A method for producing hydrogen peroxide by using organic wastewater based on a PDI / PMSO composite photocatalytic system

Abstract

The application belongs to the technical field of environmental catalysis and green chemical industry, and particularly relates to a PDI / PMSO composite photocatalytic system and a method for producing hydrogen peroxide by using organic wastewater. The PDI / PMSO composite photocatalytic system can significantly improve the yield of H2O2, and when the concentration of PMSO is 10 mM, the yield of H2O2 reaches 137.28 muM.g ‑1 ·h ‑1 -1.h-1, which is 4.3 times higher than that of a pure water system. The system can promote the separation of photo-generated electron-hole pairs (the steady-state fluorescence intensity is reduced by 37%) and enhance the electron conduction efficiency (the photocurrent is increased by 1.8 times) through synergistic effect, and has excellent cycle stability (the yield is maintained above 80% after 10 cycles) and practical water body applicability. The process is simple and low in cost, and provides an integrated solution for the resource utilization of organic wastewater and the green synthesis and application of H2O2.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of environmental catalysis and green chemical engineering, specifically relating to a method for producing hydrogen peroxide from organic wastewater based on a PDI / PMSO composite photocatalytic system. Background Technology

[0002] Hydrogen peroxide (H2O2), as a new generation of green oxidant, exhibits excellent redox properties due to its unique molecular structure-activity relationship, combining environmental compatibility (decomposition products are H2O and O2) with industrial applicability. This characteristic makes it irreplaceable in advanced oxidation processes (AOPs), fine organic synthesis, and biomedical engineering. However, currently, over 90% of global H2O2 production capacity still relies on the traditional anthraquinone cycle process, which involves multiple hydrogenation / oxidation steps and suffers from significant energy consumption and waste pollution. Therefore, developing efficient, low-energy-consumption green synthesis technologies for H2O2 has become one of the core challenges in achieving sustainable chemical manufacturing.

[0003] Photocatalytic synthesis technology offers an innovative breakthrough in overcoming the aforementioned challenges. Essentially, it drives redox reactions through photogenerated carriers (e⁻-h⁺ pairs) in semiconductor photosensitive materials, primarily involving two competing pathways: (1) a hole-dominated water oxidation pathway (Equations 1-2); and (2) an electron-mediated oxygen reduction pathway (Equations 3-5). The two-electron oxygen reduction reaction, due to its superior thermodynamic driving force and selectivity, is considered a key pathway for achieving efficient H₂O₂ synthesis. However, limited by the rapid recombination effect of photogenerated carriers (quantum efficiency generally <10%), the H₂O₂ yield of existing photocatalytic systems still falls short of industrial requirements.

[0004] To address the bottleneck of low carrier separation efficiency, the academic community has proposed strategies such as noble metal co-catalysis, band structure modulation, and sacrificial agent assistance. However, the high cost of noble metals and the large-scale consumption of sacrificial agents severely restrict their practical application. Recent research shows that introducing reversible redox mediators (such as quinone / phenol systems) can significantly improve carrier lifetime through dynamic electron transfer mechanisms. These breakthroughs reveal the crucial role of electron mediators in optimizing reaction pathways, providing a new paradigm for developing self-sustaining catalytic systems. Notably, sulfoxide pollutants widely present in industrial wastewater (such as methyl phenyl sulfoxide-PMSO) may possess the dual functions of pollutant resource utilization and electron transfer promotion due to their unique electronic structure characteristics (S=O groups contain highly active lone pairs of electrons). Theoretical studies indicate that S=O groups can act as electron acceptors to capture photogenerated electrons and lower the O2 activation barrier through intramolecular charge transfer. Constructing a photocatalytic / PMSO system and deepening the understanding of photocatalytic electron transfer mechanisms will provide theoretical support for the development of "waste-to-waste" environmental catalytic technologies. The main technical problems existing in the current technology are as follows:

[0005] 1. Low H2O2 photocatalytic yield: Traditional PDI-based catalysts achieve H2O2 yields of less than ~25 μM·g in pure water systems. -1 ·h -1 1. It is difficult to meet industrial needs; 2. High carrier recombination rate: The narrow bandgap characteristics of PDI lead to rapid recombination of photogenerated electron-hole pairs, reducing quantum efficiency; 3. Insufficient stability: The yield of most modified PDI catalysts decreases by more than 30% after 5 cycles (Zhang et al., Appl. Catal. B 2021, 298, 120558).

[0006] Existing research often improves performance through noble metal loading (such as Pt modification) or heterostructure building (such as g-C3N4 / PDI), but this approach suffers from high costs and complex processes. The applicant's research has found that coupling PMSO wastewater with PDI can significantly improve these shortcomings through interfacial electron transfer effects.

