Device and method for synergistically degrading pollutants through friction coupling photocatalysis

Abstract

The invention provides a device and a method for synergistically degrading pollutants through friction coupling photocatalysis. According to the method for synergistically degrading the pollutants through the friction coupling photocatalysis, the device for synergistically degrading the pollutants through the friction coupling photocatalysis is adopted; comprising the following steps: preparing a TiO2 / Bi2MoO6 catalyst; the method comprises the following steps: adding a TiO2 / Bi2MoO6 catalyst into a ciprofloxacin pollutant solution, and putting the ciprofloxacin pollutant solution into a reactor in a dark box; turning on a magnetic stirrer and a light source, and degrading ciprofloxacin under the action of friction coupling photocatalysis. Friction catalysis and photocatalysis are innovatively coupled, and the degradation rate can reach about 98%.

Description

Technical Field

[0001] The present invention belongs to the technical field of pollution control, and in particular relates to a device and method for friction-coupled photocatalytic synergistic degradation of pollutants. Background Art

[0002] Photocatalytic reactions were first discovered by Professor Akira Fujishima. Photocatalysts generate photogenerated electrons and holes under illumination, then utilize the reducing properties of the photogenerated electrons or the oxidizing properties of the holes to remove target pollutants. Tribocatalysis is an emerging catalytic technology that uses mechanical friction to generate active oxidizing species to oxidize and degrade pollutants. Tribo-coupled photocatalysis combines photocatalysis and tribocatalysis, addressing practical challenges in photocatalysis while improving the efficiency of tribocatalysis.

[0003] There have been many studies on photocatalysis, such as Jiang Youjun [1] et al. prepared CoAl-LDH / Bi2MoO6 for photocatalytic degradation of Rhodamine B, and the removal rate of RhB with a mass concentration of 10 mg / L reached 97.8% within 60 min; [2] et al. prepared Bi2MoO6 modified g-C3N4 for photocatalytic degradation of Rhodamine B. The g-C3N4 / Bi2MoO6 composite material showed efficient degradation activity for Rhodamine B under visible light. Among them, the best photocatalytic degradation performance was shown when the mass ratio of Bi2MoO6 to g-C3N4 was 10%, and its degradation rate was 6.5 and 3.3 times that of pure g-C3N4 and Bi2MoO6, respectively. There are not many studies on tribocatalysis at present. Xing Yulu of our group [3][4] et al. used Bi2MoO6 to tribocatalyze the degradation of Rhodamine B. Under the conditions of a rotation speed of 700 r / min, a RhB concentration of 5 mg / L, a catalyst dosage of 1 g / L, and a 35 mm PTFE magnet, the degradation rate of 5 mg / L RhB reached 99.02% after 300 minutes. These studies all focused on either photocatalytic or tribocatalytic degradation. Bi2MoO6 exhibits excellent degradation performance in both photocatalytic and tribocatalytic processes due to its narrow bandgap and unique layered structure. However, the use of Bi2MoO6 for tribo-coupled photocatalytic degradation has not yet been reported.

[0004] In practical applications, photocatalysis has two problems: 1) the water bottom is too deep and light cannot penetrate the entire water body; 2) the dye wastewater itself is colored and has poor light transmittance. As an emerging catalytic technology, friction catalysis has the problem of low catalytic efficiency.

[0005] In view of this, this application is hereby filed. Summary of the Invention

[0006] In order to solve one of the above-mentioned technical defects, an apparatus and method for friction-coupled photocatalytic synergistic degradation of pollutants are provided in an embodiment of the present application.

[0007] The technical solution of the present application provides a device for friction-coupled photocatalytic synergistic degradation of pollutants, comprising:

[0008] A dark box, wherein a magnetic stirrer is provided in the dark box;

[0009] A reactor, disposed on the magnetic stirrer, serving as a reaction vessel for friction-coupled photocatalytic synergistic degradation of pollutants;

[0010] The light source is arranged in the dark box and is used to provide light energy for friction-coupled photocatalytic synergistic degradation of pollutants.

[0011] Preferably, the light source is a 150W xenon lamp.

