Sulfuryl conjugated organic polymer activated oxygen for photocatalytic pollutant conversion

Abstract

The invention belongs to the technical field of environmental functional materials, and discloses a sulfonyl conjugated organic polymer for activating oxygen for photocatalytic pollutant conversion. The structural general formula of the polymer is as shown in formula (I), wherein R is selected from CH2, C = O or C (CH3) 2. The sulfonyl conjugated organic polymer disclosed by the invention has good visible light absorption, a unique electronic structure and an ideal spatial configuration, so that separation and migration of photo-induced electrons and holes can be promoted, and a double-electron oxygen reduction process in a water solution is assisted. When the sulfonyl conjugated organic polymer is applied to degradation of pollutants or decomposition of hydrogen peroxide under an acidic condition, the juglone conversion rate is 92% (28 min), the MB degradation rate is 98% (30 min), and the H2O2 decomposition rate is 95% (40 min); meanwhile, after five times of circulation, the activity retention rate is gt; 90%.

Description

Technical Field

[0001] This invention belongs to the field of environmental functional materials technology, specifically relating to a sulfone-based conjugated organic polymer photocatalyst and its application in activating oxygen to degrade organic pollutants and decompose hydrogen peroxide. Background Technology

[0002] The treatment of organic pollutants (such as benzene ring dyes) and the safe disposal of hazardous chemicals (such as H2O2 in industrial wastewater) are two major challenges in the environmental field. Current mainstream technologies have the following limitations: 1. Bottlenecks in photocatalytic materials: Traditional semiconductors such as TiO2 have poor visible light absorption (<420nm) and high carrier recombination rates; while emerging covalent organic framework (COF) materials have tunable band gaps, they suffer from poor water stability and complex synthesis. 2. Defects in pollutant treatment technologies: The Fenton process requires continuous addition of Fe. 2+ H2O2 produces secondary pollution from iron sludge; biological methods are difficult to degrade benzene ring substances, and H2O2 can poison microorganisms.

[0003] Although sulfone groups (-SO2-) possess strong electron-withdrawing properties, their application in the photocatalytic pollutants of conjugated polymers has not been reported. Therefore, the development of novel photocatalytic materials with broad-spectrum response, high stability, and multifunctional activity is urgently needed. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a sulfone-based conjugated organic polymer catalyst, its preparation method, and its application, so as to solve the problems mentioned in the above-mentioned technical background.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a sulfone-based conjugated organic polymer with the general structural formula shown in formula (I):

[0007]

[0008] Wherein, R is selected from CH2, C=O or C(CH3)2; n represents the number of repeating units in the polymer, which is a natural number between 80 and 300.

[0009] Preferably, the polymer with structure (I) is a polymer having any one of the structures (II) to (IV):

[0010]

[0011]

[0012] Where n represents the number of repeating units in the polymer, which is a natural number between 80 and 300.

[0013] Secondly, the present invention provides a method for preparing a sulfone-based conjugated organic polymer, comprising the following steps:

[0014] (1) Synthesis of 3,7-dibromodibenzothiophene sulfone (DBBTS)

[0015] Add 50 mL of concentrated sulfuric acid solution (2 mol L) -1 Dibenzothiophene sulfone (DBTS, 1.0813 g, 5 mmol) and N-bromosuccinimide (NBS, 3.5596 g, 20 mmol) were added sequentially to the mixture, and the mixture was stirred at 0 °C for 24 h. After the reaction was completed, the mixture was filtered, and the collected precipitate was washed several times with deionized water. Then, it was dried under vacuum at 80 °C for 12 h. After removing impurities by recrystallization from chlorobenzene, purified white needle-like crystals—3,7-dibromodibenzothiophene sulfone (DBBTS)—were obtained. The structural formula of 3,7-dibromodibenzothiophene sulfone (DBBTS) is as follows:

[0016]

[0017] (2) Synthesis of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester (DBTSB)

