Porous honeycomb-shaped CTF composite photocatalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photocatalytic energy conversion, and particularly relates to a porous honeycomb CTF composite photocatalyst as well as a preparation method and application thereof. The composite photocatalyst disclosed by the invention is obtained by modification treatment of a sulfur defect ZnIn2S4 nanosheet; the method specifically comprises the following steps: constructing a phenothiazine functionalized three-dimensional ordered macroporous covalent triazine framework by a solid-phase template method, and growing a sulfur defect ZnIn2S4 nanosheet in situ to form a three-dimensional ordered macroporous network confinement two-dimensional nanosheet multistage heterostructure; according to the method, a phenothiazine unit in CTF-PTZBN induces ZIS-Sv oriented growth through a molecular anchoring effect, an interface C-S-Zn / In bond is bridged to form a stable electron transmission channel, then an electric field is built in a skeleton to cooperate with a sulfur defect state to construct an electric field driving-channel transmission-trap capture ternary carrier regulation and control system, efficient separation and oriented migration of photo-generated charges are realized, and the photoelectric conversion efficiency is improved. And recombination of photon-generated carriers is successfully reduced. The binary composite material shows excellent hydrogen production and styrene selective epoxidation reaction performance.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic energy conversion technology, specifically relating to a porous honeycomb CTF composite photocatalyst, its preparation method, and its application. Background Technology

[0002] In the process of renewable energy technology innovation, solar-driven water splitting for hydrogen production has become a cutting-edge research direction for alleviating the fossil energy crisis due to its zero-carbon emission characteristics. Since Fujishima and Honda discovered the photoelectric splitting of water using TiO2 electrodes in 1972, this field has undergone more than 50 years of development, and the research paradigm has expanded from simple light absorption to precise control of carrier lifetime. Currently, the construction of advanced photocatalytic systems focuses on three core elements: (1) the realization of a wide-range spectral response; (2) the synergistic improvement of quantum efficiency and energy conversion efficiency; and (3) the breakthrough of high operational stability. Through dimensional control strategies such as crystal orientation regulation, heterogeneous morphology engineering, and precise construction of defect states, efficient charge-directed migration channels are constructed to improve photocatalytic efficiency. In addition, in the field of organic catalytic conversion, taking the epoxidation reaction of styrene as an example, its product, epoxide, is not only an important precursor in the fragrance industry, but also plays an irreplaceable role in the synthesis of functional polymer materials. However, the peroxyacid oxidation system commonly used in traditional production processes has significant drawbacks: on the one hand, it requires reaction in a highly corrosive medium, and on the other hand, it generates a large amount of chlorine-containing byproducts. This "end-of-pipe treatment" model is no longer sufficient to meet the development needs of green chemistry. To address these issues, developing photocatalytic systems using molecular oxygen as a green oxidant for efficient epoxidation under mild conditions has become a key area of ​​research in catalytic chemistry.

[0003] In the design of novel photocatalytic material systems, covalent triazine frameworks (CTFs) have become an important research object in the field of solar energy conversion due to their advantages in topological designability and chemical stability. As the core building block of CTFs, triazine rings achieve precise construction of active sites at the molecular level thanks to their electron-rich properties and the synergistic effect of multiple heteroatoms. However, the intrinsic kinetics of CTFs, including high exciton binding energy, limited exciton diffusion length, and rapid bulk recombination effects, result in insufficient utilization of photogenerated carriers, severely restricting further improvement of their catalytic performance. Layered ternary metal sulfides ZnIn2S4 (ZIS) have attracted much attention due to their tunable electronic band structure and excellent photoresponse characteristics. However, single ZIS nanosheets are prone to self-aggregation during catalysis, leading to a decrease in active site density and a decline in cycle stability. Further research shows that the band structure of ZIS can be precisely controlled through intrinsic vacancy construction or heteroatom doping strategies, and the interband transition efficiency of semiconductor materials can be effectively enhanced through the synergistic shift optimization of the valence band and conduction band. Therefore, this invention proposes a function-oriented multi-scale structural design strategy: synthesizing a phenothiazine-functionalized three-dimensional honeycomb covalent triazine framework (CTF-PTZBN) using a solid-phase template-assisted method, and in situ growing sulfur-defect ZnIn2S4 nanosheets (ZIS-Sv) based on its interconnected macroporous framework, thus constructing a hierarchical porous heterostructure of "three-dimensional ordered macroporous network confining two-dimensional nanosheets". This ultimately achieves the goal of improving the photocatalytic water splitting activity for hydrogen production, and realizes high selectivity and high conversion rate of styrene epoxidation reaction. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a highly active and stable porous honeycomb CTF composite photocatalyst, its preparation method, and its application.