[0012] The technical solution of the present application provides a method for the synergistic degradation of pollutants by friction-coupled photocatalysis, which uses the above-mentioned device for the synergistic degradation of pollutants by friction-coupled photocatalysis; the method comprises the following steps:

[0013] Preparation of TiO2 / Bi2MoO6 catalyst;

[0014] Ciprofloxacin was selected as the target pollutant;

[0015] The TiO2 / Bi2MoO6 catalyst was added to the ciprofloxacin pollutant solution and placed in a reactor in a dark box;

[0016] The magnetic stirrer and the light source were turned on to degrade ciprofloxacin under the action of friction-coupled photocatalysis.

[0017] Preferably, the preparation of TiO2 / Bi2MoO6 catalyst comprises:

[0018] S1: Add tetrabutyl titanate to anhydrous ethanol and stir to obtain a uniform precursor mixture;

[0019] S2: Mix anhydrous ethanol, deionized water and cetyltrimethylammonium bromide, mix with the precursor mixture in S1, wash and dry the mixture, and then place it in a muffle furnace for one calcination to obtain TiO2;

[0020] S3: Dissolve Bi(NO3)3·5H2O, Na2MoO4·2H2O and TiO2 in ethylene glycol solution, stir, and transfer the resulting transparent solution to a hydrothermal reactor; perform dissolution heat treatment under preset conditions;

[0021] S4: After cooling to room temperature, the precipitate is collected by filtration, washed, and dried;

[0022] S5: Place the mixture in a muffle furnace and calcine it a second time to obtain a TiO2 / Bi2MoO6 catalyst.

[0023] Preferably, in step S2, the primary calcination conditions are: calcination at 400-500° C. for 1-3 hours;

[0024] In step S5, the secondary calcination conditions are: calcination at 200-400° C. for 2-4 hours.

[0025] Preferably, in step S3, the preset conditions are: dissolution heat treatment at 150-170° C. for 10-14 hours.

[0026] Preferably, the magnetic stirrer and the light source are turned on, and before that, the process further comprises: performing a dark adsorption stage for 30-60 minutes until adsorption equilibrium is reached between the catalyst and ciprofloxacin.

[0027] Beneficial effects of this application:

[0028] 1. This application innovatively couples tribocatalysis with photocatalysis. On the one hand, light irradiates the catalyst surface, causing the catalyst to produce a light response. On the other hand, friction also provides energy to the catalyst, causing electronic transitions in the catalyst to generate more electrons. + The electrons generated by the electron transition are transferred from the catalyst surface to the stirring rod under the action of friction. This electron transfer process further suppresses the electrons and h + The synergistic effect between the two improves the electron transfer efficiency and enhances the photocatalytic efficiency.

[0029] 2. Bi2MoO6, as a bismuth-based material, is not only a narrow bandgap material, but also has a unique layered structure that forms an internal electric field, which is beneficial to the transfer of electrons, thereby better realizing photocatalysis and tribocatalysis. This application uses tribocatalysis to synergize photocatalysis to suppress the transfer of electrons and h + The composite improves the photocatalytic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 SEM of TiO2 / Bi2MoO6 prepared in Example 1 Figure 1 ;

[0032] Figure 2 SEM of TiO2 / Bi2MoO6 prepared in Example 1 Figure 2 ;

[0033] Figure 3 XRD patterns of TiO2 / Bi2MoO6, TiO2 and Bi2MoO6 in Example 1;

[0034] Figure 4 A diagram of the device for friction-coupled photocatalytic synergistic degradation of pollutants according to the present application;

[0035] Figure 5 This is the diagram of ciprofloxacin degradation efficiency under different systems;

[0036] Figure 6 Figure 2 shows the transient current situation under different systems. DETAILED DESCRIPTION

[0037] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless they conflict.

[0038] Example 1

[0039] First, transfer 5 mL of tetrabutyl titanate into 50 mL of anhydrous ethanol and stir at 300 r / min for 20 minutes to obtain a uniform precursor mixture; then take 10 mL of anhydrous ethanol, 5 mL of deionized water and 0.15 g of hexadecyltrimethylammonium bromide and mix them. Wash and dry the mixture, then place it in a muffle furnace and calcine it at 400-500°C for 1-3 hours to obtain TiO2.

