Double-Z-type magnetic Fe2 (MoO4) 3 / MoO3 / Fe3O4 heterojunction visible-light-driven photocatalyst as well as preparation method and application thereof

Abstract

The invention provides a preparation method of a double-Z type magnetic Fe2 (MoO4) 3 / MoO3 / Fe3O4 heterojunction visible-light-driven photocatalyst and application of the double-Z type magnetic Fe2 (MoO4) 3 / MoO3 / Fe3O4 heterojunction visible-light-driven photocatalyst in environmental remediation. The preparation method comprises the following steps: putting Fe2 (MoO4) 3 / MoO3 and Fe3O4 into a ball milling tank according to a certain proportion, carrying out mechanical ball milling, drying the obtained mixture, and calcining in an inert atmosphere; and washing and drying the calcined solid material to obtain the target catalyst. The double-Z-type magnetic heterojunction catalyst prepared by a simple mechanical ball milling-calcining method can efficiently activate persulfate under the irradiation of visible light, and is used for degrading organic pollutants in a water body. The method has the characteristics of simple process, low cost, environmental friendliness and the like, and the obtained catalyst has high catalytic activity and good magnetic recovery performance, and has wide application prospects in the fields of wastewater treatment and environmental restoration.

Description

Technical Field

[0001] This invention belongs to the field of inorganic photocatalyst materials technology, and relates to the preparation of photocatalysts. Specifically, it relates to the preparation of a double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst by mechanical ball milling, and its application in activating persulfate to treat organic pollutants in water. Background Technology

[0002] With rapid economic growth and continuous technological development, my country's pharmaceutical industry has entered a stage of rapid development.

[0003] In recent years, the advanced persulfate oxidation process has gained popularity due to its ability to generate sulfate radicals (·SO4) with strong oxidizing power and long half-life. - Persulfate has a wide effective pH range, is stable, and has low cost, making it a promising candidate for application. Meanwhile, photocatalytic oxidation can efficiently degrade antibiotics and mineralize organic matter, offering advantages such as ease of operation, stable performance, small footprint, and resistance to water quality and quantity fluctuations. However, with the increasing variety and concentration of wastewater, single technologies are no longer sufficient to consistently meet stringent discharge standards. Technology coupling has become an inevitable trend, with the combination of photocatalysis and advanced persulfate oxidation being particularly prominent: persulfate can capture photogenerated electrons and be activated, while simultaneously promoting the separation of photogenerated carriers, thereby synergistically improving pollutant degradation efficiency. This combined technology offers excellent performance, low energy consumption, and environmental friendliness, with broad engineering application prospects. However, bottlenecks remain, including insufficient visible light utilization, difficulty in catalyst recovery, and insufficient mechanistic research. Developing efficient and stable visible light photocatalysts for activating persulfate is crucial. Among these, molybdates, due to their versatility, abundant surface active sites, high specific surface area, narrow band gap, and wide spectral response range, demonstrate great potential in the field of photocatalysis (electrocatalysis). Ferric molybdate possesses a suitable band structure, and its charge space separation efficiency and catalytic performance can be significantly improved by constructing a Z-shaped heterojunction.

[0004] Of particular note is the unique synthetic advantage and innovation of mechanical ball milling in constructing multi-component heterojunction photocatalysts. Compared to traditional hydrothermal and calcination methods, mechanical ball milling, through high-intensity mechanical force, enables atomic-level homogeneous mixing and forced interfacial composite of multi-source precursors under solid-state conditions, constructing a tight heterojunction interface in a one-step process. This not only simplifies the process but also effectively avoids solvent introduction and secondary contamination. More importantly, the mechanochemical process can induce lattice defects, distortions, and even in-situ chemical reactions in the material, thereby creating abundant active sites and regulating its band structure in the composite material, further enhancing visible light absorption and charge separation efficiency.

[0005] Based on this, in order to further improve the catalyst recovery rate, the present invention provides a simple preparation method of a dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst, which is used to activate persulfate under visible light for efficient degradation of organic pollutants in water. Summary of the Invention

[0006] The primary objective of this invention is to address the technical problem of easy recombination of photogenerated carriers in existing photocatalysts. This invention successfully prepares a dual-Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible-light photocatalyst using a green and simple ball milling-calcination method. The construction of the Z-type heterojunction between Fe2(MoO4)3 and MoO3 promotes the rapid and efficient migration of photogenerated carriers, leaving behind photogenerated carriers with high redox capabilities, thereby maximizing its redox capacity and exhibiting highly efficient catalytic performance. Furthermore, the dual-Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible-light photocatalyst can activate persulfate to generate free radicals, further preventing the recombination of photogenerated carriers.

