Porphyrin-based COFs photocatalyst, preparation method thereof and application of porphyrin-based COFs photocatalyst in photocatalytic production of H2O2

Abstract

The invention discloses a porphyrinyl COFs photocatalyst, a preparation method and application in photocatalytic production of H2O2, and belongs to the technical field of material scientificity, firstly 5, 10, 15, 20-tetra (tetranitrophenyl) porphyrin is synthesized, then nitro on the porphyrin is reduced into amino, then 4, 4 '-(10-(9-anthryl)-5, 5-difluoro-3, 7-dimethyl-5H-4, 5-dipyrrolo [1, 2-c: 2', 1 '-f] [1, 3, 4] triazolo [1, 2-c: 2', 1 '-f] [1, 3, 4] triazolo [1, 3, 4] triazolo [1, 3, 4] triazolo [1, 3, 4] triazolo [1, 3, 4] triazolo 2, 2] (2, 8-diazoboron pyridinyl) dibenzaldehyde is prepared, the two monomers are dispersed in an organic solvent, and solvothermal polymerization is performed under the catalysis of anhydrous acetic acid to form the COF material. Porphyrin has a large conjugate structure of 18 pi electrons and has excellent visible light absorption capability and electron donating characteristic, and the large conjugate structure provides stable nodes for constructing a COF topological structure. In combination with the characteristics of high charge transfer rate, large specific surface area and high visible light utilization efficiency of the COF material, the prepared COFs have higher charge separation capacity and have the capacity of absorbing the whole visible light range. The synthesis process is simple, and an effective way is expected to be provided for producing H2O2 through efficient photocatalysis of the COF material.

Description

Technical Field

[0001] This invention belongs to the field of materials science and technology, specifically relating to porphyrin-based COFs photocatalysts, their preparation methods, and their application in photocatalytic H2O2 production. Background Technology

[0002] Hydrogen peroxide (H2O2), as an important green redox reagent, possesses both oxidation and reduction activities, and its reaction products are only water and oxygen. It has irreplaceable application value in fields such as pharmaceutical disinfection, chemical synthesis, pulp bleaching, environmental pollutant degradation, and energy storage. Currently, global H2O2 production mainly relies on the anthraquinone process. This process requires multiple steps including anthraquinone hydrogenation, oxidation, extraction, and distillation, involving not only the use of toxic solvents and secondary pollution emissions, but also inherent drawbacks such as high energy consumption, large equipment investment, high product separation costs, and limited process continuity and flexibility. The technological bottlenecks of the traditional anthraquinone process are becoming increasingly prominent, making the development of low-energy-consumption, low-pollution green H2O2 preparation technology an urgent industry need. Solar energy, as the most abundant renewable energy source on Earth, provides a core pathway for solving energy and environmental problems through its large-scale utilization. Photocatalytic H2O2 preparation technology driven by solar energy can directly utilize water and oxygen as raw materials to achieve the reaction at room temperature and pressure, combining energy utilization and environmental friendliness, providing a disruptive solution for the transformation of H2O2 from a high-energy-consuming product to a green chemical.

[0003] The core of photocatalytic H2O2 preparation lies in generating photocharges by absorbing light energy through a photocatalyst, which drives the oxygen reduction reaction (ORR) and water oxidation reaction (WOR) in a coordinated manner. Early research mainly focused on traditional semiconductor materials such as metal oxides (e.g., TiO2, ZnO) and metal sulfides (e.g., CdS, MoS2), but these materials suffer from problems such as low photocharge separation efficiency, narrow visible light response range, and poor chemical stability (e.g., sulfides are prone to photocorrosion). Subsequently, carbon-based materials (e.g., graphene, carbon nanotubes) and metal-organic frameworks (MOFs) attracted attention due to their tunable structural properties, but the insufficient active sites in carbon-based materials and the poor hydrothermal stability of MOFs limited their applications. In recent years, covalent organic frameworks (COFs), as a class of crystalline porous materials formed by light elements linked by covalent bonds, have shown unique advantages in the field of photocatalysis due to their precisely tunable topology, high specific surface area, controllable distribution of active sites, and excellent chemical stability. By controlling the monomer structure and connection mode, the band structure, light absorption range and charge transport performance of COFs can be precisely controlled. At present, a series of COF photocatalysts such as porphyrin, phthalocyanine and triazine have been developed.

[0004] Despite significant progress in the photocatalytic production of H2O2 using COFs-based photocatalysts, their industrial application still faces core technological bottlenecks. Firstly, charge separation efficiency is low. While the π-π conjugated structure in the COF molecular framework facilitates charge transport, the rapid recombination rate of photogenerated electron-hole pairs and the high resistance to interfacial charge transfer result in a large number of photogenerated charges becoming inactive before participating in the ORR / WOR reaction, severely limiting yield improvement. Secondly, the spectral response range is limited. The visible light absorption edge of most COFs is below 500 nm, and their utilization rate of near-infrared light, which accounts for more than 45% of the solar spectrum, is less than 5%, indicating a pressing need to improve light energy utilization efficiency. Furthermore, material stability and preparation costs are significant issues. COFs are prone to covalent bond breakage and structural collapse under strong oxidizing environments, and the monomer synthesis of high-performance COFs requires multiple organic reactions, making purification complex and resulting in high costs for large-scale preparation, thus limiting their overall performance and industrial application. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide porphyrin-based COFs photocatalysts, preparation methods, and applications in photocatalytic H2O2 production, so as to solve the technical problem of low yield caused by low charge separation efficiency of existing COFs materials in the photocatalytic H2O2 production process.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a method for preparing porphyrin-based COFs photocatalysts, comprising the following steps: 1) Synthesis of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde monomer; 2-Methylpyrrole was dissolved in ultra-dry dichloromethane to obtain solution D; 9-anthraaldehyde was dissolved in ultra-dry dichloromethane to obtain solution E; solution D and solution E were mixed, trifluoroacetic acid was added, and the reaction was carried out under nitrogen protection in the dark. Then 2,3-dichloro-5,6-dicyanobenzoquinone was added, and the reaction was stirred. Then triethylamine and etherified boron trifluoride were added, and the reaction was stirred again. After quenching, 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer was obtained. The monomer 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was dissolved in ethyl acetate to obtain solution F. An ethyl acetate solution of N-bromosuccinimide was added dropwise, and the reaction was carried out again in the dark to obtain the monomer 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine. 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridin monomer, 4-formylphenylboronic acid, tetrakis(triphenylphosphine)palladium, and sodium carbonate were dissolved in toluene aqueous solution. After heating and reacting under nitrogen protection, the mixture was extracted and dried to obtain 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridinyl)dibenzaldehyde monomer; 2) Synthesis of porphyrin-based COF photocatalysts The 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer and the 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde monomer prepared in step 1) were dissolved in an organic solvent, sonicated, and then a catalyst was added. After cyclic freezing and polymerization, the porphyrin-based COFs photocatalyst was obtained.

