A porous organic polymer containing thianthrene ring and a preparation method and application thereof

Abstract

The application discloses a porous organic polymer containing a thianthrene ring and a preparation method and application thereof. The porous organic polymer contains a plurality of repeating structural units, and the repeating structural unit has a structure shown in the following formula: wherein a dashed line represents a bond connection position. The preparation method of the porous organic polymer containing the thianthrene ring is simple in steps, mild in conditions, suitable for large-scale production, popularization and application, and meanwhile, the porous organic polymer containing the thianthrene ring prepared by the method has good photocatalytic reduction carbon dioxide performance.

Description

Technical Field

[0001] This invention belongs to the field of organic compound technology, specifically relating to a porous organic polymer containing thiaanthracene rings, its preparation method, and its application. Background Technology

[0002] Sulfur (S8) is one of the most abundant byproducts generated in the global petrochemical industry. It can slowly oxidize or burn in air, causing serious safety issues and environmental problems such as acid rain. Therefore, the resource utilization of elemental sulfur as solid waste has become a global challenge. If elemental sulfur could be directly converted into sulfur-containing functional polymers through environmentally friendly methods, it would have significant academic and industrial value. Elemental sulfur is mainly represented by the S8 ring, which can be transformed into a linear chain through the formation of a diradical intermediate at temperatures above 432 K. Homopolymerization of the S8 ring is an equilibrium process; at room temperature, long polysulfide chains tend to depolymerize, which to some extent limits the sulfur content in polymers. Furthermore, sulfur can crosslink polymer chains and copolymerize with many compounds, allowing it to be incorporated into some stable polymer products at room temperature. Currently, the conversion of elemental sulfur into sulfur-containing functional polymers has attracted the research interest of scientists. Introducing sulfur into conjugated polymer structures is beneficial for electron transport within the structure, enabling the construction of high-performance polymers. Despite significant progress in the development of elemental sulfur, directly converting sulfur powder into components of polymers remains challenging, primarily due to sulfur's poor solubility in organic solvents and its toxicity to transition metal catalysts or free radical initiators. This greatly limits their application in polymer synthesis.

[0003] Sulfur-containing polymers, as a series of relatively complex high-molecular polymers, possess some unique and excellent properties. The introduction of sulfur atoms can modulate the thermal stability, mechanical properties, electrical and optical properties of polymers. This has led to their wide application in optical, optoelectronic and photochemical materials, as well as in pharmaceutical formulations based on biopolymers, proton-conducting electrolytes, lithium-sulfur battery cathodes and electrochemical membrane processes. Timothy M. Swager's research group [Nat. Chem., 2018, 10, 1023-1030.] pioneered a new nucleophilic aromatic substitution method, using a thiol-containing monomer as a sulfur source to prepare porous organic polymers containing sulfur rings. The resulting product has a specific surface area as high as 813 m². 2 g -1However, this new method involves the use of dithiol compounds, anhydrous solvents, and a relatively long polycondensation process, making it unsuitable for scale-up experiments. Due to the unpleasant odor, instability, and lack of commercial availability of thiols, using them as starting materials for synthesis is not ideal. Compared to other sulfur-containing reagents, sulfur powder is abundant, non-toxic, non-volatile, stable, and odorless. Recent studies have shown that elemental sulfur can participate in free radical transformations, introducing sulfur atoms into the molecular backbone under mild conditions, making it an ideal source of sulfur atoms in organic molecules. A prerequisite for introducing sulfur into polymers is the opening of the S8 ring of the eight-membered ring. The opening of the S8 ring may involve free radical or ionic mechanisms; the latter mechanism can activate S8 through nucleophilic or electrophilic catalytic mechanisms. Currently, methods for preparing sulfur-containing polymers using elemental sulfur are extremely limited, with only a few studies reported. Typically, sulfurized polymers are obtained through bulk polymerization at high temperatures (≥159°C). This polymerization process suffers from numerous problems, including but not limited to: inhomogeneous synthesized polymers due to poor monomer miscibility or varying reactivity of monomers at high temperatures; completely uncontrollable self-acceleration; the release of toxic H2S gas due to side reactions; and the limitation of selecting only high-boiling-point comonomers due to the high reaction temperature. Therefore, considering both the synthesis process and operational aspects, large-scale industrial production and application of sulfur-containing polymers are currently difficult. If we want to industrially apply and prepare such sulfur-containing polymer materials, a simpler and safer method for synthesizing these polymers needs to be explored first.