[0040] Next, 0.485g of Bi(NO₃)₃·5H₂O, 0.121g of Na₂MoO₄·2H₂O, and 0.08g of TiO₂ were dissolved in 30mL of ethylene glycol solution. After stirring for 30 minutes, the resulting transparent solution was transferred to a hydrothermal reactor and heat-treated at 150-170°C for 10-14 hours. After cooling to room temperature, the resulting precipitate was collected by filtration, washed, and dried. The precipitate was then calcined in a muffle furnace at 200-400°C for 2-4 hours. This resulted in the TiO₂ / Bi₂MoO₆ catalyst.

[0041] Example 2

[0042] The experimental process involves adding a TiO2 / Bi2MoO6 catalyst to a solution of ciprofloxacin contaminants and placing it in a darkened reactor. The TiO2 / Bi2MoO6 catalyst degrades ciprofloxacin through friction-coupled photocatalysis. The specific steps include a 30-60 minute dark adsorption phase, during which neither the magnetic stirrer nor the light source is turned on. Once adsorption equilibrium is reached between the catalyst and ciprofloxacin, the magnetic stirrer and light source are turned on simultaneously. After a period of reaction, the degradation rate reaches approximately 98%.

[0043] Example 3

[0044] This application provides a device for friction-coupled photocatalytic synergistic degradation of pollutants, comprising a dark box, a reactor, and a light source. The dark box is provided with a magnetic stirrer; the reactor is mounted on the magnetic stirrer and serves as a reaction vessel for the friction-coupled photocatalytic synergistic degradation of pollutants; and the light source is disposed within the dark box to provide light energy for the friction-coupled photocatalytic synergistic degradation of pollutants.

[0045] Specifically, the entire reaction apparatus consists of a dark box, a reactor, a 150W xenon lamp light source, and a magnetic stirrer. The experimental procedure is as follows: The magnetic stirrer is placed in the dark box, a beaker is placed on top of it, and the beaker is shielded at 100 mL or below with an opaque baffle. 200 mL of a 10 mg / L aqueous solution of ciprofloxacin is added to the beaker and allowed to adsorb in the dark for a period of time until ciprofloxacin reaches adsorption equilibrium in the reactor. The light source and magnetic stirrer are then turned on simultaneously. Samples are taken at regular intervals, and the absorbance is measured at 276 nm using a UV-visible spectrophotometer to calculate the removal rate.

[0046] Specifically, Figure 1 SEM of TiO2 / Bi2MoO6 prepared in Example 1 Figure 1 ; Figure 2 SEM of TiO2 / Bi2MoO6 prepared in Example 1 Figure 2 ; Figure 3 XRD patterns of TiO2 / Bi2MoO6, TiO2 and Bi2MoO6 in Example 1;

[0047] from Figure 1 and Figure 2 As can be seen in the figure, TiO2 exhibits a flake-like structure, approximately 4-6 μm in size, while Bi2MoO6 exhibits a spherical structure, approximately 1-3 μm in diameter. Bi2MoO6 is loaded onto the surface of TiO2. SEM images demonstrate the successful preparation of our material.

[0048] from Figure 3We can see that the strong peaks of the prepared Bi2MoO6 at 2θ of 10.89°, 28.25°, 31.86°, 32.61°, 47.15°, 55.56° and 58.43° respectively conform to the (020), (131), (141), (002), (062), (133) and (262) crystal planes of the Bi2MoO6 standard card. The diffraction peaks of the prepared TiO2 at 2θ of 25.31°, 37.86°, and 62.72° correspond to the (101), (004), and (116) crystal planes of anatase TiO2 (JCPDS: 89-4921). The composite material also meets these characteristic peaks, proving the successful compounding of the materials.

[0049] Figure 5 It reflects the ciprofloxacin degradation efficiency of the three materials in the three systems. From this we can see that no matter which material, it has the best degradation effect in the friction coupled photocatalytic system.