[0018] DBBTS (1.8703 g, 5 mmol), bis(pinacol)diboron (2.5394 g, 10 mmol), potassium acetate (0.9814 g, 10 mmol), and palladium acetate (0.0225 g, 0.1 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added, and the reaction was carried out in an oil bath at 90 °C for 24 h. After cooling to room temperature, the filtrate was poured into deionized water and allowed to stand for 1 h. The solution was then extracted with ethyl acetate, dried over magnesium sulfate, and the organic phase was removed by rotary evaporation to remove water and ethyl acetate. Finally, the crude product was recrystallized from the crude product using acetonitrile under an argon atmosphere at 80 °C. After vacuum drying at 80 °C for 24 h, a purified white solid—dibenzothiophene sulfone-3,7-diboronate di(pinacol) ester (DBTSB)—was obtained. The structural formula of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester (DBTSB) is as follows:

[0019]

[0020] (3) Synthesis of FBTS

[0021] 2,7-Dibromofluorene (0.1620 g, 0.5 mmol), DBTSB (0.2341 g, 0.5 mmol), anhydrous potassium carbonate (0.0276 g, 0.2 mmol), and palladium acetate (0.0112 g, 0.05 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Next, 40.0 mL of dehydrated and argon-saturated DMF was added. The mixture was heated to 150 °C in a microwave reactor and held at that temperature for 1 h. After cooling to room temperature, the filtered precipitate was washed multiple times with DMF and deionized water. The precipitate was first stirred overnight at 25 °C in a methanol-water solution (water / methanol, 1 / 1, V / V), then extracted at 70 °C for 48 h in a Soxhlet extractor containing methanol. The extraction was then carried out with stirring in dichloromethane at 40 °C for 8 h, and finally dried under vacuum at 80 °C for 8 h to obtain brown FBTS powder. The structural formula of FBTS is shown in formula (Ⅱ).

[0022] (4) Synthesis of FOBTS

[0023] 2,7-Dibromo-9-fluorenone (0.1690 g, 0.5 mmol), DBTSB (0.2341 g, 0.5 mmol), anhydrous potassium carbonate (0.0276 g, 0.2 mmol), and palladium acetate (0.0112 g, 0.05 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added. The flask was heated to 150 °C in a microwave reactor and held at that temperature for 1 h. Dark brown powder FOBTS was then obtained using the same method as in step (3). The structural formula of FOBTS is shown in formula (Ⅲ).

[0024] (5) Synthesis of FMBTS

[0025] 2,7-Dibromo-9,9-dimethylfluorene (0.1760 g, 0.5 mmol), DBTSB (0.2341 g, 0.5 mmol), anhydrous potassium carbonate (0.0276 g, 0.2 mmol), and palladium acetate (0.0112 g, 0.05 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added. The flask was heated to 150 °C in a microwave reactor and held at that temperature for 1 h. The light yellow powder FMBTS was then obtained using a similar method to that in step (3). The structural formula of FMBTS is shown in formula (Ⅳ).

[0026] Thirdly, the present invention provides the application of the sulfone-based conjugated organic polymer described above in the photocatalytic activation of molecular oxygen.

[0027] Preferably, the polymer used has the structural formula shown in formula (II).

[0028] Preferably, the application of sulfone-based conjugated organic polymers in the degradation of pollutants or the decomposition of hydrogen peroxide under acidic conditions.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] This invention provides a sulfone-based conjugated organic polymer with good visible light absorption, a unique electronic structure, and an ideal spatial configuration that can promote the separation and migration of photogenerated electrons and holes, thereby facilitating the two-electron oxygen reduction process in aqueous solutions. It has great application potential in the application of photocatalytic pollutants.

[0031] When the sulfone-based conjugated organic polymer FBTS is used to photocatalyze pollutants, its juglone conversion rate is 92% (28 min), MB degradation rate is 98% (30 min), and H2O2 decomposition rate is 95% (40 min); at the same time, its activity retention rate is >90% after 5 cycles. Attached Figure Description

[0032] Figure 1 The 1H NMR spectrum of 3,7-dibromodibenzothiophene sulfone (DBBTS) is shown.

