Ionization irradiation modified FeOCl heterogeneous catalyst and preparation method thereof

Abstract

The invention provides an ionization irradiation modified FeOCl heterogeneous catalyst and a preparation method thereof, and the preparation method comprises the following steps: mixing FeOCl with deionized water, and adding a proper amount of a pH adjusting reagent to obtain a FeOCl-containing suspension with the pH value of 2-10; and adding a proper amount of a hydroxyl radical quencher into the suspension containing FeOCl, uniformly stirring, carrying out irradiation treatment with the irradiation dose of 1-200 kGy, carrying out vacuum filtration on the irradiated suspension, and carrying out vacuum drying on the obtained solid to obtain the modified FeOCl heterogeneous catalyst. According to the method, the structure of FeOCl is accurately regulated and controlled by controlling the irradiation conditions, so that the aim of modifying the FeOCl heterogeneous catalyst is fulfilled. The catalytic activity of the modified FeOCl heterogeneous catalyst is remarkably improved, and the modified FeOCl heterogeneous catalyst can be used for efficiently removing new pollutants in water; compared with the traditional process for modifying FeOCl, the preparation method provided by the invention has the advantages of simplicity in operation, low cost, easiness in large-scale production and no generation of organic waste liquid.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental engineering, and in particular to an ionizing radiation-modified FeOCl heterogeneous catalyst and a preparation method thereof. Background Art

[0002] Heterogeneous catalytic oxidation technology is one of the effective methods for treating new, difficult-to-degrade pollutants in water. As a common, low-cost heterogeneous catalyst, FeOCl is widely used in Fenton-like reactions due to its unique layered structure and abundant surface active sites. However, the low Fenton-like catalytic activity of traditional FeOCl limits its practical application. In view of this, researchers have conducted extensive research on the structural modification of FeOCl to improve its Fenton-like catalytic activity.

[0003] Currently, methods for enhancing the catalytic activity of FeOCl primarily include doping, pyrolysis, and chemical reduction. For example, patent (CN202310003503.3) discloses a method for preparing modified FeOCl by pyrolysis of a mixture of graphene and ferric chloride. Graphene is used to manipulate the synthesis of a T-type Fenton-like catalyst containing Fe2O3 and FeOCl, enhancing the catalytic activity of FeOCl. Wang Yuhao et al. modified FeOCl with the electron-withdrawing organic compound nitroterephthalic acid to produce an easily separable and recyclable iron-based catalyst. The modified FeOCl exhibited enhanced catalytic activity, enabling the activation of peroxymonosulfate to degrade new pollutants such as acetaminophen. While these two modification methods can enhance the catalytic activity of FeOCl, they present complex processes, high energy consumption, and the potential for introducing secondary pollution.

[0004] Therefore, it is of great significance to develop a method that is simple to operate, low-cost and can precisely control the catalytic activity of FeOCl. Summary of the Invention

[0005] In response to the above-mentioned problems existing in the prior art, the present invention uses ionizing radiation technology to develop a modification method for FeOCl that is simple to operate, low-cost, and can precisely control the catalytic activity.

[0006] The specific content of the invention is as follows: In a first aspect, the present invention provides a method for preparing an ionizing radiation-modified FeOCl heterogeneous catalyst, the preparation method comprising: Mixing FeOCl with deionized water and adding an appropriate amount of a pH adjusting agent to obtain a FeOCl-containing suspension with a pH value of 2 to 10; An appropriate amount of a hydroxyl radical quencher is added to the FeOCl-containing suspension, and after uniform stirring, the suspension is irradiated at a dose of 1 kGy to 200 kGy. The irradiated suspension is vacuum filtered, and the obtained solid is vacuum dried to obtain the modified FeOCl heterogeneous catalyst.

[0007] Optionally, the FeOCl and the deionized water are mixed at a volume ratio of 0.1 to 0.5.

[0008] Optionally, the pH adjusting agent is selected from concentrated sulfuric acid or sodium hydroxide.

[0009] Optionally, the hydroxyl radical quencher is selected from at least one of tert-butanol, isopropanol, n-butanol, methanol and ethanol.

