A composite catalytic material for efficiently activating persulfate and a preparation method thereof

Abstract

The present application relates to the technical field of catalyst, in particular to a kind of high-efficiency activation of composite catalytic material of persulfate and preparation method thereof.The composite catalytic material includes the following components: modified biochar, benzyl fluoride thiazide Fe / Co / Sb composite, sulfur hetero-compound, each component synergistic effect, effectively improve the efficiency of activated sulfate.The present application also provides the preparation method of the catalytic material, waste is turned into treasure to agricultural and forestry fertilizer, raw material is easy to obtain, easy to operate, and the high-efficiency activation of composite catalytic material of persulfate prepared has high catalytic efficiency, can efficiently activate persulfate to degrade pollutants, while the cost is relatively low, will not cause secondary pollution to the environment, and it is environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of catalytic materials technology, specifically to a highly efficient composite catalytic material for activating persulfate and its preparation method. Background Technology

[0002] Persulfate is a commonly used oxidant with advantages such as high efficiency, non-toxicity, and ease of handling, and is widely used in organic synthesis, environmental remediation, and water treatment. However, the activation rate of persulfate under normal conditions is slow, thus requiring catalytic materials to enhance its activity. Catalytic material technology for activating persulfate mainly involves two aspects: metal catalytic materials and non-metal catalytic materials. Metal catalytic materials include transition metal compounds, noble metals, and non-noble metals. Commonly used metal catalytic materials include iron, cobalt, copper, and nickel. These metal catalytic materials can react with persulfate to generate active intermediates, thereby catalyzing the oxidation of organic substrates. The selection and design of metal catalytic materials can be achieved by controlling the coordination environment, oxidation state, and crystal structure of the catalytic material. Non-metal catalytic materials mainly include carbon-based materials, nitrogen-based compounds, and sulfur-based compounds. Carbon-based materials such as graphene, carbon nanotubes, and activated carbon have good electrical conductivity and catalytic activity, and can be used as catalytic materials for activating persulfate. Nitrogen-based compounds such as boron nitride and molybdenum nitride have also been shown to have the ability to activate persulfate. In addition, sulfur hybrids such as copper sulfate can also catalyze the activation of persulfates. These catalytic materials can activate persulfates through various mechanisms, including electron transfer, redox reactions, free radical generation, and the formation of oxidative reactive intermediates. Catalytic materials for persulfate activation have broad application prospects in organic synthesis, environmental remediation, and water treatment. By optimizing the design and performance of catalytic materials, the activation efficiency and selectivity of persulfates can be improved, promoting research and application development in related fields. However, current research on catalytic materials for persulfate activation still has some shortcomings, mainly including the following aspects: Some catalytic materials exhibit low activity or stability when activating persulfates, and may deactivate or precipitate under reaction conditions, leading to a decrease in catalytic effect. Some catalytic materials may trigger side reactions when activating persulfates, resulting in the generation of unwanted byproducts or waste. Some commonly used catalytic materials use rare metals or toxic substances as the active center, which limits their sustainability in terms of large-scale application and environmental friendliness. Therefore, improving the selectivity of catalytic materials to efficiently activate persulfate and selectively oxidize substrates, and developing catalytic materials based on inexpensive, abundant, and environmentally friendly sources, is crucial for advancing the technology of activated persulfate catalytic materials. Further advancements in activated persulfate catalytic material technology can be achieved through the rational design and synthesis of novel catalytic materials, optimizing their activity, selectivity, and stability, and improving their sustainability. Summary of the Invention

[0003] To address the above technical problems, this invention proposes a highly efficient composite catalytic material for activating persulfate and its preparation method. This invention prepares modified biochar with a well-developed microporous structure and unique surface properties, including a large specific surface area, high active site density, and excellent adsorption capacity, enabling efficient enrichment of organic pollutants in water and rapid electron transfer. This invention also prepares a benzylfluorothiazide Fe / Co / Sb composite, which can efficiently activate persulfate and degrade organic pollutants in water. The modified biochar, as a carrier for the benzylfluorothiazide Fe / Co / Sb composite, enhances its special properties and specific adsorption and catalytic performance. The synergistic effect of the two results in high catalytic efficiency, efficient activation of persulfate, and good reusability. This invention prepares a sulfur hybrid compound that synergistically enhances the effect of a benzylfluorothiazide Fe / Co / Sb complex. This compound can activate persulfate separately, exhibiting rapid free radical generation and high catalytic efficiency. Combined with modified biochar, the catalytic material demonstrates strong stability. The benzylfluorothiazide Fe / Co / Sb complex prepared in this invention contains transition metals, which are stably supported on the modified biochar, thus mitigating secondary pollution caused by residual metals in water to some extent. It is also easy to recycle and reuse, reducing costs. The composite catalytic material obtained by this invention is easy to recycle, does not easily cause secondary pollution, has good dispersion, does not exhibit agglomeration, and has high catalytic efficiency.

[0004] This invention is achieved through the following technical solution: A highly efficient composite catalytic material for activating persulfate comprises the following components: modified biochar, benzylfluorothiazide Fe / Co / Sb complex, and sulfur hybrid.

[0005] Furthermore, the method for preparing the modified biochar includes the following steps: (1) The agricultural and forestry biomass waste was crushed to 2-3 cm and dried at 80℃. The agricultural and forestry biomass waste was immersed in 1 mol / L NaOH solution at a solid-liquid ratio of 20 g / L and stirred thoroughly for 24 h. Then it was washed with deionized water until the pH was stable. After that, it was immersed in 1 mol / L HCl solution for 1 h. After washing with deionized water 3 times, it was dried at 60℃ to obtain pretreated biomass waste. (2) The pretreated biomass waste obtained in step (1) was impregnated in a mixed solution of malic acid and sorbitol. The concentrations of malic acid and sorbitol were both 0.5 mol / L. The mass-volume ratio of the pretreated biomass waste to the mixed solution was 1 g: 25 mL. The mixture was shaken at 250 rpm at 30 °C for 24 h. After shaking, the solid phase was collected by filtration, dried at 60 °C, and placed in a reaction vessel and heated to 220 °C. After 2 h, it was cooled to 40 °C to obtain the primary modified product. (3) Mix the calcium salt with the primary modified product obtained in step (2) at a mass ratio of 1:15, place it in a tube furnace with an inert gas atmosphere, and calcine it at a heating rate of 5℃ / min from room temperature to 550-650℃ for 2 h in an oxygen-free environment. After calcination, let it cool naturally to room temperature, pulverize it through a 100-mesh sieve, and obtain modified biochar.