[0007] Another objective of this invention is to provide the application of the above-mentioned dual-Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst for activating persulfate degradation of organic pollutants under visible light.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst includes the following steps: (1) The molybdenum source and the iron source are added to a ball mill jar for ball milling to obtain a ferromolybdenum mixture; after drying, it is calcined in a muffle furnace to obtain Fe2(MoO4)3 / MoO3 material; (2) Dissolve a certain volume of CH3COONa, NaOH and NaNO3 in ultrapure water and stir and heat; quickly disperse FeSO4·7H2O into the above and let stand, cool to room temperature and wash Fe3O4 several times with ultrapure water and anhydrous ethanol until a clear solution is obtained; separate the particles with a magnet and dry the Fe3O4 particles in a vacuum drying oven. (3) The Fe2(MoO4)3 / MoO3 materials obtained in steps (1) and (2) are mixed with Fe3O4 in a certain proportion and placed in a ball mill jar. After reacting under certain ball milling conditions, the mixture is calcined in an inert environment in a muffle furnace to obtain a double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst. (4) The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst obtained in step (3) is washed and then dried to constant weight.

[0009] Preferably, the molybdenum source in step (1) is ammonium molybdate tetrahydrate; the iron source is ferric nitrate nonahydrate; the molar ratio of molybdenum source to iron source is 2.6; the mass ratio of molybdenum source to iron source to zirconium beads is 1:50; the ball milling time is 2 h; the ball milling speed is 450 r / min; the calcination temperature is 500 ℃; the heating rate is 5 ℃ / min; and the calcination time is 4 h.

[0010] Preferably, the settling time in step (2) is 1 hour; the vacuum drying temperature is 60°C. o C.

[0011] Preferably, the Fe3O4 doping amount in step (3) is 30%.

[0012] Preferably, the mass ratio of the raw material to the grinding ball in step (3) is 1:50.

[0013] Preferably, the calcination temperature in step (3) is 500°C. o C.

[0014] Preferably, the drying temperature in step (4) is 90 °C; the drying time is more than 24 h, and the product is dried to a constant weight.

[0015] Based on the above method, this invention prepares a dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst, which can be used to activate persulfate under visible light and degrade organic pollutants in water. The advantages of this invention are as follows: 1) The dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst proposed in this invention adopts a simple and green mechanical ball milling-calcination method. This method is simple and easy to control, does not require solvents and will not cause secondary pollution or ion loss. It is easy to industrialize and reduces the synthesis cost.

[0016] 2) The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst prepared in this invention has a uniform distribution and close contact between interfaces, which can generate more active sites.

[0017] 3) The construction of the double Z-type heterojunction optimizes the transfer path of photogenerated electrons and holes, retains photogenerated carriers with higher redox capabilities, and promotes the maximization of the redox capability of the reaction system.

[0018] 4) The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst prepared in this invention can more efficiently activate persulfate under visible light and generate holes, electrons, hydroxyl radicals, sulfate radicals, and superoxide radicals, resulting in good pollutant removal effect.

[0019] 5) The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst prepared by this invention has stable performance and leaves no residue in wastewater, showing great promise for industrial application.

[0020] 6) The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst prepared by this invention requires a small amount of material and can efficiently remove pollutants under room temperature conditions. The conditions are controllable and economically feasible. Attached Figure Description

[0021] Figure 1 XRD patterns of Fe3O4 and a series of double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalysts; Figure 2 The UV-Vis diffuse reflectance spectra of Fe3O4 and double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible photocatalysts are shown in (a) and the relationship between the light absorption coefficient (αhv) and energy (hv) is shown in (b). Figure 3 A comparison diagram of tylosin degradation under different system conditions; Figure 4 The cyclic experiment diagram (a) and XRD pattern (b) of the activated PDS degradation of tylosin by visible light catalyst of double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction are shown. Figure 5 The image shows the free radical capture diagram (a) and the corresponding reaction kinetic curve (b) of PDS activated by the visible light catalyst of the double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction under visible light to degrade tylosin. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments and accompanying drawings, but is not limited thereto.