[0007] Preferably, the method for synthesizing 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer includes: First, 5,10,15,20-tetraphenylporphyrin was dissolved in chloroform to obtain solution A. The reaction was stirred under N2, and fuming nitric acid was slowly added dropwise. The reaction was stirred continuously, and then excess ammonia was added to quench the reaction. After cooling to room temperature, the solution was extracted, recrystallized, and dried under vacuum to obtain 5,10,15,20-tetra(4-nitrophenyl)porphyrin. 5,10,15,20-tetra(4-nitrophenyl)porphyrin was dissolved in concentrated hydrochloric acid to obtain solution B; stannous chloride dihydrate was dissolved in concentrated hydrochloric acid to obtain solution C. Solution C was added dropwise to solution B, and after a gradient temperature increase reaction, the solid 5,10,15,20-tetra(4-aminophenyl)porphyrin hydrochloride was separated by an ice-water bath. The pH was adjusted to 8-9, and after filtration and vacuum drying, it was dissolved in acetone and rotary evaporated to obtain the 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer.

[0008] More preferably, the concentration of solution A is 0.005~0.02 mol / L; in solution A, the molar ratio of chloroform to 5,10,15,20-tetraphenylporphyrin is (354~1388):1; The molar ratio of fuming nitric acid to 5,10,15,20-tetraphenylporphyrin is (32~72):1; The concentration of solution B is 0.005~0.02 mol / L; the concentration of solution C is 4.4~8.8 mol / L; The temperature for stirring the reaction is -20~0℃, and the time is 10~30 min; The reaction should continue to be stirred for 0.5 to 2 hours. The organic solvent used for recrystallization is methanol, ethanol, isopropanol, acetonitrile, or a methanol-water mixture. The conditions for the gradient temperature reaction include: first reacting at room temperature for 1~3 h, then increasing the temperature to 50~100℃ and reacting for 0.5~1 h; the temperature for rotary evaporation is 50~65℃.

[0009] Preferably, in step 1), the concentration of solution D is 0.125~0.0625 mol / L; the concentration of solution E is 0.024~0.048 mol / L; the concentration of solution F is 0.03 mol / L; and the concentration of the ethyl acetate solution of N-bromosuccinimide is 0.2~0.25 mol / L. The amount of trifluoroacetic acid used is 1% to 10% of the molar mass of 9-anthraaldehyde; The amount of 2,3-dichloro-5,6-dicyanobenzoquinone used is 1.5 to 3 times the molar mass of 9-anthraaldehyde; The amount of triethylamine used is 5 to 12 times the molar mass of 9-anthraaldehyde; The volume ratio of triethylamine to etherified boron trifluoride is (2~5):(5~8).

[0010] Preferably, in step 1), the quenching solution is a sodium carbonate solution or a sodium bicarbonate solution; The reaction time in the dark is more than 4 hours; The stirring reaction time is 0.5~1 h; the stirring reaction time is more than 1 h. The time for the second light-protected reaction is 1-3 hours.

[0011] Preferably, in step 1), the molar ratio of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer, 4-formylphenylboronic acid, and sodium carbonate is (0.2~1.5):(1.0~3.0):(1~5); The amount of tetra(triphenylphosphine)palladium used is 5% to 20% of the molar mass of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine; In an aqueous solution of toluene, the volume ratio of toluene to water is 10:1. The heating reaction temperature is 85~105℃, and the heating reaction time is 15~24 h.

[0012] Preferably, in step 2), the molar ratio of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin monomer to 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde monomer is (0.002~0.008):(0.008~0.016).

[0013] Preferably, in step 2), the organic solvent is at least two of xylene, 1,2-dichlorobenzene, n-butanol, benzyl alcohol, 1,4-dioxane, ethyl acetate, n-hexane, and diethyl ether; The ultrasound session lasted 5-10 minutes. The amount of catalyst used is 1% to 8% of the solvent volume; the catalyst is anhydrous acetic acid. The freezing cycle is repeated 1 to 3 times; The polymerization conditions are: under N2 protection, reaction at 80~150℃ for 48~72 h.

[0014] This invention also discloses a porphyrin-based COFs photocatalyst, the structural formula of which is: .

[0015] The present invention also discloses the application of the porphyrin-based COFs photocatalyst prepared by the above-mentioned method in the photocatalytic production of H2O2.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for preparing porphyrin-based COF photocatalysts. The core principle is to simulate the ORR reaction in nature, converting O2 and H2O (or proton donors) into H2O2 through photogenerated charge separation and directional transfer. Both main monomers are nitrogen-containing units, with multiple active sites working synergistically to precisely regulate the two-electron ORR. In the 5,10,15,20-tetra(4-aminophenyl)porphyrin unit, the N atom (pyrrole N, pyridine N) of its porphyrin ring is a typical Lewis base site, which can strongly adsorb O2 molecules through lone pair electrons, providing an initial active site for the oxygen reduction reaction (ORR). At the same time, the large π-conjugated system of porphyrin is conducive to the separation and transfer of photogenerated charges. The polar bond formed by the B atom (electron-deficient) and F atom (strong electronegativity) in the structure of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde can regulate the distribution of the surrounding electron cloud, optimize the O2 adsorption energy and intermediates. The stability of OOH directs ORR towards a two-electron pathway (generating H2O2 instead of H2O). Large π-conjugation and multi-level charge separation enhance quantum efficiency. It significantly broadens the light absorption range (covering the visible to near-infrared region) and accelerates the separation of photogenerated electron-hole pairs, reducing recombination probability and providing sufficient photogenerated electrons for ORR. The Schiff base bond (-N=CH-) between units serves as an excellent charge transport channel: ensuring rapid electron migration from the light-absorbing unit to the O2 adsorption active site, improving electron utilization. The donor-acceptor (DA) type COF improves photogenerated charge efficiency. The built-in power plant promotes the directional migration of photogenerated electrons from the donor to the acceptor, significantly reducing the electron-hole recombination probability, providing more effective electrons for the oxygen reduction reaction (ORR), and significantly increasing the H2O2 generation rate. Ordered channels and high specific surface area enhance mass transfer and reaction kinetics. As a COF material, its periodic porous structure provides a high specific surface area, increasing the adsorption sites for O2 and proton donors (such as H2O and alcohols) on the one hand, and accelerating the desorption and diffusion of H2O2 products on the other, avoiding excessive reduction (decomposition into H2O) at active sites, thereby improving the selectivity and yield of H2O2. A porphyrin-based COF photocatalyst with a donor-acceptor structure was successfully synthesized through optimized low-temperature nitration, controllable coupling, and solvent-controlled preparation methods. This catalyst utilizes the synergistic effect of porphyrin and BODIPY units to construct multiple active sites (N, B, F) and highly efficient charge separation channels. Its broad-spectrum absorption and built-in electric field significantly suppress electron-hole recombination and precisely guide the oxygen reduction reaction (ORR) along a two-electron path, thus achieving highly active, selective, and stable H2O2 production under visible light, overcoming the limitations of traditional photocatalysts in terms of efficiency, selectivity, and stability.

[0017] Furthermore, TPP and fuming nitric acid should be reacted at the lowest possible temperature to inhibit excessive nitration, control the degree of substitution, and avoid oxidation and destruction of the TPP main structure. In addition, this can also reduce the decomposition of nitric acid and ensure experimental safety.

[0018] Furthermore, the amount of CHCl3 used should ensure that TPP is completely dissolved and uniformly mixed to match the reaction rate with the separation efficiency.

