] Example 6:

[0062] (1) Preparation of CAU-17

[0063] The preparation process of CAU-17 is described in step (1) of Example 1.

[0064] (2) Preparation of CAU-17@Bi2MoO6

[0065] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 7 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0066] Example 7:

[0067] (1) Preparation of CAU-17

[0068] The preparation process of CAU-17 is described in step (1) of Example 1.

[0069] (2) Preparation of CAU-17@Bi2MoO6

[0070] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 8 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0071] Example 8:

[0072] (1) Preparation of CAU-17

[0073] The preparation process of CAU-17 is described in step (1) of Example 1.

[0074] (2) Preparation of CAU-17@Bi2MoO6

[0075] First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to 10 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The resulting product was then vacuum dried at 60 °C for 12 h.

[0076] Results Analysis

[0077] Figure 1 The images show the physical images of the CAU-17, Bi2MoO6 and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention.

[0078] Figure 2The XRD patterns of the CAU-17, Bi2MoO6, and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention are shown. The XRD results show that the diffraction peaks of the CAU-17 sample are highly consistent with the structure of Bi-MOF (CAU-17) in the standard card, indicating that the crystal structure of CAU-17 has been successfully preserved. For the Bi2MoO6 sample, its diffraction peaks are consistent with the characteristic peaks in the Bi2MoO6 standard card (PDF#76-2388), confirming the presence of Bi2MoO6. In the XRD pattern of the CAU-17@Bi2MoO6 composite material, both the characteristic peaks of CAU-17 and the typical diffraction peaks of Bi2MoO6 are shown, indicating that Bi2MoO6 is successfully wrapped around the outside of CAU-17 to form a composite material. This result proves that the synthesized CAU-17@Bi2MoO6 material has good structural integrity and composite effect, and verifies the material synthesis process.

[0079] Figure 3 SEM images of the CAU-17, Bi2MoO6, and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention are shown. The results show that CAU-17 exhibits a typical columnar structure with a diameter of approximately 10 μm, indicating its good crystal morphology. Bi2MoO6, on the other hand, has a nanoparticle structure with a small particle size and uniform distribution. In the CAU-17@Bi2MoO6 composite material, the Bi2MoO6 nanoparticles are uniformly coated on the outer layer of CAU-17, forming a composite structure. This phenomenon indicates that Bi2MoO6 has been successfully composited with CAU-17, proving the success of the material synthesis process. The composite material retains the columnar morphology of CAU-17, while the uniform coating of Bi2MoO6 nanoparticles shows its good loading effect.

[0080] Figure 4 The photoresponse diagrams of CAU-17, Bi2MoO6, and CAU-17@Bi2MoO6 photocatalysts prepared in Example 3 of this invention are shown. The tests were conducted using a xenon lamp (PLS-SXE300C; wavelength range: 420nm≤λ≤780nm, light intensity: 350mW / cm²). 2 Using CAU-17@Bi₂MoO₆ as the light source, the photocurrent response curve was tested in a three-electrode system. An FTO photoelectrode loaded with 10 mg of catalyst was used as the anode, a Pt sheet as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Tests were conducted at 0.7 V vs. Ag / AgCl. As shown in the figure, CAU-17@Bi₂MoO₆ can reach a maximum photocurrent response of 22 μA / cm. 2The CAU-17@Bi2MoO6 material exhibits superior photoelectric conversion performance compared to CAU-17 and Bi2MoO6, and demonstrates excellent stability. This result indicates that the CAU-17@Bi2MoO6 material possesses outstanding photoelectric conversion performance under illumination, enabling it to efficiently convert light energy into electrical energy. Its stable photocurrent response further demonstrates the potential of this material in the field of photocatalysis, indicating its broad application prospects in optoelectronic technology. These performance characteristics lay a solid foundation for in-depth research on the practical applications of CAU-17@Bi2MoO6 in photocatalysis and photoelectrochemical reactions.

[0081] In summary, this invention synthesizes CAU-17@Bi2MoO6 material. This efficient synthesis method not only reduces energy consumption but also makes the production process more economical and environmentally friendly. Furthermore, the temperature during the reaction process can be precisely controlled, effectively adjusting the particle size of the CAU-17@Bi2MoO6 photocatalyst. The generated nanoparticles have a large specific surface area, significantly enhancing the activity of the photocatalyst and enabling it to exhibit higher catalytic efficiency and reaction rate in the degradation of organic pollutants. The synthesized CAU-17@Bi2MoO6 photocatalyst exhibits excellent photocatalytic performance. Its optimized crystal structure and small particle size greatly improve its activity under visible light, enabling it to efficiently degrade various organic pollutants. Therefore, this material has broad application prospects in the field of environmental remediation.

Claims

1. A photocatalyst CAU-17@Bi2MoO6 and its preparation method, characterized in that: Includes the following steps: (1) Preparation of CAU-17 First, 1 mmol Bi(NO3)3·5H2O was dissolved in 50 mL of anhydrous methanol and stirred until homogeneous. Then, 3 mmol H3BTC was added and stirred continuously for 1 h. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 10 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol. The product was then dried under vacuum at 60 °C for 12 h to obtain CAU-17. (2) Preparation of CAU-17@Bi2MoO6 First, 1 mmol of CAU-17 was dissolved in 50 mL of DMF and stirred continuously for 1 h to ensure uniform dispersion. Then, 0.5 mmol of Na2MO4·2H2O was dissolved in the suspension. The pH of the solution was adjusted to between 7 and 10 with NaOH. The solution was then transferred to a high-pressure reactor and reacted at 100 °C for 8-12 h. Finally, the product was washed five times by centrifugation with deionized water and anhydrous ethanol, and then dried under vacuum at 60 °C for 12 h.

2. The preparation method of the novel composite photocatalyst CAU-17@Bi2MoO6 according to claim 1, characterized in that: In step (2), the solution pH is 7, 8, 9 and 10, and the reaction time is 8h, 9h, 10h, 11h and 12h respectively.

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