[0023] Example 1 A method for preparing a double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst includes the following steps: (1) Weigh 0.8 g of ammonium molybdate tetrahydrate and 0.704 g of ferric nitrate nonhydrate and add them to the ball mill jar. Then weigh 75 g of zirconium beads and add them to the ball mill jar. Finally, place the jar in a planetary ball mill and mill for 2 h at a speed of 450 r / min to obtain a ferromolybdenum mixture. o After drying in an oven at C for 8 hours, place it in a muffle furnace at 5°C. o Heating rate 500 °C / min o C, and held at this temperature for 4 h, then cooled to room temperature and removed to obtain Fe2(MoO4)3 / MoO3 material; (2) Dissolve 3.5 mM CH3COONa, 4 mM NaOH and 20 mM NaNO3 in 20 mL of ultrapure water, stir and heat to 100 °C o C. 2 mM FeSO4·7H2O was rapidly dispersed into the above solution, and the mixture was kept for 1 h. After cooling to room temperature, the Fe3O4 was washed several times with ultrapure water and anhydrous ethanol until a clear solution was obtained. The Fe3O4 particles were separated using a magnet. Finally, the obtained Fe3O4 nanoparticles were subjected to a 65°C test. o Dry in a vacuum drying oven (C) for later use.

[0024] (3) Weigh 1.05 g of Fe2(MoO4)3 / MoO3 material and 0.45 g of Fe3O4 particles, then weigh 75 g of zirconium beads and add them to the ball mill jar. Finally, place it in a planetary ball mill and ball mill for 2 h at a speed of 450 r / min to obtain a ferromolybdenum mixture; after 80 o After drying in an oven at C for 8 hours, place it in a muffle furnace at 5°C. o Heating rate 500 °C / min o The catalyst was obtained by heating at C and maintaining the temperature at that temperature for 4 h, then cooling to room temperature and removing it. (4) The photocatalyst obtained in step (3) is washed three times each with ultrapure water and ethanol, and then at 90°C. o Dry in an oven at temperature C for at least 24 hours until constant weight is achieved.

[0025] Analysis of the phase lattice of the double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst, as shown in... Figure 1 As shown, the UV-Vis diffuse reflectance spectrum is as follows: Figure 2 As shown.

[0026] The prepared series of Fe2(MoO4)3 / MoO3 / Fe3O4 were characterized by XRD, and the results are as follows: Figure 1As shown in the figure, the XRD diffraction peaks of Fe3O4 are in perfect agreement with the standard card (JCPDS No. 019-0629). The characteristic peaks of Fe3O4 at 30.1°, 35.5°, 43.1°, 48.9°, 57.05°, and 62.61° correspond to the (220), (311), (400), (422), (511), and (440) crystal planes, respectively, and the main diffraction peaks are sharp and prominent. With the increase of the Fe3O4 doping ratio, the peak intensity gradually increases, but the peak shape does not change, indicating that the Fe3O4 matrix is ​​always present. No impurity XRD peaks are seen in the figure, indicating that no foreign elements contaminated the Fe3O4 nanostructure during the preparation process.

[0027] Figure 2 The UV-Vis diffuse reflectance spectra (a) and the relationship between the light absorption coefficient (αhv) and energy (hv) of Fe3O4 and double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible photocatalysts are shown in Figure (b). Figure 2 (a) It can be seen that Fe3O4 monomer has a high light absorption rate. The absorption edge of the Fe2(MoO4)3 / MoO3 heterojunction visible light catalyst is around 510 nm; the absorption edge of Fe2(MoO4)3 / MoO3 / Fe3O4 is around 640 nm. Therefore, the doping of Fe3O4 broadens the absorption range of visible light. According to Figure 2 (b) It is known that, according to the formula , Where is the absorption coefficient, h is Planck's constant, υ is the optical frequency, n is the semiconductor transfer performance (here n = 1 / 2), A is a constant, and E is the absorption coefficient. g The band gap of the Fe2(MoO4)3 / MoO3 heterojunction visible light photocatalyst is 2.11 eV. Figure 2 (b) It can be seen that the E of Fe3O4 and Fe2(MoO4)3 / MoO3 / Fe3O4 g The values ​​are 1.41 eV and 1.00 eV, respectively, which are less than the bandwidth of Fe2(MoO4)3 / MoO3.

[0028] Application Example 1 The dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst prepared above was used to degrade tylosin (TYL) in different systems.

[0029] TYL degradation experiments were conducted at room temperature using a 300 W xenon lamp with an ultraviolet filter (λ>400nm). The pH value was not adjusted.

[0030] 15 mg of a dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst was dispersed in 50 mL of a 10 mg / L pollutant solution under dark conditions and stirred for 30 min to achieve adsorption. Desorption equilibrium.