[0019] Furthermore, the amount of fuming nitric acid used is determined based on the amount of TPP used to ensure that the product with the target degree of substitution is obtained, and to avoid over-substitution and the generation of by-products.

[0020] Furthermore, methanol, ethanol, isopropanol, acetonitrile, or methanol-water mixed solvents: moderate to very strong polarity, low boiling point, capable of efficiently dissolving polar / semi-polar products, their low boiling point facilitates post-processing, and they are low in toxicity and reactivity, making them suitable for most organic products.

[0021] Furthermore, trifluoroacetic acid (TFA) is used for coupling weakly active boric acids (such as arylboronic acids) with aryl halides, and TFA can promote the deprotonation of boric acids to form active species.

[0022] Furthermore, the metal valence state in the catalytic cycle was adjusted by regulating 2,3-dichloro-5,6-dicyanobenzoquinone (oxidizing Pd(0) to Pd(II) to repair the catalytic cycle).

[0023] Furthermore, triethylamine is used to adjust the pH to ensure that the amount of trifluoroacetic acid is controlled within the range where the base can partially neutralize it; otherwise, excessive TFA will completely neutralize the base, leading to the interruption of the catalytic cycle.

[0024] Furthermore, BF3 in BF3·OEt2 is an electron-deficient Lewis acid, and the N atom of triethylamine has a lone pair of electrons, which can combine through coordinate bonds to form a stable complex (Et3N→BF3).

[0025] Furthermore, the light-avoidance reaction can minimize product deterioration.

[0026] Furthermore, selecting solvents with different solubilities is beneficial for the crystallization of COF.

[0027] Furthermore, anhydrous acetic acid can promote the condensation of aldehydes and amines to form imine bonds, and it also has good solubility for many aldehyde and amine monomers, which is beneficial for uniform reaction.

[0028] The porphyrin-based COF photocatalyst prepared by the method disclosed in this invention achieves efficient coupling of porphyrin and BODIPY units at the molecular level through a sophisticated donor-acceptor (DA) structure design. The built-in electric field greatly promotes the directional migration and separation of photogenerated electrons, effectively suppressing charge recombination. Simultaneously, the active sites within the framework, composed of nitrogen, boron, fluorine, and other heteroatoms, can precisely regulate the oxygen reduction reaction pathway, preferentially and selectively generating H2O2. Combined with its ordered pore structure, broad-spectrum absorption capacity, and the stability of its metal-organic framework, this catalyst ultimately achieves highly active, highly selective, and long-lifetime photocatalytic synthesis of H2O2 under visible light, significantly outperforming traditional materials in overall performance.

[0029] The porphyrin-based COF photocatalyst prepared by the method disclosed in this invention has the following application in photocatalytic H2O2 production: the large π-conjugated system of porphyrin and anthracene ring and the DA-type structure (donor-porphyrin / anthracycline vs. acceptor-BODIPY) significantly broadens the light absorption range (covering the visible to near-infrared region). Furthermore, by driving the directional migration of photogenerated electrons from the donor to the acceptor through a built-in electric field, it significantly inhibits charge recombination, providing sufficient effective electrons for ORR. The porphyrin N atom and the B / F heteroatom of the BODIPY serve as active sites, adsorbing and activating O2 molecules through lone pair electrons or a polar microenvironment, directionally guiding ORR along a two-step, two-electron pathway (O2→ The process avoids the four-electron pathway for H2O generation (OOH→H2O2); simultaneously, the amino group and porous structure enhance proton transport, accelerating the supply of proton-electron pairs for H2O2 generation. This mechanism achieves high activity, high selectivity, and long-term stability, enabling efficient H2O2 production even under visible light. It overcomes the design limitations of traditional photocatalytic materials by synergistically innovating multiple active sites and a DA-type structure. Compared with existing metal-based catalysts, traditional COF, or semiconductor photocatalysts, this catalyst uses a multi-heteroatom (N, B, F) synergistic DA heterojunction as the active site. Driven by a built-in electric field, it achieves an extremely low charge recombination rate and efficiently absorbs photons in a wide spectral range from visible to near-infrared light, directionally guiding the oxygen reduction reaction along a two-electron pathway. At the same time, its organic framework is free of metal contamination and exhibits excellent cycle stability. It adopts a multi-unit integrated "full-process optimization" design paradigm, comprehensively overcoming the limitations of existing technologies such as "single metal site, severe charge recombination, low ORR selectivity, narrow light absorption, metal contamination, or easy degradation of structure" from active site, charge separation, reaction selectivity, light absorption range, stability, and environmental friendliness. Attached Figure Description

[0030] Figure 1 This is a synthetic route diagram of the porphyrin-based COF photocatalyst disclosed in Example 1 of the present invention; Figure 2 The FTIR spectra of 5,10,15,20-tetra(4-aminophenyl)porphyrin, 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde and TAPP-ANBDP-COFs disclosed in Example 1 of this invention are shown below. Figure 3 The 1H NMR spectrum of 5,10,15,20-tetra(4-aminophenyl)porphyrin disclosed in Example 1 of this invention; Figure 4 The 1H NMR spectrum of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde disclosed in Example 1 of this invention; Figure 5 The H2O2 yield at different times during the TAPP-ANBDP-COF photocatalytic H2O2 production process disclosed in Example 1 of this invention. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0033] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0034] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0035] Unless otherwise specified, the components or preferred components involved in this invention can be combined with each other to form new technical solutions.

[0036] In this invention, unless otherwise specified, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" indicates that all real numbers between "6~22" have been listed in this document, and "6~22" is simply a shortened representation of these numerical combinations.

[0037] The "scope" disclosed in this invention can be in the form of a lower limit and an upper limit, and can be one or more lower limits and one or more upper limits, respectively.

[0038] In this invention, the term "and / or" as used herein refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0039] In this invention, unless otherwise stated, the various reactions or operation steps may be performed sequentially or in a particular order. Preferably, the reaction methods described herein are performed sequentially.

[0040] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0041] This invention provides a COF with high charge separation efficiency for photocatalytic H2O2 production, achieved through the following scheme: Porphyrin possesses a large conjugated structure with 18 π electrons, exhibiting excellent visible light absorption and electron-donating properties, and its large conjugated structure provides stable nodes for constructing the COF topology. By combining 5,10,15,20-tetra(4-aminophenyl)porphyrin (TAPP) with 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde (ANBDP), the prepared COF exhibits high charge separation efficiency and absorption across the entire visible light range.

[0042] A porphyrin-based COF photocatalyst has the following structural formula: .