[0007] Therefore, this application proposes to form a composite photocatalytic system by combining perylene imide (PDI) and methyl phenyl sulfoxide (PMSO), which can be used for in-situ production of hydrogen peroxide from organic wastewater. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a PDI / PMSO composite photocatalytic system by combining PDI and methyl phenyl sulfoxide (PMSO). This system can improve the yield of H2O2 under light irradiation and also achieve efficient degradation of various pollutants (bisphenol A, fluoroquinolones, and dyes) under light irradiation.

[0009] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0010] A PDI / PMSO composite photocatalytic system includes a PDI supramolecular photocatalyst and PMSO, wherein the mass ratio of the PDI supramolecular photocatalyst to PMSO is (0.03~7.5):1, preferably (0.036-7.143):1, and more preferably 0.143:1.

[0011] Specifically, in the PDI / PMSO composite photocatalytic system, the PDI concentration is 0.1~0.5 g / L (preferably 0.2 g / L), and the PMSO concentration is 0.5~20 mM (preferably 10 mM).

[0012] Furthermore, the present invention also provides a method for preparing the PDI / PMSO composite photocatalytic system, specifically, dispersing PDI supramolecular photocatalyst and PMSO sequentially in water to construct the PDI / PMSO composite photocatalytic system.

[0013] Furthermore, the preparation method of PDI supramolecular photocatalyst includes the following steps:

[0014] 1) Under a protective atmosphere, perylene-3,4,9,10-tetracarboxylic acid dianhydride, β-alanine and imidazole were mixed and placed in a reaction vessel, and then reacted at a certain temperature for a certain time under a protective atmosphere. After the reaction, the mixture was cooled to room temperature (25±5℃) and ground into powder.

[0015] 2) Wash the product from step 1) sequentially with anhydrous ethanol and HCl solution for 6-18 hours, then filter until the pH of the filtrate is neutral;

[0016] 3) After drying the product from step 2), disperse it in water, add triethylamine and HCl solution, shake for 1-3 h, filter, dry, and finally obtain powdered PDI supramolecular photocatalyst.

[0017] Specifically, in step 1), the protective atmosphere is an atmosphere formed by nitrogen, argon, etc.

[0018] Specifically, in step 1), the mass ratio of perylene-3,4,9,10-tetracarboxylic dianhydride to β-alanine is 1:(1~2).

[0019] Specifically, in step 1), the mass ratio of β-alanine to imidazole is 1:(4~6).

[0020] Specifically, the reaction temperature in step 1) is 100~120℃, and the reaction time is 2~6h.

[0021] Specifically, in step 3), the ratio of the amount (mass) of the product to triethylamine and HCl solution is (1~2.68):(0.6~1):(2~4).

[0022] Furthermore, the present invention also provides the application of the PDI / PMSO composite photocatalytic system in the photocatalytic production of hydrogen peroxide.

[0023] Furthermore, based on a general inventive concept, the present invention also provides a method for photocatalytic production of hydrogen peroxide using the aforementioned PDI / PMSO composite photocatalytic system, comprising the following steps:

[0024] First, powdered PDI supramolecular photocatalyst was prepared, then the powdered PDI supramolecular photocatalyst was dispersed in water, and then PMSO was added to construct a PDI / PMSO composite photocatalytic system. The photocatalytic reaction was carried out by irradiation with a light source for 5-60 min, and the H2O2 concentration was measured.

[0025] Specifically, in the PDI / PMSO composite photocatalytic system, the PDI concentration is 0.1~0.5 g / L (preferably 0.2 g / L), and the PMSO concentration is 0.5~20 mM (preferably 10 mM).

[0026] Specifically, the light source is a xenon lamp or a mercury lamp with a wavelength greater than 400 nm and an illuminance of 100±3 mW·cm. -2 .

[0027] Alternatively, the light source is sunlight with a wavelength greater than 295 nm and an illuminance of 95 mW·cm. -2 .

[0028] Preferably, the light source used in the photocatalytic reaction can also be a blue LED lamp (wavelength 455-460nm, illuminance 6.2mW cm⁻¹). -2 ), UV LED lights (wavelength 390-400nm, illuminance 4.0 mW cm⁻¹) -2 Green LED lights (wavelength 515-530nm, illuminance 6.0 mW cm⁻¹) -2 ), yellow LED lights (wavelength 590-595nm, illuminance 4.0 mW cm⁻¹) -2 ), red LED light (wavelength 655-660nm, illuminance 11.0 mW cm⁻¹) -2 ).