[0033] Figure 2 The 1H NMR spectrum of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester (DBTSB);

[0034] Figure 3 Synthetic routes for catalysts FBTS, FOBTS, and FMBTS;

[0035] Figure 4 For FBTS 13 C NMR spectrum;

[0036] Figure 5 The infrared spectrum of FBTS;

[0037] Figure 6 The infrared spectrum of FOBTS;

[0038] Figure 7 The infrared spectrum of FMBTS;

[0039] Figure 8 Mapping images of EDS elements for FBTS;

[0040] Figure 9 XPS spectra of the FBTS surface;

[0041] Figure 10 XPS spectrum of S(VI) in standard material;

[0042] Figure 11XPS spectrum of FBTS surface S(VI);

[0043] Figure 12 XPS spectra of oxygen on the FBTS surface;

[0044] Figure 13 XRD patterns of FBTS, FOBTS, and FMBTS;

[0045] Figure 14 SEM image of FBTS;

[0046] Figure 15 The N2 adsorption-desorption isotherm and pore size distribution diagram of FBTS are shown in the inset.

[0047] Figure 16 UV-Vis diffuse reflectance spectra and band gap values ​​of different catalysts FBTS, FOBTS, and FMBTS (inset);

[0048] Figure 17 Band structure diagrams of different catalysts FBTS, FOBTS, and FMBTS;

[0049] Figure 18 Photocurrent response curves for different catalysts FBTS, FOBTS, and FMBTS;

[0050] Figure 19 Electrochemical impedance spectroscopy for different catalysts FBTS, FOBTS, and FMBTS;

[0051] Figure 20 Selective oxidation of 1,5-DHN under catalyst-free dark conditions;

[0052] Figure 21 Selective oxidation of 1,5-DHN under photocatalysis without catalyst;

[0053] Figure 22 Photo-induced selective oxidation of 1,5-DHN catalyzed by Pd(OAc)2;

[0054] Figure 23 Photo-induced selective oxidation of 1,5-DHN under FBTS catalysis;

[0055] Figure 24 Photo-induced selective oxidation of 1,5-DHN under FMBTS catalysis;

[0056] Figure 25 Photo-induced selective oxidation of 1,5-DHN under FOBTS catalysis;

[0057] Figure 26The curves showing the change in juglone yield with light exposure time under different catalysts FBTS, FOBTS, and FMBTS are shown.

[0058] Figure 27 Cyclic experiments were conducted on the catalyst FBTS in the photocatalytic selective oxidation of 1,5-DHN.

[0059] Figure 28 Degradation of MB under light-protected conditions without a catalyst;

[0060] Figure 29 This represents the degradation of MB under photocatalytic induction without a catalyst.

[0061] Figure 30 The degradation of MB catalyzed by FBTS under light and its kinetic curves (inset);

[0062] Figure 31 FMBTS catalyzes the degradation of MB under light irradiation;

[0063] Figure 32 FOBTS-catalyzed degradation of MB under light irradiation;

[0064] Figure 33 The relationship between MB degradation rate and CO2 concentration and light exposure time under different catalysts FBTS, FOBTS, and FMBTS;

[0065] Figure 34 Cyclic stability experiments for the photocatalytic degradation of MB by FBTS;

[0066] Figure 35 The relationship between H2O2 decomposition rate and O2 production concentration as a function of light exposure time under the action of different catalysts FBTS, FOBTS, and FMBTS;

[0067] Figure 36 Kinetic curves of photocatalytic decomposition of H2O2 using different catalysts FBTS, FOBTS, and FMBTS;

[0068] Figure 37 Cyclic stability experiment for FBTS photocatalytic decomposition of H2O2;

[0069] Figure 38 The rate of H2O2 photocatalytic decomposition by FBTS under different acidic conditions. Detailed Implementation

[0070] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0071] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0072] Example 1

[0073] This embodiment provides a sulfone-based conjugated organic polymer FBTS, prepared by the following method:

[0074] (1) Synthesis of 3,7-dibromodibenzothiophene sulfone

[0075] Add 50 mL of concentrated sulfuric acid solution (2 mol·L⁻¹) -1 Dibenzothiophene sulfone (DBTS, 1.0813 g, 5 mmol) and N-bromosuccinimide (NBS, 3.5596 g, 20 mmol) were added sequentially to the mixture, and the mixture was stirred at 0 °C for 24 h. After the reaction was completed, the mixture was filtered, and the collected precipitate was washed several times with deionized water. Then, it was dried under vacuum at 80 °C for 12 h. After removing impurities by recrystallization from chlorobenzene, purified white needle-like crystals—3,7-dibromodibenzothiophene sulfone (DBBTS, 2.7845 g, yield 60%)—were obtained. The structural formula of 3,7-dibromodibenzothiophene sulfone (DBBTS) is as follows:

[0076] The 1H NMR spectrum of 3,7-dibromodibenzothiophene sulfone (DBBTS) is as follows: Figure 1 As shown:

[0077] 1HNMR (400MHz, Chloroform-d): δ7.87 (d, J = 1.7 Hz, 2H), 7.71 (dd, J = 8.2, 1.8 Hz, 1H), 7.58 (d, J = 8.2 Hz, 1H).

