Porous squaric acid-phenylenediamine polymer as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photocatalysis, and particularly relates to a porous squaric acid-phenylenediamine polymer and a preparation method and application thereof.The preparation method comprises the steps that squaric acid and phenylenediamine are subjected to a solvothermal reaction to form a Schiff base polymer, and the porous squaric acid-phenylenediamine polymer is obtained; the phenylenediamine is o-phenylenediamine or m-phenylenediamine. The prepared porous squaric acid-phenylenediamine polymer serves as a catalyst, the light absorption range of the porous squaric acid-phenylenediamine polymer is widened to the infrared range, and due to effective electron and hole regulation and control, H2O2 can be efficiently produced in a visible light source and pure water without the existence of a sacrificial agent. And the produced H2O2 is further disinfected and sterilized, and pollutants are removed through an in-situ Fenton reaction, so that relatively good application potential is shown.

Description

Technical Field

[0001] This invention belongs to the field of photocatalysis technology, specifically relating to a porous squaric acid-phenylenediamine polymer, its preparation method, and its application. Background Technology

[0002] Hydrogen peroxide (H2O2) is an environmentally friendly oxidant widely used in environmental remediation due to its high efficiency in pollutant degradation and antibacterial activity. However, the production of industrial-grade hydrogen peroxide mainly relies on the energy-intensive and environmentally harmful anthraquinone process. Furthermore, the storage and transportation of hydrogen peroxide pose significant safety risks due to its instability and explosive potential. To address these challenges, in-situ hydrogen peroxide generation technologies, particularly photocatalytic generation technologies, have emerged as a sustainable alternative, offering advantages such as operational safety, renewable energy utilization, and on-demand applicability.

[0003] Developing efficient and stable photocatalytic materials is a core challenge in realizing the green synthesis of H2O2 driven by solar energy. Among numerous candidate materials, donor-acceptor (DA) type conjugated polymers have attracted much attention due to their advantages such as tunable band structure, high charge separation efficiency, and good stability. Among them, DA polymers constructed based on Schiff base condensation reactions can achieve effective separation and transport of photogenerated charge carriers through flexible molecular design, exhibiting significant photocatalytic potential.

[0004] However, current research in this field mostly focuses on conventional monomers such as terephthalaldehyde as building blocks, and the homogeneity of their molecular structures limits a deeper understanding of their structure-activity relationship and further breakthroughs in their performance.

[0005] Therefore, developing high-performance photocatalytic materials for the preparation of H2O2 is a technical problem that needs to be solved. Summary of the Invention

[0006] As one aspect of the present invention, the present invention provides a method for preparing a porous squaric acid-phenylenediamine polymer, which includes reacting squaric acid and phenylenediamine through a solvothermal reaction to form a Schiff base polymer, thereby obtaining a porous squaric acid-phenylenediamine polymer; wherein the phenylenediamine is o-phenylenediamine or m-phenylenediamine.

[0007] As a preferred embodiment of the preparation method of the porous squaric acid-phenylenediamine polymer of the present invention, the molar ratio of squaric acid to phenylenediamine is 1:1-1.2.

[0008] As a preferred embodiment of the preparation method of the porous squaric acid-phenylenediamine polymer of the present invention: squaric acid and phenylenediamine are added to a mixed solution of n-butanol and o-dichlorobenzene, mixed evenly, and reacted at 120-140 °C for 48-72 h to obtain the porous squaric acid-phenylenediamine polymer.

[0009] As a preferred embodiment of the preparation method of the porous squaric acid-phenylenediamine polymer of the present invention, the volume ratio of n-butanol to o-dichlorobenzene is 2.5-3.5:1:1.

[0010] The present invention also provides a porous squaric acid-phenylenediamine polymer prepared by the method of preparing the porous squaric acid-phenylenediamine polymer, wherein the absorption edge of the ultraviolet-visible diffuse reflectance absorption spectrum of the porous squaric acid-phenylenediamine polymer extends into the near-infrared region.

[0011] The present invention also provides the application of the porous squaric acid-phenylenediamine polymer prepared by the method of preparation of the above-mentioned porous squaric acid-phenylenediamine polymer as a photocatalyst, wherein the photocatalyst is used to catalyze the preparation of hydrogen peroxide from water.