[0010] Optionally, in the FeOCl-containing suspension, the concentration of the hydroxyl radical quencher is 27 mM to 3000 mM.

[0011] Optionally, the irradiation dose of the irradiation treatment is 1 to 10 kGy.

[0012] Optionally, the radiation source of the irradiation treatment is an electron accelerator, 60 Co or 137 Cs.

[0013] Optionally, the vacuum drying temperature is 45-70° C., and the time is 6-48 h.

[0014] Optionally, the pH value of the FeOCl-containing suspension is 8-10.

[0015] In a second aspect, the present invention provides an ionizing radiation-modified FeOCl heterogeneous catalyst, wherein the ionizing radiation-modified FeOCl heterogeneous catalyst is obtained by the preparation method described in the first aspect.

[0016] Compared with the prior art, the present invention has the following advantages: The present invention provides a method for preparing an ionizing radiation-modified FeOCl heterogeneous catalyst. The method comprises: mixing FeOCl with deionized water and adding an appropriate amount of a pH adjusting agent to obtain a FeOCl-containing suspension having a pH of 2 to 10; adding an appropriate amount of a hydroxyl radical quencher to the FeOCl-containing suspension, stirring the mixture uniformly, and irradiating the suspension to a dose of 1 kGy to 200 kGy. The irradiated suspension is vacuum filtered, and the resulting solid is vacuum dried to obtain the modified FeOCl heterogeneous catalyst. The present invention precisely regulates the structure of FeOCl by controlling the irradiation conditions, thereby modifying the catalytic activity of FeOCl. Compared with traditional FeOCl modification processes, the method for preparing the ionizing radiation-modified FeOCl heterogeneous catalyst provided by the present invention has the advantages of simple operation, low cost, easy scale-up, and no generation of organic wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 The flowchart of the preparation method of the ionizing radiation modified FeOCl heterogeneous catalyst provided in an embodiment of the present invention is shown; Figure 2 The electron paramagnetic resonance spectra of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 1 of the present invention are shown; Figure 3 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 1 of the present invention are shown; Figure 4 SEM images of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 2 of the present invention are shown; Figure 5 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 2 of the present invention are shown; Figure 6 shows the XRD patterns of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 3 of the present invention; Figure 7 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 3 of the present invention are shown; Figure 8 shows the XRD patterns of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 4 of the present invention; Figure 9 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 4 of the present invention are shown. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the present invention and its application or use. Based on the embodiments of the present invention, any product that is identical or similar to the present invention and is obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts falls within the scope of protection of the present invention. In addition, all other embodiments obtained by ordinary technicians in this field without carrying out creative work fall within the scope of protection of the present invention.

[0020] Where specific experimental steps or conditions are not specified in the examples, the conventional experimental steps or conditions described in the prior art in the art may be used. Reagents and other instruments used, for which the manufacturer is not specified, are commercially available conventional reagent products. Furthermore, the accompanying drawings are merely schematic illustrations of embodiments of the present invention and are not necessarily drawn to scale. Identical reference numerals in the figures denote identical or similar parts, and their repeated descriptions will be omitted. Some block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0021] Technologies, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies, methods, and equipment should be considered part of the description of the present invention.

[0022] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0023] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Ionizing radiation technology is a physical method that uses high-energy radiation (such as gamma rays, X-rays, or electron beams) to treat materials. Its mechanism primarily involves the interaction of high-energy radiation with the material, exciting or ionizing molecules, initiating chemical bond breakage or free radical formation, thereby altering the material's physical and chemical properties. This technology offers advantages such as zero chemical contamination, strong penetration, high treatment efficiency, and excellent controllability. This invention utilizes ionizing radiation technology for the targeted regulation of FeOCl catalytic activity, developing a simple, low-cost method for precisely controlling FeOCl catalytic activity. This method provides additional avenues for the industrial modification of catalytic materials. Specific implementation methods are as follows: In a first aspect, the present invention provides a method for preparing an ionizing radiation-modified FeOCl heterogeneous catalyst. Figure 1 The flow chart of the preparation method of the ionizing radiation modified FeOCl heterogeneous catalyst provided in the embodiment of the present invention is shown as follows: Figure 1 As shown, the preparation method comprises: S1. Mixing FeOCl with deionized water and adding an appropriate amount of a pH adjusting agent to obtain a FeOCl-containing suspension with a pH value of 2 to 10; S2. Add an appropriate amount of a hydroxyl radical quencher to the FeOCl-containing suspension, stir evenly, and then irradiate the suspension at a dose of 1 kGy to 200 kGy. The irradiated suspension is vacuum filtered, and the obtained solid is vacuum dried to obtain the modified FeOCl heterogeneous catalyst.