[0043] A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1) Synthesis of 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer (TAPP); First, 5,10,15,20-tetraphenylporphyrin (TPP) was dissolved in chloroform (CHCl3) to prepare a solution with a concentration of 0.005~0.02 mol / L. Under N2 protection and at a temperature of -20 to 0℃, the solution was stirred for 10-30 min. Fuming nitric acid was slowly added dropwise. After the addition was complete, the reaction was allowed to proceed for 0.5~2 h. Excess ammonia was added to quench the reaction. After the solution temperature reached room temperature, the solution was extracted, recrystallized, and dried under vacuum to obtain a crude purple product of 5,10,15,20-tetra(4-nitrophenyl)porphyrin (TNPP). The crude product was separated by silica gel column chromatography and analyzed by chromatographic analysis. The crude TNPP product was dissolved in concentrated hydrochloric acid to prepare a solution with a concentration of 0.005~0.02 mol / L. Stannous chloride dihydrate was dissolved in concentrated hydrochloric acid to prepare a solution with a concentration of 4.4~8.8 mol / L. The solutions were added dropwise over 10 min. After the addition was complete, the reaction was carried out at room temperature for 1~3 h, and then at 50~100℃ for 0.5~1 h. After the reaction, the solid 5,10,15,20-tetra(4-aminophenyl)porphyrin hydrochloride was separated by an ice-water bath. The pH was adjusted to 8~9 with ammonia water, and the product was filtered, dried under vacuum, dissolved in acetone, and rotary evaporated at 50-65℃ to obtain the crude 5,10,15,20-tetra(4-aminophenyl)porphyrin (TAPP). The crude product was separated by silica gel column chromatography and analyzed by chromatographic analysis.

[0044] Step 2) Synthesize 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde monomer (ANBDP); 21) Synthesis of 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer (ABBDP); 2-Methylpyrrole and 9-anthraaldehyde were dissolved in ultra-dry dichloromethane to prepare solutions of 0.125~0.0625 mol / L and 0.024~0.048 mol / L, respectively. After reacting under nitrogen protection with trifluoroacetic acid (TFA), 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ), triethylamine (Net3), and etherified boron trifluoride (BF3·Et2O) were added. The reaction was quenched, purified by silica gel column chromatography, and analyzed by chromatography to obtain 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer.

[0045] 22) Synthesis of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer (ABBDP-Br); The monomer 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was dissolved in ethyl acetate to prepare a 0.03 mol / L solution. An ethyl acetate solution of N-bromosuccinimide (0.2~0.25 mol / L) was added dropwise. After reaction, the mixture was purified by silica gel column chromatography and analyzed to obtain the monomer 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine.

[0046] 23) Synthesis of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde monomer (ANBDP); 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridium, 4-formylphenylboronic acid, tetrakis(triphenylphosphine)palladium, and sodium carbonate were dissolved in an aqueous toluene solution. The reaction was carried out under nitrogen protection and heated. After the reaction was completed, the product was poured into deionized water, extracted with dichloromethane, and dried with anhydrous sodium sulfate to obtain crude 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde. The crude product was purified by silica gel column chromatography and analyzed by chromatographic analysis.

[0047] Step 3) Synthesize TAPP-ANBDP-COF 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer (TAPP) and 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde monomer (ANBDP) were dissolved in organic solvents 1,2-dichlorobenzene and n-butanol (1,2-dichlorobenzene:n-butanol = V:V = 9:1) to prepare solutions with concentrations of 0.002~0.008 mol / L and 0.008~0.016 mol / L, respectively. After sonication for 5~10 min, anhydrous acetic acid catalyst was added at a volume of 1%~8% of the solvent volume. After cyclic freezing 1~3 times, polymerization was carried out to generate COFs.

[0048] Preferably, in step 1), fuming nitric acid is used to synthesize 5,10,15,20-tetra(4-nitrophenyl)porphyrin, resulting in a relatively high synthesis yield; The reaction time for reducing nitro to amino is 1-3 hours. A large amount of heat will be released when adjusting the pH, so it should be carried out in an ice-water bath. Attention should also be paid to the dropping rate of ammonia (about 40 drops / min). In a CHCl3 solution containing TPP, the amount of CHCl3 is determined by the amount of TPP, and the molar ratio of CHCl3 to TPP is (354~1388):1.

[0049] The amount of fuming nitric acid added to the CHCl3 solution containing TPP is determined by the amount of TPP used, and the molar ratio of fuming nitric acid to TPP is 32~72:1.

[0050] The organic solvent used for recrystallization can be methanol, ethanol, isopropanol, acetonitrile, or a methanol-water mixture.

[0051] Preferably, in step 21), the reaction will be more complete after the monomer is fully dispersed. Therefore, the amount of solvent should be as much as possible within the range of sufficient dissolution and dispersion, but it should not be too much, otherwise it will reduce the probability of intermolecular collisions and reduce the reaction efficiency. The purpose of adding 2,3-dichloro-5,6-dicyanobenzoquinone is to activate the reaction sites, so the reaction should be carried out in air for 40 minutes.

[0052] The amount of trifluoroacetic acid used is 1% to 10% of the molar mass of 9-anthraaldehyde.

[0053] The amount of 2,3-dichloro-5,6-dicyanobenzoquinone used is 1.5 to 3 times the molar mass of 9-anthraaldehyde.

[0054] The amount of triethylamine used is 5 to 12 times the molar mass of 9-anthraaldehyde; preferably 8 times.

[0055] The volume ratio of triethylamine to etherified boron trifluoride is (2~5):(5~8); preferably 4:7.

[0056] After the reaction is complete, the quenching solution can be either sodium carbonate solution or sodium bicarbonate solution.

[0057] After adding trifluoroacetic acid, the reaction should be carried out in the dark for more than 4 hours. After adding 2,3-dichloro-5,6-dicyanobenzoquinone, the reaction should be carried out for 0.5 to 1 hour. After adding triethylamine and etherified boron trifluoride, the reaction should be carried out for more than 1 hour.

[0058] Preferably, in step 22), to ensure complete reaction between N-bromosuccinimide and 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine, the dropping rate of the ethyl acetate solution of N-bromosuccinimide is 30 drops / min; The ethyl acetate solution of N-bromosuccinimide should be added dropwise in the dark, and the reaction time should be 1-3 h.

[0059] The drying conditions are: vacuum drying; temperature 40~60℃; time 12~24h.

[0060] Preferably, in step 23), 0.2-1.5 mmol of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine, 1.0-3.0 mmol of 4-formylphenylboronic acid, 1-5 mmol of sodium carbonate, and 5%-20% of tetrakis(triphenylphosphine)palladium based on the molar mass of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine are added to an aqueous toluene solution with a concentration of 6-10 g / mL (preferably 8.66 g / mL).

[0061] The reaction temperature is 85~105℃ (preferably 90℃), and the reaction time is 15~24 h.

[0062] Preferably, in step 3), the organic solvent is two of the following: n-butanol, xylene, 1,2-dichlorobenzene, benzyl alcohol, 1,4-dioxane, ethyl acetate, n-hexane, and diethyl ether. The organic solvent includes at least one highly soluble organic solvent and one less soluble organic solvent; two monomers, with each solvent having high solubility for one and low solubility for the other; the solubility of organic solvents for 5,10,15,20-tetra(4-aminophenyl)porphyrin is ranked as follows: benzyl alcohol, n-butanol, 1,4-dioxane, ethyl acetate, 1,2-dichlorobenzene, diethyl ether, n-hexane; the solubility of organic solvents for 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde is ranked as follows: 1,2-dichlorobenzene, xylene, 1,4-dioxane, benzyl alcohol, n-butanol, ethyl acetate, diethyl ether, n-hexane.

[0063] The catalyst is anhydrous acetic acid; the polymerization conditions are under N2 protection, 80~150℃ (preferably 120℃), for 48~72 h.

