Yeast bionic BiVO4 composite photocatalytic material as well as synthesis method and application thereof

Abstract

The invention discloses a yeast bionic BiVO4 composite photocatalytic material and a synthesis method and application thereof.The synthesis method comprises the steps that firstly, bismuth nitrate pentahydrate, sodium dodecyl benzene sulfonate, nitric acid, ammonium metavanadate and sodium hydroxide serve as raw materials, yeast is added at the same time, and a yeast / BiVO4 composite photocatalyst is prepared through a hydrothermal reaction; and the photocatalyst is used for photocatalytic degradation of 2, 4-dichlorophenol. A hydrothermal reaction method is used, and the synthesis process is simple; the yeast / BiVO4 composite material is of a spherical structure, and compared with a traditional nano-powder or random-form catalyst, the three-dimensional spherical photocatalyst has the main advantages that the three-dimensional spherical photocatalyst is derived from a unique physical structure and can bring chemical property improvement, so that the efficiency of photocatalytic degradation of 2, 4-dichlorophenol is improved.

Description

Technical Field

[0001] This invention belongs to the technical field, specifically relating to a yeast-inspired BiVO4 composite photocatalytic material, its synthesis method, and its application. Background Technology

[0002] Water pollution poses a severe challenge to ecological security, necessitating the search for efficient treatment methods. Compared to traditional wastewater treatment processes, utilizing solar energy to drive pollutant degradation is an environmentally friendly and efficient technological strategy. The key to achieving this process lies in developing high-performance photocatalysts. Existing photocatalytic materials suffer from problems such as narrow light response range, low electron-hole pair separation efficiency, and low photocatalytic degradation rate. Researchers have employed various methods to improve their photocatalytic activity, such as doping, the construction of heterojunctions, and the deposition of co-catalysts.

[0003] BiVO4 is a promising visible-light-driven semiconductor photocatalyst with advantages such as low production cost, good photostability, and good response to visible light excitation. However, the rapid recombination of photoinduced charge carriers limits its photocatalytic activity. Synthetic systems mimicking natural enzymes are renowned for their high catalytic activity and diverse substrate selectivity, and have been extensively studied in the fields of energy and environmental crises for many years. However, the practical application of natural enzymes as oxidation catalysts is limited by their insufficient operational stability under harsh environments, oxidative degradation problems, synthetic difficulties, and high costs. Yeast, as a single-celled eukaryotic model organism, has inspired the development of dynamic material systems with self-repair or self-growth potential due to its efficient self-replication and proliferation capabilities. Yeast's precise self-assembly capabilities (such as forming multilayered cell walls with excellent mechanical properties and selective permeability, or adhesive and resistant biofilms) provide a structural blueprint for the development of high-performance biomimetic composite materials, selective barrier membranes, and smart coatings.

[0004] Furthermore, yeast is readily available. Therefore, if yeast can be used to biomimetically regulate the structure of BiVO4, it is expected to improve ion transport efficiency from a structural perspective, thereby improving electrochemical performance, which is also conducive to environmental and economic sustainable development. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for synthesizing a yeast-inspired BiVO4 composite photocatalytic material.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including, Bismuth nitrate pentahydrate and sodium dodecylbenzenesulfonate were dissolved in nitric acid solution and stirred to obtain solution I; Ammonium metavanadate is dissolved in sodium hydroxide solution and stirred to obtain solution II; After mixing solutions I and II, stirring was continued. The pH was adjusted to alkaline, and yeast was added. After being fully dispersed, the mixture was placed in a reaction vessel for hydrothermal reaction. After the reaction was completed, the mixture was cooled, centrifuged, washed with water and ethanol, and dried to obtain the yeast-inspired BiVO4 composite photocatalytic material.

[0009] In a preferred embodiment of the synthesis method of the yeast biomimetic BiVO4 composite photocatalytic material of the present invention, the molar ratio of bismuth nitrate pentahydrate, sodium dodecylbenzenesulfonate, and ammonium metavanadate is 1.4:0.8~1.2:1.4.

[0010] In a preferred embodiment of the synthesis method of the yeast biomimetic BiVO4 composite photocatalytic material of the present invention, the volume ratio of the nitric acid solution to the sodium hydroxide solution is 1~3:1~3.

[0011] In a preferred embodiment of the synthesis method of the yeast-inspired BiVO4 composite photocatalytic material of the present invention, the mass ratio of ammonium metavanadate to yeast is 177:5~30.

[0012] In a preferred embodiment of the synthesis method of the yeast-inspired BiVO4 composite photocatalytic material of the present invention, the hydrothermal reaction temperature is 160~180℃.