[0006] Furthermore, the agricultural and forestry biomass waste mentioned in step (1) includes one or more of the following: sawdust, bark, branches, corn cobs, straw, fruit shells, fruit pomace, distiller's grains, and medicinal residues.

[0007] Further, the calcium salt in step (3) is a mixture of calcium chloride and calcium fluoride in a mass ratio of 11:8.

[0008] Furthermore, the preparation method of the benzylfluorothiazide Fe / Co / Sb complex includes the following steps: I. Benzylfluorothiazide, FeCl3, CoCl2, and Sb(CH3CO2)3 were dissolved in N,N-dimethylformamide at a mass ratio of 100:25:30:18, with a mass-to-volume ratio of 1 g:200 mL for benzylfluorothiazide. The mixture was stirred at 180 rpm for 40-50 min at 65 °C, then transferred to a polytetrafluoroethylene reactor and reacted at 140-170 °C for 6-7 h. After centrifugation at 10000 rpm for 50-60 min, the precipitate was collected to obtain reaction mixture I. II. The reaction mixture I obtained in step I was washed 6 times with N,N-dimethylformamide and deionized water, dried under vacuum to constant weight, placed in a crucible, covered and transferred to a tube furnace, and calcined at 500°C for 2 h at a rate of 2°C / min under an inert argon atmosphere to obtain reaction mixture II. III. Humin and fulvic acid were added to a 50 vol% aqueous ethanol solution at a mass ratio of 1:2 to obtain a mixed solution. The mass-volume ratio of humin to aqueous ethanol solution was 1 g: 30 mL. After the reaction mixture II obtained in step II was naturally cooled to room temperature, it was added to the mixed solution. The mass-volume ratio of reaction mixture II to the mixed solution was 3 g: 200 mL. The mixture was stirred at 25 °C for 2 h and filtered. The precipitate was washed with deionized water until the pH was 6.8-7.2 and dried under vacuum to constant weight to obtain the benzylfluorothiazide Fe / Co / Sb complex.

[0009] Furthermore, the method for preparing the sulfur hybrid includes the following steps: (a) Diaminothioyl and 3-chlorosulfonylbenzoyl chloride were ultrasonicated in water at 150 W for 2 h. The mass ratio of diaminothioyl to 3-chlorosulfonylbenzoyl chloride was 1:1.2. The mixture was stirred in a constant temperature water bath at 60-70℃ for 5-6 h, aged for 15-18 h, and then separated into solid and liquid to obtain precipitate a. (b) Wash the precipitate a obtained in step a with deionized water three times, dry it at 60°C, put it in a vacuum tube furnace, heat it to 400-600°C under vacuum conditions, calcine it under vacuum for 1 h, and cool it to room temperature to obtain the calcined product. (c) Dissolve the calcined product obtained in step b in methanol, put it into a reaction vessel, heat it to 70°C to evaporate the methanol, fill it with nitrogen and seal it, and then react it in an oven at 200°C for 1-2 h to obtain a sulfur hybrid.