[0064] This invention discloses a COF photocatalyst with high charge separation capability and high H2O2 yield. It combines 5,10,15,20-tetratetra(4-aminophenyl)porphyrin (TAPP) with 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde (ANBDP). The prepared COF exhibits high charge separation capability and high H2O2 yield, with multiple absorption peaks across the entire visible light range. The synthesis process of this invention is simple and is expected to provide an effective approach to solving the problems of low charge separation efficiency and low yield in the photocatalytic H2O2 production process of COFs.

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0066] Example 1 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Preparation of 5,10,15,20-tetra(4-aminophenyl)porphyrin Add 1.0 g of 5,10,15,20-tetraphenylporphyrin to a three-necked flask, use CHCl3 as solvent, and stir at -20°C for 10 min under N2 protection. 0.67 mL (0.016 mol) of fuming nitric acid was slowly added using a dropping funnel, and the reaction continued for 1 h after the addition was complete. After quenching the reaction with excess ammonia, the solution was allowed to return to room temperature, extracted, recrystallized, and vacuum dried to obtain the crude product of purple 5,10,15,20-tetra(4-nitrophenyl)porphyrin. Dissolve 1.31 g (0.005 mol) of crude 5,10,15,20-tetra(4-nitrophenyl)porphyrin in 80 mL of concentrated hydrochloric acid; Add 20 mL of concentrated hydrochloric acid solution containing 16.2 g of stannous chloride dihydrate, and stir the reaction for 2 h; The temperature was raised to 50℃ and the reaction was carried out for 0.5 h. The dark green hydrochloride solid was separated by cooling in an ice-water bath and then dispersed in 200 mL of deionized water. Neutralize with concentrated ammonia to pH 8; The brownish-purple solid after filtration and vacuum drying; The above product was dissolved in acetone, filtered to obtain a dark red solution, evaporated to dryness to obtain blue-purple crystals, separated by column chromatography, and analyzed by chromatography.

[0067] Step 2: Preparation of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde; 21) Synthesis of 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP) monomer: 2-methylpyrrole (1 g) and 9-anthraaldehyde (0.5 g) were added to a three-necked flask. The mixture was kept under nitrogen protection for 15 min using CH2Cl2 as solvent. 0.1 mL of trifluoroacetic acid was added and the reaction proceeded for 4 h. 2,3-dichloro-5,6-dicyanobenzoquinone (6 mmol) was added and the reaction proceeded for 40 min. Triethylamine (32 mmol) and etherified boron trifluoride (56 mmol) were then added and the reaction proceeded for 1 minute. After h, the monomer 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was obtained by quenching with saturated sodium carbonate solution, separation and purification by silica gel column chromatography, and chromatographic analysis.

[0068] 22) Synthesis of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP-Br) monomer: 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was added to a three-necked flask in ethyl acetate to prepare a 0.03 mol / L solution. An ethyl acetate solution (0.2 mol / L) of N-bromosuccinimide was added dropwise at a rate of 30 drops / min. The reaction proceeded for 1 minute. After h of silica gel column chromatography separation and purification, and chromatographic analysis, 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer was obtained.

[0069] 23) Synthesis of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde (ANBDP) monomer: 0.2 mmol of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridyl, 1 mmol of 4-formylphenylboronic acid, 0.001 mmol of tetrakis(triphenylphosphine)palladium, 1.0 mmol of sodium carbonate, 1 mL of water, and 10 mL of toluene were added to a reaction tube. The reaction was carried out at 90°C under nitrogen protection for 24 days. h; After the reaction was completed, the product was poured into deionized water, extracted with dichloromethane, and dried with anhydrous sodium sulfate to obtain crude 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde. The product was purified by silica gel column chromatography and analyzed by chromatographic analysis.

[0070] Step 3: Synthesis of TAPP-ANBDP-COF Weigh 0.01 mmol of TAPP monomer and 0.02 mmol of ANBDP monomer into a reaction tube, add 9 ml of 1,4-dichlorobenzene and 1 ml of n-butanol, cycle and freeze 3 times, sonicate for 10 min, and then add 0.3 ml of anhydrous acetic acid. React at 120℃ under N2 protection for 72 h.

[0071] After the reaction was complete, the sample was washed with distilled water, anhydrous ethanol, acetone, and dichloromethane. After filtration, the sample was dried at 100°C for 24 h to obtain COFs.

[0072] Figure 1 This is a synthetic route diagram of the porphyrin-based COF photocatalyst disclosed in Example 1 of the present invention. As can be seen from the diagram, the synthesis of TAPP-ANBDP-COF requires 5 steps: (a) synthesis of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, (b)(c)(d) synthesis of ANBDP, and (e) synthesis of COF.

[0073] Figure 2 The FTIR spectra of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde and TAPP-ANBDP-COFs disclosed in Example 1 of this invention are shown in the figure. It can be seen from the figure that the infrared curve of TAPP-ANBDP-COF is at 1625 cm⁻¹. -1 The presence of a peak belonging to an imine bond (-C=N) indicates the successful synthesis of COF.

[0074] Figure 3 The image shows the 1H NMR spectrum of 5,10,15,20-tetra(4-aminophenyl)porphyrin disclosed in Example 1 of this invention; as can be seen from the image, 5,10,15,20-tetra(4-aminophenyl)porphyrin was successfully synthesized.

[0075] Figure 4 The image shows the 1H NMR spectrum of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde disclosed in Example 1 of this invention. As can be seen from the image, 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde was successfully synthesized.

[0076] Figure 5 The figure shows the H2O2 yield at different times during the photocatalytic H2O2 production process of TAPP-ANBDP-COF disclosed in Example 1 of this invention. As can be seen from the figure, during the two-hour photocatalytic reaction, TAPP-ANBDP-COF can continuously produce H2O2, with a maximum yield of about 0.7 mmol, indicating that TAPP-ANBDP-COF has the ability to photocatalytically produce H2O2.

[0077] Example 2 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Preparation of 5,10,15,20-tetra(4-aminophenyl)porphyrin Add 1.0 g of 5,10,15,20-tetraphenylporphyrin to a three-necked flask using CHCl3 as solvent, and stir at -10°C for 10 min under N2 protection. 1.68 mL (0.04 mol) of fuming nitric acid was slowly added using a dropping funnel, and the reaction continued for 1 h after the addition was complete. After quenching the reaction with excess ammonia, the solution was allowed to return to room temperature, extracted, recrystallized, and vacuum dried to obtain the crude product of purple 5,10,15,20-tetra(4-nitrophenyl)porphyrin. Dissolve 2.62 g (0.01 mol) of crude 5,10,15,20-tetra(4-nitrophenyl)porphyrin in 80 mL of concentrated hydrochloric acid; Add 20 mL of concentrated hydrochloric acid solution containing 20.25 g of stannous chloride dihydrate, and stir the reaction for 2 h; The temperature was raised to 55℃ and the reaction was carried out for 0.5 h. The dark green hydrochloride solid was separated by cooling in an ice-water bath and then dispersed in 200 mL of deionized water. Neutralize with concentrated ammonia to pH 8; The brownish-purple solid after filtration and vacuum drying; The above product was dissolved in acetone, filtered to obtain a dark red solution, evaporated to dryness to obtain blue-purple crystals, separated by column chromatography, and analyzed by chromatography.