[0012] Preferably, the porous squaric acid-phenylenediamine polymer is dispersed in water at a wavelength of 420-1200 nm, and hydrogen peroxide is prepared by photocatalysis at room temperature; the concentration of the photocatalyst in water is 0.05-0.1 mg / mL.

[0013] Preferably, the photocatalytic preparation of hydrogen peroxide is suitable for water bodies including lake water, tap water, and highly saline water; the suitable water body pH range is 3-11.

[0014] The present invention also provides the application of the porous squaric acid-phenylenediamine polymer prepared by the method of preparation in the removal of pollutants in water, wherein the pollutants in the water include sulfadiazine, ciprofloxacin and bisphenol A.

[0015] The beneficial effects of this invention are as follows: This invention uses ortho- and p-phenylenediamine as the amino-starting monomer and reacts it with squaric acid in a Schiff base polymerization reaction. The strong electron delocalization effect of squaric acid can effectively reduce the optical band gap of the material and broaden the spectral response range of the DA polymer. The selection of ortho- and p-phenylenediamine allows the amino group to form three isomers at the ortho- and meta-positions. Since the ortho- and meta-positions affect the electron distribution, the separation of electrons and holes in the DA unit can be controlled, and the in-situ generation of H2O2 can be enhanced through isomerization engineering. The porous squaric acid-phenylenediamine polymer prepared by this invention, as a catalyst, has a light absorption range that extends to the infrared range. Due to the effective electron and hole control, H2O2 can be efficiently generated in visible light and pure water without the presence of sacrificial agents. Furthermore, the generated H2O2 was sterilized and disinfected, and in-situ Fenton reaction was used to remove pollutants, demonstrating good application potential.

[0016] Compared with the prior art, the present invention has the following characteristics:

[0017] 1) This invention utilizes squaric acid and phenylenediamine as starting monomers to form Schiff base polymers. In particular, the isomerism engineering caused by the ortho-, meta-, and para-positions of the amino groups is a first-time discovery in the field of photocatalytic H2O2 production from porous squaric acid-based polymers. The H2O2 production rate is 3.9 times higher than that of common terephthalaldehyde and phenylenediamine polymers, reaching 5083.0 μmol g without aeration. -1 h -1 It can reach up to 8515.0 μmol g under oxygen aeration. -1 h -1 This significantly improved the performance of photocatalytic H2O2 production;

[0018] 2) The porous squaric acid-phenylenediamine polymer photocatalyst prepared by this invention does not require the presence of a sacrificial agent for photocatalytic water production of H2O2. It can react in visible light and pure water, and has the advantages of simple preparation method, simple equipment, and stable photocatalytic performance.

[0019] 3) The photocatalytic mechanism of the porous squaric acid-phenylenediamine polymer prepared in this invention is to produce H2O2 through a dual-channel photocatalytic process of oxygen reduction and water oxidation.

[0020] 4) The porous squaric acid-phenylenediamine polymer prepared by the present invention controls the separation of electrons and holes through isomeric positions, and extends the light absorption range from the visible light to the infrared region, resulting in good photocatalytic performance.

[0021] 5) The porous squaric acid-phenylenediamine polymer prepared by this invention has the potential to kill bacteria and remove pollutants in situ under light irradiation. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein:

[0023] Figure 1 The images show the scanning electron microscope (SEM) morphology of the photocatalysts prepared in Examples 1-3 and Comparative Example 1.

[0024] Figure 2 Solid-state NMR spectrum of the porous squaric acid-o-phenylenediamine polymer prepared in Example 1;

[0025] Figure 3 Solid-state NMR spectrum of the porous squaric acid-m-phenylenediamine polymer prepared in Example 2;

[0026] Figure 4 The UV-Vis diffuse reflectance absorption spectra and band gap diagrams of the four photocatalysts prepared in Examples 1-3 and Comparative Example 1 are shown.

[0027] Figure 5 The fluorescence spectra (PL) of the four photocatalysts prepared in Examples 1-3 and Comparative Example 1 are shown below.