[0025] In a specific implementation, FeOCl can be commercially available or synthesized experimentally, and the pH adjusting agent is selected from concentrated sulfuric acid or sodium hydroxide. The present invention mixes FeOCl with deionized water to form a suspension containing FeOCl. In this process, FeOCl and deionized water are mixed at a volume ratio of 0.1 to 0.5, and an appropriate amount of pH adjusting agent is added to adjust the pH of the suspension containing FeOCl to 2 to 10. The pH adjusting agent can be selected from concentrated sulfuric acid or sodium hydroxide. The suspension containing FeOCl with a pH value of 2 to 10 is irradiated, and the irradiation source of the irradiation treatment is an electron accelerator, 60 Co or 137 Cs, with an irradiation dose of 1 kGy to 200 kGy, under different pH conditions, the active species generated by irradiation interact with FeOCl, regulate the lattice defects and surface acid-base active sites of FeOCl, and significantly improve its catalytic performance.

[0026] In some embodiments, the pH of the FeOCl-containing suspension is preferably 8-10, and the irradiation dose of the irradiation treatment is preferably 1-10 kGy.

[0027] In practice, an appropriate amount of a hydroxyl radical quencher is added to a FeOCl-containing suspension. The hydroxyl radical quencher is selected from at least one of tert-butyl alcohol, isopropyl alcohol, n-butyl alcohol, methanol, and ethanol. The concentration of the hydroxyl radical quencher in the FeOCl-containing suspension is 27 mM to 3000 mM. The hydroxyl radical quencher regulates the intensity of the interaction between hydroxyl radicals generated during irradiation and FeOCl, thereby controlling the oxidative effects of hydroxyl radicals. Defects are created by utilizing reducing-active species such as hydrated electrons and oxidizing-active species such as hydroxyl radicals.

[0028] It is worth noting that when irradiation treatment is carried out directly without the addition of a hydroxyl radical quencher, the hydroxyl radicals generated in the solution may undergo a strong oxidation reaction with FeOCl, thereby destroying its structure and ultimately leading to a significant decrease in its catalytic performance.

[0029] In some embodiments, the concentration of the hydroxyl radical quencher in the FeOCl-containing suspension is preferably 200 mM.

[0030] In a specific implementation, the irradiated suspension is vacuum filtered, and the separated solid is vacuum dried at a temperature of 45-70°C for 6-48 hours to obtain a modified FeOCl heterogeneous catalyst.

[0031] In a second aspect, the present invention provides an ionizing radiation-modified FeOCl heterogeneous catalyst, wherein the modified FeOCl heterogeneous catalyst is obtained by the preparation method described in the first aspect.

[0032] To enable those skilled in the art to more clearly understand the present invention, the following examples are used to describe in detail the ionizing radiation-modified FeOCl heterogeneous catalyst and its preparation method according to the present invention.

[0033] Example 1 First, 0.1 g of FeOCl was added to a centrifuge tube containing 20 ml of deionized water, and then an appropriate amount of hydroxyl radical quencher was added and stirred to form a suspension containing FeOCl; wherein, the concentration of the hydroxyl radical quencher was 200 mM.

[0034] Then use 60 The FeOCl-containing suspension was irradiated with a Co irradiation source at a dose of 10 kGy. The irradiated suspension was vacuum filtered and the obtained solid was vacuum dried at 45°C for 48 h to obtain an ionizing radiation-modified FeOCl heterogeneous catalyst.