[0004] The key to CO2 reduction lies in the adsorption and activation of CO2. Traditional CO2 reduction requires a high-temperature, high-pressure environment to activate CO2 molecules. Introducing light energy into this reaction system makes it possible to achieve the reaction at room temperature and pressure. Photocatalytic CO2 reduction utilizes the light response of semiconductor photocatalysts to convert CO2 into C1 compounds, thus converting light energy into chemical energy. Due to its energy-saving and environmentally friendly nature, it has become an important scientific and technological issue in the field of photocatalysis. The core issue of photocatalytic CO2 reduction is the design, development, and fabrication of suitable photocatalysts. Developing novel, highly efficient photocatalytic materials is crucial for achieving photocatalytic CO2 reduction using solar energy and is also an inevitable trend and development direction for the further practical application of photocatalysis. Hexaazatrinaphthalene, with its conjugated structure, can be used as a luminescent material. Currently, synthesized hexaazatrinaphthalene compounds are mainly organic porous materials, but hexaazatrinaphthalene-type porous polymers containing thiathracene rings have not yet been reported. Therefore, there is an urgent need to develop a porous polymer containing thiathracene rings for use as a highly efficient photocatalyst.

[0005] Photocatalytic CO2 reduction reaction (CO2RR) is essentially a photoinduced redox process, mainly consisting of two processes: (1) adsorption of CO2 molecules by the reaction sites of the photocatalytic material; and (2) the redox process between the adsorbed CO2 and photogenerated electrons and holes. Therefore, improving the light absorption efficiency of the photocatalytic material, enhancing its adsorption and activation capacity for CO2, and improving the photogenerated electron-hole separation efficiency are key factors in constructing efficient photoreduction catalysts. However, currently developed catalysts are limited by narrow light absorption, slow charge transfer, and limited catalytic active sites, resulting in serious photogenerated charge recombination problems, which significantly limit their photocatalytic efficiency. Therefore, developing efficient, inexpensive, and highly stable photocatalysts is a major challenge in improving the efficiency of photocatalytic carbon dioxide reduction.

[0006] In recent years, well-ordered crystalline covalent organic frameworks (COFs) have been regarded as a new type of organic semiconductor polymer material due to their π-conjugated skeleton and the ease of tunable and functionalized pore structure, showing great application potential in the artificial synthesis of photocatalysis. Among them, crystalline covalent triazine frameworks (CTFs) composed of triazine groups linked together with excellent light absorption capabilities have attracted widespread research attention. Their excellent organic semiconductor properties have led to their widespread application in various photocatalytic processes, such as water splitting to produce hydrogen and heterogeneous organic reactions. Some reported triazine organic polymer materials have shown photocatalytic activity comparable to or even better than inorganic semiconductors in hydrolysis reactions. However, due to band mismatch, they cannot meet high overpotentials, limiting the application of triazine polymers in photocatalytic CO2 conversion. CTFs utilize covalent chemical bonds to link triazine and other organic structural units at the molecular scale, thereby forming periodically ordered framework materials. For example, crystalline CTFs can be prepared by high-temperature (low-temperature) self-condensation polymerization of aromatic cyano groups under Lewis acid (Brown acid) catalysis. Additionally, the condensation polymerization between aromatic aldehydes / amines and dimethylamidine also provides an important route for creating crystalline CTFs. However, it should be noted that all of the above preparation methods have a significant drawback: it is difficult to easily functionalize the framework structure of the prepared CTFs. Typically, specific molecular structural design of the organic building blocks of the CTFs is required to achieve secondary modification or control of the pore structure. However, the multi-step and complex preparation process often hinders its further application in artificial photocatalysis. Therefore, providing a simple method for preparing functionalized triazine polymers and using them for carbon dioxide reduction is an urgent problem to be solved. Summary of the Invention

[0007] The main objective of this invention is to provide a methylated covalent triazine polymer, its preparation method, and its application, in order to overcome the shortcomings of the prior art.