[0028] Figure 6 The photocurrent diagrams are shown for the four photocatalysts prepared in Examples 1-3 and Comparative Example 1 under cyclic light irradiation-darkness conditions.

[0029] Figure 7 The photocatalytic performance of the four photocatalysts prepared in Examples 1-3 and Comparative Example 1 in producing H2O2 from water;

[0030] Figure 8 The photocatalytic H2O2 production performance of the porous squaric acid-phenylenediamine polymer prepared in Example 1 in pure water at different pH ranges;

[0031] Figure 9 The photocatalytic recycling performance of the porous squaric acid-phenylenediamine polymer prepared in Example 1;

[0032] Figure 10 The recycling performance of the two photocatalysts prepared in Example 2 and Comparative Example 1;

[0033] Figure 11 The performance of the porous squaric acid-phenylenediamine polymer prepared in Example 1 in the long-term photocatalytic production of H2O2 in pure water;

[0034] Figure 12 The bactericidal effect of the porous squaric acid-m-phenylenediamine polymer prepared in Example 2;

[0035] Figure 13 The effect of the porous squaric acid-o-phenylenediamine polymer photocatalyst prepared in Example 1 on the removal of simulated wastewater by Fenton reaction;

[0036] Figure 14 The effect of the porous squaric acid-m-phenylenediamine polymer photocatalyst prepared in Example 2 on the removal of simulated wastewater by Fenton reaction;

[0037] Figure 15 The porous squaric acid-o-phenylenediamine polymer photocatalyst coated panel reactor prepared in Example 14 was used to treat simulated wastewater under sunlight irradiation.

[0038] Figure 16 The porous squaric acid-m-phenylenediamine polymer photocatalyst coated panel reactor prepared in Example 15 was used to treat simulated wastewater under sunlight.

[0039] Figure 17 The performance of the porous squaric acid-o-phenylenediamine polymer photocatalyst prepared in Example 1 in producing H2O2 under inhibitor and different gas atmosphere conditions is shown. Detailed Implementation

[0040] To make the above-mentioned objectives, 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 specific examples.

[0041] Example 1:

[0042] A porous squaric acid-o-phenylenediamine polymer, the preparation method of which includes the following steps:

[0043] 0.186 g of squaric acid and 0.174 g of o-phenylenediamine were dispersed in a mixed solution of 12 mL of n-butanol and 4 mL of o-dichlorobenzene. The mixture was ultrasonically mixed for 15 min, transferred to the lining of a reactor to remove oxygen, and subjected to solvothermal polymerization under sealed conditions at 120 °C for 72 h. After the reaction was completed and cooled, the mixture was washed three times with ethanol and water, respectively, to obtain the squaric acid-o-phenylenediamine polymer, labeled SOA.

[0044] Example 2:

[0045] A porous squaric acid-m-phenylenediamine polymer, the preparation method of which includes the following steps:

[0046] 0.186 g of squaric acid and 0.174 g of m-phenylenediamine were dispersed in a mixed solution of 12 mL of n-butanol and 4 mL of o-dichlorobenzene. The mixture was ultrasonically mixed for 15 min, transferred to the lining of a reactor to remove oxygen, and subjected to solvothermal polymerization under sealed conditions at 120 °C for 72 h. After the reaction was completed and cooled, the mixture was washed three times with ethanol and water, respectively, to obtain the squaric acid-m-phenylenediamine polymer, labeled as SMA.

[0047] Example 3:

[0048] A porous squaric acid-p-phenylenediamine polymer, the preparation method of which includes the following steps:

[0049] 0.186 g of squaric acid and 0.174 g of p-phenylenediamine were dispersed in a mixed solution of 12 mL n-butanol and 4 mL o-dichlorobenzene. The mixture was ultrasonically mixed for 15 min, transferred to the lining of a reactor to remove oxygen, and subjected to solvothermal polymerization under sealed conditions at 120 °C for 72 h. After the reaction was completed and cooled, the polymer was washed three times with ethanol and water, respectively, to obtain the squaric acid-p-phenylenediamine polymer, labeled STA.