[0013] In a preferred embodiment of the synthesis method of the yeast-inspired BiVO4 composite photocatalytic material of the present invention, the hydrothermal reaction time is 3-12 h.

[0014] The purpose of this invention is to provide a yeast-inspired BiVO4 composite photocatalytic material and its application in the degradation of 2,4-dichlorophenol.

[0015] Beneficial effects of this invention: This invention utilizes a yeast-inspired BiVO4 composite photocatalyst to prepare and degrade 2,4-dichlorophenol in wastewater. The multilayered and porous nature of yeast, when combined with BiVO4, expands the contact area between the material and the target pollutant, increasing the probability of generating active species (superoxide radicals, hydroxyl radicals, etc.) and thus enhancing the degradation efficiency of 2,4-dichlorophenol in the environment. Compared to other modification methods, it can serve as a template to regulate the growth morphology of BiVO4, thereby altering catalytic activity and significantly improving pollutant degradation rates. This method avoids resource waste and the formation of additional pollution, is simple to operate, and represents a green and environmentally friendly high-efficiency treatment technology. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 The steady-state fluorescence images are of the yeast / BiVO4 composite photocatalyst prepared in Example 1 and the BiVO4 photocatalyst prepared in Comparative Example 1.

[0017] Figure 2 The UV-Vis diffuse reflectance spectra of the yeast / BiVO4 composite photocatalyst prepared in Example 1 and the BiVO4 photocatalyst prepared in Comparative Example 1 are shown.

[0018] Figure 3 The images show SEM images of the yeast / BiVO4 composite photocatalyst prepared in Example 1 and the BiVO4 photocatalyst prepared in Comparative Example 1.

[0019] Figure 4 The graph shows a comparison of the photocatalytic activity test results of the catalysts prepared in Examples 1 to 5 and Comparative Example 1. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0023] Unless otherwise specified, all raw materials used in this invention are commercially available in the art. Specifically, the bismuth nitrate pentahydrate (Bi(NO3)3·5H2O) and sodium dodecylbenzenesulfonate (C) used in this invention are... 18 H 29 NaO3S), sodium metavanadate (NH4VO3), nitric acid solution, sodium hydroxide solution, ethanol, and 2,4-dichlorophenol were purchased from Sinopharm Chemical Reagent Co., Ltd., and the yeast was Angel Yeast purchased from a supermarket.

[0024] The method for evaluating the photocatalytic activity of the prepared catalyst in this invention is as follows: In a photochemical reactor, irradiated with a 300 W xenon lamp, 50 mL of simulated 2,4-dichlorophenol wastewater at a concentration of 10 mg / L was added to the reactor and its initial concentration was measured. Then, 10 mg of catalyst was added, and the reactor was magnetically stirred to keep the catalyst in a suspended or floating state. After dark adsorption for half an hour, samples were taken for analysis at 15-30 min intervals during the light irradiation process. After centrifugation, the absorbance of the supernatant was measured using a spectrophotometer. The degradation rate was calculated using the following formula: ƞ=[( 1-C t / C0)]×100% Where C0 is the absorbance of 2,4-dichlorophenol at adsorption equilibrium, and C... t The absorbance of the 2,4-dichlorophenol solution was measured by sampling at regular intervals.

[0025] Example 1 This embodiment provides a method for synthesizing a yeast-inspired BiVO4 composite photocatalytic material, specifically: 0.4851 g of bismuth nitrate pentahydrate and 0.25 g of sodium dodecylbenzenesulfonate were dissolved in 10 mL of 4M nitric acid solution; 0.1170 g of ammonium metavanadate was dissolved in 10 mL of 2M sodium hydroxide solution; At this point, the molar ratio of bismuth nitrate pentahydrate, sodium dodecylbenzenesulfonate, and ammonium metavanadate is 1.4:1:1.4; After 30 minutes, the two solutions were mixed and stirred for another 30 minutes. The pH was adjusted to 7 with 2 M sodium hydroxide solution, and 15 mg of yeast was added and dispersed evenly. The mass ratio of ammonium metavanadate to yeast was 117:15. The reaction was carried out at 160°C for 6 hours. After the reaction was completed, the mixture was washed with water and ethanol in sequence and then dried to obtain the yeast / BiVO4 composite photocatalyst of this embodiment.