[0008] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0009] This invention provides a porous organic polymer containing thiaanthracene rings, the porous organic polymer comprising a plurality of repeating structural units, the repeating structural units having structures as shown in formulas (I)-(III):

[0010]

[0011] The dashed lines represent key connection positions.

[0012] This invention also provides a method for preparing a porous organic polymer containing thiaanthracene rings, comprising:

[0013] A porous organic polymer containing thiaanthracene rings was prepared by ball milling a mixture containing halogenated monomers, elemental sulfur, and an alkaline catalyst using at least mechanical ball milling.

[0014] The present invention also provides porous organic polymers containing thiaanthracene rings prepared by the aforementioned preparation method.

[0015] This invention also provides the use of the aforementioned porous organic polymer containing thiaanthracene rings in the photocatalytic reduction of carbon dioxide.

[0016] This invention also provides a photocatalytic material comprising at least the aforementioned porous organic polymer containing thiaanthracene rings, wherein the photocatalytic material is used at least in the reaction of reducing carbon dioxide.

[0017] This invention also provides a method for photocatalytic reduction of carbon dioxide, comprising:

[0018] The catalyst is placed in a gas-solid photocatalytic reaction system containing water and carbon dioxide, and then subjected to photocatalytic reaction to reduce carbon dioxide to carbon monoxide.

[0019] The photocatalyst includes the aforementioned porous organic polymer or photocatalytic material containing thiaanthracene rings.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) This invention regulates the DA structural units in polymers through a halogen doping strategy. The structural differences are small and the degree of comparison is high through the substitution of halogen atoms. At the same time, the optical band gap and LUMO energy level of the polymer can be regulated to achieve the purpose of regulating photocatalytic activity. Meanwhile, the porous organic polymer containing thiaanthracene rings prepared by this invention has good dispersibility and stability.

[0022] (2) The present invention adopts a simple, efficient and mild ball milling synthesis method to effectively avoid the defect of a small amount of metal residue in the polymer pores caused by the high temperature of traditional heating reaction.

[0023] (3) The present invention further improves the photocatalytic activity of polymers by introducing N and S atoms that can serve as active sites for redox reactions at the photocatalytic interface in the polymer structure design. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is the 1H NMR spectrum of the model monomer anthrathiol in Example 1 of this invention;

[0026] Figure 2 This is the carbon NMR spectrum of the model monomer anthrathiamine in Example 1 of this invention;

[0027] Figure 3 This is the mass spectrum of the model monomer anthrathiamine in Example 1 of this invention;

[0028] Figures 4a-4b These are the nitrogen adsorption isotherms and pore size distribution curves of BM-S-HATN-Cl prepared in Example 2 of this invention;

[0029] Figure 5 This is the Fourier transform infrared (FT-IR) image of BM-S-HATN-Cl prepared in Example 2 of this invention;

[0030] Figure 6 The solid-state carbon NMR spectrum (SMR) of BM-S-HATN-Cl prepared in Example 2 of this invention is shown. 13 C NMR spectrum;

[0031] Figures 7a-7b This is a catalytic performance diagram of BM-S-HATN-F and BM-S-HATN-Cl in Example 3 of the present invention;

[0032] Figure 8 This is a schematic diagram of the photocatalytic cycle of BM-S-HATN-Cl in Example 2 of the present invention. Detailed Implementation

[0033] In view of the deficiencies of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention, which mainly utilizes sulfur powder, halogenated monomers, solid base catalysts, and ball milling to prepare porous organic polymers containing thiaanthracene rings. The synthesis steps are simple, the conditions are mild, and it is suitable for large-scale production, promotion and application, and has good practical prospects for photocatalytic reduction of carbon dioxide.

[0034] 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.

[0035] Specifically, as one aspect of the technical solution of the present invention, a porous organic polymer containing thiaanthracene rings includes a plurality of repeating structural units, wherein the repeating structural units have structures as shown in formulas (I)-(III):

[0036]

[0037] The dashed lines represent key connection positions.

[0038] Furthermore, the specific surface area of ​​the porous organic polymer containing thiaanthracene rings is 120–950 m². 2 / g, with a pore size of 1–100 nm.

[0039] Furthermore, the repeating structural unit has a structure as shown in equation (II):

[0040]

[0041] The dashed lines represent key connection positions.