[0029] Specifically, during illumination, the power is (100~300)W, preferably 300W.

[0030] Preferably, before irradiation, the PDI / PMSO composite photocatalytic system is subjected to a dark reaction under dark conditions for (10-60) min.

[0031] Furthermore, the PDI / PMSO composite photocatalytic system can be reused during photocatalytic hydrogen peroxide production, with a reuse frequency of 1-10 times, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 times.

[0032] Specifically, the water refers to tap water, rainwater, domestic sewage, industrial wastewater, agricultural wastewater, river water, lake water, or seawater, etc.

[0033] Furthermore, the present invention also provides the application of the PDI / PMSO composite photocatalytic system in the photocatalytic degradation of organic pollutants.

[0034] Specifically, the PDI / PMSO composite photocatalytic system described in this invention can efficiently degrade a variety of water pollutants (bisphenol A pollutants, fluoroquinolone pollutants, and / or dye pollutants) in the presence of various pollutants.

[0035] Furthermore, based on a general inventive concept, the present invention also provides a method for photocatalytic degradation of water pollutants using the aforementioned PDI / PMSO composite photocatalytic system, comprising the following steps:

[0036] First, powdered PDI supramolecular photocatalyst is prepared. Then, the powdered PDI supramolecular photocatalyst is dispersed in water containing water pollutants. PMSO is then added to construct a PDI / PMSO composite photocatalytic system. The photocatalytic reaction is carried out by irradiation with a light source for 5-60 minutes.

[0037] Specifically, in the PDI / PMSO composite photocatalytic system, the PDI concentration is 0.1~0.5 g / L (preferably 0.2 g / L), and the PMSO concentration is 0.5~20 mM (preferably 10 mM).

[0038] Preferably, before irradiation, the PDI / PMSO composite photocatalytic system is subjected to a dark reaction under dark conditions for (10-60) min.

[0039] Specifically, the light source is a xenon lamp or a mercury lamp with a wavelength greater than 400 nm and an illuminance of 100±3 mW·cm. -2 .

[0040] Alternatively, the light source is sunlight with a wavelength greater than 295 nm and an illuminance of 95 mW·cm. -2 .

[0041] Preferably, the light source used in the photocatalytic reaction can also be a blue LED lamp (wavelength 455-460nm, illuminance 6.2mW cm⁻¹). -2 ), UV LED lights (wavelength 390-400nm, illuminance 4.0 mW cm⁻¹) -2 Green LED lights (wavelength 515-530nm, illuminance 6.0 mW cm⁻¹) -2 ), yellow LED lights (wavelength 590-595nm, illuminance 4.0 mW cm⁻¹) -2 ), red LED light (wavelength 655-660nm, illuminance 11.0 mW cm⁻¹) -2 ).

[0042] Specifically, during illumination, the power is (100~300)W, preferably 300W.

[0043] Specifically, the water pollutants are bisphenol A pollutants, fluoroquinolone pollutants, and / or dye pollutants.

[0044] Preferably, it is one or more of BPA (bisphenol A), BPAF (bisphenol AF), BPB (bromophenol blue), BPF (bisphenol F), CIP (ciprofloxacin), ENX (enoxacin), NOR (norfloxacin), OFX (ofloxacin), RMB (rhodamine B), MLB (methylene blue), NGB (naphthol green B), and MTO (methyl orange).

[0045] Specifically, the concentration of pollutants in the water is 1~5 mg / L, preferably 2 mg / L.

[0046] Specifically, the water refers to tap water, rainwater, domestic sewage, industrial wastewater, agricultural wastewater, river water, lake water, or seawater, etc.

[0047] This invention is highly innovative, revealing for the first time the nonlinear enhancement effect of PMSO concentration gradient (0.5-20 mM) on the photocatalytic H2O2 production performance of PDI. Compared with traditional modification techniques, this invention overcomes the limitations of relying on complex chemical modifications, achieving a significant increase in yield simply by mixing PDI with PMSO wastewater, thus successfully realizing a technological breakthrough in "wastewater photocatalytic resource utilization".

[0048] This invention utilizes a simple preparation process to add PDI to PMSO wastewater, achieving a 4.3-fold increase in yield and overcoming the complexity of traditional processes. The wastewater treatment method described in this invention can be applied to wastewater treatment following H2O2 synthesis, as well as various other types of wastewater treatment.