[0050] Comparative Example 1:

[0051] A terephthalaldehyde-p-phenylenediamine polymer, the preparation method of which includes the following steps:

[0052] 0.215 g of terephthalaldehyde and 0.174 g of p-phenylenediamine were dispersed in a mixed solution of 12 mL n-butanol and 4 mL o-dichlorobenzene. The mixture was ultrasonically mixed for 15 min, transferred to the liner of a reactor to remove oxygen, and subjected to solvothermal polymerization under sealed conditions at 120 °C for 72 h. After the reaction was completed and cooled, the polymer was washed three times with ethanol and three times with water to obtain the terephthalaldehyde-p-phenylenediamine polymer, labeled as TMD.

[0053] The above four photocatalysts were characterized, and the following results were obtained:

[0054] Figure 1 Scanning electron microscopy (SEM) images of SOA, SMA, STA, and TMD are shown. The microstructure reveals that SOA and SMA exhibit a three-dimensional, rolled-up, lamellar structure with a highly porous morphology. In contrast, STA particles formed from p-phenylenediamine and squaric acid are disordered, significantly larger than SOA and SMA particles, and lack a clear morphological pattern. TMD formed from p-phenylenediamine and terephthalaldehyde exhibits spherical particles with a size less than 2 μm. Regular morphologies indicate better organic polymer formation, while disordered morphologies suggest an uncontrollable polymerization process, with amino groups affecting the stable and continuous formation of DA units. Furthermore, porous morphologies are more conducive to the contact between photocatalytic reactants and to effective light irradiation.

[0055] Figure 2 and Figure 3 The solid-state NMR spectra of SOA and SMA, respectively, both contain two main signals located at 173 ppm and 168 ppm, corresponding to C=O and C=N carbon groups, respectively. The carbon resonance signal at 168 ppm confirms the formation of an imine bond. In addition, characteristic signals from carbon atoms in the benzene ring are revealed in the spectral region of 110-140 ppm.

[0056] Figure 4 The UV-Vis diffuse reflectance absorption spectra and band gap diagrams for four photocatalysts: SOA, SMA, STA, and TMD, are shown, where (ahV) 2 represents the absorption coefficient multiplied by the square of the photon energy, where hV represents the photon energy. From Figure 4It can be seen that the squaric acid-based polymers all have a wider light absorption range than the terephthalaldehyde-based polymers, and still exhibit absorption in the infrared region; the three isomer positions show higher absorption intensity in the visible light region compared to SOA. Combining the Mott-Schottky diagrams of the four catalysts, the conductivity positions were determined to be -0.59, -0.40, -0.61, and -0.66 V (vs RHE), all possessing sufficient reduction potential to provide driving force for the subsequent oxygen reduction reaction to generate H₂O₂; the corresponding conduction band potentials were 1.26, 1.41, 1.26, and 2.62 V (vs RHE), all capable of undergoing water oxidation to provide hydrogen protons for the oxygen reduction reaction.

[0057] Figure 5 The photoluminescence (PL) spectra of four photocatalysts—SOA, SMA, STA, and TMD—are shown. Electron-hole recombination triggers fluorescence emission; therefore, PL intensity serves as an indicator of charge separation efficiency. The fluorescence intensity of the squaric acid polymer is significantly lower than that of TMD, while the fluorescence intensity of SOA is significantly lower than that of the other two squaric acid polymers. A larger proportion of excitons participate in the SOA photocatalytic process, and the PL intensity with the least radiative decay indicates that SOA exhibits the weakest electron-hole recombination. This is crucial for the efficient utilization of separated electrons and holes.

[0058] Example 4:

[0059] This embodiment investigates the photocurrent of the porous squaric acid-phenylenediamine polymers prepared in Examples 1-3 and Comparative Example 1, and the terephthalaldehyde-p-phenylenediamine polymer synthesized under the same conditions. To prepare the working electrode, 5 mg of catalyst was dispersed in 1 mL of 0.5% Nafion ethanol solution, and then the solution was ultrasonically treated for 30 min to ensure homogeneity. Next, 100 μL of the prepared slurry was coated onto conductive glass. Using the electrode prepared above as the working electrode, and an Ag / AgCl electrode and a platinum sheet as the reference and counter electrodes, respectively, the photocurrent was measured under illumination-shielding cycling tests with a cutoff wavelength of 420 nm.