[0042] Another aspect of the present invention provides a method for preparing a porous organic polymer containing thiaanthracene rings, comprising:

[0043] A porous organic polymer containing thiaanthracene rings was prepared by ball milling a mixture containing halogenated monomers, elemental sulfur, and an alkaline catalyst using at least mechanical ball milling.

[0044] In some preferred embodiments, the halogenated monomer is selected from any one or more combinations of compounds having the following structure:

[0045]

[0046] Where X is a halogen atom, and R is selected from any one of -CHO, -OH, -CN, and -COOH.

[0047] Furthermore, the halogenated monomer is selected from compounds having the following structure:

[0048]

[0049] Where X is a halogen atom.

[0050] In some preferred embodiments, the halogenated monomer comprises any one or more combinations of, but is not limited to, octafluoronaphthalene, tris(pentafluorophenyl)phosphine, 2,3,5,6-tetrafluorohydroquinone, 2,3,5,6-tetrafluoroterephthalaldehyde, 2,3,5,6-tetrafluorothiophenol, 2,3,5,6-tetrafluoroterephthalonitrile, 2,3,5,6-tetrachloroterephthalonitrile, 1,2,7,8,13,14-hexachlorosubstituted hexaazanaphthalene, 1,2,7,8,13,14-hexafluorosubstituted hexaazanaphthalene, 1,2,7,8,13,14-hexabromosubstituted hexaazanaphthalene, and 2,3,6,7,10,11-hexabromotriene.

[0051] In some preferred embodiments, the halogenated monomer includes, but is not limited to, halohexaazatrinaphthalene.

[0052] In some preferred embodiments, the elemental sulfur includes S8, but is not limited thereto.

[0053] In some preferred embodiments, the alkaline catalyst includes any one or more combinations of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium tert-butoxide, sodium methoxide, sodium ethoxide, sodium carbonate, potassium carbonate, and cesium carbonate, and is not limited thereto.

[0054] In some preferred embodiments, the preparation method specifically includes: mixing a halogenated monomer, elemental sulfur, and an alkaline catalyst, and then ball milling the obtained mixture in a protective atmosphere using a mechanical ball milling method to obtain the porous organic polymer containing thiaanthracene rings; wherein the ball milling frequency is 10-30 Hz, the ball milling time is 0.5-20 h, and the ball-to-material ratio is 5-40:1.

[0055] In some preferred embodiments, the ball mill used for the ball milling process includes one of a cryogenic mixing ball mill and a planetary ball mill.

[0056] In some preferred embodiments, to prevent the temperature inside the jar from getting too high during ball milling, a 10-minute rest is taken after every 30 minutes of milling to obtain the corresponding organic porous polymer.

[0057] In some preferred embodiments, the mass ratio of the halogenated monomer, elemental sulfur, and alkaline catalyst is 1:0.5-10:4-20.

[0058] In some preferred embodiments, the preparation method further includes: after the ball milling process is completed, the obtained product is subjected to an alkali removal treatment.

[0059] This invention utilizes a green and simple mechanical ball milling method to synthesize a novel thiaanthracene-linked organic conjugated polymer (BM-S-HATN-X) with a π-π stacked structure by combining nitrogen-rich precursor halogenated hexaazatrinaphthalene (HATN-(X)6) (X being a halogen) with elemental sulfur. This directly and rapidly converts elemental sulfur into a redox-active porous organic polymer in a solid-phase reaction. Mechanochemical synthesis, derived from mechanical energy, is an environmentally friendly method with advantages such as short reaction time, homogeneous reaction phase, and high atom economy. Compared to traditional thermal synthesis routes for preparing sulfur-containing polymers, mechanochemical polymerization requires no heating, is fast, solvent-free, has fewer side reactions, no self-acceleration, a wider range of monomer choices, and a more homogeneous reaction (regardless of the miscibility of sulfur and monomers). Through detailed studies of the effects of ball milling materials, milling time, catalyst type and amount, halogen atom type of monomer, and milling type on polymer yield and material porosity, a porous thiaanthracene-based two-dimensional covalent organic porous polymer material with π-electron conjugated azaaryral rings was successfully prepared. The hexaazanaphthalene and thiathracene ring structural units contained in the material can improve the charge carrier mobility in the polymer network. For sulfur-containing heterocycles, the empty d orbitals of sulfur may interact with guest ions for charge storage, and the low electronegativity of sulfur also provides lone pairs of electrons for the CS bonds of the heterocycles. This type of polymer has advantages such as good light-harvesting ability, suitable band gap, and strong DA interaction, which can improve the efficiency of photocatalytic carbon dioxide reaction.

