Catalyst preparation method, catalyst and full-spectrum response dioxin degradation method

Abstract

The invention discloses a catalyst preparation method, a catalyst and a full-spectrum response dioxin degradation method. The catalyst preparation method comprises the following steps: dropwise adding TBOT into ethanol, stirring, dropwise adding ethanol, and stirring to form a first solution; drying the first solution to obtain a solid precursor; adding a doping agent into the solid precursor, roasting and naturally cooling; then washing to obtain an atom-doped TiO2 catalyst substrate; immersing into a saturated calcium hydroxide solution, stirring to obtain a uniform suspension, heating, cooling, collecting a precipitate, washing, and drying; carrying out alkali removal treatment and filtering to obtain a filtered substance; and washing the filtrate by using deionized water and ethanol, and drying to obtain the m-TiO2atCaTiO3 catalyst. According to the application, the catalyst is optimized, and the absorption band is widened, so that the performance of photocatalytic degradation of dioxin is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of environmental treatment of dioxins, and specifically relates to a catalyst preparation method, a catalyst and a dioxin degradation method with full spectrum response. Background Art

[0002] Dioxins are a type of pollutants produced by human production activities. They come from a variety of sources, including solid waste incineration, chemical manufacturing, metal smelting, and biochemical processes. Among them, solid waste incineration is the main source of dioxin emissions. The chemical properties of dioxins are extremely stable and not easy to decompose in the environment. At the same time, their metabolism in the human body is very slow. Since dioxins are significantly fat-soluble, they tend to accumulate in adipose tissue. In addition, dioxins also pose a serious threat to human health due to their potential teratogenicity, carcinogenicity, and mutagenicity, the so-called "three-hazard" toxicity [see Wang Xinge, Li Na, Han Yingnan, et al. Research progress on the mechanism of immunotoxicity caused by dioxins and dioxin-like pollutants [J]. Journal of Ecotoxicology, 2023, 18(01): 138-148].

[0003] Therefore, developing effective dioxin degradation technologies to mitigate their negative impacts on the environment and public health has become a focus and challenge of current research.

[0004] Although there are various methods for dioxin degradation, including high-temperature pyrolysis, chemical treatment, mechanochemical method, biodegradation and low-temperature pyrolysis technology [see Xie Danping, Han Jinglei, Fu Jianping, et al. Review and Development Outlook of Dioxin Pollution Prevention and Control in 2023 [J]. China Environmental Protection Industry, 2024, (05): 36-39], there are still some limitations that hinder the application and promotion of these technologies.

[0005] Although high-temperature pyrolysis technology has shown remarkable efficiency in dioxin degradation, its high energy consumption and potential secondary pollution problems limit its widespread use in practical applications.

[0006] Selective catalytic oxidation (SCO) technology enhances the degradation efficiency by improving the performance of the catalyst. However, the cost of the catalyst and its stability in long-term operation are still urgent issues to be addressed.

[0007] Low-temperature pyrolysis technology has attracted attention for its low energy consumption and environmental friendliness, but it may lead to the resynthesis of dioxins during the treatment process, thereby increasing the toxicity of dioxins in the gas phase. This problem needs to be controlled through technological improvements.

[0008] Biodegradation technology is seen as a promising alternative due to its environmental compatibility and low energy consumption, but its complex treatment process and long treatment cycle limit its application in large-scale treatment.

[0009] Photocatalytic degradation technology is a sustainable treatment method with high environmental compatibility. It relies on the excitation of photons on catalysts to produce strong oxidizing hydroxyl radicals (•OH), which can effectively degrade dioxins. The advantages of this technology are its simple operation process, zero energy consumption, and the ability to use natural light for photocatalytic degradation of dioxins, which fully reflects the sustainable concept of green chemistry and therefore has broad application prospects. However, current photocatalytic technology still faces several challenges in practical application: including the high cost of photocatalysts, limited spectral response range, and relatively low degradation efficiency. Summary of the invention

[0010] In order to overcome the deficiencies of the prior art, the present application provides a dioxin degradation method, a catalyst and a preparation method thereof with full spectrum response, so as to solve the main problems in the photocatalytic degradation of dioxins technology, including insufficient degradation efficiency, limited spectral response range and high catalyst preparation cost.