[0010] This invention also provides a method for preparing the aforementioned highly efficient activated persulfate composite catalytic material, comprising the following steps: S1: Modified biochar was added to n-hexanol at a mass-to-volume ratio of 5 mg:3 mL. The mixture was sonicated at 150 W for 2 h to obtain suspension S1. The benzylfluorothiazide Fe / Co / Sb complex was dissolved in another portion of n-hexanol at a volume ratio of 0.3 g:80 mL to obtain mixture S1. Mixture S1 and suspension S1 were mixed evenly at a volume ratio of 2:5 and stirred at room temperature for 0.5 h. After reflux heating at 140 °C for 12 h, the mixture was cooled to room temperature and centrifuged at 8000 rpm for 40-50 min. The precipitate was washed three times with ethanol and dried in a vacuum oven at 60 °C to obtain reaction mixture S1. S2: Sodium hydroxide, urea and deionized water were mixed in a mass ratio of 7:12:79 to obtain a mixed solution S2. After cooling at 4°C for 3 h, a sulfur hybrid was added to it. The mass ratio of the sulfur hybrid to the mixed solution S2 was 1:50. The mixture was stirred rapidly at 16000 rpm for 5 min and then stirred at 160 rpm for 2 h to obtain the reaction mixture S2. S3: Add the reaction mixture S1 obtained in step S1 to the reaction mixture S2 obtained in step S2 at a rate of 0.3-0.5 g / s. The mass-volume ratio of reaction mixture S1 to reaction mixture S2 is 1 g: 1.5 mL. Stir evenly and sonicate at 180 W for 10 min, stir at 10000 rpm for 30 min, stir at 100 rpm for 8 h, filter with a polytetrafluoroethylene membrane, and dry at 60℃ for 12 h to obtain a composite catalyst material for activating persulfate.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This invention prepares modified biochar, which exhibits high density of active sites, excellent adsorption capacity, a well-developed microporous structure, and unique surface properties, making it less prone to aggregation. It possesses numerous and uniformly distributed catalytic active sites with a large specific surface area, increasing the effective contact area between the catalytic active sites and persulfate. Furthermore, it enhances mass transfer efficiency and strengthens the interaction among the catalytic active sites, persulfate, and pollutants. This invention also prepares a benzylfluorothiazide Fe / Co / Sb composite, possessing both non-metallic and metallic catalytic activities. It can efficiently activate persulfate and degrade organic pollutants in water, demonstrating high persulfate activation efficiency and significant environmental and economic benefits. The modified biochar, as a carrier for the benzylfluorothiazide Fe / Co / Sb composite, enhances its specific properties and adsorption and catalytic performance. The synergistic effect of the two results in high catalytic efficiency, efficient persulfate activation, and good reusability. This invention prepares a sulfur hybrid compound that synergistically enhances the effect of a benzylfluorothiazide Fe / Co / Sb complex. This compound can activate persulfate separately, exhibiting rapid free radical generation and high catalytic efficiency. The sulfur hybrid compound and the benzylfluorothiazide Fe / Co / Sb complex show good dispersibility on modified biochar, which is beneficial for adsorption and mass transfer during the catalytic reaction, improving catalytic activity and efficiency. It can efficiently enrich organic pollutants in water and rapidly transfer electrons. The combination of the benzylfluorothiazide Fe / Co / Sb complex, sulfur hybrid compound, and modified biochar, with the benzylfluorothiazide Fe / Co / Sb complex containing a transition metal, exhibits an interaction between the transition metal and the modified biochar, ensuring stable loading of the transition metal on the support. This results in high catalytic stability, low metal dissolution rate, and to some extent avoids secondary pollution caused by residual metal in the water. It is also easy to recycle and reuse, reducing costs. The composite catalytic material prepared by this invention is not prone to agglomeration, has a uniform distribution, which is beneficial for adsorption and mass transfer during the catalytic reaction, improving catalytic activity and efficiency. Furthermore, the composite catalytic material is in solid particulate form, making it convenient to use and easy to separate and recycle. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in this 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 for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 The images shown are scanning electron microscope (SEM) images of the modified biochar, benzylfluorothiazide Fe / Co / Sb complex, sulfur hybrid, and composite catalytic material described in Example 1 of this invention. In the images, a is the modified biochar, b is the benzylfluorothiazide Fe / Co / Sb complex, c is the sulfur hybrid, and d is the composite catalytic material. Figure 2These are activation efficiency test graphs of the composite catalytic materials described in Examples 1-3 and Comparative Examples 1-3 of the present invention; Figure 3 These are metal ion dissolution test diagrams of the composite catalytic materials described in Examples 1-3 and Comparative Examples 1-3 of the present invention; Figure 4 These are cycle activity test diagrams of the composite catalytic materials described in Examples 1-3 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0015] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0016] Example 1: This example provides a highly efficient composite catalytic material for activating persulfate, comprising the following components: modified biochar, benzylfluorothiazide Fe / Co / Sb complex, and sulfur hybrid.

[0017] The method for preparing modified biochar described in this embodiment includes the following steps: (1) The corn cob was crushed to 3 cm and dried at 80℃. The corn cob was immersed in 1 mol / L NaOH solution at a solid-liquid ratio of 20 g / L and stirred thoroughly for 24 h. Then it was washed with deionized water until the pH was stable. After that, it was immersed in 1 mol / L HCl solution for 1 h. After washing with deionized water 3 times, it was dried at 60℃ to obtain pretreated biomass waste. (2) The pretreated biomass waste obtained in step (1) was impregnated in a mixed solution of malic acid and sorbitol. The concentrations of malic acid and sorbitol were both 0.5 mol / L. The mass-volume ratio of the pretreated biomass waste to the mixed solution was 1 g: 25 mL. The mixture was shaken at 250 rpm at 30 °C for 24 h. After shaking, the solid phase was collected by filtration, dried at 60 °C, and placed in a reaction vessel and heated to 220 °C. After 2 h, it was cooled to 40 °C to obtain the primary modified product. (3) The calcium salt and the primary modified product obtained in step (2) were mixed evenly at a mass ratio of 1:15. The calcium salt was a mixture of calcium chloride and calcium fluoride at a mass ratio of 11:8. The mixture was placed in a tube furnace with an inert gas atmosphere and calcined at 650°C for 2 hours under an oxygen-free environment, with the temperature increased from room temperature to 650°C at a heating rate of 5°C / min. After calcination, the mixture was allowed to cool naturally to room temperature and then pulverized through a 100-mesh sieve to obtain modified biochar. The scanning electron microscope image is shown below. Figure 1As shown, the modified biochar prepared in this embodiment contains a large number of micropores, has a large specific surface area, strong adsorption capacity, and can load catalytic active substances to improve catalytic efficiency.

[0018] The preparation method of the benzylfluorothiazide Fe / Co / Sb complex described in this embodiment includes the following steps: I. Benzylfluorothiazide, FeCl3, CoCl2, and Sb(CH3CO2)3 were dissolved in N,N-dimethylformamide at a mass ratio of 100:25:30:18, with a mass-to-volume ratio of 1 g:200 mL for benzylfluorothiazide. The mixture was stirred at 180 rpm for 50 min at 65 °C, then transferred to a polytetrafluoroethylene reactor and reacted at 170 °C for 7 h. After centrifugation at 10,000 rpm for 60 min, the precipitate was collected to obtain reaction mixture I. II. The reaction mixture I obtained in step I was washed 6 times with N,N-dimethylformamide and deionized water, dried under vacuum to constant weight, placed in a crucible, covered and transferred to a tube furnace, and calcined at 500°C for 2 h at a rate of 2°C / min under an inert argon atmosphere to obtain reaction mixture II. III. Humin and fulvic acid were added to a 50 vol% ethanol aqueous solution at a mass ratio of 1:2 to obtain a mixed solution. The mass-volume ratio of humin to the ethanol aqueous solution was 1 g: 30 mL. Reaction mixture II obtained in step II was naturally cooled to room temperature and then added to the mixed solution. The mass-volume ratio of reaction mixture II to the mixed solution was 3 g: 200 mL. The mixture was stirred at 25 °C for 2 h and filtered. The precipitate was washed with deionized water until the pH reached 7.2 and dried under vacuum to constant weight to obtain the benzylfluorothiazide Fe / Co / Sb complex. The scanning electron microscope image is shown below. Figure 1 As shown, the benzylfluorothiazide Fe / Co / Sb composite prepared in this embodiment exhibits a non-uniform layered structure.