[0078] (2) Synthesis of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester

[0079] DBBTS (1.8703 g, 5 mmol), bis(pinacol)diboron (2.5394 g, 10 mmol), potassium acetate (0.9814 g, 10 mmol), and palladium acetate (0.0225 g, 0.1 mmol) were sequentially added to a flame-dried round-bottom flask. The mixture was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added, and the reaction was carried out in an oil bath at 90 °C for 24 h. After cooling to room temperature, the filtrate was poured into deionized water and allowed to stand for 1 h. The solution was then extracted with ethyl acetate, dried over magnesium sulfate, and the organic phase was removed by rotary evaporation to remove water and ethyl acetate. Finally, the crude product was recrystallized from the crude product using acetonitrile under an argon atmosphere at 80 °C. After vacuum drying at 80 °C for 24 h, a purified white solid—dibenzothiophene sulfone-3,7-diboronate di(pinacol) ester (DBTSB, 1.9844 g, yield 45%)—was obtained. The structural formula of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester (DBTSB) is as follows:

[0080] The 1H NMR spectrum of dibenzothiophene sulfone-3,7-diboronate di(pinacol) ester (DBTSB) is as follows: Figure 2 As shown:

[0081] 1HNMR (400MHz, Chloroform-d): δ8.28 (s, 2H), 8.05 (d, J = 7.7Hz, 2H), 7.80 (d, J = 7.7Hz, 2H), 1.36 (s, 24H).

[0082] (3) Synthesis of FBTS

[0083] 2,7-Dibromofluorene (0.1620 g, 0.5 mmol), DBTSB (0.2341 g, 0.5 mmol), anhydrous potassium carbonate (0.0276 g, 0.2 mmol), and palladium acetate (0.0112 g, 0.05 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added. The flask was heated to 150 °C in a microwave reactor and kept at that temperature for 1 h. After cooling to room temperature, the precipitate obtained by filtration was washed several times with DMF and deionized water. It was first stirred overnight at 25°C in a solution (water / methanol, 1 / 1, V / V), then extracted at 70°C for 48 h in a Soxhlet extractor containing methanol, followed by stirring at 40°C for 8 h in dichloromethane, and finally vacuum dried at 80°C for 8 h to obtain brown powder FBTS (0.2218 g, yield 56%). The structural formula of FBTS is shown in formula (II):

[0084]

[0085] Example 2

[0086] This embodiment provides a sulfone-based conjugated organic polymer, FOBTS, prepared by the following method:

[0087] (1) Synthesis of 3,7-dibromodibenzothiophene sulfone (DBBTS), the steps of which are the same as in Example 1;

[0088] (2) Synthesis of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester (DBTSB), the steps of which are the same as in Example 1;

[0089] (3) Synthesis of FOBTS

[0090] 2,7-Dibromo-9-fluorenone (0.1690 g, 0.5 mmol), DBTSB (0.2341 g, 0.5 mmol), anhydrous potassium carbonate (0.0276 g, 0.2 mmol), and palladium acetate (0.0112 g, 0.05 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added. The flask was heated to 150 °C in a microwave reactor and held at that temperature for 1 h. Dark brown powder FOBTS was then obtained using the same method as in step (3) of Example 1. The structural formula of FOBTS is shown in formula (Ⅲ).