[0005] The porous honeycomb CTF composite photocatalyst provided by this invention is obtained by modifying sulfur-deficient ZnIn2S4 nanosheets (ZIS-Sv). The specific preparation steps are as follows: (1) Templated polymerization: Benzonitrile-functionalized phenothiazine monomer (PTZBN) is blended with terephthalonitrile in tetrahydrofuran solution, and silica microspheres are introduced as template agents. Under the catalysis of trifluoromethanesulfonic acid, the monomer material undergoes a polymerization reaction around the silica spheres to form a monomer / template complex. (2) Framework construction: After neutralizing the product in step (1) with alkaline solution, the template is selectively removed by etching with ammonium bifluoride solution to form a macroporous framework structure, denoted as CTF-PTZBN; (3) In-situ solvothermal preparation of composite photocatalyst (constructing sulfur defects): The CTF-PTZBN obtained in step (2) is dispersed in a water / glycerol mixed solvent, and the corresponding zinc source, indium source and sulfur source are added to ensure that the sulfur source is in excess to construct sulfur defects; then the system is placed in a constant temperature magnetic stirring reactor and reacted for a period of time. After centrifugation, washing and drying, a light brown powder sample is finally obtained, which is the composite photocatalyst, denoted as ZIS-Sv / CTF-PTZBN.

[0006] Furthermore: In step (1), the amount of silica nanotemplate is 300-500 mg; the amount of terephthalonitrile is 100-150 mg; the amount of PTZBN is 10-20 mg; the amount of tetrahydrofuran is 10-30 mL; the polycondensation reaction temperature is 80-120 °C; and the reaction time is 20-30 h.

[0007] In step (2), the etching time of ammonium bifluoride solution is 20-30 h.

[0008] In step (3), the amount of CTF-PTZBN is 5-450 mg; the zinc source, indium source and sulfur source are zinc chloride, indium chloride and thioacetamide, respectively, and the molar ratio of the three is 1:(1.5-2.5):(4~8); the reaction temperature is 60-100 °C and the reaction time is 1-3 h.

[0009] Furthermore, the specific operation process of the preparation method of the sulfur-deficient ZnIn2S4 nanosheet-modified porous honeycomb CTF composite photocatalyst provided by the present invention is as follows: (1) First, porous honeycomb CTF-PTZBN is prepared. The specific process is as follows: 300-500 mg of vacuum-dried silica nanotemplate and monomer solution (containing 100-150 mg of terephthalonitrile, 10-20 mg of PTZBN and 10-30 mL of tetrahydrofuran) are dispersed by ultrasonication to form a uniform composite system. The solvent is removed to obtain monomer / template composite precursor. The precursor is subjected to acid-catalyzed polycondensation reaction at 80-120 °C for 20-30 h.

[0010] (2) After the reaction is completed, the product in step (1) is neutralized with alkali and then preliminarily separated by centrifugation and washing. Subsequently, the silica template is removed by selective etching with ammonium bifluoride solution for 20-30 h, and finally the product is washed and dried to obtain a dark yellow solid CTF-PTZBN.