[0019] The method for preparing the sulfur hybrid described in this embodiment includes the following steps: (a) Diaminothioyl and 3-chlorosulfonylbenzoyl chloride were ultrasonicated in water at 150 W for 2 h. The mass ratio of diaminothioyl to 3-chlorosulfonylbenzoyl chloride was 1:1.2. The mixture was stirred in a constant temperature water bath at 70 °C for 6 h, aged for 18 h, and then the solid and liquid were separated to obtain precipitate a. (b) Wash the precipitate a obtained in step a three times with deionized water, dry it at 60°C, put it in a vacuum tube furnace, heat it to 600°C under vacuum conditions, calcine it under vacuum for 1 h, and cool it to room temperature to obtain the calcined product. (c) The calcined product obtained in step b was dissolved in methanol, placed in a reaction vessel, heated to 70°C to evaporate the methanol, sealed with nitrogen, and reacted in an oven at 200°C for 2 h to obtain a sulfur hybrid. The scanning electron microscope image is shown below. Figure 1 As shown, the sulfur hybrid obtained in this embodiment is distributed in particulate form.

[0020] This embodiment also provides a method for preparing the highly efficient activated persulfate composite catalytic material, including the following steps: S1: Modified biochar was added to n-hexanol at a mass-to-volume ratio of 5 mg:3 mL. The mixture was sonicated at 150 W for 2 h to obtain suspension S1. The benzylfluorothiazide Fe / Co / Sb complex was dissolved in another portion of n-hexanol at a volume ratio of 0.3 g:80 mL to obtain mixture S1. Mixture S1 and suspension S1 were mixed evenly at a volume ratio of 2:5 and stirred at room temperature for 0.5 h. After reflux heating at 140 °C for 12 h, the mixture was cooled to room temperature and centrifuged at 8000 rpm for 50 min. The precipitate was washed three times with ethanol and dried in a vacuum oven at 60 °C to obtain reaction mixture S1. S2: Sodium hydroxide, urea and deionized water were mixed in a mass ratio of 7:12:79 to obtain a mixed solution S2. After cooling at 4°C for 3 h, a sulfur hybrid was added to it. The mass ratio of the sulfur hybrid to the mixed solution S2 was 1:50. The mixture was stirred rapidly at 16000 rpm for 5 min and then stirred at 160 rpm for 2 h to obtain the reaction mixture S2. S3: Add the reaction mixture S1 obtained in step S1 to the reaction mixture S2 obtained in step S2 at a rate of 0.5 g / s. The mass-to-volume ratio of reaction mixture S1 to reaction mixture S2 is 1 g: 1.5 mL. Stir until homogeneous, sonicate at 180 W for 10 min, stir at 10000 rpm for 30 min, and stir at 100 rpm for 8 h. Filter using a polytetrafluoroethylene membrane and dry at 60℃ for 12 h to obtain a highly efficient composite catalyst for activating persulfate. The scanning electron microscope image is shown below. Figure 1 As shown, the composite catalyst material prepared in this embodiment is granular, uniform in size, relatively dispersed, and without agglomeration.

[0021] Example 2: This example provides a highly efficient composite catalytic material for activating persulfate, comprising the following components: modified biochar, benzylfluorothiazide Fe / Co / Sb complex, and sulfur hybrid.

[0022] The method for preparing modified biochar described in this embodiment includes the following steps: (1) The corn stalks were crushed to 2 cm and dried at 80℃. The corn stalks were then immersed in a 1 mol / L NaOH solution at a solid-liquid ratio of 20 g / L and stirred thoroughly for 24 h. Then, they were washed with deionized water until the pH stabilized. After that, they were immersed in a 1 mol / L HCl solution for 1 h and washed three times with deionized water. Finally, they were dried at 60℃ to obtain pretreated biomass waste. (2) The pretreated biomass waste obtained in step (1) was impregnated in a mixed solution of malic acid and sorbitol. The concentrations of malic acid and sorbitol were both 0.5 mol / L. The mass-volume ratio of the pretreated biomass waste to the mixed solution was 1 g: 25 mL. The mixture was shaken at 250 rpm at 30 °C for 24 h. After shaking, the solid phase was collected by filtration, dried at 60 °C, and placed in a reaction vessel and heated to 220 °C. After 2 h, it was cooled to 40 °C to obtain the primary modified product. (3) Mix the calcium salt with the primary modified product obtained in step (2) at a mass ratio of 1:15. The calcium salt is a mixture of calcium chloride and calcium fluoride at a mass ratio of 11:8. Place it in a tube furnace with an inert gas atmosphere and calcine it at 550°C for 2 hours under an oxygen-free environment, starting from room temperature and increasing the temperature at a rate of 5°C / min. After calcination, allow it to cool naturally to room temperature and crush it through a 100-mesh sieve to obtain modified biochar.

[0023] The preparation method of the benzylfluorothiazide Fe / Co / Sb complex described in this embodiment includes the following steps: I. Benzylfluorothiazide, FeCl3, CoCl2, and Sb(CH3CO2)3 were dissolved in N,N-dimethylformamide at a mass ratio of 100:25:30:18, with a mass-to-volume ratio of 1 g:200 mL for benzylfluorothiazide. The mixture was stirred at 180 rpm for 40 min at 65 °C, transferred to a polytetrafluoroethylene reactor, and reacted at 140 °C for 6 h. After centrifugation at 10,000 rpm for 50 min, the precipitate was collected to obtain reaction mixture I. II. The reaction mixture I obtained in step I was washed 6 times with N,N-dimethylformamide and deionized water, dried under vacuum to constant weight, placed in a crucible, covered and transferred to a tube furnace, and calcined at 500°C for 2 h at a rate of 2°C / min under an inert argon atmosphere to obtain reaction mixture II. III. Humin and fulvic acid were added to a 50 vol% aqueous ethanol solution at a mass ratio of 1:2 to obtain a mixed solution. The mass-volume ratio of humin to aqueous ethanol solution was 1 g: 30 mL. The reaction mixture II obtained in step II was naturally cooled to room temperature and then added to the mixed solution. The mass-volume ratio of reaction mixture II to the mixed solution was 3 g: 200 mL. The mixture was stirred at 25 °C for 2 h and filtered. The precipitate was washed with deionized water until the pH reached 6.8 and dried under vacuum to constant weight to obtain the benzylfluorothiazide Fe / Co / Sb complex.