[0011] In order to achieve the above objectives, this application adopts the following technical solutions: A method for preparing a catalyst, wherein the catalyst is used to degrade dioxins, the method comprising: Add TBOT dropwise into ethanol, then stir at 50-60° C., then add ethanol dropwise, and continue stirring for 2-4 hours to form a first solution; Drying the first solution in an oven to obtain a solid precursor; Adding a dopant to the solid precursor, followed by calcination, and then naturally cooling; After natural cooling, the TiO2 was washed with deionized water and ethanol to obtain the atomically doped TiO2. 2 Catalyst substrate; The atoms doped TiO 2 The catalyst substrate is immersed in a saturated calcium hydroxide solution and stirred to obtain a uniform suspension; The uniform suspension is heated at 150-180° C. for 10-14 hours, and after cooling, a precipitate is collected and washed with deionized water and ethanol, and then the washed precipitate is dried; The dried precipitate is subjected to a de-alkali treatment and filtered to obtain a filtrate; and The filtrate was washed with deionized water and ethanol and dried to obtain m-TiO 2 @CaTiO 3 Catalyst, wherein m represents a heteroatom.

[0012] Furthermore, the dopant includes at least one of sodium borohydride, melamine, ammonium dihydrogen phosphate and thiourea.

[0013] Furthermore, m is any one of an O atom, a N atom, a P atom and a S atom.

[0014] Further, the de-alkali treatment comprises: The dried precipitate was dispersed in a solution containing 0.1 M hydrochloric acid; performing sonication; and Mechanical stirring is performed to remove excess alkali.

[0015] In addition, the present application also provides a catalyst, which is used for degrading dioxins and is prepared by the above-mentioned catalyst preparation method.

[0016] Furthermore, the catalyst comprises O-TiO 2 @CaTiO 3 、N-TiO 2 @CaTiO 3 、P-TiO 2 @CaTiO 3 and S-TiO 2 @CaTiO 3 At least one of .

[0017] In addition, the present application also provides a dioxin degradation method with full spectrum response, including: Passing an oxygen source into the dioxin aqueous solution; adding the catalyst prepared according to the above catalyst preparation method into the dioxin aqueous solution; and The solution is stirred under light conditions to degrade dioxins in the dioxin aqueous solution.

[0018] Furthermore, it also includes: Persulfate is added as an additive to the aqueous dioxin solution before stirring under light conditions.

[0019] Furthermore, the persulfate includes at least one of ammonium persulfate, potassium persulfate, calcium persulfate and sodium persulfate.

[0020] Further, the temperature during the degradation process is controlled to be 10-40°C; The oxygen source is air or oxygen; The light source of the lighting condition includes at least one of an LED lamp, a xenon lamp, a mercury lamp and natural light.

[0021] Compared with the prior art, this application has the following advantages: The present application provides a catalyst preparation method, a catalyst and a dioxin degradation method with full spectrum response. First, the catalyst is optimized to broaden its absorption spectrum of light waves, thereby improving the utilization rate of light energy; second, the photocatalytic activity of the catalyst is improved to ensure efficient degradation of dioxins in the photocatalytic reaction; third, the advanced oxidation process is integrated to enhance the degradation rate and thoroughness of dioxins. The present application is not only intended to improve the performance of photocatalytic degradation of dioxins, but also to reduce costs to promote commercialization and large-scale application in the field of environmental governance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application but do not constitute an improper limitation on the present application. In the drawings: Figure 1 This is a flow chart of the catalyst preparation method of the present application; Figure 2 A physical picture of the catalyst of this application; Figure 3 The flowchart of the dioxin degradation method with full spectrum response of the present application; Figure 4 This is a graph showing the change in concentration of the dioxin degradation solution of the present application versus reaction time; Figure 5 This is a graph showing the change in concentration of the degraded dichlorophenol solution versus reaction time in the present application. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0024] In the description of the present application, it should be understood that the relationship between the method steps can be in sequence or not, as long as it does not affect the overall technical effect, and therefore cannot be understood as a limitation on the present application. The following description of the present application is only to be understood as a description of individual embodiments of the technical solution of the present application. Other embodiments are not reflected in the following description, but it does not mean that the present application excludes these other embodiments, and the technical solution of the present application is not limited to the specific implementation methods described below, and the scope of protection of the present application is not limited to only the specific implementation methods described below. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present application.