[0049] Compared with the prior art, the advantages of the present invention are:

[0050] 1. Breakthrough in Yield: Compared with traditional pure PDI catalysts, the H2O2 yield of the PDI / PMSO composite photocatalytic system of this invention is increased by 4.3 times (e.g., ...). Figure 1 (As shown in the figure). This significant yield increase indicates that the composite system has great application potential in the photocatalytic resource-based synthesis of H2O2.

[0051] 2. Carrier modulation: 1) Increased photocurrent intensity. Photocurrent intensity is an important indicator of the separation and transport efficiency of photogenerated carriers. Experimental results show that when the PMSO concentration is 10 mM, the photocurrent intensity is increased by 1.8 times compared to pure PDI (e.g., ...). Figure 2(As shown). This indicates that the addition of PMSO effectively promotes the transport of photogenerated electrons and reduces carrier recombination; 2) the steady-state fluorescence intensity decreases, and the steady-state fluorescence spectrum can reflect the recombination of photogenerated carriers. Pure PDI has a strong fluorescence peak at 674 nm, while the fluorescence intensity decreases by 37% after the addition of 10 mM PMSO (as shown). Figure 3 (As shown). This further demonstrates that the composite system can effectively suppress the recombination of photogenerated electron-hole pairs and improve quantum efficiency.

[0052] 3. Cyclic Stability: To evaluate the stability of the composite photocatalytic system, cyclic stability tests were conducted. The results showed that after 10 cycles, the H2O2 yield remained above 80% of its initial value (e.g., ...). Figure 4 (As shown in the figure). This excellent cycling stability indicates that the PDI / PMSO composite photocatalytic system has good durability and can meet the long-term operating requirements of actual industrial production.

[0053] 4. Structural stability: This is demonstrated by TEM (e.g., ...). Figure 5 (as shown in ad), DRS (as shown in ad) Figure 5 (as shown in e) and FT-IR (as shown in e) Figure 5 Characterization techniques (as shown in f) were used to analyze the materials before and after the reaction. The results showed that the crystal structure, optical properties, and functional groups of PDI did not change significantly before and after the reaction. This indicates that the composite photocatalytic system possesses good structural stability during the photocatalytic reaction, providing a strong guarantee for its long-term stable operation.

[0054] 5. Reliability in application: Evaluate different light sources (such as...) Figure 6 ), different coexisting pollutants (such as Figure 7 ) and different water bodies (such as Figure 8 The activity of the PDI / PMSO composite photocatalytic system under various conditions was investigated. The results showed that the PDI / PMSO composite photocatalytic system has good adaptability and high H2O2 yield and activity in multiple scenarios. Attached Figure Description

[0055] Figure 1 A comparison chart showing the yield of H2O2 produced by the PDI / PMSO composite photocatalytic system described in Example 2 under different PMSO concentrations;

[0056] Figure 2 Photocurrent response curves for PDI and different composite photocatalytic systems;

[0057] Figure 3 Steady-state fluorescence spectra of PDI and different PMSO concentrations;

[0058] Figure 4Cyclic stability test of H2O2 production by the PDI / PMSO composite photocatalytic system described in Example 2 at a certain concentration of PMSO;

[0059] Figure 5 For material characterization comparison, among which, Figure 5 ad is a TEM image. Figure 5 a and 5c are before the lights are turned on. Figure 5 b represents the reaction time after 60 minutes. Figure 5 d represents PDI; Figure 5 e is the DRS diagram. Figure 5 f is the FT-IR plot;

[0060] Figure 6 Tests were conducted on the H2O2 production of the PDI / PMSO composite photocatalytic system described in Example 2 under different light sources.

[0061] Figure 7 Photocatalytic degradation test of the PDI / PMSO composite photocatalytic system described in Example 2 under conditions of coexistence of different pollutants;

[0062] Figure 8 The test results of the PDI / PMSO composite photocatalytic system described in Example 2 under different water conditions were used to evaluate the production of H2O2. Detailed Implementation

[0063] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0064] Unless otherwise specified, the instruments and equipment used in the following examples are all commercially available conventional instruments and equipment; unless otherwise specified, the reagents, raw materials, etc. used in the following examples are all conventional commercially available products and can be obtained through commercial channels.

[0065] Example 1

[0066] A method for preparing a PDI supramolecular photocatalyst, the specific steps of which are as follows:

[0067] 1) Under an argon atmosphere, 6 mmol of perylene-3,4,9,10-tetracarboxylic dianhydride (2.353 g), 40 mmol of β-alanine (3.563 g), and 18.0 g of imidazole were mixed and placed in a reaction vessel, and then the mixture was incubated at 5 °C·min under an argon atmosphere. -1 The temperature was increased to 100℃ and reacted for 4 hours. After the reaction, the mixture was cooled to room temperature (25±5℃) and then ground into powder.