[0024] The method for preparing the sulfur hybrid described in this embodiment includes the following steps: (a) Diaminothioyl and 3-chlorosulfonylbenzoyl chloride were ultrasonicated in water at 150 W for 2 h. The mass ratio of diaminothioyl to 3-chlorosulfonylbenzoyl chloride was 1:1.2. The mixture was stirred in a constant temperature water bath at 60℃ for 5 h, aged for 15 h, and then the solid and liquid were separated to obtain precipitate a. (b) Wash the precipitate a obtained in step a with deionized water three times, dry it at 60°C, put it in a vacuum tube furnace, heat it to 400°C under vacuum conditions, calcine it under vacuum for 1 h, and cool it to room temperature to obtain the calcined product. (c) Dissolve the calcined product obtained in step b in methanol, put it into a reaction vessel, heat it to 70°C to evaporate the methanol, fill it with nitrogen and seal it, and then react it in an oven at 200°C for 1 h to obtain a sulfur hybrid.

[0025] This embodiment also provides a method for preparing the highly efficient activated persulfate composite catalytic material, including the following steps: S1: Modified biochar was added to n-hexanol at a mass-to-volume ratio of 5 mg:3 mL. The mixture was sonicated at 150 W for 2 h to obtain suspension S1. The benzylfluorothiazide Fe / Co / Sb complex was dissolved in another portion of n-hexanol at a volume ratio of 0.3 g:80 mL to obtain mixture S1. Mixture S1 and suspension S1 were mixed evenly at a volume ratio of 2:5 and stirred at room temperature for 0.5 h. After reflux heating at 140 °C for 12 h, the mixture was cooled to room temperature and centrifuged at 8000 rpm for 40 min. The precipitate was washed three times with ethanol and dried in a vacuum oven at 60 °C to obtain reaction mixture S1. S2: Sodium hydroxide, urea and deionized water were mixed in a mass ratio of 7:12:79 to obtain a mixed solution S2. After cooling at 4°C for 3 h, a sulfur hybrid was added to it. The mass ratio of the sulfur hybrid to the mixed solution S2 was 1:50. The mixture was stirred rapidly at 16000 rpm for 5 min and then stirred at 160 rpm for 2 h to obtain the reaction mixture S2. S3: Add the reaction mixture S1 obtained in step S1 to the reaction mixture S2 obtained in step S2 at a rate of 0.3 g / s. The mass-volume ratio of reaction mixture S1 to reaction mixture S2 is 1 g: 1.5 mL. Stir evenly and sonicate at 180 W for 10 min, stir at 10000 rpm for 30 min, stir at 100 rpm for 8 h, filter with a polytetrafluoroethylene membrane, and dry at 60℃ for 12 h to obtain a composite catalyst material for activating persulfate.

[0026] Example 3: This example provides a highly efficient composite catalytic material for activating persulfate, comprising the following components: modified biochar, benzylfluorothiazide Fe / Co / Sb complex, and sulfur hybrid.

[0027] The method for preparing modified biochar described in this embodiment includes the following steps: (1) Crush peanut shells to 2.5 cm, dry them at 80℃, and immerse them in 1 mol / L NaOH solution at a solid-liquid ratio of 20 g / L. Stir them thoroughly for 24 h, then wash them with deionized water until the pH is stable. After that, immerse them in 1 mol / L HCl solution for 1 h, wash them three times with deionized water, and dry them at 60℃ to obtain pretreated biomass waste. (2) The pretreated biomass waste obtained in step (1) was impregnated in a mixed solution of malic acid and sorbitol. The concentrations of malic acid and sorbitol were both 0.5 mol / L. The mass-volume ratio of the pretreated biomass waste to the mixed solution was 1 g: 25 mL. The mixture was shaken at 250 rpm at 30 °C for 24 h. After shaking, the solid phase was collected by filtration, dried at 60 °C, and placed in a reaction vessel and heated to 220 °C. After 2 h, it was cooled to 40 °C to obtain the primary modified product. (3) Mix the calcium salt with the primary modified product obtained in step (2) at a mass ratio of 1:15. The calcium salt is a mixture of calcium chloride and calcium fluoride at a mass ratio of 11:8. Place it in a tube furnace with an inert gas atmosphere and calcine it at 600°C from room temperature for 2 hours under an oxygen-free environment at a heating rate of 5°C / min. After calcination, allow it to cool naturally to room temperature and crush it through a 100-mesh sieve to obtain modified biochar.

[0028] The preparation method of the benzylfluorothiazide Fe / Co / Sb complex described in this embodiment includes the following steps: I. Benzylfluorothiazide, FeCl3, CoCl2, and Sb(CH3CO2)3 were dissolved in N,N-dimethylformamide at a mass ratio of 100:25:30:18, with a mass-to-volume ratio of 1 g:200 mL for benzylfluorothiazide. The mixture was stirred at 180 rpm for 45 min at 65 °C, then transferred to a polytetrafluoroethylene reactor and reacted at 160 °C for 6.5 h. After centrifugation at 10,000 rpm for 55 min, the precipitate was collected to obtain reaction mixture I. II. The reaction mixture I obtained in step I was washed 6 times with N,N-dimethylformamide and deionized water, dried under vacuum to constant weight, placed in a crucible, covered and transferred to a tube furnace, and calcined at 500°C for 2 h at a rate of 2°C / min under an inert argon atmosphere to obtain reaction mixture II. III. Humin and fulvic acid were added to a 50 vol% aqueous ethanol solution at a mass ratio of 1:2 to obtain a mixed solution. The mass-volume ratio of humin to aqueous ethanol solution was 1 g: 30 mL. The reaction mixture II obtained in step II was naturally cooled to room temperature and then added to the mixed solution. The mass-volume ratio of reaction mixture II to the mixed solution was 3 g: 200 mL. The mixture was stirred at 25 °C for 2 h and filtered. The precipitate was washed with deionized water until the pH reached 7 and dried under vacuum to constant weight to obtain the benzylfluorothiazide Fe / Co / Sb complex.