[0060] The results are as follows Figure 6 As shown in the photocurrent diagrams under cyclic illumination-dark conditions, among the four photocatalysts, the one exhibiting the most significant current peak immediately after illumination indicates excellent charge separation capability. Among the four photocatalysts, SOA exhibits the highest stable photocurrent density, indicating higher photogenerated carrier transfer efficiency. The photocurrent gradually decreases under dark conditions, and the photocurrent under repeated on-off operation shows a trend of "generation-decrease to 0," demonstrating that all four photocatalysts can stably generate photocurrent.

[0061] Example 5:

[0062] This embodiment is used to investigate the photocatalytic performance of porous squaric acid-phenylenediamine polymers prepared in Examples 1-3 and Comparative Example 1, and terephthalaldehyde-p-phenylenediamine polymers synthesized under the same conditions for H2O2 production from water. The specific process includes:

[0063] M1: Disperse 5 mg of the above catalyst in 50 mL of water, stir and sonicate until uniformly dispersed to form a reaction solution, sonicate for 15 min, and adsorb in the dark for 15 min.

[0064] M2: Place the well-dispersed reaction solution from step M1 under a 300 W xenon lamp light source and turn on visible light to irradiate the photocatalytic reaction. The light wavelength is preferably greater than 420 nm. React for 60 min at room temperature (25°C).

[0065] M3: Samples were taken and filtered at 0 min, 10 min, 20 min, 30 min, 40 min, 50 min and 60 min respectively, and the H2O2 concentration in the filtrate was determined by iodometric titration.

[0066] Test results as follows Figure 7 As shown, after reacting in pure water under visible light for 60 min, the H2O2 production of the four photocatalysts all exhibited a linear growth trend. The efficiency of TMD catalysis for H2O2 production using terephthalaldehyde and p-phenylenediamine as reactants was 1495.0 μmol g. -1 h -1 When squaric acid replaces terephthalaldehyde, the H2O2 production efficiencies of the formed SOA and SMA reach 5798.3 μmol g, respectively. -1 h -1 and 2196.5 μmol g -1 h -1 Of the three isomer positions, only the polymer STA formed by p-phenylenediamine and squaric acid exhibits low H2O2 production performance, with only 289.0 μmol g. -1 h -1 The main reason is that STA has an irregular morphology, small specific surface area, and easy recombination of electrons and holes. By replacing squaric acid, it can be seen that due to the broadening of the light absorption range and the better electron-hole separation efficiency, the efficiency of H2O2 production by SOA and SMA is 3.9 times that of the control group TMD.

[0067] Example 6:

[0068] This embodiment is used to investigate the photocatalytic H2O2 production performance of the porous squaric acid-o-phenylenediamine polymer prepared in Example 1 in different water qualities: lake water (taking water taken from the lake on the campus of Shanghai University of Engineering Science as an example), tap water, purified water, and water with different salinity. The specific process is the same as that in Example 5, except that the purified water is replaced with other corresponding water qualities. Samples are taken and filtered at a specific time (60 min of reaction) and the H2O2 concentration in the filtrate is detected by iodometric titration.

[0069] As shown in Table 1, different water quality substrates have little effect on the photocatalytic production of H2O2 by SOA. In particular, H2O2 can still be effectively produced in high-concentration salt solutions, indicating that this catalyst has strong applicability to different water quality conditions, especially for high-concentration salt solutions (H2O2 reaching over 4800 μmol g / L). -1 h -1 It has the potential to produce H2O2 by photocatalysis of seawater.

[0070] Table 1. Performance of porous squaric acid-o-phenylenediamine polymer in photocatalytic H2O2 production in different water qualities

[0071]

[0072] Example 7:

[0073] This embodiment is used to examine the photocatalytic H2O2 production performance of the porous squaric acid-o-phenylenediamine polymer prepared in Example 1 in pure water at different pH ranges. The specific process is the same as that in Example 5, except that the pure water is adjusted to different pH values, and samples are taken and filtered at a specific time (60 min of reaction) and the H2O2 concentration in the filtrate is detected by iodometric titration.