[0025] It should be noted that if the terms "first", "second", etc. appear in the specification and claims of the present application and the above-mentioned drawings, the description is only used to distinguish similar objects, and is not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] In some embodiments, Figure 1 As shown, the present application provides a method for preparing a catalyst, wherein the catalyst is used to degrade dioxins, and the method comprises: S11: adding TBOT dropwise to ethanol, and then stirring at 50-60° C., then adding ethanol dropwise, and continuing stirring for 2-4 hours to form a first solution; S12: drying the first solution in an oven to obtain a solid precursor; S13: adding a dopant to the solid precursor, followed by calcination, and then natural cooling; S14: After natural cooling, washing is performed with deionized water and ethanol to obtain atomically doped TiO 2 Catalyst substrate; S15: The atom-doped TiO 2 The catalyst substrate is immersed in a saturated calcium hydroxide solution and stirred to obtain a uniform suspension; S16: heating the uniform suspension at 150-180° C. for 10-14 hours, collecting the precipitate after cooling, washing it with deionized water and ethanol, and then drying the washed precipitate; S17: de-alkali-treating and filtering the dried precipitate to obtain a filtrate; and S18: Wash the filtrate with deionized water and ethanol, and dry it to obtain m-TiO 2 @CaTiO 3 Catalyst, wherein m represents a heteroatom.

[0027] Specifically, in the above catalyst preparation, tetrabutyl titanate (TBOT) is used as a titanium source, and sodium borohydride (NaBH 4 ), melamine (C 3 H 6 N 6 )、diammonium phosphate ((NH4 ) 2 HPO 4 ), thiourea (CH 4 N 2 S) etc. are used as dopants to obtain different oxygen, nitrogen, phosphorus, and sulfur-doped TiO 2 catalysts, and finally obtain different oxygen, nitrogen, phosphorus, and sulfur-doped m-TiO 2 @CaTiO 3 The catalyst, wherein m is any one of an O atom, a N atom, a P atom and a S atom.

[0028] In some embodiments, the above-mentioned de-alkali treatment includes: The dried precipitate was dispersed in a solution containing 0.1 M hydrochloric acid; performing ultrasonic treatment; and Mechanical stirring is performed to remove excess alkali.

[0029] In some embodiments, taking oxygen doping as an example, the catalyst can be prepared by the following specific method: Tetrabutyl titanate (TBOT) was used as the titanium source, sodium borohydride (NaBH 4 ) as a dopant. First, 6 ml of TBOT was added dropwise to ethanol, and then stirred at 50-60 °C for 1 hour; then, 10 ml of 95% ethanol was slowly added dropwise and stirred for 3 hours to form a milky white solution, which was dried in an oven at 80 °C overnight to obtain a white solid precursor; sodium borohydride was added, and the precursor was then calcined at 600 °C in a muffle furnace for 3 hours. After natural cooling, it was washed with deionized water and ethanol 4 times each to finally obtain oxygen-doped TiO 2 Catalyst substrate; Similarly, by selecting different dopants such as melamine, diammonium phosphate, and thiourea, nitrogen-, phosphorus-, and sulfur-doped TiO 2 catalyst.

[0030] The O-TiO 2 The obtained homogeneous suspension was immersed in 60 mL of saturated calcium hydroxide (Ca(OH)2) solution and ultrasonically stirred for 30 minutes. The obtained homogeneous suspension was then subjected to hydrothermal reaction and heated in an oven at 160 °C for 12 hours. After cooling, the milky white precipitate was collected and washed with deionized water and ethanol several times, and then dried in a vacuum oven at 80 °C. Subsequently, the obtained material was dispersed in 0.1 M hydrochloric acid, ultrasonically treated for 45 minutes, and then mechanically stirred for 1 hour to remove excess alkali. The filtered sample was collected by vacuum filtration, and the filter cake was washed with deionized water and ethanol until the pH value of the filtrate was close to neutral. After drying, O-TiO 2 @CaTiO 3Similarly, by selecting titanium dioxide substrates doped with different heteroatoms, different m-TiO doped with nitrogen, phosphorus, and sulfur can be prepared respectively. 2 @CaTiO3 catalyst.