[0029] The method for preparing the sulfur hybrid described in this embodiment includes the following steps: (a) Diaminothioyl and 3-chlorosulfonylbenzoyl chloride were ultrasonicated in water at 150 W for 2 h. The mass ratio of diaminothioyl to 3-chlorosulfonylbenzoyl chloride was 1:1.2. The mixture was stirred in a constant temperature water bath at 65℃ for 5.5 h, aged for 16 h, and the solid and liquid were separated to obtain precipitate a. (b) Wash the precipitate a obtained in step a with deionized water three times, dry it at 60°C, put it in a vacuum tube furnace, heat it to 500°C under vacuum conditions, calcine it under vacuum for 1 h, and cool it to room temperature to obtain the calcined product. (c) Dissolve the calcined product obtained in step b in methanol, put it into a reaction vessel, heat it to 70°C to evaporate the methanol, fill it with nitrogen and seal it, and then react it in an oven at 200°C for 1.5 h to obtain a sulfur hybrid.

[0030] This embodiment also provides a method for preparing the highly efficient activated persulfate composite catalytic material, including the following steps: S1: Modified biochar was added to n-hexanol at a mass-to-volume ratio of 5 mg:3 mL. The mixture was sonicated at 150 W for 2 h to obtain suspension S1. The benzylfluorothiazide Fe / Co / Sb complex was dissolved in another portion of n-hexanol at a volume ratio of 0.3 g:80 mL to obtain mixture S1. Mixture S1 and suspension S1 were mixed evenly at a volume ratio of 2:5 and stirred at room temperature for 0.5 h. After reflux heating at 140 °C for 12 h, the mixture was cooled to room temperature and centrifuged at 8000 rpm for 40-50 min. The precipitate was washed three times with ethanol and dried in a vacuum oven at 60 °C to obtain reaction mixture S1. S2: Sodium hydroxide, urea and deionized water were mixed in a mass ratio of 7:12:79 to obtain a mixed solution S2. After cooling at 4°C for 3 h, a sulfur hybrid was added to it. The mass ratio of the sulfur hybrid to the mixed solution S2 was 1:50. The mixture was stirred rapidly at 16000 rpm for 5 min and then stirred at 160 rpm for 2 h to obtain the reaction mixture S2. S3: Add the reaction mixture S1 obtained in step S1 to the reaction mixture S2 obtained in step S2 at a rate of 0.4 g / s. The mass-volume ratio of reaction mixture S1 to reaction mixture S2 is 1 g: 1.5 mL. Stir evenly and sonicate at 180 W for 10 min, stir at 10000 rpm for 30 min, stir at 100 rpm for 8 h, filter with a polytetrafluoroethylene membrane, and dry at 60℃ for 12 h to obtain a composite catalyst material for activating persulfate.

[0031] The difference between Comparative Example 1 and Example 1 lies only in that the preparation of the modified biochar includes the following steps: corn cobs are crushed to 3 cm, dried at 80°C, and agricultural and forestry biomass waste is immersed in a 1 mol / L NaOH solution at a solid-liquid ratio of 20 g / L, stirred thoroughly for 24 h, then washed with deionized water until pH stabilized, and then immersed in a 1 mol / L HCl solution, washed three times with deionized water, and dried at 60°C to obtain pretreated biomass waste; calcium salt is mixed evenly with the pretreated biomass waste at a mass ratio of 1:15, the calcium salt being calcium chloride and calcium fluoride mixed evenly at a mass ratio of 11:8, and placed in a tube furnace with an inert gas atmosphere, and calcined at 650°C for 2 h under an oxygen-free environment by heating from room temperature at a heating rate of 5°C / min, and then naturally cooled to room temperature after calcination, crushed and passed through a 100-mesh sieve to obtain modified biochar.

[0032] The difference between Comparative Example 2 and Example 1 lies only in the preparation method of the benzylfluorothiazide Fe / Co / Sb composite, which includes the following steps: benzylfluorothiazide, FeCl3, CoCl2, and Sb(CH3CO2)3 are dissolved in N,N-dimethylformamide at a mass ratio of 100:25:30:18, with a mass-to-volume ratio of 1 g:200 mL for benzylfluorothiazide and N,N-dimethylformamide. The mixture is stirred at 180 rpm for 50 min at 65 °C, transferred to a polytetrafluoroethylene reactor, reacted at 170 °C for 7 h, centrifuged at 10,000 rpm for 60 min, and the precipitate is collected to obtain reaction mixture I. Reaction mixture I is washed 6 times with N,N-dimethylformamide and deionized water, dried under vacuum to constant weight, placed in a crucible, covered, and transferred to a tube furnace. Under an inert argon atmosphere, the mixture is heated to 500 °C at a rate of 2 °C / min and calcined for 2 h. After cooling to room temperature, the benzylfluorothiazide Fe / Co / Sb composite is obtained.

[0033] The difference between Comparative Example 3 and Example 1 lies only in the preparation method of the sulfur hybrid, which includes the following steps: Diaminothioyl and 3-chlorosulfonylbenzoyl chloride are ultrasonically dissolved in water at 150 W for 2 h, with a mass ratio of 5:1. The mixture is stirred in a constant temperature water bath at 70°C for 2 h, aged for 10 h, and then separated into solid and liquid phases to obtain precipitate a. Precipitate a is washed three times with deionized water, dried at 60°C, placed in a vacuum tube furnace, heated to 300°C under vacuum conditions, calcined under vacuum for 1 h, and cooled to room temperature to obtain the calcined product. The calcined product is dissolved in methanol, placed in a reaction vessel, heated to 70°C to evaporate the methanol, sealed with nitrogen, and reacted in an oven at 200°C for 2 h to obtain the sulfur hybrid.