[0078] Step 2: Preparation of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde; 21) Synthesis of 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP) monomer: 2-methylpyrrole (0.8 g) and 9-anthraaldehyde (0.67 g) were added to a three-necked flask. The mixture was kept under nitrogen protection for 15 min using CH2Cl2 as solvent. 0.1 mL of trifluoroacetic acid was added and the reaction proceeded for 4 h. 2,3-dichloro-5,6-dicyanobenzoquinone (9 mmol) was added and the reaction proceeded for 40 min. Triethylamine (36 mmol) and boron trifluoride ether (63 mmol) were then added and the reaction proceeded for 1 minute. After h, the monomer 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was obtained by quenching with saturated sodium carbonate solution, separation and purification by silica gel column chromatography, and chromatographic analysis.

[0079] 22) Synthesis of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP-Br) monomer: 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was added to a three-necked flask in ethyl acetate to prepare a 0.03 mol / L solution. An ethyl acetate solution (0.22 mol / L) of N-bromosuccinimide was added dropwise at a rate of 30 drops / min. The reaction proceeded for 1 minute. After h of silica gel column chromatography separation and purification, and chromatographic analysis, 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer was obtained.

[0080] 23) Synthesis of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde (ANBDP) monomer: 0.5 mmol of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridyl, 2.0 mmol of 4-formylphenylboronic acid, 0.05 mmol of tetrakis(triphenylphosphine)palladium, 2.0 mmol of sodium carbonate, 1 mL of water, and 10 mL of toluene were added to a reaction tube. The reaction was carried out at 90°C under nitrogen protection for 24 days. h; After the reaction was completed, the product was poured into deionized water, extracted with dichloromethane, and dried with anhydrous sodium sulfate to obtain crude 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde. The product was purified by silica gel column chromatography and analyzed by chromatographic analysis.

[0081] Step 3: Synthesis of TAPP-ANBDP-COF Weigh 0.02 mmol of TAPP monomer and 0.05 mmol of ANBDP monomer into a reaction tube, add 9 ml of ethyl acetate and 1 ml of diethyl ether, cycle and freeze 3 times, sonicate for 10 min, and then add 0.5 ml of anhydrous acetic acid. React at 120℃ under N2 protection for 72 h.

[0082] After the reaction was complete, the sample was washed with distilled water, anhydrous ethanol, acetone, and dichloromethane. After filtration, the sample was dried at 100°C for 24 h to obtain COFs.

[0083] Example 3 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Preparation of 5,10,15,20-tetra(4-aminophenyl)porphyrin Add 1.0 g of 5,10,15,20-tetraphenylporphyrin to a three-necked flask, use CHCl3 as solvent, and stir at -5°C for 10 min under N2 protection. Slowly add 5.00 mL (0.112 mol) of fuming nitric acid using a dropping funnel, and continue the reaction for 1 h after the addition is complete; After quenching the reaction with excess ammonia, the solution was allowed to return to room temperature, extracted, recrystallized, and vacuum dried to obtain the crude product of purple 5,10,15,20-tetra(4-nitrophenyl)porphyrin. Dissolve 13.93 g (0.015 mol) of crude 5,10,15,20-tetra(4-nitrophenyl)porphyrin in 80 mL of concentrated hydrochloric acid; Add 20 mL of concentrated hydrochloric acid solution containing 24.30 g of stannous chloride, and stir to react for 2 h; The temperature was raised to 60℃ and the reaction was carried out for 0.5 h. The dark green hydrochloride solid was separated by cooling in an ice-water bath and then dispersed in 200 mL of deionized water. Neutralize with concentrated ammonia to pH 8; The brownish-purple solid after filtration and vacuum drying; The above product was dissolved in acetone, filtered to obtain a dark red solution, evaporated to dryness to obtain blue-purple crystals, separated by column chromatography, and analyzed by chromatography.

[0084] Step 2: Preparation of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde; 21) Synthesis of 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP) monomer: 2-methylpyrrole (12 mmol) and 9-anthraaldehyde (4.8 mmol) were added to a three-necked flask. The mixture was kept under nitrogen protection for 15 min using CH2Cl2 as solvent. 0.1 mL of trifluoroacetic acid was added and the reaction proceeded for 4 h. 2,3-dichloro-5,6-dicyanobenzoquinone (9.6 mmol) was added and the reaction proceeded for 40 min. Triethylamine (38.4 mmol) and boron trifluoride ether (67.2 mmol) were then added and the reaction proceeded for 1 minute. After h, the monomer 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was obtained by quenching with saturated sodium bicarbonate solution, separation and purification by silica gel column chromatography, and chromatographic analysis.

[0085] 22) Synthesis of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP-Br) monomer: 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was added to a three-necked flask in ethyl acetate to prepare a 0.03 mol / L solution. An ethyl acetate solution (0.25 mol / L) of N-bromosuccinimide was added dropwise at a rate of 30 drops / min. The reaction proceeded for 1 minute. After h of silica gel column chromatography separation and purification, and chromatographic analysis, 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer was obtained.

[0086] 23) Synthesis of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde (ANBDP) monomer: 1 mmol of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridyl, 3 mmol of 4-formylphenylboronic acid, 0.15 mmol of tetrakis(triphenylphosphine)palladium, 3.0 mmol of sodium carbonate, 1 mL of water, and 10 mL of toluene were added to a reaction tube. The reaction was carried out at 90°C under nitrogen protection for 24 days. h; After the reaction was completed, the product was poured into deionized water, extracted with dichloromethane, and dried with anhydrous sodium sulfate to obtain crude 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde. The product was purified by silica gel column chromatography and analyzed by chromatographic analysis.

[0087] Step 3: Synthesis of TAPP-ANBDP-COF Weigh 0.03 mmol of TAPP monomer and 0.07 mmol of ANBDP monomer into a reaction tube, add 9 ml of xylene and 1 ml of benzyl alcohol, cycle and freeze 3 times, sonicate for 10 min, and then add 0.6 ml of anhydrous acetic acid. React at 150℃ under N2 protection for 48 h.

[0088] After the reaction was complete, the sample was washed with distilled water, anhydrous ethanol, acetone, and dichloromethane. After filtration, the sample was dried at 100°C for 24 h to obtain COFs.

[0089] Example 4 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Preparation of 5,10,15,20-tetra(4-aminophenyl)porphyrin Add 1.0 g of 5,10,15,20-tetraphenylporphyrin to a three-necked flask, use CHCl3 as solvent, and stir at 0°C for 10 min under N2 protection. 2.28 mL (0.0512 mol) of fuming nitric acid was slowly added using a dropping funnel, and the reaction continued for 1 h after the addition was complete. After quenching the reaction with excess ammonia, the solution was allowed to return to room temperature, extracted, recrystallized, and vacuum dried to obtain the crude product of purple 5,10,15,20-tetra(4-nitrophenyl)porphyrin. Dissolve 5.24 g (0.02 mol) of crude 5,10,15,20-tetra(4-nitrophenyl)porphyrin in 80 mL of concentrated hydrochloric acid; Add 20 mL of concentrated hydrochloric acid solution containing 32.4 g of stannous chloride, and stir the reaction for 2 h; The temperature was raised to 65℃ and the reaction was carried out for 0.5 h. The dark green hydrochloride solid was separated by cooling in an ice-water bath and then dispersed in 200 mL of deionized water. Neutralize with concentrated ammonia to pH 8; The brownish-purple solid after filtration and vacuum drying; The above product was dissolved in acetone, filtered to obtain a dark red solution, evaporated to dryness to obtain blue-purple crystals, separated by column chromatography, and analyzed by chromatography.