[0068] 2) Wash the product from step 1) sequentially with 100 mL of anhydrous ethanol and 300 mL of 2.0 M HCl solution with stirring for 12 h, and then filter until the pH of the filtrate is neutral;

[0069] 3) The product from step 2) was dried at 60°C and dispersed in 200 mL of ultrapure water. 0.83 mL of triethylamine and 27.30 mL of 4.0 M HCl solution were added. After shaking for 3 h, the mixture was filtered and dried to obtain powdered PDI supramolecular photocatalyst.

[0070] Example 2

[0071] Construction of the PDI / PMSO composite photocatalytic system:

[0072] 0.01 g of powdered PDI supramolecular photocatalyst was dispersed in 50 mL of ultrapure water. Then, PMSO was added to final concentrations of 0, 0.5, 1, 5, 10, and 20 mM, respectively, to construct a PDI / PMSO composite photocatalytic system.

[0073] Application Experiment 1

[0074] The experiment on the photocatalytic production of H2O2 using the PDI / PMSO composite photocatalytic system described in Example 2 is as follows:

[0075] 1. The PDI / PMSO composite system of Example 2 (where the final PMSO concentrations were 0, 0.5, 1, 5, 10, and 20 mM, respectively) was first placed in a dark environment for adsorption for 30 min, and then subjected to simulated sunlight (PLS-SXE300 / 300UV light source (xenon lamp), light intensity 100±3 mW·cm). -2 The reaction was carried out for 60 min at a wavelength greater than 400 nm and an illumination power of 300 W.

[0076] 2. Take samples at regular intervals (take a sample every 10 minutes, with a sample volume of 1 mL) and determine the H2O2 concentration using the iodometric method (the determination method is referenced in: Environmental Science & Technology, 1988, 22(7): 798-806).

[0077] Test results are as follows Figure 1 As shown, from Figure 1 As can be seen, the optimal group (final PMSO concentration of 10 mM) achieved an H2O2 yield of 137.28 μM·g. -1 ·h -1 Compared with traditional pure PDI catalysts, the H2O2 yield of the PDI / PMSO composite photocatalytic system is increased by 4.3 times (e.g., ...). Figure 1(As shown in the figure). This significant yield increase indicates that the composite system has great application potential in the photocatalytic resource-based synthesis of H2O2.

[0078] Performance testing of PDI / PMSO composite photocatalytic system

[0079] 1. Photocurrent response test: The photocurrent response curve was measured using a CHI-760 E electrochemical workstation (CH Instruments, USA).

[0080] Test results are as follows Figure 2 As shown, the test groups were: pure PDI, PDI + 1 mM PMSO, and PDI + 10 mM PMSO.

[0081] Photocurrent intensity is an important indicator for measuring the efficiency of photogenerated carrier separation and transport. Figure 2 The results showed that when the PMSO concentration was 10 mM, the photocurrent intensity was increased by 1.8 times compared to pure PDI (e.g., ...). Figure 2 (As shown). This indicates that the addition of PMSO effectively promotes the transport of photogenerated electrons and reduces carrier recombination.

[0082] 2. Steady-state fluorescence spectroscopy was performed using a Hitachi F7000 fluorescence spectrometer (Japan). Different concentrations of PMSO were prepared in the PDI mixture, stirred and mixed, and 1 mL was placed in the fluorescence detector for analysis. The excitation wavelength was 390 nm.

[0083] Test results are as follows Figure 3 As shown, the test groups were: pure PDI, 1 mM PMSO, 5 mM PMSO, and 10 mM PMSO; from Figure 3 As can be seen from the data, the characteristic peak positions are: the pure PDI group has a strong fluorescence peak at 674 nm, while the fluorescence intensity of the 10 mM PMSO group decreases by 37%.

[0084] Steady-state fluorescence spectroscopy can reflect the recombination of photogenerated carriers. Figure 3 The results showed that pure PDI had a strong fluorescence peak at 674 nm, but when 10 mM PMSO was added, the fluorescence intensity decreased from 418 au at 674 nm to 263 au, a decrease of 37% (e.g., Figure 3 (As shown). This further demonstrates that the composite system can effectively suppress the recombination of photogenerated electron-hole pairs and improve quantum efficiency.