[0034] Experimental Example 1: 5 mg of the composite catalyst material prepared in Examples 1-3 and Comparative Examples 1-3 was placed in 100 mL of bisphenol A solution. The pH was adjusted to 6.65 with hydrochloric acid and sodium hydroxide, and the concentration of bisphenol A was 20 mg / L. After sonication at 120 W for 30 min, 20 mg of potassium persulfate composite salt was added to initiate the reaction. The mixture was placed on a constant temperature water bath shaker at 120 r / min, with the temperature set at 25℃. 5 mL samples were taken every 2 min and added to a centrifuge tube containing 2 mL of methanol. The mixture was mixed thoroughly and filtered through a 0.22 μm microporous membrane. The absorbance was measured using a UV-Vis spectrophotometer. Each experiment was repeated three times, and the average value was taken to calculate the bisphenol A degradation rate. Bisphenol A degradation rate (%) = [(C0-C t ) / C0]×100%, C t C is the current concentration of bisphenol A, and C0 is the initial concentration of bisphenol A. The results are as follows: Figure 2 As shown.

[0035] Figure 2The results showed that the composite catalytic materials prepared in Examples 1-3 and Comparative Examples 1-3 all achieved a degradation rate of over 95% for bisphenol A within 8 minutes, with the degradation rate of Examples 1-3 reaching over 99%. The degradation effect of Examples 1-3 was better than that of Comparative Examples 1-3, indicating that the composite catalytic material for highly efficient activation of persulfate of the present invention can efficiently catalyze the activation of persulfate, thereby efficiently degrading pollutants in water, verifying the high efficiency of the catalytic material.

[0036] Experimental Example 2: 5 mg of the composite catalyst prepared in Examples 1-3 and Comparative Examples 1-3 was placed in 100 mL of phenol solution (pH 6.65, phenol concentration 20 mg / L). After sonication at 120 W for 30 min, 10 mg of potassium persulfate and 10 mg of sodium persulfate were added to initiate the reaction. The mixture was placed in a constant temperature water bath at 120 r / min and the temperature was set to 25℃. After 30 min, 5 mL of the mixture was taken and added to a centrifuge tube containing 2 mL of methanol. The mixture was mixed thoroughly, and the resulting reaction solution was filtered through a 0.22 μm microporous membrane. The Fe content was determined using an ion chromatograph. 3+ Co 2+ and Sb 3+ The concentration, the results are as follows Figure 3 As shown.

[0037] Figure 3 The results showed that the metal ion concentrations in Examples 1-3 and Comparative Examples 1-3 were all low, indicating that the composite catalytic material for activating persulfate of the present invention has good stability, low metal ion dissolution rate, and is not prone to secondary pollution.

[0038] Experimental Example 3: The composite catalytic materials prepared in Examples 1-3 and Comparative Examples 1-3 were recycled four times. The experimental conditions for each recycling were the same as those in Example 1, except that the bisphenol A solution was replaced with 100 mL of 0.2 mmol / L methyl orange solution, and sodium persulfate was used instead of potassium persulfate. Each recycling was carried out until the methyl orange degradation rate reached 99.99%. After each recycling, the material was filtered, washed three times with ethanol, three times with deionized water, dried at 60°C, and recovered. After four recycling cycles, the material was reused, and the methyl orange removal rate was recorded after 8 min. The results are shown below. Figure 4 As shown.

[0039] Figure 4 The results showed that after four cycles, the composite catalytic materials prepared in Examples 1-3 and Comparative Examples 1-3 still had high catalytic efficiency, with a degradation rate of over 95% for methyl orange within 8 minutes, indicating that the composite catalytic material for activating persulfate of the present invention has good reusability.

[0040] Example 4: 5 mg of the composite catalyst material prepared in Examples 1-3 and Comparative Examples 1-3 was placed in 100 mL of sulfamethoxazole solution (sulfamethoxazole concentration: 20 mg / L). The pH was adjusted with hydrochloric acid and sodium hydroxide. After sonication at 120 W for 30 min, 20 mg of potassium persulfate was added to initiate the reaction. The mixture was placed on a constant temperature water bath shaker at 120 r / min. For each example and comparative example, the pH was set to 6.65, and the temperatures were 15, 25, 40, and 60 °C. Another group was set at 25 °C with pH values ​​of 2, 4, 7, 11, and 13. After 8 min, 5 mL of the sample was taken and added to a centrifuge tube containing 2 mL of methanol. The mixture was thoroughly mixed, filtered through a 0.22 μm microporous membrane, and the absorbance was measured using a UV-Vis spectrophotometer. Each experiment was repeated three times, and the average value was taken to calculate the sulfamethoxazole degradation rate. The results are shown in Table 1.

[0041] Table 1. Degradation rate of sulfamethoxazole by catalytic materials at different temperatures and pH values

[0042] Table 1 shows that, under different temperatures and pH values, the degradation rate of sulfamethoxazole by the composite catalytic materials prepared in Example 1 and Comparative Example 1 decreased less, indicating that the catalytic activity of the composite catalytic material for activating persulfate of the present invention is not limited by temperature and pH, has a wide range of applications, and high catalytic efficiency.