[0090] Step 2: Preparation of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde; 21) Synthesis of 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP) monomer: 2-methylpyrrole (13 mmol) and 9-anthraaldehyde (5 mmol) were added to a three-necked flask. The mixture was kept under nitrogen protection for 15 min using CH2Cl2 as solvent. 0.1 mL of trifluoroacetic acid was added and the reaction proceeded for 4 h. 2,3-dichloro-5,6-dicyanobenzoquinone (10 mmol) was added and the reaction proceeded for 40 min. Triethylamine (40 mmol) and boron trifluoride ether (69.4 mmol) were then added and the reaction proceeded for 1 minute. After h, the monomer 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was obtained by quenching with saturated sodium bicarbonate solution, separation and purification by silica gel column chromatography, and chromatographic analysis.

[0091] 22) Synthesis of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine (ABBDP-Br) monomer: 10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine was added to a three-necked flask in ethyl acetate to prepare a 0.03 mol / L solution. An ethyl acetate solution (0.2 mol / L) of N-bromosuccinimide was added dropwise at a rate of 30 drops / min. The reaction proceeded for 1 minute. After h of silica gel column chromatography separation and purification, and chromatographic analysis, 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridine monomer was obtained.

[0092] 23) Synthesis of 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde (ANBDP) monomer: 0.2 mmol of 10-(9-anthrayl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazoboridyl, 1 mmol of 4-formylphenylboronic acid, 0.04 mmol of tetrakis(triphenylphosphine)palladium, 5.0 mmol of sodium carbonate, 1 mL of water, and 10 mL of toluene were added to a reaction tube. The reaction was carried out at 90°C under nitrogen protection for 24 days. h; After the reaction was completed, the product was poured into deionized water, extracted with dichloromethane, and dried with anhydrous sodium sulfate to obtain crude 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazoboridyl)dibenzaldehyde. The product was purified by silica gel column chromatography and analyzed by chromatographic analysis.

[0093] Step 3: Synthesis of TAPP-ANBDP-COF Weigh 0.01 mmol of TAPP monomer and 0.02 mmol of ANBDP monomer into a reaction tube, add 9 ml of 1,4-dioxane and 1 ml of n-hexane, cycle and freeze 3 times, sonicate for 10 min, and then add 0.8 ml of anhydrous acetic acid. React at 150 °C under N2 protection for 48 h.

[0094] After the reaction was complete, the sample was washed with distilled water, anhydrous ethanol, acetone, and dichloromethane. After filtration, the sample was dried at 100°C for 24 h to obtain COFs.

[0095] Example 5 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Add 1.0 g of 5,10,15,20-tetraphenylporphyrin in CHCl3 as solvent, stir at 0°C for 30 min under N2 protection; add fuming nitric acid in an appropriate ratio dropwise, and continue the reaction for 0.5 h; recrystallize using methanol; gradually increase the temperature to room temperature for 1 h, then react at 100°C for 1 h; neutralize and adjust the pH to 9. Subsequent steps are the same as in Example 1 to obtain the TAPP monomer.

[0096] Step 2: Same as Example 1, except the reaction time in the dark is changed to 3 hours. ANBDP monomer is obtained.

[0097] Step 3: Weigh 0.002 mmol TAPP and 0.008 mmol ANBDP, add 9 mL of 1,2-dichlorobenzene and 1 mL of diethyl ether, cycle and freeze once, sonicate for 5 min, add 0.1 mL of anhydrous acetic acid; react at 80 °C under N2 protection for 48 h. Subsequent washing and drying steps are the same as in Example 1, to obtain the porphyrin-based COFs photocatalyst.

[0098] Example 6 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Add 1.0 g of 5,10,15,20-tetraphenylporphyrin in CHCl3 as solvent, stir at -15°C for 20 min under N2 protection; add fuming nitric acid in an appropriate ratio dropwise, and continue the reaction for 2 h; recrystallize using isopropanol; gradually increase the temperature to room temperature for 3 h, then react at 80°C for 0.8 h; neutralize and adjust the pH to 8.5. Subsequent steps are the same as in Example 1 to obtain the TAPP monomer.

[0099] Step 2: Same as in Example 3, except that the concentration of the ethyl acetate solution of N-bromosuccinimide was changed to 0.23 mol / L, and the reaction time was changed to 2 h. The ANBDP monomer was obtained.

[0100] Step 3: Weigh 0.008 mmol TAPP and 0.016 mmol ANBDP, add 9 mL of 1,2-dichlorobenzene and 1 mL of benzyl alcohol, cycle and freeze twice, sonicate for 8 min, add 0.5 mL of anhydrous acetic acid; react at 100 °C under N2 protection for 60 h. Subsequent washing and drying steps are the same as in Example 1, to obtain the porphyrin-based COFs photocatalyst.

[0101] Example 7 A method for preparing a porphyrin-based COF photocatalyst includes the following steps: Step 1: Add 1.0 g of 5,10,15,20-tetraphenylporphyrin in CHCl3 as solvent, stir at -10°C for 25 min under N2 protection; add fuming nitric acid in an appropriate ratio dropwise, and continue the reaction for 1.5 h; recrystallize using acetonitrile; gradually increase the temperature to room temperature for 2 h, then react at 90°C for 0.6 h; neutralize and adjust the pH to 9. Subsequent steps are the same as in Example 1 to obtain the TAPP monomer.

[0102] Step 2: Same as Example 2, except that the quenching solution is replaced with a saturated sodium bicarbonate solution, and the stirring reaction time is changed to 1 hour. ANBDP monomer is obtained.

[0103] Step 3: Weigh 0.005 mmol TAPP and 0.012 mmol ANBDP, add 9 mL of 1,2-dichlorobenzene and 1 mL of n-hexane, cycle and freeze twice, sonicate for 7 min, and add 0.4 mL of anhydrous acetic acid; react at 130 °C under N2 protection for 50 h. Subsequent washing and drying steps are the same as in Example 1 to obtain the porphyrin-based COFs photocatalyst.