[0026] Comparative Example 1 This comparative example provides a method for preparing BiVO4, specifically: 0.4851 g of bismuth nitrate pentahydrate and 0.25 g of sodium dodecylbenzenesulfonate were dissolved in 10 mL of 4M nitric acid solution; 0.1170 g of ammonium metavanadate was dissolved in 10 mL of 2M sodium hydroxide solution; After 30 minutes, the two solutions were mixed and stirred for another 30 minutes. The pH was adjusted to 7 with 2 M sodium hydroxide solution, and the reaction was carried out at 160℃ for 6 hours. After the reaction was completed, the mixture was washed with water and ethanol in sequence and then dried to obtain the BiVO4 photocatalyst of this comparative example.

[0027] Figure 1 The steady-state fluorescence images of the yeast / BiVO4 photocatalyst prepared in Example 1 and the BiVO4 photocatalyst prepared in Comparative Example 1 are shown. It can be seen from the figure that the fluorescence intensity of the yeast / BiVO4 material is lower than that of BiVO4, indicating that the recombination time of electron and hole pairs of the yeast / BiVO4 material under light irradiation is longer, thus providing a greater probability of generating active species and improving the photocatalytic degradation rate.

[0028] Figure 2 The UV-Vis diffuse reflectance spectra of the yeast / BiVO4 photocatalyst prepared in Example 1 and the BiVO4 photocatalyst prepared in Comparative Example 1 are shown in the figure. It can be seen from the figure that the photoresponse range of the yeast / BiVO4 material is wider than that of BiVO4, and the visible light absorption capacity is stronger. This indicates that the yeast / BiVO4 material formed is more conducive to the utilization of light energy, providing more opportunities for the generation of active species in the photocatalytic process, thereby improving the degradation efficiency.

[0029] Figure 3 The images show SEM images of the yeast / BiVO4 photocatalyst prepared in Example 1 and the BiVO4 photocatalyst prepared in Comparative Example 1. As can be seen from the images, the yeast / BiVO4 material is a spherical material, similar to the microstructure of yeast. The sheet-like material is pure BiVO4. The spherical structure of the catalyst is conducive to the contact between pollutants, thereby improving the catalytic efficiency and degradation rate.

[0030] Example 2 The difference between this embodiment and Example 1 is that the amount of yeast added to the system is adjusted to 5 mg, while the remaining steps and processes are the same as in Example 1, thus obtaining the yeast / BiVO4 composite photocatalyst of this embodiment.

[0031] Example 3 The difference between this embodiment and Example 1 is that the amount of yeast added to the system is adjusted to 10 mg, while the remaining steps and processes are the same as in Example 1, thus obtaining the yeast / BiVO4 composite photocatalyst of this embodiment.

[0032] Example 4 The difference between this embodiment and Example 1 is that the amount of yeast added to the system is adjusted to 20 mg, while the remaining steps and processes are the same as in Example 1, thus obtaining the yeast / BiVO4 composite photocatalyst of this embodiment.

[0033] Example 5 The difference between this embodiment and Example 1 is that the amount of yeast added to the system is adjusted to 30 mg, while the remaining steps and processes are the same as in Example 1, thus obtaining the yeast / BiVO4 composite photocatalyst of this embodiment.

[0034] The photocatalytic activity of the catalysts prepared in Examples 1-5 and Comparative Example 1 was tested, and the results are shown in Table 1 and 2. Figure 4 As shown.

[0035] Table 1

[0036] From Table 1 and Figure 4 The results show that the degradation rate of pure-phase BiVO4 materials is significantly lower than that of yeast / BiVO4 composite materials. The amount of yeast added has a significant impact on performance, and the reaction time also has some influence on performance.

[0037] Comparative Example 1 This comparative example cites the literature "Highly visible-light active, eco-friendly artificial enzyme and 3D Bi4Ti30". 12 As a comparison, this approach immobilizes the artificial enzyme heme on the semiconductor photocatalyst Bi4Ti30. 12 On the surface, a biomimetic photocatalyst, heme-Bi4Ti30, was prepared. 12(HBTO) exhibits extremely high photochemical efficiency in the photodegradation of tetracycline hydrochloride (TCHCL) and the photoreduction of Cr(VI) to Cr(II).

[0038] However, since this scheme uses biological enzymes as modifiers, its catalytic activity mainly depends on the peroxidase-like activity of heme. During the reaction, H2O2 needs to be consumed as an oxidant, which can easily cause secondary pollution and has a high cost. At the same time, heme is easily affected by pH and temperature, and its activity is significantly reduced under acidic conditions (pH<4).

[0039] This application uses yeast as raw material and utilizes its special structure BiVO4 to provide a three-dimensional growth scaffold, which not only increases the adsorption sites for pollutants, but also promotes the separation of photogenerated carriers through the confinement effect. It is not easily denatured by temperature. In addition, the oxygen vacancies naturally formed on the surface of BiVO4 through the carbonization process of yeast can serve as electron capture centers, prolonging the carrier lifetime and further enhancing the reduction ability.