[0085] 3. Material Characterization Comparison and Catalyst Characterization Methods: Under an accelerating voltage of 200 kV, the morphology, surface properties, and agglomeration of the photocatalyst were analyzed using transmission electron microscopy (TEM, JEM-2100F, Japan Electron Optics Laboratory, Japan). The spectral characteristics of the prepared photocatalyst were tested in the wavelength range of 200–800 nm using a UV-Vis diffuse reflectance spectrometer (UV-Vis / DRS, UV-3600 plus, SHIMADZU, Japan). Covalent bonds and special functional groups in the photocatalyst were determined using a Nicolet 6700 Fourier transform infrared spectroscopy (FTIR, Thermo Fisher Scientific, USA).

[0086] The concentration of PDI in the system was 0.2 g / L, and the concentration of PMSO was 10 mM.

[0087] via TEM (e.g.) Figure 5 As shown in AD; TEM images of PDI before the light is turned on (a) and (c), and after 60 minutes of reaction (b) and (d), DRS (as shown in AD). Figure 5 (as shown in e) and FT-IR (as shown in e) Figure 5 Characterization techniques such as (as shown in f) were used to analyze the materials before and after the reaction. Figure 5 The results showed that, in the TEM image, the morphology of PDI did not change significantly before and after the reaction; in the DRS image, the absorption edge position remained consistent; and in the FT-IR image, the characteristic functional groups did not shift significantly. These results indicate that the crystal structure, optical properties, and functional groups of PDI did not change significantly before and after the reaction in the first application experiment. This demonstrates that the composite photocatalytic system exhibits good structural stability during the photocatalytic reaction, providing a strong guarantee for its long-term stable operation.

[0088] Application Experiment 2: Cyclic Stability Test

[0089] The cycle stability of the PDI / PMSO composite photocatalytic system described in Example 2 was tested using the following steps: The stability of the catalyst was evaluated by repeatedly placing the recovered PDI catalyst in PMSO (10 mM) wastewater (refer to Application Experiment 1, where PMSO was added to ultrapure water to simulate wastewater) for multiple rounds of photocatalytic H2O2 synthesis experiments. The PDI concentration was 0.2 g / L, and the lamp source was a xenon lamp (light intensity 100 ± 3 mW·cm²). -2 (Wavelength greater than 400 nm, illumination power 300 W).

[0090] Cyclic stability test results are as follows Figure 4 As shown (PMSO concentration is 10 mM). Figure 4 In the middle, the horizontal axis represents the number of cycles (1-10), and the vertical axis represents the H2O2 yield (μM·g) on ​​the left. -1·h -1 The right side shows the H2O2 yield retention rate (%).

[0091] from Figure 4 As can be seen, the morphology and spectral characteristics of the catalyst remain unchanged before and after the reaction. After 10 cycles, the H2O2 yield can still maintain more than 80% of the initial value (e.g., Figure 4 (As shown in the figure). This excellent cycling stability indicates that the PDI / PMSO composite photocatalytic system has good durability and can meet the long-term operating requirements of actual industrial production.

[0092] Application Experiment 3: Testing with Different Light Sources

[0093] The experiment of photocatalytic H2O2 production using the PDI / PMSO composite photocatalytic system described in Example 2 under different light source conditions was conducted using the same test method as Application Experiment 1. The difference was that after the dark reaction was completed, light of different wavelengths was used as the reaction light source to carry out the photocatalytic reaction, and the power of each lamp was the same as in Application Experiment 1.

[0094] Test results are as follows Figure 6 As shown, Figure 6 In the middle (PMSO concentration is 10 mM), the lower horizontal axis represents the absorption of PDI light source and the corresponding sunlight spectrum; the upper horizontal axis represents different light sources; the left vertical axis represents absorbance; and the right vertical axis represents H2O2 yield.

[0095] from Figure 6 It can be seen that under different light source conditions (direct sunlight, wavelength greater than 295 nm, illuminance of 95 mW / cm²), 2 Blue LED light, wavelength 455-460nm, illuminance 6.2mW / cm². -2 The ultraviolet LED light has a wavelength of 390-400nm and an illuminance of 4.0 mW / cm². -2 Green LED light, wavelength 515-530nm, illuminance 6.0 mW / cm². -2 Yellow LED light, wavelength 590-595nm, illuminance 4.0 mW / cm². -2 Red LED light, wavelength 655-660nm, illuminance 11.0 mW / cm². -2The PDI / PMSO composite photocatalytic system described in Example 2 exhibits good H2O2 yields. It shows a significant increase in H2O2 yield under different light source conditions, both in real and simulated sunlight, and even under long-wavelength red light, demonstrating a yield increase of 0.76 times compared to the xenon lamp-only system (Vis-PDI). This further indicates that the addition of PMSO not only effectively enhances the ability of PDI to photosynthesize H2O2, but also has great potential for H2O2 photosynthesis under renewable sunlight.