[0060] In some more specific embodiments, the method for preparing the porous organic polymer containing thiaanthracene rings includes:

[0061] (1) The halogenated monomer, sulfur powder and alkaline catalyst are mixed in a certain proportion and then ground by mechanical ball milling to obtain the corresponding donor-acceptor type porous polymer, that is, a porous organic polymer containing thiaanthracene ring. The certain proportion refers to the mass ratio of the halogenated monomer, the sulfur powder and the alkaline catalyst being 1:0.5-10:4-20. In the mechanical ball milling, the ball-to-material ratio is 5-40:1. The process is carried out under nitrogen or argon protection, the ball milling frequency is 10-30 Hz and the ball milling time is 0.5-20 h.

[0062] (2) Take out the mixed powder obtained in step (1) and add 0.5-3M hydrochloric acid to it and stir for 1-6 hours to remove excess alkali.

[0063] In some more specific embodiments, the method for preparing the porous organic polymer containing thiaanthracene rings includes:

[0064] 1) Weigh out sulfur powder, halohexaazatrinaphthalene HATN-(X)6 (X = F, Cl or Br) and alkaline catalyst according to a certain stoichiometric ratio, and place them in a ball mill jar;

[0065] 2) After mixing the above mixture in a tank, start ball milling. After the reaction is complete, use dilute acid to neutralize the base, and then wash and purify with water, DMF and ethanol respectively. Then use DMF under nitrogen protection to heat and remove the residual sulfur powder in the reaction product. Collect the product, vacuum and heat to dry it, which is the halogen-doped porous organic polymer photocatalyst containing thiathracene rings, i.e., porous organic polymer containing thiathracene rings.

[0066] Furthermore, the type of grinding jar mentioned in step 1) is one of the following materials: tungsten oxide, zirconium oxide, agate, stainless steel, etc.

[0067] Furthermore, the volume of the ball mill jar in step 1) is 10mL-200mL, and the number of milling beads is 1-10.

[0068] Further, the alkaline catalyst mentioned in step 1) is one or more of the following: sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium tert-butoxide, sodium methoxide, sodium ethoxide, sodium carbonate, potassium carbonate, and cesium carbonate.

[0069] Furthermore, the ball milling frequency described in step 2) is maintained within the range of 10-30Hz.

[0070] Furthermore, the ball milling reaction time in step 2) is 1h-20h.

[0071] Further, the type of dilute acid mentioned in step 2) is one or more of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and acetic acid.

[0072] Furthermore, the concentration of the dilute acid mentioned in step 2) is 0.5M-2M.

[0073] Furthermore, the DMF heating temperature in step 2) is between 50-150℃. The heating time for the sulfur washing powder is 10-72 hours.

[0074] Furthermore, the specific surface area of ​​the material prepared in step 2) is 120–950 m². 2 / g, with pore sizes ranging from 1 to 100 nm.

[0075] Another aspect of the present invention provides a porous organic polymer containing thiaanthracene rings prepared by the aforementioned preparation method.

[0076] Furthermore, the specific surface area of ​​the porous organic polymer containing thiaanthracene rings is 120–950 m². 2 / g, with a pore size of 1–100 nm.

[0077] Another aspect of the present invention provides the use of the aforementioned porous organic polymer containing thiaanthracene rings in the photocatalytic reduction of carbon dioxide.

[0078] In this invention, under the conditions of light irradiation, carbon dioxide saturation, and the absence of photosensitizers and sacrificial agents, a porous organic polymer containing thiathracene rings is used as a catalyst for photocatalytic carbon dioxide reduction.

[0079] Another aspect of the present invention provides a photocatalytic material comprising at least the aforementioned porous organic polymer containing thiaanthracene rings, said photocatalytic material being used at least in the reaction of reducing carbon dioxide.