[0031] In some embodiments, the present application further provides a catalyst for degrading dioxins, wherein the catalyst is prepared by the above-mentioned catalyst preparation method.

[0032] In some embodiments, the catalyst comprises an O-doped catalyst (O-TiO 2 @CaTiO 3 ), N-doped catalysts (N-TiO 2 @CaTiO 3 ), P-doped catalysts (P-TiO 2 @CaTiO 3 ) and S-doped catalysts (S-TiO 2 @CaTiO 3 ), such as Figure 2 shown.

[0033] In some embodiments, Figure 3 As shown, the present application also provides a dioxin degradation method with full spectrum response, comprising: S21: passing an oxygen source into the dioxin aqueous solution; S22: adding the catalyst prepared according to the above catalyst preparation method into the dioxin aqueous solution; and S23: Stirring under light conditions to degrade dioxins in the dioxin aqueous solution.

[0034] In some embodiments, the present application further includes: Persulfate is added as an additive to the aqueous dioxin solution before stirring under light conditions.

[0035] In some embodiments, the persulfate may be ammonium persulfate (NH 4 S 2 O 8 )、Potassium persulfate(K 2 S 2 O 8 ), calcium persulfate (Ca 2 S 2 O 8 ) and sodium persulfate (Na 2 S 2 O 8 ).

[0036] In some embodiments, the temperature during the above-mentioned degradation process is controlled to be 10-40°C; The oxygen source is air or oxygen; The light source of the lighting condition includes at least one of an LED lamp, a xenon lamp, a mercury lamp and natural light.

[0037] In some embodiments, the dioxin degradation method of the present application is carried out in the presence of sodium persulfate and a catalyst, by irradiation with artificial light or natural light, and the temperature is strictly controlled at 10-40°C.

[0038] In some embodiments, the degradation efficiency of dioxins can be evaluated by measuring their concentrations using gas chromatography-triple quadrupole mass spectrometry (GC-MS / MS, Shimazu, Japan).

[0039] Specifically, in some embodiments, oxygen is used as the oxygen source, sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives to (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the specific degradation process experimental steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 min under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and tested for dioxin concentration, which was 117.64 ng / g. Figure 4 ; (2) The degradation was continued at 20°C for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept flowing in and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested. The concentration was 75.93 ng / g. Figure 4 ; (3) The degradation was continued at 20°C for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept flowing in and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested. The concentration was 31.25 ng / g. Figure 4 ; (4) The degradation was continued at 20°C for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept flowing in and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested. The concentration was 12.08 ng / g. Figure 4 ; (5) The degradation was continued at 20°C for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept flowing in and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested. The concentration was 3.67 ng / g. Figure 4 ; (6) The degradation was continued at 20°C for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept flowing in and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested. The concentration was 0 ng / g. Figure 4 ; from Figure 4 It can be seen that as the degradation time increases, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 60 minutes.

[0040] In some embodiments, oxygen is used as the oxygen source, sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, and a xenon lamp as the light source. The steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W and the light power density was 200 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the xenon lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and tested for dioxin concentration, which was 104.72 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the xenon lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 53.22 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation of the xenon lamp and stirring. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 17.11 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation of the xenon lamp and stirring. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration tended to 0; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 40 minutes. Its degradation rate is better than that of LED lamps due to the strong light intensity and the intervention of ultraviolet light.

[0041] In some embodiments, oxygen is used as the oxygen source and sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, and mercury lamp as the light source. The steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The mercury lamp was 200 W and the light power density was 100 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the mercury lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and tested for dioxin concentration, which was 80.01 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation of the mercury lamp and stirring. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 23.97 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation of the mercury lamp and stirring. During the entire reaction process, oxygen was kept flowing and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration tended to zero.