[0011] (3) Take 5-450 mg of the CTF-PTZBN solid obtained in step (2) and disperse it in a water / glycerol mixed solvent. Then add zinc chloride, indium chloride and thioacetamide in the above mixture in a molar ratio of 1:(1.5-2.5):(4~8) to ensure that the sulfur source is in excess to construct sulfur defects. Place the system in a constant temperature magnetic stirring reactor at 60-100 °C and continue to react for 1-3 hours. After centrifugation, washing and drying, a light brown ZIS-Sv / CTF-PTZBN powder sample is finally obtained, which is the composite photocatalyst.

[0012] The present invention also provides a porous honeycomb CTF composite photocatalyst modified with sulfur-defect ZnIn2S4 nanosheets prepared by the above preparation method.

[0013] This invention also provides the application of sulfur-deficient ZnIn2S4 nanosheet-modified porous honeycomb CTF composite photocatalyst in water splitting for hydrogen production; the specific steps are as follows: (1) Configure the photocatalytic system by ultrasonically dispersing the porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets into an aqueous solution containing triethanolamine sacrificial agent to form a mixed solution, and placing it in a light-transmitting closed system. (2) Prepare green hydrogen by irradiating the sealed system obtained in step (1) with full-band light.

[0014] The specific operation process is as follows: A porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets is dispersed in an aqueous solution containing triethanolamine (TEOA) as a sacrificial agent to obtain a mixed reaction solution. This solution is then transferred to a light-transmitting sealed system, and the temperature is controlled at 15-25 °C using a circulating water cooling system. The mixed reaction solution is irradiated with a 300 W xenon lamp to produce hydrogen. The amount of hydrogen produced is measured using an online gas chromatograph, with gas samples extracted and analyzed every 60 minutes.

[0015] This invention also provides the application of a porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets in the selective epoxidation of styrene to prepare epoxide. The specific steps are as follows: (1) Configure the photocatalytic system by ultrasonically dispersing the porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets into N,N-dimethylacetamide solvent containing styrene (substrate) to form a mixed solution, and placing it in a light-transmitting closed system; (2) Prepare epoxide phenyl ethane from the sealed system obtained in step (1) by LED lamp irradiation.

[0016] The specific operation process is as follows: A porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets was ultrasonically dispersed in an N,N-dimethylacetamide solvent containing styrene (substrate) to form a mixed solution. The mixed solution was then sealed and transferred to a temperature-controlled high-throughput photocatalytic reactor. The mixed solution was irradiated with an LED at a wavelength of 375 nm, and the epoxidation reaction of styrene was carried out for 10 h at a controlled temperature of 80 °C. Subsequently, the reaction solution was filtered, and the yield and selectivity of epoxide were analyzed by gas chromatography.

[0017] The present invention also provides two photocatalytic systems: (1) a hydrogen production system: composed of a porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets obtained above and an aqueous solution containing triethanolamine (TEOA) sacrificial agent; (2) a styrene epoxidation system: composed of a porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets and an N,N-dimethylacetamide solvent containing styrene (substrate).

[0018] This invention benefits from the molecular anchoring effect of phenothiazine units in CTF-PTZBN, which induces the directional growth of ZIS-Sv. The interface CS-Zn / In bonds bridge this to form stable electron transport channels. Subsequently, an internal electric field, in conjunction with sulfur defect states, constructs a ternary carrier regulation system of "electric field-driven - channel transport - trap capture," achieving efficient separation and directional migration of photogenerated charges and successfully reducing recombination of photogenerated carriers. The exposed active sites in the multi-scale porous structure greatly promote the photocatalytic hydrogen production and photocatalytic styrene epoxidation reactions of the composite material; therefore, this binary composite material exhibits excellent redox capabilities.

[0019] Compared with the prior art, the present invention has the following positive effects: (1) The catalyst has high selectivity for photocatalytic styrene epoxidation reaction, which is better than most of the photocatalytic styrene epoxidation processes reported in the current literature; at the same time, compared with simple CTF and ZnIn2S4 materials, the catalyst also has high photocatalytic hydrogen production activity.