[0080] Another aspect of the present invention provides a method for photocatalytic reduction of carbon dioxide, comprising:

[0081] The catalyst is placed in a gas-solid photocatalytic reaction system containing water and carbon dioxide, and then subjected to photocatalytic reaction to reduce carbon dioxide to carbon monoxide.

[0082] The photocatalyst includes the aforementioned porous organic polymer or photocatalytic material containing thiaanthracene rings.

[0083] Furthermore, the illumination uses visible light with a wavelength of λ > 420 nm.

[0084] Furthermore, the conditions for the catalytic reaction include: xenon lamp illumination range of 420 nm to 780 nm; required carbon dioxide mass percentage of 5% to 99.99%; required catalyst dosage of 1 to 10 mg; and water mass percentage in the solvent of 0% to 100%.

[0085] Furthermore, the reaction temperature of the photocatalytic carbon dioxide reduction experiment is 25°C.

[0086] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0087] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0088] Example 1

[0089] In an argon-filled glove box, anhydrous o-dichlorobenzene (0.5 ml), solid base catalyst cesium carbonate (978 mg), and sulfur powder (0.48 g) were mixed thoroughly and placed into a 10 ml agate ball mill jar. The jar was tightened and placed on a ball mill. The reaction was carried out at 10-30 Hz for 0.5-5 hours. The product was removed and washed with deionized water to remove unreacted inorganic salts. Then, it was extracted with water and dichloromethane, and the organic phase was concentrated. The organic phase was purified by silica gel column chromatography using n-hexane as the eluent to obtain a white crystalline product with a yield of 47-71%.

[0090] For characterization of the model compound, please refer to [reference needed]. Figure 1 , Figure 2 and Figure 3 . 1 H NMR (400MHz, DMSO-d6, ppm): δ7.60 (4H, dd), δ7.37 (4H, dd); 13 C NMR (151MHz, DMSO-d6, ppm): δ134.90, 129.26, 128.75.MS (EI): calc.for C 12 H8S2: 216.0065; found: 216.0065

[0091] Example 2

[0092] 1.46 g of HATN-Cl6, 1.94 g of alkaline catalyst cesium carbonate, and 1 g of sulfur powder were mixed and placed in a 200 mL ball mill jar along with ball milling balls. The mixture was ball milled at room temperature for 4 h under nitrogen protection. After the reaction was completed, the ball mill jar was cooled to room temperature, the jar was opened, and the solid powder was removed. The powder was rinsed several times with 1% hydrochloric acid to remove unreacted inorganic salts, and excess sulfur powder was washed away with carbon disulfide. The powder was then refluxed in N,N-dimethylformamide solution for 24 h to remove oligomers. The final product was filtered and washed with methanol and ethanol to obtain a dark brown product. The product was dried overnight in a vacuum oven at 100 °C to obtain 1.25 g of solid product, a porous organic polymer containing thiathracene rings, BM-S-HATN-Cl.

[0093] The nitrogen adsorption isotherm and pore size distribution curve of BM-S-HATN-Cl prepared in this embodiment are shown in the figure below. Figures 4a-4b As shown, the results indicate that its BET specific surface area is 574 m². 2 g-1 has a pore size distribution concentrated at 1.5 nm and 2.6 nm.

[0094] The Fourier transform infrared (FT-IR) image of BM-S-HATN-Cl prepared in this embodiment is shown below. Figure 5 As shown, the results indicate that the 1620 cm⁻¹ infrared spectrum of the polymer shows... -1The peak value at 1090 cm⁻¹ is a characteristic stretching vibration peak found in the HATN ring, demonstrating the integrity of the HATN structure. -1 The weak peak at that point is a vibrational peak unique to the CS bond in the anthrathiol ring.

[0095] The solid-state carbon NMR spectrum (SMR) of BM-S-HATN-Cl prepared in this embodiment is shown in the figure. 13 (C NMR) image as follows Figure 6 As shown, the results indicate that the peak at 145 ppm corresponds to carbon atoms in the HATN ring, and the peak at 133 ppm corresponds to the presence of CS bonds in the anthrathiol ring.