[0091]

[0092] Example 3

[0093] This embodiment provides a sulfone-based conjugated organic polymer, FMBTS, prepared by the following method:

[0094] (1) Synthesis of 3,7-dibromodibenzothiophene sulfone (DBBTS), the steps of which are the same as in Example 1;

[0095] (2) Synthesis of dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester (DBTSB), the steps of which are the same as in Example 1;

[0096] (3) Synthesis of FMBTS

[0097] 2,7-Dibromo-9,9-dimethylfluorene (0.1760 g, 0.5 mmol), DBTSB (0.2341 g, 0.5 mmol), anhydrous potassium carbonate (0.0276 g, 0.2 mmol), and palladium acetate (0.0112 g, 0.05 mmol) were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. Subsequently, 40.0 mL of dehydrated and argon-saturated DMF was added. The flask was heated to 150 °C in a microwave reactor and held at that temperature for 1 h. The light yellow powder FMBTS was then obtained using a similar method to step (3) in Example 1. The structural formula of FMBTS is shown in formula (Ⅳ).

[0098]

[0099] The synthetic routes of the conjugated organic polymer catalysts FBTS, FOBTS, and FMBTS obtained in Examples 1-3 are as follows: Figure 3 As shown.

[0100] Structural characterization

[0101] This invention synthesizes a sulfone-containing DA-type conjugated organic polymer FBTS by Suzuki coupling of 2,7-dibromofluorene (FB) and dibenzothiophene sulfone-3,7-diboronate di(pinacol) ester (DBTSB) in a microwave reactor. Subsequently, the 9-position of the fluorene unit is modified with ketone and methyl groups, and photocatalysts FOBTS and FMBTS with different structures are prepared using the same method. Solid-state carbon NMR spectroscopy of FBTS... Figure 4 As can be seen from the data, signals at 130 ppm and 135 ppm appear simultaneously, proving the formation of new CC bonds. Furthermore, from... Figures 5-7 It can be seen that the symmetric stretching vibration of the methylene group in monomer FB (1460 cm⁻¹) -1 ), and the stretching vibration of the CS bond in the monomer DBTSB (572 cm). -1 Symmetrical stretching vibration of S=O (1305cm) -1 All of these can be observed in the transmission infrared spectrum of FBTS, which together proves the successful coupling from monomer to polymer. Similar conclusions can be drawn from the infrared spectra of FOBTS and FMBTS.

[0102] Depend on Figures 8-12Table 1-4 shows that energy-dispersive X-ray spectroscopy (EDS) reveals the presence of palladium (0.42%) and sulfur (5.01%) in the FBTS structure, both uniformly distributed on the material surface. Inductively coupled plasma atomic emission spectrometry (ICP) further determined the palladium content in the polymer to be 0.35%. Although the introduction of Pd in ​​the Suzuki reaction is unavoidable, most of it was completely removed after multiple purification processes. X-ray photoelectron spectroscopy (XPS) results showed that the Pd content on the material surface was only 0.17%, indicating that most of the Pd was encapsulated within the catalyst during synthesis. Elemental analysis revealed a sulfur content of 4.78% in the catalyst; comparison with the valence state of sulfur in the standard revealed that only hexavalent sulfur was present on the FBTS surface.

[0103] Table 1. Energy Dispersive X-ray Spectroscopy (EDS) of FBTS

[0104]

[0105] Table 2 shows the inductively coupled plasma emission spectra (ICP) of FBTS.

[0106]

[0107] Table 3. X-ray photoelectron spectroscopy (XPS) of FBTS surface

[0108]

[0109] Table 4 Elemental Analysis of FBTS

[0110]

[0111] Depend on Figures 13-14 As can be seen from the powder X-ray diffraction (XRD) pattern, FBTS exhibits a distinct, broad, and flat diffraction peak. Scanning electron microscopy (SEM) results show that at the micrometer scale, it is composed of numerous randomly arranged spherical particles, collectively confirming the amorphous nature of the catalyst. Figure 15 Based on the adsorption-desorption isotherm of the polymer under N2 atmosphere, and using the BET method for data processing, we determined the specific surface area of ​​FBTS to be 342 m². 2 ·g -1 The pore width is around 3.8 nm, which is consistent with the characteristics of mesoporous materials.