[0020] (2) The catalyst has a special morphology. The CTF-PTZBN matrix exhibits a highly ordered macroporous framework structure, while the ZIS-Sv nanosheets are uniformly distributed inside and on the surface of the CTF framework through in-situ growth, providing more active sites for subsequent photocatalytic redox reactions.

[0021] (3) The catalyst has a novel compositional structure. The phenothiazine unit induces the directional growth of ZIS-Sv through molecular anchoring. The interface CS-Zn / In bond bridge forms a stable electron transport channel. It works in conjunction with the sulfur defect state to construct a ternary carrier regulation system of "electric field driven-channel transport-trap capture", realizing efficient separation and directional migration of photogenerated charges. It provides valuable reference for designing CTF-based or ZnIn2S4-based high-efficiency multifunctional composite photocatalysts. Attached Figure Description

[0022] Figure 1 Scanning electron microscope (SEM) images of CTF-PTZBN, sulfur-deficient ZnIn2S4, and ZIS-Sv / CTF-PTZBN composite catalysts.

[0023] Figure 2 X-ray powder diffraction patterns of CTF-PTZBN, sulfur-defective ZnIn2S4, and ZIS-Sv / CTF-PTZBN composite catalysts.

[0024] Figure 3 Fourier transform infrared spectra of CTF-PTZBN, sulfur-deficient ZnIn2S4, and ZIS-Sv / CTF-PTZBN composite catalysts. Detailed Implementation

[0025] The present invention will be further illustrated below with specific embodiments, which are intended to explain the invention rather than limit it. Example 1

[0026] (1) The CTF-PTZBN monomer / template composite was prepared by solid-phase template method. The specific process was as follows: 400 mg of vacuum-dried silica nanotemplate and monomer solution (containing 130 mg terephthalonitrile, 15 mg PTZBN and 20 mL tetrahydrofuran) were dispersed by ultrasonication to form a uniform composite system. The solvent was removed to obtain the monomer / template composite precursor. The precursor was subjected to acid-catalyzed polycondensation reaction at 80 °C for 30 h.

[0027] (2) Constructing a macroporous framework CTF structure: The product in step (1) was neutralized with alkali and then preliminarily separated by centrifugation and washing. Subsequently, the silica template was removed by selective etching with ammonium bifluoride solution for 28 h, and finally, the product was washed and dried to obtain a deep yellow solid CTF-PTZBN.

[0028] (3) In-situ solvothermal preparation of ZIS-Sv / CTF-PTZBN composite catalyst, the specific process is as follows: 450 mg of CTF-PTZBN solid obtained in step (2) is dispersed in a water / glycerol mixed solvent, and zinc chloride, indium chloride and thioacetamide are added to the above mixture in a molar ratio of 1:2:4. The system is placed in an 80 °C constant temperature magnetic stirring reactor and reacted continuously for 2 h. After centrifugation, washing and drying, a light brown ZIS-Sv / CTF-PTZBN powder sample is finally obtained, which is the composite photocatalyst (denoted as 1). # ).

[0029] Hydrogen production reaction: Weigh 20 mg of the above composite catalyst and ultrasonically disperse it in 100 mL of 10% TEOA sacrificial agent solution to obtain a mixed reaction solution. Add chloroplatinic acid solution (10 mg / mL, 28 μL). Transfer the mixed reaction solution to a light-transmitting sealed system and irradiate the mixed reaction solution with a 300 W xenon lamp. Monitor the amount of hydrogen produced every 60 minutes using a gas chromatograph.

[0030] Styrene epoxidation reaction: 10 mg of the above composite catalyst was ultrasonically dispersed in N,N-dimethylacetamide (DMA) solvent containing 5.7 μL of styrene (solvent volume was 2 mL). The mixed solution was sealed and transferred to a temperature-controlled high-throughput photocatalytic reactor. The mixed solution was irradiated with a 375 nm LED lamp, the reaction temperature was adjusted to 25 °C, and the reaction time was 10 h. After the reaction was completed, the catalyst was filtered, and the reaction products were detected and analyzed by gas chromatography. Example 2

[0031] (1) The CTF-PTZBN monomer / template composite was prepared by solid-phase template method. The specific process was as follows: 400 mg of vacuum-dried silica nanotemplate and monomer solution (containing 130 mg terephthalonitrile, 15 mg PTZBN and 20 mL tetrahydrofuran) were ultrasonically dispersed to form a uniform composite system. The solvent was removed to obtain the monomer / template composite precursor. The precursor was subjected to acid-catalyzed polycondensation reaction at 90 °C for 28 h.