[0050] from Figure 6 We can clearly see the synergistic effect between photocatalysis and tribocatalysis from the current signal intensity. The mechanism is as follows: on the one hand, light irradiates the catalyst surface, and the catalyst produces a photoresponse. On the other hand, friction also provides energy to the catalyst, causing electronic transitions in the catalyst, generating more electrons, h + The electrons generated by the electron transition are transferred from the catalyst surface to the stirring rod under the action of friction. This electron transfer process further suppresses the electrons and h + The synergistic effect between the two improves the electron transfer efficiency and enhances the photocatalytic efficiency.

[0051] In summary, this application innovatively couples tribocatalysis with photocatalysis. On the one hand, light irradiates the catalyst surface, causing the catalyst to produce a light response. On the other hand, friction also provides energy to the catalyst, causing electronic transitions in the catalyst to generate more electrons. + The electrons generated by the electron transition are transferred from the catalyst surface to the stirring rod under the action of friction. This electron transfer process further suppresses the electrons and h + The synergistic effect between the two improves the electron transfer efficiency and enhances the photocatalytic efficiency.

[0052] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0053] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A device for friction-coupled photocatalytic synergistic degradation of pollutants, characterized in that: include: A dark box, wherein a magnetic stirrer is provided in the dark box; A reactor, disposed on the magnetic stirrer, serving as a reaction vessel for friction-coupled photocatalytic synergistic degradation of pollutants; The light source is arranged in the dark box and is used to provide light energy for friction-coupled photocatalytic synergistic degradation of pollutants.

2. The device for friction-coupled photocatalytic synergistic degradation of pollutants according to claim 1, characterized in that: The light source is a 150W xenon lamp.

3. A method for synergistic degradation of pollutants by friction-coupled photocatalysis, characterized in that: The device for synergistically degrading pollutants by friction-coupled photocatalysis as described in any one of claims 1-2 comprises the following steps: Preparation of TiO2 / Bi2MoO6 catalyst; Ciprofloxacin was selected as the target pollutant; The TiO2 / Bi2MoO6 catalyst was added to the ciprofloxacin pollutant solution and placed in a reactor in a dark box; The magnetic stirrer and the light source were turned on to degrade ciprofloxacin under the action of friction-coupled photocatalysis.

4. The method for tribo-coupled photocatalytic synergistic degradation of pollutants according to claim 3, characterized in that: Preparation of TiO2 / Bi2MoO6 catalyst; include: S1: Add tetrabutyl titanate to anhydrous ethanol and stir to obtain a uniform precursor mixture; S2: Mix anhydrous ethanol, deionized water and cetyltrimethylammonium bromide, mix with the precursor mixture in S1, wash and dry the mixture, and then place it in a muffle furnace for one calcination to obtain TiO2; S3: Dissolve Bi(NO3)3·5H2O, Na2MoO4·2H2O and TiO2 in ethylene glycol solution, stir, and transfer the resulting transparent solution to a hydrothermal reactor; perform dissolution heat treatment under preset conditions; S4: After cooling to room temperature, the precipitate is collected by filtration, washed, and dried; S5: Place the mixture in a muffle furnace and calcine it a second time to obtain a TiO2 / Bi2MoO6 catalyst.

5. The method for tribo-coupled photocatalytic synergistic degradation of pollutants according to claim 4, characterized in that: In step S2, the primary calcination conditions are: calcination at 400-500°C for 1-3h; In step S5, the secondary calcination conditions are: calcination at 200-400° C. for 2-4 hours.

6. The method for tribo-coupled photocatalytic synergistic degradation of pollutants according to claim 4, characterized in that: In step S3, the preset conditions are: dissolution heat treatment at 150-170° C. for 10-14 hours.

7. The method for tribo-coupled photocatalytic synergistic degradation of pollutants according to claim 3, characterized in that: The magnetic stirrer and the light source were turned on, and a dark adsorption phase was performed for 30-60 minutes until the adsorption equilibrium between the catalyst and ciprofloxacin was reached.

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