[0096] Example 3

[0097] 1.5 g of HATN-F6, 1.2 g of alkaline catalyst cesium carbonate, and 1 g of sulfur powder were mixed and placed in a 200 mL ball mill jar along with ball milling balls. The mixture was ball milled at room temperature for 4 h under nitrogen protection. After the reaction was completed, the ball mill jar was cooled to room temperature, the jar was opened, and the solid powder was removed. The powder was rinsed several times with 1% hydrochloric acid to remove unreacted inorganic salts, and excess sulfur powder was washed away with carbon disulfide. The powder was then refluxed in N,N-dimethylformamide solution for 24 h to remove oligomers. The final product was filtered and washed with methanol and ethanol to obtain a dark brown product. The product was dried overnight in a vacuum oven at 100 °C to obtain 1.42 g of solid product, a porous organic polymer containing thiathanthracene rings, BM-S-HATN-F.

[0098] The following experiments were conducted to verify the beneficial effects of the present invention:

[0099] To investigate the photocatalytic carbon dioxide reduction effect of this series of organic porous polymers, their photocatalytic carbon dioxide reduction performance was tested using the following method.

[0100] The testing procedure is as follows: 5 mg of BM-S-HATN-F prepared in Example 3 and BM-S-HATN-Cl prepared in Example 2 were dispersed in 10 mL of ultrapure water, respectively. The mixture was then filtered and loaded onto a nylon filter membrane, followed by vacuum drying to remove water. The nylon filter membrane with the catalyst was placed in a gas-solid photocatalytic reaction system of water and carbon dioxide, and irradiated with a xenon lamp (λ > 420 nm) for 4 hours. Figures 7a-7b As shown, the gaseous and liquid phase products were detected using a GC7900 chromatograph and a Bruker AC 400FT spectrometer (400MHz), respectively. The results indicate that the photocatalytic CO2 to carbon monoxide conversion rates of the BM-S-HATN-F and BM-S-HATN-Cl catalysts prepared in this example were 607 μmol / g / h and 445 μmol / g / h, respectively.

[0101] This invention modulates the DA interaction force of a porous organic polymer containing thiathanthracene rings by doping it with different halogens (F, Cl or Br), thereby enabling BM-S-HATN-X to not only have controllable light-harvesting capabilities but also modulate the exciton dissociation energy, thus improving photocatalytic efficiency. This significantly enhances its efficiency in photocatalytic reduction of carbon dioxide.

[0102] The BM-S-HATN-Cl material prepared in Example 2 was subjected to a photocatalytic cycling experiment (catalytic reduction of carbon dioxide), and the results are as follows: Figure 8 As shown, the prepared porous organic polymer containing thiaanthracene rings exhibits excellent stability.

[0103] Ultrasonic dispersion of the BM-S-HATN-F material prepared in Example 3 and the BM-S-HATN-Cl material prepared in Example 2 in water yielded a uniformly dispersed solution, indicating that the prepared porous organic polymer containing thiathracene rings has excellent dispersibility.

[0104] Example 4

[0105] 500 mg of 2,3,6,7,10,11-hexabromotriene (HBTPE), 800 mg of sodium ethoxide as an alkaline catalyst, and 300 mg of sulfur powder were mixed and placed in a 50 mL ball mill jar along with ball milling balls. The mixture was ball milled at room temperature for 3-10 h under nitrogen protection. After the reaction was completed, the ball mill jar was cooled to room temperature, the jar was opened, and the solid powder was removed. The powder was rinsed several times with 1% hydrochloric acid to remove unreacted alkaline catalyst, and excess sulfur powder was washed away with carbon disulfide. The powder was then refluxed in N,N-dimethylformamide solution for 24 h to remove oligomers. The final product was filtered and washed with methanol and ethanol to obtain a yellow-brown product. The product was dried overnight in a vacuum oven at 120 °C to obtain 432 mg of solid product, a porous organic polymer containing thiaanthracene rings, BM-S-HBTPE.