[0032] (2) Constructing a macroporous framework CTF structure: The product in step (1) was neutralized with alkali and then preliminarily separated by centrifugation and washing. Subsequently, the silica template was removed by selective etching with ammonium bifluoride solution for 24 h, and finally, the product was washed and dried to obtain a deep yellow solid CTF-PTZBN.

[0033] (3) In-situ solvothermal preparation of ZIS-Sv / CTF-PTZBN composite catalyst, the specific process is as follows: 120 mg of CTF-PTZBN solid obtained in step (2) is dispersed in a water / glycerol mixed solvent, and zinc chloride, indium chloride and thioacetamide are added to the above mixture in a molar ratio of 1:2:6. The system is placed in a 60 °C constant temperature magnetic stirring reactor and reacted continuously for 3 h. After centrifugation, washing and drying, a light brown ZIS-Sv / CTF-PTZBN powder sample is finally obtained, which is the composite photocatalyst (denoted as 2). # ).

[0034] The hydrogen production reaction steps are the same as in Example 1.

[0035] Example 1: Styrene epoxidation reaction steps. Example 3

[0036] (1) The CTF-PTZBN monomer / template composite was prepared by solid-phase template method. The specific process was as follows: 400 mg of vacuum-dried silica nanotemplate and monomer solution (containing 130 mg terephthalonitrile, 15 mg PTZBN and 20 mL tetrahydrofuran) were ultrasonically dispersed to form a uniform composite system. The solvent was removed to obtain the monomer / template composite precursor. The precursor was subjected to acid-catalyzed polycondensation reaction at 100 °C for 24 h.

[0037] (2) Constructing a macroporous framework CTF structure: The product in step (1) was neutralized with alkali and then preliminarily separated by centrifugation and washing. Subsequently, the silica template was removed by selective etching with ammonium bifluoride solution for 24 h, and finally, the product was washed and dried to obtain a deep yellow solid CTF-PTZBN.

[0038] (3) In-situ solvothermal preparation of ZIS-Sv / CTF-PTZBN composite catalyst, the specific process is as follows: Take 50 mg of CTF-PTZBN solid obtained in step (2) and disperse it in a water / glycerol mixed solvent. Then add zinc chloride, indium chloride and thioacetamide in the above mixture in a molar ratio of 1:2:8. Place the system in an 80 °C constant temperature magnetic stirring reactor and continue to react for 2 h. After centrifugation, washing and drying, a light brown ZIS-Sv / CTF-PTZBN powder sample is finally obtained, which is the composite photocatalyst (denoted as 3). # ).

[0039] The hydrogen production reaction steps are the same as in Example 1.

[0040] Example 1: Styrene epoxidation reaction steps. Example 4

[0041] (1) The CTF-PTZBN monomer / template composite was prepared by solid-phase template method. The specific process was as follows: 400 mg of vacuum-dried silica nanotemplate and monomer solution (containing 130 mg terephthalonitrile, 15 mg PTZBN and 20 mL tetrahydrofuran) were dispersed by ultrasonication to form a uniform composite system. The solvent was removed to obtain the monomer / template composite precursor. The precursor was subjected to acid-catalyzed polycondensation reaction at 110 °C for 24 h.

[0042] (2) Constructing a macroporous framework CTF structure: The product in step (1) was neutralized with alkali and then preliminarily separated by centrifugation and washing. Subsequently, the silica template was removed by selective etching with ammonium bifluoride solution for 20 h, and finally, the product was washed and dried to obtain a deep yellow solid CTF-PTZBN.