[0042] From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 30 minutes. Its degradation rate is better than that of LED lamps and xenon lamps due to the strong light intensity and the intervention of ultraviolet light.

[0043] In some embodiments, air is used as the oxygen source and sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (50ng / g) as the degradation system, natural light as the light source, and the reaction environment switched to the outdoors. The steps are as follows: (1) 5 mL of a dioxin aqueous solution (50 ng / g) was loaded into a reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. Under natural light (August 25, 2024, Shenzhen), the degradation was carried out at 20°C for 10 min under the irradiation and stirring of the natural light. During the entire reaction process, the degradation system was in an open state, and air was supplemented with oxygen through a gas-liquid mass transfer process. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration was 35.73 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation of natural light and stirring. After the degradation time was up, the reaction solution was collected and its dioxin concentration was tested, which was 28.28 ng / g; (3) Degradation was continued at 20° C. for 10 min under the irradiation of natural light and stirring. After the degradation time was up, the reaction solution was collected and its dioxin concentration was tested, which was 21.54 ng / g; (4) Degradation was continued at 20° C. for 10 min under the irradiation of natural light and stirring. After the degradation time was up, the reaction solution was collected and its dioxin concentration was tested, which was 16.15 ng / g; (5) Degrading the mixture under the above-mentioned natural light and stirring at 20° C. for 10 min. After the degradation time is up, the reaction solution is collected and its dioxin concentration is tested, which is 7.5 ng / g. (6) The degradation was continued at 20° C. for 10 min under the irradiation of natural light and stirring. After the degradation time was up, the reaction solution was collected and its dioxin concentration was tested, which was 3.24 ng / g; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases, and 93% is degraded in about 60 minutes, which shows its application potential under natural light.

[0044] In some embodiments, oxygen is used as the oxygen source and potassium persulfate (K 2 S2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration was 120.21 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 76 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 30.11 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 11.15 ng / g. (5) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 4.76 ng / g. (6) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 60 minutes. Its degradation rate is equivalent to that of sodium persulfate.

[0045] In some embodiments, oxygen is used as the oxygen source and ammonium persulfate (NH 4 S 2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration was 115.50 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 76.18 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 30.9 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 13.76 ng / g. (5) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 4.17 ng / g. (6) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 60 minutes. Its degradation rate is equivalent to that of sodium persulfate.

[0046] In some embodiments, oxygen is used as the oxygen source and sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives, with (S-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED lamp as the light source, and the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and tested for dioxin concentration, which was 118.14 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 69.81 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 28.70 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 9.91 ng / g. (5) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 3.14 ng / g. (6) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 60 minutes. Its degradation rate is slightly better than that of O-TiO 2 @CaTiO 3 system, indicating that the S-doped catalyst can absorb a wider spectral range.

[0047] In some embodiments, oxygen is used as the oxygen source and sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives, with (N-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the LED lamp, during the entire reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and tested for dioxin concentration, which was 127.15 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 86.19 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 44.27 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 22.15 ng / g. (5) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 5.90 ng / g. (6) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 60 minutes. Its degradation rate is slightly lower than that of O-TiO 2 @CaTiO 3 The system is equivalent.

[0048] In some embodiments, oxygen is used as the oxygen source and sodium persulfate (Na 2 S 2 O 8 ) (100 μM) additives, with (P-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and tested for dioxin concentration, which was 125.12 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 70.19 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 37.27 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 18.14 ng / g. (5) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 4.12 ng / g. (6) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, it can be seen that with the increase of degradation time, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 60 minutes. Its degradation rate is slightly lower than that of O-TiO 2 @CaTiO 3 system.

[0049] In some embodiments, oxygen is used as the oxygen source and calcium persulfate (Ca 2 S 2 O 8 ) (100 μM) as additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 minutes under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration was 95.12 ng / g; (2) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 50.44 ng / g. (3) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 19.08 ng / g. (4) Degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, it can be seen that as the degradation time increases, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 40 minutes. 2 S 2 O 8 The reaction system with ) (100 μM) as the additive had a higher efficiency in degrading dioxins than other systems, which was presumably due to the dechlorination effect of calcium ions.