[0112] Photoelectric properties

[0113] From the UV / Vis diffuse reflectance spectrum ( Figure 16As can be seen from the data, the maximum absorption edge of all three synthesized sulfone polymers extends into the visible light region. When the 9-H of the fluorene unit is replaced by a ketone or methyl group, the original rigid conjugated plane is distorted, the steric hindrance is changed, and the electron transfer path is affected, leading to a change in the band structure. For FBTS, its conduction band value is below 0.68V, indicating that photogenerated electrons can reduce O2 to ·O2. - This leads to the formation of H₂O₂, while the valence band value is higher than 1.23V, such as... Figure 17 As shown, photogenerated holes can oxidize water to oxygen, theoretically forming a catalytic cycle. The FOBTS band gap is too small to facilitate this cycle, while the FMBTS band gap is too large, hindering the separation of photogenerated carriers. The results of the photoresponse curve and electrochemical impedance spectroscopy (see...) Figures 18-19 The results showed that after photoexcitation, the FBTS surface had the highest concentration of photogenerated carriers and the strongest migration ability, indicating that good visible light absorption, unique electronic structure, and ideal spatial configuration can promote the separation and migration of photogenerated electrons and holes, and facilitate the two-electron oxygen reduction process in aqueous solution.

[0114] Example 4 Photocatalysis Experiment

[0115] Selective oxidation of 1,5-dihydroxynaphthalene (1,5-DHN), degradation of methylene blue (MB), and decomposition of hydrogen peroxide under acidic conditions were used to evaluate the photocatalytic performance of FBTS.

[0116] 1,5-DHN is a crucial dye intermediate, producing dyes with rich colors, good fastness, and low price, holding a significant position in the dye industry. However, some enterprises with outdated dyeing processes discharge a portion of 1,5-DHN into their production wastewater without achieving complete conversion. 1,5-DHN is highly irritating and toxic, causing developmental deformities and cancer in animals and plants, posing a significant threat to the aquatic environment and biological health. Selectively converting 1,5-dihydroxynaphthalene to juglone using a catalyst under room temperature, air, and visible light irradiation is a green, economical, and effective method for treating pollutants. Juglone is an aromatic compound with a quinone structure. It can disrupt ion channels in cell membranes, hindering nutrient transmembrane transport, interfering with cell wall synthesis and cell differentiation, thereby eliminating or inhibiting pests and diseases, and possessing strong medicinal value.

[0117] MB is a common organic dye and chemical indicator. Due to its presence of benzene rings, heterocycles, and other structures that are difficult to decompose, it can remain stable for a long time once it enters the aquatic environment or organisms. Under mild conditions, the complete mineralization of MB into carbon dioxide with the aid of a catalyst is an ideal method for degrading pollutants.

[0118] Hydrogen peroxide is one of the world's 100 most important chemicals, widely used in inorganic synthesis, organic synthesis, medical disinfection, and textile bleaching. At room temperature, the decomposition rate of H₂O₂ in a sulfuric acid solution with pH = 4.0 does not exceed 4 × 10⁻⁶. -6 Acidic industrial wastewater often contains low concentrations of H2O2, which can react with organic matter to form explosive peroxides. The oxygen produced by its decomposition can also form flammable mixtures with organic vapors. Long-term accumulation, coupled with exposure to high temperatures or violent impacts, can pose serious safety hazards. Therefore, the harmless elimination of H2O2 in acidic environments is a crucial step in reducing production risks for enterprises.

[0119] (1) Photocatalytic conversion of 1,5-dihydroxynaphthalene

[0120] 25 mg of catalyst (polymers FBTS, FOBTS, FMBTS) was uniformly dispersed in 100 mL of solution (acetonitrile / water, 1 / 1, v / v), followed by the addition of 1 mL of 1×10⁻⁶ catalyst. -4 mol·L -1 A solution of 1,5-dihydroxynaphthalene (1,5-DHN) was stirred for 30 min at room temperature, in air, and in the dark to allow the reactants to reach adsorption-desorption equilibrium on the catalyst surface. Then, 120 Wm... -2 Irradiate the solution with a white LED light, take samples at fixed intervals, centrifuge, collect the supernatant, filter, and measure the absorption spectrum of the solution using a UV-Vis spectrophotometer. 1,5-DHN has an absorption peak at around 300 nm, while the product juglone has an absorption peak at around 425 nm.

[0121] Yield juglone =100%×(I juglone ÷ε juglone ÷D)÷C initial1,5-DHN

[0122] Where I juglone The absorbance of juglone is represented by ε. juglone The molar extinction coefficient of juglone (3567 L·mol) -1 ·cm -1 D represents the thickness of the solution (1 cm), C initial1,5-DHN This represents the initial concentration of 1,5-DHN.