[0096] Application Experiment 4: Degradation Test of Different Coexisting Pollutants

[0097] The experiment of photocatalytic degradation of various water pollutants using the PDI / PMSO composite photocatalytic system described in Example 2 was conducted. The test method was the same as in Application Experiment 1, except that photocatalytic degradation was carried out under the condition of coexistence of different water pollutants, including BPA (bisphenol A), BPAF (bisphenol AF), BPB (bromophenol blue), BPF (bisphenol F), CIP (ciprofloxacin), ENX (enoxacin), NOR (norfloxacin), OFX (ofloxacin), RMB (rhodamine B), MLB (methylene blue), NGB (naphthol green B), and MTO (methyl orange). Specifically, the concentration of each water pollutant was 2 mg / L.

[0098] Experimental conditions were as follows: simulated sunlight (PLS-SXE300 / 300UV light source (xenon lamp, light intensity 100±3 mW·cm)). -2 The reaction was carried out for 60 min at a wavelength greater than 400 nm and an illumination power of 300 W.

[0099] Test results are as follows Figure 7 As shown, Figure 7 (PMSO concentration is 10 mM) In the diagram, the horizontal axis represents different pollutants (bisphenol A, fluoroquinolones, and dyes); the left vertical axis represents the pollutant degradation rate; the inset shows the PMSO degradation.

[0100] The results showed that in the pre-generated H2O2 + mercury lamp system, the PDI / PMSO composite photocatalytic system described in Example 2 effectively degraded twelve coexisting (added separately) new pollutants, including bisphenol A, fluoroquinolones, and dyes. Compared with mercury lamp degradation alone, the rate constants were significantly improved (23.1%-352.0%, with an average improvement of 98.6%). This indicates that the PDI-coupled PMSO system developed in this study has the ability to produce H2O2 from resources, and the generated H2O2 can be applied to the degradation of new environmental pollutants.

[0101] Application Experiment 5: Tests in Different Water Bodies

[0102] The experiment of photocatalytic H2O2 production using the PDI / PMSO composite photocatalytic system described in Example 2 was conducted under different water conditions. The test method was the same as in Application Experiment 1, except that the photocatalytic reaction was carried out under different water conditions, including seawater, lake water, tap water, river water, and pure water.

[0103] Test results are as follows Figure 8 As shown, Figure 8 In the middle, the horizontal axis represents different water bodies; the left vertical axis represents the yield of H2O2.

[0104] The results showed that the systems containing PMSO pollutants (PMSO concentration of 10 mM) in different water bodies did not have a significant impact on the yield of H2O2, and all of them maintained a high level.

[0105] In summary, this invention couples perylene imide (PDI) supramolecular photocatalyst with methyl phenyl sulfoxide (PMSO) wastewater at a specific concentration ratio to obtain a PDI / PMSO composite photocatalytic system. This system promotes the separation of photogenerated electron-hole pairs (reducing steady-state fluorescence intensity by 37%) and enhances electron conduction efficiency (increasing photocurrent by 1.8 times) through synergistic effects, while maintaining excellent cycling stability (yield remains above 80% after 10 cycles) and practical applicability in aquatic environments. This invention offers a simple and low-cost process, providing an integrated solution for the resource recovery of organic wastewater and the green synthesis and application of H2O2.

[0106] Experiments have demonstrated that the PDI / PMSO composite system performs excellently under different light sources, coexistence of different pollutants, and different water body conditions. In terms of pollutant degradation, the degradation rate constant is significantly improved compared to untreated H2O2 (23.1%-352.0%, with an average improvement of 98.6%). Therefore, it has broad application prospects in wastewater treatment, water reduction, and adsorption degradation.

[0107] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. The application of PDI / PMSO composite photocatalytic system in photocatalytic degradation of water pollutants, characterized in that, The water pollutants are one or more of bisphenol A, bisphenol AF, bromophenol blue, bisphenol F, enoxacin, ofloxacin, rhodamine B, methylene blue, naphthol green B, and methyl orange; The concentration of the water pollutants is 1-5 mg / L; The PDI / PMSO composite photocatalytic system comprises a PDI supramolecular photocatalyst and PMSO, and the mass ratio of the PDI supramolecular photocatalyst to PMSO is (0.03-7.5):1; The PDI / PMSO composite photocatalytic system is prepared by the following steps: The PDI supramolecular photocatalyst and PMSO are sequentially dispersed in water to construct the PDI / PMSO composite photocatalytic system; In the PDI / PMSO composite photocatalytic system, the concentration of PDI is 0.1-0.5 g / L, and the concentration of PMSO is 0.5-20 mM; The PDI supramolecular photocatalyst is prepared by the following steps: 1) Under a protective atmosphere, perylene-3,4,9,10-tetracarboxylic dianhydride, β-alanine and imidazole are mixed and placed in a reaction container, then reacted at a certain temperature for a certain time under a protective atmosphere, and then cooled to room temperature and ground into powder; 2) The product of step 1) is sequentially washed with anhydrous ethanol and HCl solution for 6-18 hours, and then suction filtered to a filtrate with neutral pH; 3) The product of step 2) is dried and dispersed in water, triethylamine and HCl solution are added, shaken for 1-3 hours, suction filtered, and dried to obtain a powder of the PDI supramolecular photocatalyst.