[0050] In some embodiments, oxygen is used as the oxygen source and calcium persulfate (Ca 2 S 2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as the catalyst, dioxin aqueous solution (150 ng / g) as the degradation system, LED light as the light source, the steps are as follows: (1) 5 mL of dioxin aqueous solution (150 ng / g) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 40°C for 10 minutes under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, and the concentration was 85.27 ng / g; (2) Degradation was continued at 40° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 47.71 ng / g. (3) Degradation was continued at 40° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 20.17 ng / g. (4) Degradation was continued at 40° C. for 10 min under the irradiation and stirring of the LED lamp. During the entire reaction process, oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dioxin concentration was tested, which was 0; From the results, we can see that as the degradation time increases, the concentration of dioxins in the degradation system gradually decreases and approaches zero at around 40 minutes. Increasing the temperature has little effect on the reaction.

[0051] In some embodiments, the catalyst of the present application is used to degrade dichlorophenol, using oxygen as the oxygen source and calcium persulfate (Ca 2 S 2 O 8 ) (100 μM) additives, with (O-TiO 2 @CaTiO 3 ) as a catalyst, dichlorophenol aqueous solution (50ppm) as the degradation system, LED lamp as the light source, the steps are as follows: (1) 5 mL of dichlorophenol aqueous solution (50 ppm) was placed in the reactor and oxygen was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The LED light was W (300 W) and the light power density was 250 mW / cm 2 , degraded at 20°C for 10 min under the irradiation and stirring of the LED lamp, during the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction solution was collected and its dichlorophenol concentration was tested, and its concentration was 38.42 ppm. Figure 5 ; (2) The degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept in the air and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dichlorophenol concentration was tested. The concentration was 23.24 ppm. Figure 5 ; (3) The degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction liquid was collected and its dichlorophenol concentration was tested. The concentration was 12.19 ppm. Figure 5 ; (4) The degradation was continued at 20° C. for 10 min under the irradiation and stirring of the LED lamp. During the whole reaction process, the oxygen was kept introduced and the gas outlet provided on the side wall of the reactor was kept open. After the degradation time was up, the reaction solution was collected and its dichlorophenol concentration was tested. The concentration was 0. Figure 5 ; from Figure 5 It can be seen that with the increase of degradation time, the concentration of dichlorophenol in the degradation system gradually decreases and approaches zero at around 40 min, indicating that the catalyst has the ability to degrade other organic pollutants.

[0052] The dioxin degradation mechanism of the present application is that during the photoexcitation process, the catalyst generates electron-hole pairs, in which the electrons migrate to the conduction band and the holes remain in the valence band. The electrons in the conduction band can react with dissolved oxygen to generate superoxide radicals (•O 2 – ); at the same time, electrons can also activate persulfate (PDS) to produce sulfate radicals (•SO 4 – On the other hand, holes in the valence band can directly oxidize dioxins, or react with water molecules or hydroxide ions to generate hydroxyl radicals (•OH) with strong oxidizing properties. These highly reactive free radicals can destroy dioxins and achieve effective treatment of difficult-to-degrade dioxins.

[0053] Compared with the prior art, the method described in this application has the following beneficial technical effects: (1) Broadening of the spectral response range: Through the heteroatom doping (N, P, S, O doping) strategy, this application successfully broadened the absorption range of the catalyst to the light spectrum, especially enhanced the absorption capacity in the visible light region, thereby improving the photocatalytic efficiency of the catalyst.

[0054] (2) Enhancement of photocatalytic activity: The in-situ growth technique was used to introduce calcium ions to construct a heterostructure, which significantly promoted the effective separation of charge carriers and photogenerated holes and enhanced the photocatalytic activity of the catalyst, which is of great significance for improving the efficiency of dioxin degradation.

[0055] (3) Imparting dechlorination function: The introduction of calcium ions provides the catalyst with dechlorination ability, which is crucial for the thorough mineralization process of dioxin molecules, achieving efficient and full-spectrum responsive dioxin photocatalytic degradation.

[0056] (4) Improvement of degradation rate and thoroughness: By integrating the advanced oxidation process, this application further enhances the degradation rate and thoroughness of dioxins, providing technical support for achieving faster and more thorough degradation of pollutants.