[0104] In summary, the porphyrin-based COF photocatalyst, its preparation method, and its application in photocatalytic H2O2 production disclosed in this invention first synthesizes 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin, then reduces the nitro group on the porphyrin to an amino group, and then synthesizes 4,4'-(10-(9-anthrayl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaboridyl)dibenzaldehyde. The two monomers are dispersed in an organic solvent, and under the catalysis of anhydrous acetic acid, a solvothermal polymerization is performed to form the COF material. Combining the characteristics of COF materials—fast charge transport rate, large specific surface area, and high visible light utilization efficiency—the synthesis process of this invention is simple and is expected to provide an effective way to solve the problem of low H2O2 yield in photocatalytic production of COF materials.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a porphyrin-based COFs photocatalyst, characterized in that, The method comprises the following steps: 1) Synthesis of 4,4'-(10-(9-anthracenyl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] (2,8-diazaborinyl) benzaldehyde monomer 2-methylpyrrole is dissolved in super-dry dichloromethane to obtain solution D; 9-anthracenaldehyde is dissolved in super-dry dichloromethane to obtain solution E; after mixing solution D and solution E, trifluoroacetic acid is added, and after reaction under nitrogen protection and in the dark, 2,3-dichloro-5,6-dicyanoquinone is added, and after stirring reaction, triethylamine and ether boron trifluoride are added, and after stirring reaction again, quenching is performed to obtain 10-(9-anthracenyl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] diazaborine monomer; 10-(9-anthracenyl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] diazaborine monomer is dissolved in ethyl acetate to obtain solution F, and an ethyl acetate solution of N-bromosuccinimide is added dropwise, and after reaction again in the dark, 10-(9-anthracenyl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] diazaborine monomer is obtained; 10-(9-anthracenyl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] diazaborine monomer, 4-formylphenylboronic acid, tetrakis(triphenylphosphine)palladium, and sodium carbonate are dissolved in toluene aqueous solution, and after heating reaction under nitrogen protection, extraction and drying are performed to obtain 4,4'-(10-(9-anthracenyl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] (2,8-diazaborinyl) benzaldehyde monomer; 2) Synthesis of porphyrin-based COFs photocatalyst 5,10,15,20-tetra(4-aminophenyl) porphyrin monomer and 4,4'-(10-(9-anthracenyl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2] (2,8-diazaborinyl) benzaldehyde monomer prepared in step 1) are dissolved in an organic solvent, and after ultrasonic treatment, a catalyst is added, and after polymerization reaction through cycle freezing, a porphyrin-based COFs photocatalyst is obtained.

2. The method of claim 1, wherein the preparation of the porphyrin-based COFs photocatalyst is characterized by, The synthesis method of the 5,10,15,20-tetra(4-aminophenyl) porphyrin monomer comprises the following steps: First, 5,10,15,20-tetraphenylporphyrin is dissolved in chloroform to obtain solution A, and after stirring reaction under N2, fuming nitric acid is slowly added dropwise; after continuing stirring reaction, excess ammonia water is added for quenching reaction, and after being reduced to room temperature, extraction, recrystallization, and vacuum drying are performed to obtain 5,10,15,20-tetra(4-nitrophenyl) porphyrin; 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer is obtained by dissolving 5,10,15,20-tetra(4-nitrophenyl)porphyrin in concentrated hydrochloric acid to obtain solution B, dissolving stannous chloride dihydrate in concentrated hydrochloric acid to obtain solution C, adding solution C dropwise into solution B, and separating 5,10,15,20-tetra(4-aminophenyl)porphyrin hydrochloride solid after gradient temperature reaction in an ice water bath, adjusting the pH value to 8-9, and vacuum drying after filtration and extraction in acetone, and then rotary evaporation to obtain 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer.

3. The method of claim 2, wherein the method is characterized by, The concentration of the solution A is 0.005-0.02 mol / L; the molar ratio of chloroform to 5,10,15,20-tetraphenylporphyrin in the solution A is (354-1388):1; The molar ratio of fuming nitric acid to 5,10,15,20-tetraphenylporphyrin is (32-72):1; The concentration of the solution B is 0.005-0.02 mol / L; the concentration of the solution C is 4.4-8.8 mol / L; The temperature of the stirring reaction is -20-0 ℃, and the time is 10-30 min; The time of the continued stirring reaction is 0.5-2 h; The organic solvent for recrystallization is methanol, ethanol, isopropanol, acetonitrile or a methanol-water mixed solvent; The conditions of the gradient temperature reaction include: first reaction at room temperature for 1-3 h, and then reaction at 50-100 ℃ for 0.5-1 h; and the temperature of the rotary evaporation is 50-65 ℃.

4. The method of claim 1, wherein the preparation of the porphyrin-based COFs photocatalyst is characterized by, In step 1), the concentration of the solution D is 0.125-0.0625 mol / L; the concentration of the solution E is 0.024-0.048 mol / L; the concentration of the solution F is 0.03 mol / L; and the concentration of the ethyl acetate solution of N-bromosuccinimide is 0.2-0.25 mol / L; The amount of the trifluoroacetic acid is 1%-10% of the molar mass of 9-anthracenaldehyde; The amount of the 2,3-dichloro-5,6-dicyano-benzoquinone is 1.5-3 times of the molar mass of 9-anthracenaldehyde; The amount of the triethylamine is 5-12 times of the molar mass of 9-anthracenaldehyde; The volume ratio of the triethylamine to boron trifluoride etherate is (2-5):(5-8).

5. The method of claim 1, wherein the preparation of the porphyrin-based COFs photocatalyst is characterized by, In step 1), the quenching solution is a sodium carbonate solution or a sodium bicarbonate solution; The time of the light-shielded reaction is more than 4 h; The time of the stirring reaction is 0.5-1 h; and the time of the re-stirring reaction is more than 1 h; The time of the re-light-shielded reaction is 1-3 h.

6. The method of claim 1, wherein the preparation of the porphyrin-based COFs photocatalyst is characterized by, In step 1), the molar ratio of the 10-(9-anthracenyl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinine monomer, 4-formylphenylboronic acid and sodium carbonate is (0.2-1.5):(1.0-3.0):(1-5). The amount of the tetra(triphenylphosphine)palladium is 5%~20% of the molar mass of 10-(9-anthryl)-2,8-dibromo-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinine; In the aqueous toluene solution, the volume ratio of toluene to water is 10:1; The temperature of the heating reaction is 85~105℃, and the time of the heating reaction is 15~24 h.

7. The method of claim 1, wherein the preparation of the porphyrin-based COFs photocatalyst is characterized by, In step 2), the molar ratio of the 5,10,15,20-tetra(4-aminophenyl)porphyrin monomer to the 4,4'-(10-(9-anthryl)-5,5-difluoro-3,7-dimethyl-5H-4,5-dipyrrolo[1,2-c:2',1'-f][1,3,2](2,8-diazaborinyl)dibenzaldehyde monomer is (0.002~0.008):(0.008~0.016).

8. The method of claim 1, wherein the preparation of the porphyrin-based COFs photocatalyst is characterized by, In step 2), the organic solvent is at least two of xylene, 1,2-dichlorobenzene, n-butanol, benzyl alcohol, 1,4-dioxane, ethyl acetate, n-hexane and diethyl ether; The time of the ultrasonic is 5-10 min; The amount of the catalyst is 1%~8% of the volume of the solvent; the catalyst is anhydrous acetic acid; The number of the cyclic freezing is 1~3 times; The condition of the polymerization reaction is: under the protection of N2, at 80~150℃ for 48~72 h.

9. A porphyrin-based COFs photocatalyst, characterized in that, The structural formula of the porphyrin-based COFs photocatalyst is: 。 10. The application of the porphyrin-based COFs photocatalyst prepared by the preparation method of the porphyrin-based COFs photocatalyst in photocatalytic production of H2O2.

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