[0123] (2) Decomposition experiment of H2O2 in acidic solution

[0124] Add 5 mg of catalyst (polymers FBTS, FOBTS, FMBTS) to 100 mL of H₂O₂ solution (1% wt, pH = 4) and react for 1 h at 20 °C in the dark. Then add excess H₂SO₄ solution to the filtrate, using 0.05 mol·L⁻¹. -1The remaining H2O2 was titrated with KMnO4 solution, and the average of three experiments was taken as the final result. After the test, the catalyst was washed with deionized water, dried under vacuum at 80℃ for 12 h, and then recovered. The reaction equation (1) and the formula for calculating the decomposition rate of H2O2 (2) are as follows:

[0125] 2KMnO4+5H2O2+3H2SO4=K2SO4+2MnO4+5O2↑+8H2O (1)

[0126]

[0127] Where V i —Consumption of KMnO4 solution, L; m b —The mass of H2O2 solution added before the reaction, in g.

[0128] (3) Methylene blue degradation experiment

[0129] Add 5 mg of catalyst (polymers FBTS, FOBTS, FMBTS) to 20 mL of methylene blue (MB) aqueous solution (10 -5 mol·L -1 The reactants are evenly dispersed in the catalyst and stirred for 30 minutes under room temperature, air, and light-protected conditions to allow the reactants to reach adsorption-desorption equilibrium on the catalyst surface.

[0130] Using a 300W xenon lamp as the light source, samples were taken at fixed intervals. After centrifugation, the supernatant was collected, filtered, and the absorption spectrum of the solution was measured using a UV-Vis spectrophotometer. The degradation rate of MB was calculated by the change in the intensity of the characteristic absorption peak near 675 nm with the illumination time. After the test, the catalyst was washed with deionized water, vacuum dried at 80℃ for 12 h, and then recovered. The formula for calculating the MB decomposition rate (3) is as follows:

[0131]

[0132] Where C0 is the concentration of the substrate before illumination; C t —The concentration of the substrate at reaction time t.

[0133] The above experimental results are as follows Figures 20-38 As shown,

[0134] Depend on Figures 20-27 Experimental results show that Juglone is generated only in the presence of both light and polymer, while palladium acetate has no catalytic effect. When FBTS is applied to a white LED (120Wm²),... -2When 1,5-DHN was catalyzed under irradiation and in air, the UV / Vis absorption spectrum of the solution showed an absorption peak of juglone at 425 nm. The absorbance increased with time, reaching a maximum after 28 min, with a yield of 92%, significantly higher than the other two materials (FOBTS-70 min-52%; FMBTS-70 min-47%). Even after 5 cycles, FBTS maintained excellent performance, demonstrating good photostability and chemical stability.

[0135] Depend on Figures 28-34 Experimental results show that light irradiation and polymer materials are indispensable conditions for MB degradation. When the reaction is catalyzed by FBTS under 300W xenon lamp irradiation, air, and room temperature, the absorbance of MB at 665 nm decreases with time, while the degradation rate and the concentration of carbon dioxide after degradation both increase with time, reaching their maximum values ​​of 98% and 2.92 μmol, respectively, after 30 min, with a decomposition rate constant of 0.12 min. -1 It is significantly better than FOBTS (90 min - 45% - 0.03 min). -1 ) and FMBTS (90min-21%-0.01min) -1 After three cycles, the catalytic activity of FBTS remained essentially unchanged.

[0136] Depend on Figures 35-38 Experimental results showed that when H2O2 was decomposed using FBTS at room temperature under 300W xenon lamp irradiation, both the decomposition rate and the concentration of oxygen after decomposition increased with time, reaching their maximum values ​​of 95% and 2.18 mmol, respectively, after 40 min, with a decomposition rate constant of 0.070 min. -1 It is significantly better than FOBTS (40 min - 45% - 0.015 min). -1 ) and FMBTS (40min-33%-0.011min) -1 After 5 cycles, the catalytic effect did not change significantly. Furthermore, acid sensitivity experiments showed that the higher the hydrogen ion concentration in the solution, the lower the H2O2 decomposition rate; however, even at pH 2, the decomposition rate remained above 85%.