[0057] (5) Optimization of cost-effectiveness: By using titanium dioxide as the catalyst substrate and selecting economical and affordable melamine, diammonium phosphate, thiourea, etc. as dopants, combined with calcium hydroxide (Ca(OH) 2 ) solution as raw material, this application successfully reduced the overall preparation cost of the catalyst and promoted the commercialization and large-scale application of photocatalytic technology in the field of environmental governance.

[0058] (6) Environmental friendliness: The method of the present application avoids the use of harmful chemicals and the generation of secondary pollution, conforms to the development trend of green environmental protection, and helps to achieve the goal of sustainable development of environmental governance.

[0059] (7) Expansion of application prospects: The technical solution of this application has a wide range of application potentials. It is not only suitable for the degradation of dioxins, but can also be extended to the treatment of other persistent organic pollutants, providing a new technical approach for environmental pollution control. The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the selection and description of the implementation scheme is to best illustrate the principles of the present application and its practical application, so as to enable other technicians in the field to best use the present application and the various described implementation schemes with various modifications suitable for the specific purpose conceived.

Claims

1. A method for preparing a catalyst for degrading dioxins, characterized in that: The method comprises: Add TBOT dropwise into ethanol, then stir at 50-60° C., then add ethanol dropwise, and continue stirring for 2-4 hours to form a first solution; Drying the first solution in an oven to obtain a solid precursor; Adding a dopant to the solid precursor, followed by calcination, and then naturally cooling; After natural cooling, the catalyst was washed with deionized water and ethanol to obtain an atomically doped TiO2 catalyst substrate; Immersing the atomically doped TiO2 catalyst substrate in a saturated calcium hydroxide solution and stirring to obtain a uniform suspension; The uniform suspension is heated at 150-180° C. for 10-14 hours, and after cooling, a precipitate is collected and washed with deionized water and ethanol, and then the washed precipitate is dried; The dried precipitate is subjected to a de-alkali treatment and filtered to obtain a filtrate; and The filtrate was washed with deionized water and ethanol, and dried to obtain an m-TiO2@CaTiO3 catalyst, wherein m represents a heteroatom.

2. The method for preparing a catalyst according to claim 1, characterized in that: The dopant includes at least one of sodium borohydride, melamine, ammonium dihydrogen phosphate and thiourea.

3. The method for preparing a catalyst according to claim 1, characterized in that: The m is any one of an O atom, a N atom, a P atom and a S atom.

4. The method for preparing a catalyst according to claim 1, characterized in that: The de-alkali treatment comprises: The dried precipitate was dispersed in a solution containing 0.1 M hydrochloric acid; performing ultrasonic treatment; and Mechanical stirring is performed to remove excess alkali.

5. A catalyst for degrading dioxins, characterized in that: The catalyst is prepared by the catalyst preparation method according to any one of claims 1 to 4.

6. The catalyst according to claim 5, characterized in that: The catalyst includes at least one of O-TiO2@CaTiO3, N-TiO2@CaTiO3, P-TiO2@CaTiO3 and S-TiO2@CaTiO3.

7. A dioxin degradation method with full spectrum response, characterized in that: include: Passing an oxygen source into the dioxin aqueous solution; adding the catalyst prepared by the catalyst preparation method according to any one of claims 1 to 4 into the dioxin aqueous solution; as well as The solution is stirred under light conditions to degrade dioxins in the dioxin aqueous solution.

8. The method for degrading dioxins with full spectrum response according to claim 7, characterized in that: Also includes: Persulfate is added as an additive to the aqueous dioxin solution before stirring under light conditions.

9. The method for degrading dioxins with full spectrum response according to claim 8, characterized in that: The persulfate includes at least one of ammonium persulfate, potassium persulfate, calcium persulfate and sodium persulfate.

10. The method for degrading dioxins with full spectrum response according to claim 7, characterized in that: The temperature during the degradation process was controlled at 10-40°C; The oxygen source is air or oxygen; The light source of the lighting condition includes at least one of an LED lamp, a xenon lamp, a mercury lamp and natural light.

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