[0074] like Figure 8 As shown, within the acidic to alkaline pH range of pure water (3, 5, 7, 9, 11), the H2O2 production under SOA (porous squaric acid-o-phenylenediamine polymer) irradiation was 486.6, 501.2, 519.6, 532.5, and 454.3 μmol L, respectively. -1 This indicates that the squaric acid polymer has a wide applicable pH range for producing H2O2 in pure water.

[0075] Example 8:

[0076] This embodiment was used to investigate the cyclic performance of the porous squaric acid-o-phenylenediamine polymer prepared in Example 1 for photocatalytic H2O2 production in pure water. The specific process was the same as in Example 5. Samples were taken at a specific time (60 min of reaction) for filtration, and the H2O2 concentration in the filtrate was determined by iodometric titration. The catalyst was recycled after each cycle (60 min), by filtration to separate the squaric acid-o-phenylenediamine polymer, washing it three times, drying it at 60 degrees Celsius, and then using it for the next cycle.

[0077] like Figure 9 As shown, SOA can maintain stable and efficient H2O2 production in seven repeated cycles. After seven cycles, H2O2 production still reaches 4992.0 μmol g / L. -1 h -1 .

[0078] Example 9:

[0079] This example compares the cyclic performance of the SMA and TMD photocatalysts prepared in Example 2 and Comparative Example 1 in the photocatalytic production of H2O2 in pure water. The specific procedure is the same as in Example 5. Samples were taken at a specific time (60 min of reaction) for filtration, and the H2O2 concentration in the filtrate was determined by iodometric titration. The catalyst was recycled after each cycle (60 min), by filtration to separate the squaric acid-o-phenylenediamine polymer, washing it three times, drying it at 60 degrees Celsius, and then using it for the next cycle.

[0080] like Figure 10 As shown, the H2O2 production performance of SMA and TMD decreased slightly in the seven-cycle reuse test, but they were still able to maintain stable and efficient H2O2 production. After seven cycles, the H2O2 production reached 1871.0 and 958.0 μmolg, respectively. -1 h -1 Cyclic tests showed that the photocatalytic performance of the squaric acid-based polymer was stable.

[0081] Example 10:

[0082] This example was used to investigate the performance of the porous squaric acid-o-phenylenediamine polymer prepared in Example 1 in the long-term photocatalytic production of H2O2 in pure water. The specific procedure was the same as in Example 5. Samples were taken and filtered at specific times (every 60 min), and the H2O2 concentration in the filtrate was determined by iodometric titration.

[0083] like Figure 11 As shown, prolonged irradiation of SOA results in a linear increase in H2O2 production, consistent with theoretical predictions. After 6 hours of continuous irradiation, SOA cumulatively produced 2158.0 μmol L⁻¹. -1 The H2O2 concentration can reach the level of practical utilization.

[0084] Example 11:

[0085] This embodiment is used to examine the dispersion of the porous squaric acid-m-phenylenediamine polymer prepared in Example 2 in lake water and to compare the colony formation in the lake water before and after light exposure.

[0086] like Figure 12The untreated water sample was able to cultivate multiple bacterial colonies, while the water sample containing the porous squaric acid-m-phenylenediamine polymer showed almost no bacterial colonies on the culture medium after 1 hour of light exposure. This indicates that the H2O2 produced by the porous squaric acid-m-phenylenediamine polymer has a bactericidal effect on natural water bodies.

[0087] Example 12:

[0088] This embodiment was used to investigate the removal of 5 mg / L ciprofloxacin (CIP) simulated wastewater by a Fenton-like reaction using a porous squaric acid-o-phenylenediamine polymer photocatalyst prepared in Example 1. The pure water in Example 5 was replaced with ciprofloxacin (CIP) simulated wastewater. After the catalyst was dispersed in the pollutant solution, illumination was turned on and 1 mM ferrous ions were added to remove CIP using an in-situ Fenton-like reaction.