[0031] Different systems were set up to degrade TYL: Vis (visible light only), PDS (persulfate only), Vis+PDS (persulfate under visible light), Cat (catalyst only), Cat+PDS (catalyst and persulfate), Vis+Cat (catalyst under visible light), and Cat+Vis+PDS (catalyst and persulfate under visible light). At regular intervals, 3 mL of solution was taken, filtered through a 0.22 μm filter membrane, and the TYL concentration was determined using high-performance liquid chromatography (HPLC). The degradation effect was analyzed, such as... Figure 3 As shown.

[0032] Depend on Figure 3It was found that tylosin alone did not degrade under visible light irradiation in the system without the addition of catalyst and PS, proving that tylosin cannot be degraded by visible light alone. In the PS oxidation system of tylosin, only 5% of tylosin was degraded, indicating that the oxidizing power of PS itself is insufficient to degrade tylosin. When only Fe2(MoO4)3 / MoO3 / Fe3O4 was present in the system, only 4.3% of tylosin was adsorbed, and the adsorption amount remained almost unchanged with the extension of reaction time, indicating that the adsorption equilibrium between Fe2(MoO4)3 / MoO3 / Fe3O4 and tylosin was reached within 30 min. Therefore, before conducting the photocatalytic experiment, the reaction system was subjected to a 30 min dark reaction to reach an adsorption equilibrium, thereby eliminating the influence of catalyst adsorption on the photocatalytic degradation of tylosin. When Fe2(MoO4)3 / MoO3 / Fe3O4 and PS were present in the system, the degradation rate of tylosin increased by 84% compared to the PS-only system, indicating that Fe2(MoO4)3 / MoO3 / Fe3O4 could activate PS to generate active free radicals that oxidize tylosin. In the PS / Vis system, 66% of tylosin was degraded, likely due to the activation effect of visible light on PS. However, in the Fe2(MoO4)3 / MoO3 / Fe3O4 / Vis system, only 4.3% of tylosin was removed, significantly lower than the catalytic degradation rate of the Fe2(MoO4)3 / MoO3 / Fe3O4 / PS / Vis system. This suggests that the photocatalytic performance of the catalyst is weak and that PS, as an electron acceptor, promotes the catalytic reaction. In contrast, the Fe2(MoO4)3 / MoO3 / Fe3O4 / PS / Vis system showed higher degradation efficiency for tylosin than other systems, achieving complete degradation within 12 minutes.

[0033] Application Example 2 The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst prepared above was subjected to cyclic degradation experiments in a Cat+Vis+PDS system.

[0034] TYL degradation experiments were conducted at room temperature using a 300 W xenon lamp with an ultraviolet filter (λ>400nm). The pH value was not adjusted.

[0035] 15 mg of a dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst was dispersed in 50 mL of a 10 mg / L pollutant solution under dark conditions and stirred for 30 min to achieve adsorption. Desorption equilibrium was reached. The light source was then turned on, and 1 mM PDS was added to initiate the reaction. At regular intervals, 1 mL of solution was taken, filtered through a 0.22 μm filter membrane, and the TYL concentration was determined using high-performance liquid chromatography (HPLC). After degradation, the catalyst was recovered, washed, and dried for use in the next cycle. The degradation effect was analyzed as follows: Figure 4 As shown.

[0036] Depend on Figure 4 As shown in (a) and (b), after 5 cycles, TYL was still completely degraded in the Cat+Vis+PDS system, and the characteristic peaks of the catalyst did not change significantly. This indicates that the catalyst has excellent catalytic stability and recyclability, and has broad application prospects and value.

[0037] Application Example 3 The above-prepared dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst was used in a Cat+Vis+PDS system for capture experiments.

[0038] TYL degradation experiments were conducted at room temperature using a 300 W xenon lamp with an ultraviolet filter (λ>400nm). The pH value was not adjusted.

[0039] 15 mg of a dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst was dispersed in 50 mL of a 10 mg / L pollutant solution under dark conditions and stirred for 30 min to achieve adsorption. Desorption equilibrium was reached. The light source was then turned on, and 1 mM PDS was added to initiate the reaction. At regular intervals, 1 mL of the solution was taken, filtered through a 0.22 μm filter membrane, and the TYL concentration was determined using high-performance liquid chromatography (HPLC). Methanol (MeOH), tert-butanol (TBA), p-benzoquinone (BQ), disodium ethylenediaminetetraacetate (EDTA-2Na), and potassium dichromate (K₂Cr₂O₄) were added to this system as... · OH and SO4 ·- , · OH、 · O2 - h + and e - The capture agent. Analysis of degradation effect as follows: Figure 5 As shown.