[0043] (3) In-situ solvothermal preparation of ZIS-Sv / CTF-PTZBN composite catalyst, the specific process is as follows: 20 mg of CTF-PTZBN solid obtained in step (2) is dispersed in a water / glycerol mixed solvent, and zinc chloride, indium chloride and thioacetamide are added to the above mixture in a molar ratio of 1:2:6. The system is placed in a 100 °C constant temperature magnetic stirring reactor and reacted continuously for 1 h. After centrifugation, washing and drying, a light brown ZIS-Sv / CTF-PTZBN powder sample is finally obtained, which is the composite photocatalyst (denoted as 4). # ).

[0044] The hydrogen production reaction steps are the same as in Example 1.

[0045] Example 1: Styrene epoxidation reaction steps. Example 5

[0046] (1) Solid-phase template method for preparing CTF-PTZBN monomer / template composite: 400 mg of vacuum-dried silica nanotemplate and monomer solution (containing 130 mg terephthalonitrile, 15 mg PTZBN and 20 mL tetrahydrofuran) were ultrasonically dispersed to form a uniform composite system. The solvent was removed to obtain the monomer / template composite precursor. The precursor was subjected to acid-catalyzed polycondensation reaction at 120 °C for 20 h.

[0047] (2) Constructing a macroporous framework CTF structure: The product in step (1) was neutralized with alkali and then preliminarily separated by centrifugation and washing. Subsequently, the silica template was removed by selective etching with ammonium bifluoride solution for 20 h, and finally, the product was washed and dried to obtain a deep yellow solid CTF-PTZBN.

[0048] (3) In-situ solvothermal preparation of ZIS-Sv / CTF-PTZBN composite catalyst, the specific process is as follows: Take 5 mg of CTF-PTZBN solid obtained in step (2) and disperse it in a water / glycerol mixed solvent. Then add zinc chloride, indium chloride and thioacetamide in the above mixture in a molar ratio of 1:2:4. Place the system in an 80 °C constant temperature magnetic stirring reactor and continue to react for 2 h. After centrifugation, washing and drying, a light brown ZIS-Sv / CTF-PTZBN powder sample is finally obtained, which is the composite photocatalyst (denoted as 5 mg / mg). # ).

[0049] The hydrogen production reaction steps are the same as in Example 1.

[0050] Example 1: Styrene epoxidation reaction steps. Comparative Example 1

[0051] To compare the hydrogen production and epoxidation activities of porous honeycomb CTF composite photocatalysts modified with sulfur-deficient ZnIn2S4 nanosheets, this invention separately investigated the reactivity of porous honeycomb CTF-PTZBN without ZIS modification. The specific preparation process is as follows: (1) The CTF-PTZBN monomer / template composite was prepared by solid-phase template method. The specific process was as follows: 400 mg of vacuum-dried silica nanotemplate and monomer solution (containing 130 mg terephthalonitrile, 15 mg PTZBN and 20 mL tetrahydrofuran) were ultrasonically dispersed to form a uniform composite system. The solvent was removed to obtain the monomer / template composite precursor. The precursor was subjected to acid-catalyzed polycondensation reaction at 100 °C for 24 h.

[0052] (2) Construction of macroporous framework CTF structure, the specific process is as follows: the product in step (1) is neutralized with alkali, and the product is initially separated by centrifugation and washing. Then, the silica template is removed by selective etching with ammonium bifluoride solution for 24 h, and finally, the product is washed and dried to obtain a deep yellow solid CTF-PTZBN (1 & ).

[0053] Hydrogen production reaction: Weigh 20 mg of CTF-PTZBN catalyst and ultrasonically disperse it in 100 mL of 10% TEOA sacrificial agent solution to obtain a mixed reaction solution. Add chloroplatinic acid solution (10 mg / mL, 28 μL). Transfer the mixed reaction solution to a light-transmitting sealed system and irradiate the mixed reaction solution with a 300 W xenon lamp. Monitor the amount of hydrogen produced every 60 minutes using a gas chromatograph.