[0089] like Figure 13 As shown, it can be seen that H2O2 generated in situ under SOA irradiation can react with Fe. 2+ The effect of producing a Fenton-like effect to remove CIP is significantly stronger than that of the control group with catalyst in the dark and protected from light, and no catalyst but only light. After 3 hours of treatment, the removal rate of CIP reaches 90%.

[0090] Example 13:

[0091] This example was used to investigate the removal of simulated 5 mg / L sulfadiazine (SMX) wastewater by a Fenton-like reaction using a porous squaric acid-m-phenylenediamine polymer photocatalyst prepared in Example 2. The pure water from Example 5 was replaced with simulated wastewater containing the emerging pollutant SMX. After the catalyst was dispersed in the pollutant solution, illumination was turned on and 1 mM ferrous ions were added to remove SMX using an in-situ Fenton-like reaction.

[0092] like Figure 14 As shown, compared with the control group (catalyst in darkness, no catalyst, only light exposure), the H2O2 generated in situ under SMA light exposure can react with Fe. 2+ It produces a Fenton-like effect, and after 3 hours of action, the removal rate of SMX reaches 93%.

[0093] Example 14:

[0094] This embodiment is used to examine the effect of the porous squaric acid-o-phenylenediamine polymer photocatalyst coated panel reactor prepared in Example 1 on the continuous flow reaction treatment of simulated CIP wastewater under sunlight irradiation.

[0095] like Figure 15 As shown, under sunlight irradiation, the SOA continuous flow reactor operated for 3 hours, and the treated wastewater maintained a stable CIP removal rate of over 90%. This indicates that the catalyst has great potential for treating emerging pollutant wastewater using solar energy.

[0096] Example 15:

[0097] This embodiment is used to examine the effect of the porous squaric acid-m-phenylenediamine polymer photocatalyst coated panel reactor prepared in Example 2 on the continuous flow reaction treatment to simulate bisphenol A (BPA) under sunlight irradiation.

[0098] like Figure 16 As shown, under sunlight, the SMA continuous flow reactor operated for 3 hours, and the effluent treatment rate consistently remained above 90%. This indicates that the catalyst has great potential for treating emerging pollutant wastewater using solar energy.

[0099] Example 16:

[0100] This example is used to investigate the photocatalytic performance of the porous squaric acid-o-phenylenediamine polymer photocatalyst prepared in Example 1 in the production of H2O2 from water under the condition of inhibitor and different gas atmosphere. Except for the catalyst, inhibitor (benzoquinone BQ), and gas atmosphere (O2, air, and N2 at normal pressure; unless otherwise specified, all examples are carried out under air), the other processes and conditions are the same as in Example 5. The inhibitor is 1 mmol / L.

[0101] Test results as follows Figure 17 As shown, after the introduction of oxygen, due to the enhanced oxygen reduction reaction, the photocatalytic performance of porous squaric acid-o-phenylenediamine polymer SOA in producing H2O2 from water was significantly higher than that of the air-atmosphere control group, increasing from 508.3 μmol / L. -1 Increased to 665.0 μmol L -1 The H2O2 production performance decreased significantly after nitrogen gas was introduced, from 508.3 μmol L⁻¹. -1 Decreased to 244.4 μmol L -1 This result indicates that H2O2 production may coexist via the oxygen reduction pathway and the water oxidation pathway. p-Benzoquinone BQ, as an inhibitor of superoxide radicals, significantly reduced H2O2 production, to only 67.2 μmol / L. -1 The yield indicates the existence of a two-step single-electron oxygen reduction reaction pathway to produce H2O2. Therefore, the porous squaric acid-o-phenylenediamine polymer SOA prepared in this invention produces H2O2 via photocatalysis through an oxygen reduction channel.

[0102] Example 17:

[0103] A porous squaric acid-o-phenylenediamine polymer, the preparation method of which includes the following steps:

[0104] 0.186 g of squaric acid and 0.209 g of o-phenylenediamine were dispersed in a mixed solution of 14 mL of n-butanol and 4 mL of o-dichlorobenzene. The mixture was ultrasonically mixed for 20 min, transferred to the lining of a reactor to remove oxygen, and subjected to solvothermal polymerization under sealed conditions at 140 °C for 48 h. After the reaction was completed and cooled, the mixture was washed three times with ethanol and water, respectively, to obtain the squaric acid-o-phenylenediamine polymer.