[0035] The obtained ionizing radiation-modified FeOCl heterogeneous catalyst was added to a mixed system containing sulfamethoxazole and peroxymonosulfate, where the initial concentration of sulfamethoxazole was 10 mg / L, the initial concentration of peroxymonosulfate was 0.6 mM, and the added mass of the ionizing radiation-modified FeOCl heterogeneous catalyst was 0.1 g / L. After a period of reaction, the change in sulfamethoxazole concentration was tested.

[0036] Figure 2 1 shows the electron paramagnetic resonance spectra of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 1 of the present invention. Figure 2 As shown in the figure, there is no obvious peak at g=2.03 before ionizing radiation modification, but an obvious characteristic peak appears at g=2.03 after ionizing radiation modification, indicating that radiation modification introduces oxygen vacancies.

[0037] Figure 3 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 1 of the present invention are shown. Figure 3 As shown in the figure, the catalytic activity of FeOCl modified by ionizing radiation increased significantly compared with FeOCl without any modification.

[0038] Example 2 First, 0.1g of FeOCl was added to a centrifuge tube containing 20ml of deionized water. Then, an appropriate amount of hydroxyl radical quencher was added and stirred to form a FeOCl suspension. The pH of the FeOCl suspension was adjusted to 2.0 using 1M H2SO4. The concentration of the hydroxyl radical quencher was 200 mM.

[0039] Then use 60 The FeOCl-containing suspension was irradiated with a Co irradiation source at a dose of 10 kGy. The irradiated suspension was vacuum filtered and the obtained solid was vacuum dried at 65°C for 24 h to obtain an ionizing radiation-modified FeOCl heterogeneous catalyst.

[0040] The obtained ionizing radiation-modified FeOCl heterogeneous catalyst was added to a mixed system containing sulfamethoxazole and peroxymonosulfate, where the initial concentrations of sulfamethoxazole were 10 mg / L, the initial concentrations of peroxymonosulfate were 0.6 mM, and the added mass of the ionizing radiation-modified FeOCl heterogeneous catalyst was 0.1 g / L. After a period of reaction, the change in sulfamethoxazole concentration was tested.

[0041] Figure 4 The SEM images of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 2 of the present invention are shown, wherein: Figure 4(A) is the SEM image of FeOCl without any modification. Figure 4 (B) is the SEM image of the FeOCl heterogeneous catalyst modified by ionizing radiation. Figure 4 As shown in the figure, the surface roughness of the FeOCl heterogeneous catalyst increases after irradiation treatment. Compared with FeOCl without any modification, the catalytic activity of FeOCl modified by ionizing radiation is significantly increased.

[0042] Figure 5 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 2 of the present invention are shown. Figure 5 As shown in the figure, the catalytic activity of FeOCl modified by ionizing radiation increased significantly compared with FeOCl without any modification.

[0043] Example 3 First, 0.1 g of FeOCl was added to a centrifuge tube containing 10 ml of deionized water. Then, an appropriate amount of a hydroxyl radical quencher was added and stirred to form a FeOCl suspension. The pH of the FeOCl suspension was adjusted to 10.0 using 1 M NaOH. The concentration of the hydroxyl radical quencher was 200 mM.

[0044] Then use 60 The FeOCl-containing suspension was irradiated by a Co irradiation source with an irradiation dose of 1 kGy. The irradiated suspension was vacuum filtered and the obtained solid was vacuum dried at 75°C for 20 h to obtain an ionizing irradiation-modified FeOCl heterogeneous catalyst.

[0045] The obtained ionizing radiation-modified FeOCl heterogeneous catalyst was added to a mixed system containing sulfamethoxazole and peroxymonosulfate, where the initial concentrations of sulfamethoxazole were 10 mg / L, the initial concentrations of peroxymonosulfate were 0.6 mM, and the added mass of the ionizing radiation-modified FeOCl heterogeneous catalyst was 0.1 g / L. After a period of reaction, the change in sulfamethoxazole concentration was tested.

[0046] Figure 6 The XRD patterns of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 3 of the present invention are shown. Figure 6 As shown in Figure 5, the lattice defects of FeOCl increase after irradiation treatment.

[0047] Figure 7 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 3 of the present invention are shown. Figure 7 As shown in the figure, the catalytic activity of FeOCl modified by ionizing radiation increased significantly compared with FeOCl without any modification.