[0040] from Figure 5 As shown in (a) and (b), the addition of EDTA-2Na inhibited the degradation of tylosin, and the corresponding reaction rate constant k decreased from 0.339 min. -1 Reduced to 0.044 min -1 Prove h +It is the main active substance in the photocatalytic degradation process of tylosin. When TBA, MeOH, and K2Cr2O4 are added to the system, the corresponding reaction rate constants are 0.079 min. -1 0.123 min -1 and 0.102 min -1 This confirms that the system also contains [this feature]. · SO4 - , · OH and e - Furthermore, BQ has a weak inhibitory effect on the degradation of tylosin, indicating that... · O2 - The contribution of different scavenging agents to the degradation of tylosin is relatively small. Therefore, the effects of different scavenging agents on inhibiting tylosin degradation are ranked as follows: EDTA-2Na > TBA > MeOH > K2Cr2O4 > BQ. This indicates that the contribution rate of the active substances present in this system is ranked in order of h. + > · OH> · SO4 - >e - > · O2 - .

[0041] The above description is merely a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in this embodiment. Therefore, any equivalent or modified versions made without departing from the spirit of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a magnetic double Z-type Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst, characterized in that, This method includes: preparing a catalyst precursor by ball milling, and then calcining it in a muffle furnace to prepare a double Z-type Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst; the method specifically includes the following steps: (1) Preparation of Fe2(MoO4)3 / MoO3: Molybdenum source and iron source were added to a ball mill jar and ball milled to obtain a ferromolybdenum mixture; after drying, it was calcined in a muffle furnace to obtain Fe2(MoO4)3 / MoO3 material; (2) Preparation of Fe3O4: A certain volume of CH3COONa, NaOH and NaNO3 were dissolved in ultrapure water and stirred and heated; FeSO4·7H2O was rapidly dispersed in the above solution and allowed to stand. After cooling to room temperature, Fe3O4 was washed several times with ultrapure water and anhydrous ethanol until a clear solution was obtained. The Fe3O4 particles were dried in a vacuum drying oven after the particles were separated by a magnet. (3) The Fe2(MoO4)3 / MoO3 materials obtained in steps (1) and (2) are mixed with Fe3O4 in a certain proportion and placed in a ball mill jar. After reacting under certain ball milling conditions, the mixture is calcined in an inert environment in a muffle furnace to obtain a double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst. (4) The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst obtained in step (3) is washed and then dried to constant weight.

2. The method according to claim 1, characterized in that, The molybdenum source in step (1) is ammonium molybdate tetrahydrate; the iron source is ferric nitrate nonahydrate; the molar ratio of the molybdenum source to the iron source is 2.5; the mass ratio of the raw material to the grinding balls is 1:50; the ball milling time is 2 h; the ball milling speed is 450 r / min; and the calcination temperature is 500 °C. o C.

3. The method according to claim 1, characterized in that, The settling time mentioned in step (2) is 1 hour; the vacuum drying temperature is 60°C. o C.

4. The method according to claim 1, characterized in that, In step (3), the Fe3O4 doping amount obtained in step (2) is 2%-40%; the mass ratio of the raw material to the grinding balls is 1:5-1:50; the ball milling time is 0.5-3 h; the ball milling speed is 450 r / min; and the calcination temperature is 300-600 °C. o C; The heating rate is 5 o C / min; the calcination time is 4 h.

5. The method according to claim 1, characterized in that, The drying temperature mentioned in step (4) is 90°C. o C; The drying time is more than 24 hours, and the product is dried to a constant weight.

6. The double Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst prepared by the method according to claims 1-5.

7. The application of the dual Z-type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light catalyst as described in claim 5 for activating persulfate under visible light and degrading organic pollutants in water.

8. The application according to claim 7, characterized in that, A dual-Z type magnetic Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst was added to wastewater containing organic pollutants and stirred at room temperature to form a mixture. Persulfate was added to the mixture to form a reaction system. The reaction system was irradiated with a light source, and the dual-Z type Fe2(MoO4)3 / MoO3 / Fe3O4 heterojunction visible light photocatalyst was used to catalyze the activation of the persulfate to generate free radicals that degrade the organic pollutants.

9. The method according to claim 8, characterized in that, The organic pollutant is tylosin; the persulfate is sodium persulfate; and the light source is a 300 W xenon lamp with a wavelength greater than 400 nm.

Images