[0043] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0044] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A composite catalytic material for highly efficient activation of persulfate, characterized in that, It includes the following components: modified biochar, benzylfluorothiazide Fe / Co / Sb complex, and sulfur hybrids; The method for preparing the modified biochar includes the following steps: (1) The agricultural and forestry biomass waste was crushed to 2-3 cm and dried at 80℃. The agricultural and forestry biomass waste was immersed in 1 mol / L NaOH solution at a solid-liquid ratio of 20 g / L and stirred thoroughly for 24 h. Then it was washed with deionized water until the pH was stable. After that, it was immersed in 1 mol / L HCl solution for 1 h. After washing with deionized water 3 times, it was dried at 60℃ to obtain pretreated biomass waste. (2) The pretreated biomass waste obtained in step (1) was impregnated in a mixed solution of malic acid and sorbitol. The concentrations of malic acid and sorbitol were both 0.5 mol / L. The mass-volume ratio of the pretreated biomass waste to the mixed solution was 1 g: 25 mL. The mixture was shaken at 250 rpm at 30℃ for 24 h. After shaking, the solid phase was collected by filtration, dried at 60℃, and put into a reaction vessel and heated to 220℃. After 2 h, it was cooled to 40℃ to obtain the primary modified product. (3) Mix the calcium salt with the primary modified product obtained in step (2) at a mass ratio of 1:15, place it in a tube furnace with an inert gas atmosphere, and calcine it at a temperature of 5℃ / min from room temperature to 550-650℃ for 2 h in an oxygen-free environment. After calcination, cool it naturally to room temperature, crush it through a 100-mesh sieve, and obtain modified biochar. The preparation method of the benzylfluorothiazide Fe / Co / Sb complex includes the following steps: I. Benzylfluorothiazide, FeCl3, CoCl2, and Sb(CH3CO2)3 were dissolved in N,N-dimethylformamide at a mass ratio of 100:25:30:18, with a mass-to-volume ratio of 1 g:200 mL for benzylfluorothiazide to N,N-dimethylformamide. The mixture was stirred at 180 rpm for 40-50 min at 65 °C, then transferred to a polytetrafluoroethylene reactor and reacted at 140-170 °C for 6-7 h. After centrifugation at 10000 rpm for 50-60 min, the precipitate was collected to obtain reaction mixture I. II. The reaction mixture I obtained in step I was washed 6 times with N,N-dimethylformamide and deionized water, dried under vacuum to constant weight, placed in a crucible, covered and transferred to a tube furnace, and calcined at 500°C for 2 h at a rate of 2°C / min under an inert argon atmosphere to obtain reaction mixture II. III. Humin and fulvic acid were added to a 50 vol% aqueous ethanol solution at a mass ratio of 1:2 to obtain a mixed solution. The mass-volume ratio of humin to aqueous ethanol solution was 1 g: 30 mL. After the reaction mixture II obtained in step II was naturally cooled to room temperature, it was added to the mixed solution. The mass-volume ratio of reaction mixture II to the mixed solution was 3 g: 200 mL. The mixture was stirred at 25 °C for 2 h and filtered. The precipitate was washed with deionized water until the pH was 6.8-7.2 and dried under vacuum to constant weight to obtain the benzylfluorothiazide Fe / Co / Sb complex. The method for preparing the sulfur hybrid includes the following steps: (a) Diaminothioyl and 3-chlorosulfonylbenzoyl chloride were ultrasonicated in water at 150 W for 2 h. The mass ratio of diaminothioyl to 3-chlorosulfonylbenzoyl chloride was 1:1.

2. The mixture was stirred in a constant temperature water bath at 60-70℃ for 5-6 h, aged for 15-18 h, and then separated into solid and liquid to obtain precipitate a. (b) Wash the precipitate a obtained in step a with deionized water three times, dry it at 60°C, put it in a vacuum tube furnace, heat it to 400-600°C under vacuum conditions, calcine it under vacuum for 1 h, and cool it to room temperature to obtain the calcined product. (c) Dissolve the calcined product obtained in step b in methanol, put it into a reaction vessel, heat it to 70°C to evaporate the methanol, fill it with nitrogen and seal it, and then react it in an oven at 200°C for 1-2 h to obtain the sulfur hybrid.

2. The composite catalytic material for highly efficient activation of persulfate according to claim 1, characterized in that, The agricultural and forestry biomass waste mentioned in step (1) includes one or more of the following: sawdust, bark, branches, corn cobs, straw, fruit shells, fruit pomace, distiller's grains, and medicinal residues.

3. The composite catalytic material for highly efficient activation of persulfate according to claim 2, characterized in that, The calcium salt in step (3) is a mixture of calcium chloride and calcium fluoride in a mass ratio of 11:

8.

4. The method for preparing the highly efficient activated persulfate composite catalytic material according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Modified biochar was added to n-hexanol at a mass-to-volume ratio of 5 mg:3 mL. The mixture was sonicated at 150 W for 2 h to obtain suspension S1. The benzylfluorothiazide Fe / Co / Sb complex was dissolved in another portion of n-hexanol at a volume ratio of 0.3 g:80 mL to obtain mixture S1. Mixture S1 and suspension S1 were mixed evenly at a volume ratio of 2:5 and stirred at room temperature for 0.5 h. After reflux heating at 140 °C for 12 h, the mixture was cooled to room temperature and centrifuged at 8000 rpm for 40-50 min. The precipitate was washed three times with ethanol and dried in a vacuum oven at 60 °C to obtain reaction mixture S1. S2: Sodium hydroxide, urea and deionized water were mixed in a mass ratio of 7:12:79 to obtain a mixed solution S2. After cooling at 4°C for 3 h, a sulfur hybrid was added to it. The mass ratio of the sulfur hybrid to the mixed solution S2 was 1:

50. The mixture was stirred rapidly at 16000 rpm for 5 min and then stirred at 160 rpm for 2 h to obtain the reaction mixture S2. S3: Add the reaction mixture S1 obtained in step S1 to the reaction mixture S2 obtained in step S2 at a rate of 0.3-0.5 g / s. The mass-volume ratio of reaction mixture S1 to reaction mixture S2 is 1 g: 1.5 mL. Stir evenly and sonicate at 180 W for 10 min, stir at 10000 rpm for 30 min, stir at 100 rpm for 8 h, filter using a polytetrafluoroethylene membrane, and dry at 60℃ for 12 h to obtain a composite catalyst material for activating persulfate.

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