[0106] Example 5

[0107] 200 mg of 2,3,5,6-tetrafluoroterephthalonitrile (TFTPA), 400 mg of potassium tert-butoxide as an alkaline catalyst, and 100 mg of sulfur powder were mixed and placed in a 30 mL ball mill jar along with ball milling balls. The mixture was ball milled at room temperature for 4-8 h under nitrogen protection. After the reaction was completed, the ball mill jar was cooled to room temperature, the jar was opened, and the solid powder was removed. The powder was rinsed several times with 1% hydrochloric acid to remove unreacted alkaline catalyst, and excess sulfur powder was washed away with carbon disulfide. The powder was then refluxed in N,N-dimethylformamide solution for 24 h to remove oligomers. The final product was filtered and washed with methanol and ethanol to obtain a yellow product. The product was dried overnight in a vacuum oven at 100 °C to obtain 216 mg of solid product, a porous organic polymer containing thiaanthracene rings, BM-S-TFTPA.

[0108] The BM-S-HBTPE and BM-S-TFTPA prepared in Examples 4-5 were used for photocatalytic reduction of carbon dioxide, and the method was the same as in Example 3. The reduction effect was also relatively good, but the ability to reduce carbon dioxide was not as good as that of the BM-S-HATN-Cl and BM-S-HATN-F materials prepared in Examples 2-3.

[0109] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0110] It should be understood that the technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made to the technical solutions of the present invention without departing from the spirit and scope of the claims are within the scope of protection of the present invention.

Claims

1. A porous organic polymer containing thiaanthracene rings, characterized in that: The porous organic polymer comprises a plurality of repeating structural units, which have any one or more combinations of structures shown in formulas (I) to (III): ； The dashed lines represent key connection positions; The method for preparing the porous organic polymer containing thiathracene rings includes: A porous organic polymer containing thiaanthracene rings was prepared by at least mechanical ball milling of a mixture containing halogenated monomers, elemental sulfur, and an alkaline catalyst. The halogenated monomer is selected from any one or more combinations of compounds having the following structure: ； Where X is a halogen atom.

2. The porous organic polymer containing thiaanthracene rings according to claim 1, characterized in that: The specific surface area of ​​the porous organic polymer containing thiathracene rings is 120~950 m². 2 / g, with a pore size of 1~100nm.

3. The porous organic polymer containing thiaanthracene rings according to claim 1, characterized in that: The repeating structural unit has a structure as shown in equation (II).

4. A method for preparing a porous organic polymer containing thiathracene rings, characterized in that, include: A porous organic polymer containing thiaanthracene rings was prepared by at least mechanical ball milling of a mixture containing halogenated monomers, elemental sulfur, and an alkaline catalyst. The halogenated monomer is selected from any one or more combinations of compounds having the following structure: ； Where X is a halogen atom.

5. The preparation method according to claim 4, characterized in that: The sulfur is selected from S8.

6. The preparation method according to claim 4, characterized in that: The alkaline catalyst is selected from any one or more combinations of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium tert-butoxide, sodium methoxide, sodium ethoxide, sodium carbonate, potassium carbonate, and cesium carbonate.

7. The preparation method according to claim 4, characterized in that, Specifically, it includes: The halogenated monomer, elemental sulfur, and alkaline catalyst are mixed, and then the mixture is ball-milled in a protective atmosphere using mechanical ball milling to obtain the porous organic polymer containing thiaanthracene rings; wherein the ball milling frequency is 10-30 Hz, the ball milling time is 0.5-20 h, and the ball-to-material ratio is 5-40:

1.

8. The preparation method according to claim 4, characterized in that: The mass ratio of the halogenated monomer, elemental sulfur, and alkaline catalyst is 1:0.5-10:4-20.

9. The preparation method according to claim 4, characterized in that, Also includes: After the ball milling process is completed, the obtained product is subjected to alkali removal treatment.

10. Use of the porous organic polymer containing thiathracene rings according to any one of claims 1-3 in the photocatalytic reduction of carbon dioxide.

11. A photocatalytic material, characterized in that: The photocatalytic material comprises at least the porous organic polymer containing thiaanthracene rings as described in any one of claims 1-3, and is used at least in the reaction for reducing carbon dioxide.

12. A method for photocatalytic reduction of carbon dioxide, characterized in that, include: The catalyst is placed in a gas-solid photocatalytic reaction system containing water and carbon dioxide, and then subjected to photocatalytic reaction to reduce carbon dioxide to carbon monoxide. The catalyst comprises a porous organic polymer containing thiaanthracene rings as described in any one of claims 1-3 or a photocatalytic material as described in claim 11.

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