[0105] Example 18:

[0106] A porous squaric acid-m-phenylenediamine polymer, the preparation method of which includes the following steps:

[0107] 0.186 g of squaric acid and 0.209 g of m-phenylenediamine were dispersed in a mixed solution of 14 mL of n-butanol and 4 mL of o-dichlorobenzene. The mixture was ultrasonically mixed for 15 min, transferred to the lining of a reactor to remove oxygen, and subjected to solvothermal polymerization under sealed conditions at 120 °C for 72 h. After the reaction was completed and cooled, the mixture was washed three times with ethanol and water, respectively, to obtain the squaric acid-m-phenylenediamine polymer.

[0108] Example 19:

[0109] This test example is used to examine the photocatalytic production performance of the squaric acid-phenylenediamine polymer prepared in Examples 1, 2, 17, and 18 for H2O2. Except for the selection of catalyst and the sampling time being only 60 min, the other processes and conditions are the same as in Test Example 1.

[0110] Table 2 Comparison of the photocatalytic performance of four squaric acid-phenylenediamine polymers in preparing H2O2 from water.

[0111]

[0112] The test results are shown in Figure 2. When reacting in pure water under visible light for 60 min, a comparison between Example 1 and Example 17 shows that with increasing solvothermal temperature, the photocatalytic H2O2 production performance decreased from 5798.3 μmol / g to 4173.8 μmol / g. -1 h -1 The results indicate that higher solvothermal temperatures during synthesis have a certain impact on the photocatalytic H2O2 production performance of the polymer, with the optimal temperature being 120 °C.

[0113] When reacting in pure water under visible light for 60 min, the comparison between Example 2 and Example 18 shows that the photocatalytic effect of the squaric acid-phenylenediamine polymer is better when the volume ratio of n-butanol to o-dichlorobenzene in the solvent is 3:1.

[0114] 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 preparing a porous squaraine-phenylenediamine polymer, characterized by: The method comprises forming a squaraine-benzene diamine polymer by a solvothermal reaction of squaraine and benzene diamine to obtain a porous squaraine-benzene diamine polymer; the benzene diamine is ortho-benzene diamine or meta-benzene diamine.

2. The method of claim 1, wherein: The molar ratio of the squaraine to the benzene diamine is 1:1-1.

2.

3. The method for preparing a porous squarryl-phenylenediamine polymer according to claim 1 or 2, characterized by: The squaraine and the benzene diamine are added into a mixed solution of n-butanol and ortho-dichlorobenzene, uniformly mixed, and reacted at 120-140 ℃ for 48-72 h to obtain the porous squaraine-benzene diamine polymer.

4. The method of claim 3, wherein the porous para-phenylenediamine polymer is prepared by: The volume ratio of the n-butanol to the ortho-dichlorobenzene is 2.5-3.5:

1.

5. The porous squarylium-benzene diamine polymer prepared according to the method of claim 1, characterized in that: The absorption edge of the porous squaraine-benzene diamine polymer in the ultraviolet-visible diffuse reflection absorption spectrum extends to the near-infrared region.

6. The application of the porous squarryl-phenylenediamine polymer prepared by the method of claim 1 as a photocatalyst, characterized in that: The photocatalyst is used for catalyzing water to prepare hydrogen peroxide.

7. Use according to claim 6, characterized in that: The porous squaraine-benzene diamine polymer is dispersed in water at a wavelength of 420-1200 nm, and the photocatalytic preparation of hydrogen peroxide is carried out at room temperature; the concentration of the photocatalyst in water is 0.05-0.1 mg / mL.

8. Use according to claim 7, characterized in that: The photocatalytic preparation of hydrogen peroxide is applicable to water bodies including lake water, tap water and high-salinity water; the pH range of the applicable water bodies is 3-11.

9. Use of the porous squarryl-phenylenediamine polymer prepared according to the method of claim 1 for removing pollutants from water bodies, characterized in that: The pollutants in the water bodies include sulfadiazine, ciprofloxacin and bisphenol A.

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