2. Use according to claim 1, wherein The PDI / PMSO composite photocatalytic system simultaneously degrades multiple water pollutants.

3. The use according to claim 1, wherein the compound is ###0002### In step 1), the mass ratio of perylene-3,4,9,10-tetracarboxylic dianhydride to β-alanine is 1:(1-2); and in step 1), the mass ratio of β-alanine to imidazole is 1:(4-6).

4. The use according to claim 1, wherein In step 1), the reaction temperature is 100-120°C, and the reaction time is 2-6 hours.

5. The use according to claim 1, wherein In step 3), the mass ratio of the product to triethylamine, HCl solution is (1-2.68):(0.6-1):(2-4).

6. A method for photocatalytic degradation of water pollutants using PDI / PMSO composite photocatalytic system characterized in that, Comprising the following steps: First, a powder of the PDI supramolecular photocatalyst is prepared, then the powder of the PDI supramolecular photocatalyst is dispersed in water containing water pollutants, and then PMSO is added to construct the PDI / PMSO composite photocatalytic system; The photocatalytic reaction is performed by irradiation with a light source for 5-60 minutes; In the PDI / PMSO composite photocatalytic system, the concentration of PDI is 0.1-0.5 g / L, and the concentration of PMSO is 0.5-20 mM; The water pollutants are one or more of bisphenol A, bisphenol AF, bromophenol blue, bisphenol F, enoxacin, ofloxacin, rhodamine B, methylene blue, naphthol green B, and methyl orange; The concentration of the water pollutants is 1-5 mg / L; The PDI supramolecular photocatalyst is prepared by the following steps: 1) Under a protective atmosphere, perylene-3,4,9,10-tetracarboxylic dianhydride, β-alanine and imidazole are mixed and placed in a reaction container, then reacted at a certain temperature for a certain time under a protective atmosphere, and then cooled to room temperature and ground into powder; 2) The product of step 1) is washed with anhydrous ethanol and HCl solution for 6-18 hours, respectively, and then filtered to a filtrate with neutral pH; 3) The product of step 2) is dried and dispersed in water, and then triethylamine and HCl solution are added, and the mixture is shaken for 1-3 hours, filtered, and dried to obtain a powder of PDI supramolecular photocatalyst; The light source is a xenon lamp or a mercury lamp, wavelength greater than 400 nm, illuminance 100±3 mW·cm -2 ; Alternatively, the light source is sunlight, wavelength greater than 295 nm, and the illumination is 95 mW-cm -2 ; or a blue LED lamp with a wavelength of 455-460 nm, an irradiance of 6.2 mW-cm -2 or a violet LED lamp with a wavelength of 390-400 nm, an irradiance of 4.0 mW-cm -2 or a green LED lamp with a wavelength of 515-530 nm, an irradiance of 6.0 mW-cm -2 or a yellow LED lamp with a wavelength of 590-595 nm, an irradiance of 4.0 mW-cm -2 or a red LED lamp with a wavelength of 655-660 nm, an irradiance of 11.0 mW-cm -2 or a red LED lamp with a wavelength of 655-660 nm, an irradiance of 11.0 mW-cm During irradiation, the power is 100-300 W; Before irradiation, the PDI / PMSO composite photocatalytic system is dark reacted for 10-60 minutes in dark conditions.

7. The method of claim 6, wherein, In step 1), the mass ratio of perylene-3,4,9,10-tetracarboxylic dianhydride to β-alanine is 1:(1-2); in step 1), the mass ratio of β-alanine to imidazole is 1:(4-6).

8. The method of claim 6, wherein, In step 1), the reaction temperature is 100-120°C, and the reaction time is 2-6 hours.

9. The method of claim 6, wherein, In step 3), the mass ratio of the product to triethylamine, HCl solution is (1-2.68):(0.6-1):(2-4).

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