[0040] Comparative Example 2 This comparative example references the patent "Magnetic Yeast Carbon Supported BiVO4 Photocatalyst and Its Preparation and Application", publication number CN107684913 A. This scheme uses yeast as the carbon source and Fe3O4 as the magnetic source, and uses hydrothermal and solvothermal methods to prepare magnetic yeast carbon supported BiVO4 composite photocatalyst BiVO4 / Fe3O4 / C for photocatalytic degradation of phenolic pollutants under visible light conditions.

[0041] In this scheme, the yeast is aged and carbonized with zinc chloride and then used as a Fe3O4 / C carrier. Its main function is to provide high specific surface area BiVO4 loaded on the surface in a dumbbell shape. The yeast used in this application serves as a biological template, guiding BiVO4 to grow along the porous network of the cell wall under hydrothermal conditions to form a spherical biomimetic structure. This provides a three-dimensional growth scaffold for BiVO4, forming a hierarchical porous structure and achieving a three-in-one optimization of morphology regulation, adsorption enhancement, and carrier separation.

[0042] Furthermore, the methods in Comparative Examples 1 and 2 target tetracycline (TC) and / or Cr (VI) for degradation. While they exhibit high degradation efficiency for the target pollutants, their catalytic mechanisms have limited applicability to chlorophenolic pollutants. In contrast, the yeast / BiVO4 of this application can simultaneously generate active and non-radical pathways, demonstrating a broader catalytic capacity. Moreover, the amino and carboxyl functional groups of the yeast cell wall can synergistically adsorb negatively charged 2,4-dichlorophenol molecules through electrostatic interactions, achieving highly efficient degradation.

[0043] In summary, the yeast-inspired BiVO4 composite photocatalyst material of this invention achieves the purpose of preparing a yeast-inspired BiVO4 composite photocatalyst and degrading 2,4-dichlorophenol in wastewater. The multilayered and porous nature of yeast, after being combined with BiVO4, can expand the contact area between the material and the target pollutant, increase the probability of the catalyst generating active species (superoxide radicals, hydroxyl radicals, etc.), and increase the degradation efficiency of 2,4-dichlorophenol in the environment. Compared with other modification methods, it can be used as a template to regulate the growth morphology of BiVO4, thereby changing the catalytic ability and significantly improving the pollutant degradation rate. This method does not cause resource waste or the formation of additional pollution, and is simple to operate, making it a green and environmentally friendly high-efficiency treatment technology.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for synthesizing a yeast-inspired BiVO4 composite photocatalytic material, characterized in that: include, Bismuth nitrate pentahydrate and sodium dodecylbenzenesulfonate were dissolved in nitric acid solution and stirred to obtain solution I; Ammonium metavanadate is dissolved in sodium hydroxide solution and stirred to obtain solution II; After mixing solutions I and II, stirring was continued. The pH was adjusted to alkaline, and yeast was added. After being fully dispersed, the mixture was placed in a reaction vessel for hydrothermal reaction. After the reaction was completed, the mixture was cooled, centrifuged, washed with water and ethanol, and dried to obtain the yeast-inspired BiVO4 composite photocatalytic material.

2. The method for synthesizing the yeast-inspired BiVO4 composite photocatalytic material as described in claim 1, characterized in that: The molar ratio of bismuth nitrate pentahydrate, sodium dodecylbenzenesulfonate, and ammonium metavanadate is 1.4:0.8 to 1.2:1.

4.

3. The method for synthesizing the yeast-inspired BiVO4 composite photocatalytic material as described in claim 1, characterized in that: The volume ratio of the nitric acid solution to the sodium hydroxide solution is 1~3:1~3.

4. The method for synthesizing the yeast-inspired BiVO4 composite photocatalytic material as described in claim 2, characterized in that: The mass ratio of ammonium metavanadate to yeast is 177:5~30.

5. The method for synthesizing the yeast-inspired BiVO4 composite photocatalytic material as described in claim 1, characterized in that: The hydrothermal reaction temperature is 160~180℃.

6. The method for synthesizing the yeast-inspired BiVO4 composite photocatalytic material as described in claim 5, characterized in that: The hydrothermal reaction takes 3 to 12 hours.

7. The yeast-inspired BiVO4 composite photocatalytic material synthesized by the synthesis method described in any one of claims 1 to 6.

8. The application of the yeast-inspired BiVO4 composite photocatalytic material as described in claim 7 in the degradation of 2,4-dichlorophenol.

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