[0048] Example 4 First, 0.1 g of FeOCl was added to a centrifuge tube containing 10 ml of deionized water, and then an appropriate amount of hydroxyl radical quencher was added and stirred to form a suspension containing FeOCl; wherein the concentration of the hydroxyl radical quencher was 200 mM.

[0049] Then use 60 The FeOCl-containing suspension was irradiated by a Co irradiation source with an irradiation dose of 1 kGy. The irradiated suspension was vacuum filtered and the obtained solid was vacuum dried at 45°C for 48 h to obtain an ionizing radiation-modified FeOCl heterogeneous catalyst.

[0050] The obtained ionizing radiation-modified FeOCl heterogeneous catalyst was added to a mixed system containing sulfamethoxazole and peroxymonosulfate, where the initial concentrations of sulfamethoxazole were 10 mg / L, the initial concentrations of peroxymonosulfate were 0.6 mM, and the added mass of the ionizing radiation-modified FeOCl heterogeneous catalyst was 0.1 g / L. After a period of reaction, the change in sulfamethoxazole concentration was tested.

[0051] Figure 8 The XRD patterns of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 4 of the present invention are shown. Figure 8 As shown in Figure 5, the lattice defects of FeOCl increase after irradiation treatment.

[0052] Figure 9 The catalytic activity test results of the FeOCl heterogeneous catalyst before and after ionizing radiation modification in Example 4 of the present invention are shown. Figure 9 As shown in the figure, the catalytic activity of FeOCl modified by ionizing radiation increased significantly compared with FeOCl without any modification.

[0053] As shown in Examples 1-4, the preparation method of the ionizing radiation-modified FeOCl heterogeneous catalyst provided by the present invention has the advantages of simple operation, low cost, easy scale-up production, and no generation of organic waste liquid; and the catalytic activity is significantly increased compared to unmodified FeOCl.

[0054] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0055] For simplicity of description, the method embodiments are described as a series of actions. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, as certain steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also be aware that the embodiments described in this specification are preferred embodiments, and the actions and components involved are not necessarily required for the present invention.

[0056] The above describes in detail an ionizing radiation-modified FeOCl heterogeneous catalyst and preparation method provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the method and core concept of the present invention. At the same time, for those skilled in the art, according to the concept of the present invention, there may be changes in the specific implementation method and application scope. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing an ionizing radiation-modified FeOCl heterogeneous catalyst, characterized in that: The preparation method comprises: Mixing FeOCl with deionized water and adding an appropriate amount of a pH adjusting agent to obtain a FeOCl-containing suspension with a pH value of 2 to 10; An appropriate amount of a hydroxyl radical quencher is added to the FeOCl-containing suspension, and after uniform stirring, the suspension is irradiated at a dose of 1 kGy to 200 kGy. The irradiated suspension is vacuum filtered, and the obtained solid is vacuum dried to obtain the modified FeOCl heterogeneous catalyst.

2. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: The FeOCl and the deionized water are mixed at a volume ratio of 0.1 to 0.

5.

3. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: The pH adjusting agent is selected from concentrated sulfuric acid or sodium hydroxide.

4. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: The hydroxyl radical quencher is selected from at least one of tert-butanol, isopropanol, n-butanol, methanol and ethanol.

5. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: In the FeOCl-containing suspension, the concentration of the hydroxyl radical quencher is 27 mM to 3000 mM.

6. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: The irradiation dose of the irradiation treatment is 1 to 10 kGy.

7. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, characterized in that: The radiation source of the irradiation treatment is an electron accelerator, 60 Co or 137 Cs.

8. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: The vacuum drying temperature is 45-70° C. and the time is 6-48 h.

9. The method for preparing the ionizing radiation modified FeOCl heterogeneous catalyst according to claim 1, wherein: The pH value of the FeOCl-containing suspension is 8-10.

10. An ionizing radiation modified FeOCl heterogeneous catalyst, characterized in that: The modified FeOCl heterogeneous catalyst is obtained by the preparation method described in any one of claims 1 to 9.

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