[0054] Styrene epoxidation reaction: 10 mg of CTF-PTZBN catalyst was ultrasonically dispersed in N,N-dimethylacetamide (DMA) solvent containing 5.7 μL of styrene (solvent volume was 2 mL). The mixed solution was sealed and transferred to a temperature-controlled high-throughput photocatalytic reactor. The mixed solution was irradiated with a 375 nm LED lamp, the reaction temperature was adjusted to 25 °C, and the reaction time was 10 h. After the reaction was completed, the catalyst was filtered, and the reaction products were detected and analyzed by gas chromatography. Comparative Example 2

[0055] To compare the hydrogen production and epoxidation activities of porous honeycomb CTF composite photocatalysts modified with sulfur-deficient ZnIn2S4 nanosheets, this invention separately investigated the reactivity of sulfur-deficient ZnIn2S4 nanoflowers prepared by a solvothermal method without combining with the CTF framework. The specific preparation process is as follows: Zinc chloride, indium chloride, and thioacetamide were added sequentially to a water / glycerol mixed solvent (volume ratio 4:1, total volume 10 mL) in a molar ratio of 1:2:8. The system was placed in an 80 °C magnetically stirred reactor and reacted continuously for 2 h. After centrifugation, washing, and drying, a light yellow sulfur-defective ZnIn2S4 powder sample was finally obtained (2...). & ).

[0056] Hydrogen production reaction: Weigh 20 mg of sulfur-deficient ZnIn2S4 catalyst and ultrasonically disperse it in 100 mL of 10% TEOA sacrificial agent solution to obtain a mixed reaction solution. Add chloroplatinic acid solution (10 mg / mL, 28 μL). Transfer the mixed reaction solution to a light-transmitting sealed system and irradiate the mixed reaction solution with a 300 W xenon lamp. Monitor the amount of hydrogen produced every 60 minutes using a gas chromatograph.

[0057] Styrene epoxidation reaction: 10 mg of sulfur-deficient ZnIn2S4 catalyst was ultrasonically dispersed in N,N-dimethylacetamide (DMA) solvent containing 5.7 μL of styrene (solvent volume 2 mL). The mixed solution was sealed and transferred to a temperature-controlled high-throughput photocatalytic reactor. The mixed solution was irradiated with a 375 nm LED lamp, the reaction temperature was adjusted to 25 °C, and the reaction time was 10 h. After the reaction was completed, the catalyst was filtered, and the reaction products were detected and analyzed by gas chromatography.

[0058] The hydrogen production activities of the above embodiments are shown in Table 1, and the styrene epoxidation activities are shown in Table 2.

[0059] Table 1. Hydrogen production activity of CTF-PTZBN, sulfur-deficient ZnIn2S4, and ZIS-Sv / CTF-PTZBN composite catalysts catalyst Catalyst dosage (mg) sacrificial agent Hydrogen production (mmol / g) Example 1 <![CDATA[1 # ]]> 20 10% TEOA 9.23 Example 2 <![CDATA[2 # ]]> 20 10% TEOA 13.56 Example 3 <![CDATA[3 # ]]> 20 10% TEOA 16.32 Example 4 <![CDATA[4 # ]]> 20 10% TEOA 15.14 Example 5 <![CDATA[5 # ]]> 20 10% TEOA 10.58 Comparative Example 1 <![CDATA[1 & ]]> 20 10% TEOA 0.37 Comparative Example 2 <![CDATA[2 & ]]> 20 10% TEOA 6.96

[0060] Table 2. Styrene epoxidation activity of CTF-PTZBN, sulfur-deficient ZnIn2S4, and ZIS-Sv / CTF-PTZBN composite catalysts catalyst Catalyst dosage (mg) LED lights Styrene conversion rate (%) Yield of epoxide (%) Selectivity of epoxides (%) Example 1 <![CDATA[1 # ]]> 10 375 nm 73.2 68.3 93.3 Example 2 <![CDATA[2 # ]]> 10 375 nm 82.7 77.5 93.7 Example 3 <![CDATA[3 # ]]> 10 375 nm 97.2 92.7 95.4 Example 4 <![CDATA[4 # ]]> 10 375 nm 74.3 70.4 94.7 Example 5 <![CDATA[5 # ]]> 10 375 nm 64.3 60.2 93.7 Comparative Example 1 <![CDATA[1 & ]]> 10 375 nm 71.0 66.1 93.1 Comparative Example 2 <![CDATA[2 & ]]> 10 375 nm 33.8 27.0 80.0