[0137] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A sulfone-based conjugated organic polymer, characterized in that, Its general structural formula is shown in equation (Ⅰ): Wherein, R is selected from CH2, C=O or C(CH3)2; n represents the number of repeating units in the polymer, which is a natural number between 80 and 300.

2. The sulfone-based conjugated organic polymer according to claim 1, characterized in that, Polymers with structure (I) are polymers having any one of the structures (II) to (IV): Where n represents the number of repeating units in the polymer, which is a natural number between 80 and 300.

3. A method for preparing a sulfone-based conjugated organic polymer according to any one of claims 1-2, characterized in that, Includes the following steps: Synthesis of S1,3,7-dibromodibenzothiophene sulfone: Dibenzothiophene sulfone and N-bromosuccinimide were added sequentially to a concentrated sulfuric acid solution and stirred at 0°C for 24 h. After the reaction was completed, the mixture was filtered, and the collected precipitate was washed several times with deionized water. Then, it was dried under vacuum at 80°C for 12 h. After removing impurities by recrystallization with chlorobenzene, a refined white needle-like crystal was obtained, which is 3,7-dibromodibenzothiophene sulfone. Synthesis of S2, dibenzothiophene sulfone-3,7-diboronic acid di(pinacol) ester: 3,7-Dibromodibenzothiophene sulfone, bis(pinacol)diboron, potassium acetate, and palladium acetate were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. DMF saturated with argon and dehydrated was added, and the mixture was reacted in an oil bath at 90°C for 24 hours. After cooling to room temperature, the filtrate was poured into deionized water and allowed to stand for 1 hour. The solution was then extracted with ethyl acetate, dried over magnesium sulfate, and rotary evaporated to remove water and ethyl acetate from the organic phase. Finally, the crude product was recrystallized from the crude product using acetonitrile under an argon atmosphere at 80°C. After vacuum drying at 80°C for 24 hours, a purified white solid was obtained, which is dibenzothiophene sulfone-3,7-diboronate di(pinacol) ester. Synthesis of S3, sulfone-based conjugated organic polymers: The monomer, dibenzothiophene sulfone-3,7-diborate di(pinacol), anhydrous potassium carbonate, and palladium acetate were sequentially added to a flame-dried round-bottom flask. The flask was then evacuated and purged with argon three times. DMF saturated with argon and dehydrated was then added. The mixture was heated to 150°C in a microwave reactor and held at that temperature for 1 hour. After cooling to room temperature, the filtered precipitate was washed multiple times with DMF and deionized water. The precipitate was first stirred overnight in a methanol-water solution at 25°C, then extracted for 48 hours in a Soxhlet extractor containing methanol at 70°C. Finally, it was stirred in dichloromethane at 40°C for 8 hours and then vacuum-dried at 80°C for 8 hours to obtain the sulfone-based conjugated organic polymer.

4. The method for preparing a sulfone-based conjugated organic polymer according to claim 3, characterized in that, In step S1, the molar ratio of dibenzothiophene sulfone and N-bromosuccinimide is 1:

4.

5. The method for preparing a sulfone-based conjugated organic polymer according to claim 3, characterized in that, In step S2, the molar ratio of 3,7-dibromodibenzothiophene sulfone, bis(pinacol)diboron, potassium acetate, and palladium acetate is 1:2:2:0.

02.

6. The method for preparing a sulfone-based conjugated organic polymer according to claim 3, characterized in that, In step S3, the monomer is any one of 2,7-dibromofluorene, 2,7-dibromo-9-fluorene ketone, and 2,7-dibromo-9,9-dimethylfluorene.

7. The method for preparing a sulfone-based conjugated organic polymer according to claim 6, characterized in that, In step S3, the monomer is 2,7-dibromofluorene.

8. The application of the sulfone-based conjugated organic polymer according to claim 2 in photocatalytic activation of molecular oxygen.

9. The application according to claim 8, characterized in that, The polymer has the structural formula shown in formula (Ⅱ).

10. The application according to claim 8, the application of sulfone-based conjugated organic polymers in pollutant degradation or hydrogen peroxide decomposition under acidic conditions.

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