Claims

1. A method for preparing a porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets, characterized in that, The specific steps are as follows: (1) Templated polymerization: Benzonitrile-functionalized phenothiazine monomer (PTZBN) is blended with terephthalonitrile in tetrahydrofuran solution, and silica microspheres are introduced as template agents. Under the catalysis of trifluoromethanesulfonic acid, the monomer material is polymerized around the silica spheres to form a monomer / template complex. (2) Framework construction: After neutralizing the product in step (1) with alkaline solution, the template is selectively removed by etching with ammonium bifluoride solution to form a macroporous framework structure, denoted as CTF-PTZBN; (3) Preparation of composite photocatalyst by in-situ solvothermal method: The CTF-PTZBN obtained in step (2) is dispersed in a water / glycerol mixed solvent, and the corresponding zinc source, indium source and sulfur source are added to ensure that the sulfur source is in excess to construct sulfur defects; then the system is placed in a constant temperature magnetic stirring reactor for continuous reaction; after the reaction is completed, it is centrifuged, washed and dried to finally obtain a light brown powder sample, which is the composite photocatalyst, denoted as ZIS-Sv / CTF-PTZBN.

2. The preparation method according to claim 1, characterized in that: In step (1), the amount of terephthalonitrile is 100-150 mg, the amount of PTZBN is 10-20 mg, the solvent is tetrahydrofuran, and the amount used is 10-30 mL; the amount of silica nanotemplate is 300-500 mg.

3. The preparation method according to claim 1, characterized in that: In step (2), the etching time of ammonium bifluoride solution is 20-30 h.

4. The preparation method according to claim 1, characterized in that: In step (3), the amount of CTF-PTZBN is 5-450 mg; the zinc source, indium source and sulfur source are zinc chloride, indium chloride and thioacetamide, respectively, and the molar ratio of the three is 1:(1.5-2.5):(4~8); the reaction temperature is 60-100 °C and the reaction time is 1-3 h.

5. A porous honeycomb CTF composite photocatalyst modified with sulfur-defect ZnIn2S4 nanosheets prepared according to any one of claims 1 to 4.

6. The application of the porous honeycomb CTF composite photocatalyst as described in claim 1 in water splitting for hydrogen production, characterized in that, The specific steps are as follows: (1) Configure the photocatalytic system by ultrasonically dispersing the porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets into an aqueous solution containing triethanolamine sacrificial agent to form a mixed solution, and placing it in a light-transmitting closed system. (2) Prepare green hydrogen by irradiating the sealed system obtained in step (1) with full-band light.

7. A photocatalytic system, characterized in that, The porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets as described in claim 5 is formed by ultrasonically dispersing it in an aqueous solution containing triethanolamine sacrificial agent.

8. The application of the porous honeycomb CTF composite photocatalyst as described in claim 1 in the selective epoxidation of styrene to prepare epoxide, characterized in that, The specific steps are as follows: (1) Configure the photocatalytic system by ultrasonically dispersing the porous honeycomb CTF composite photocatalyst modified with sulfur-deficient ZnIn2S4 nanosheets into N,N-dimethylacetamide solvent containing styrene to form a mixed solution, and placing it in a light-transmitting closed system; (2) Prepare epoxide phenyl ethane from the sealed system obtained in step (1) by LED lamp irradiation.

9. A photocatalytic system, characterized in that, The porous honeycomb CTF composite photocatalyst as described in claim 5 is formed by ultrasonically dispersing it in N,N-dimethylacetamide solvent.

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