Preparation method and application of senna leaf catalyst for uranium extraction from seawater
Patent Information
- Application Number
- CN202610811048.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-05
- Publication Date
- 2026-08-28
Smart Images
Figure CN122646800A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of seawater uranium extraction catalyst technology, and particularly relates to a method for preparing a senna leaf catalyst for seawater uranium extraction and its application. Background Technology
[0002] Uranium is a crucial raw material for the nuclear energy industry. Compared to the limited and non-renewable nature of terrestrial uranium resources, seawater has vast reserves of uranium, totaling billions of tons. However, its concentration is extremely low, approximately 3.3 ppb, posing a significant technical challenge to the efficient enrichment and conversion of uranium. Currently, seawater uranium extraction technology mainly relies on two systems: adsorption separation and photocatalytic reduction. This involves constructing functional sites with complexing capabilities to capture uranyl ions. In recent years, metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have been widely studied as adsorbent materials for seawater uranium extraction due to their high specific surface area and designable pore structures.
[0003] However, existing MOF or COF-based catalytic materials generally suffer from low adsorption efficiency, limited selectivity, and insufficient stability under real seawater conditions. Public research shows that even functionalized COF or MOF materials, such as amylopectin-based porous polymers, often have long reaction cycles in natural seawater or high-salt competitive systems, typically requiring tens of days to reach adsorption equilibrium. Each milligram of catalyst can only yield about 0.05 mg of uranium product per day, with a uranium content of only 52.0-58.5% in the product. Furthermore, the seawater treatment capacity is low, with an average daily processing capacity of only 0.10-0.25 L·mg. - ¹·d - ¹ The adsorption level corresponds to a low uranium yield per unit material, which is difficult to meet the requirements of high throughput and high efficiency for engineering applications. At the same time, the preparation process of this type of material usually involves multi-step organic ligand synthesis, framework construction and subsequent functionalization modification. It often relies on high-purity raw materials, organic solvent systems and strict reaction conditions. The overall process is complex and energy-intensive, making it difficult to achieve low-cost large-scale preparation. According to calculations, the cost of the above materials is as high as about 2000-3000 yuan / kg. In addition, the metal nodes in MOF materials may also suffer structural degradation in high-salt seawater environments, which further affects their long-term stability.
[0004] As can be seen from the above, existing seawater uranium extraction catalysts based on MOF, COF, and similar porous aromatic framework structures generally have the following shortcomings: 1) The adsorption efficiency in real seawater environments is limited, and the uranium yield per unit of material is low. Most MOF materials (such as UiO-66-AO and UiO-66-NH2@HDU-27) can only process 0.012~0.022 kg of seawater per milligram of catalyst per day in natural seawater, and the uranium content in the uranium product is only 38%~45%. Even the high-performance conjugated microporous polymer CMP-AO (electrochemical assisted system) can only process 0.085 kg of seawater per milligram of catalyst per day, and the uranium content in the uranium product is no more than 52%. The seawater processing capacity and uranium separation and purification efficiency per unit of catalyst are difficult to meet the requirements of large-scale application.
[0005] 2) Susceptible to competing ions and biofouling, resulting in insufficient cycle stability; The system is susceptible to competing ions such as a large number of coexisting cations and carbonates in seawater, as well as biofouling. After multiple cycles, the amount of seawater treated per milligram of catalyst per day decreases by 40% to 70%, and the proportion of uranium in uranium products decreases by -25% to 30% simultaneously, resulting in severely insufficient cycle stability.
[0006] 3) The material synthesis routes are complex and the cost is high, which is not conducive to engineering scale-up applications. MOF and COF materials are mostly synthesized by high-temperature solvothermal methods, which have harsh reaction conditions, complex synthesis routes, and large consumption of organic solvents, resulting in high raw material and preparation costs, which is not conducive to engineering scale-up applications.
[0007] In summary, existing adsorption materials are no longer sufficient to meet the practical application requirements of uranium extraction from seawater. Therefore, how to develop a photocatalytic uranium extraction material with a simple preparation process, strong environmental adaptability, and excellent long-term stability to construct an efficient and feasible new seawater uranium extraction technology is an urgent problem to be solved. Summary of the Invention
[0008] In view of this, the present invention aims to provide a method for preparing senna leaf catalyst for uranium extraction from seawater and its application, so as to solve the technical problems of complex preparation process, high cost and difficulty in large-scale production of existing photocatalytic materials for uranium extraction from seawater.
[0009] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, senna leaves and a sacrificial agent are mixed in a certain mass ratio to obtain a senna leaf catalyst; wherein the sacrificial agent is a mixture of methanol and NaOH solution; S2: Senna leaf catalyst is mixed with seawater and reacted under light of a certain wavelength to catalyze the production of uranyl peroxide tetrahydrate.
[0010] Furthermore, the mass ratio of senna leaves to sacrificial agent is 1:5 to 1:1.
[0011] Furthermore, in S1, senna leaves are mixed with a sacrificial agent for 2-5 minutes to obtain a senna leaf catalyst.
[0012] Furthermore, in S1, the volume ratio of methanol to NaOH solution is 1:2 to 1:1.
[0013] Furthermore, in S1, the concentration of NaOH is 0.05M-1M.
[0014] Furthermore, in S2, senna leaf catalyst is mixed with seawater at a mass ratio of 1:250000-1:50000.
[0015] Furthermore, in S2, the reaction is carried out under light irradiation with a wavelength of 400-780 nm to catalyze the production of uranyl peroxide tetrahydrate.
[0016] Furthermore, in S2, the reaction conditions are 0℃-35℃, and the reaction time is 18-24 days.
[0017] Furthermore, in S1, when senna leaves are mixed with the sacrificial agent, a magnetic stirring rotor is used for mechanical stirring and constant temperature ultrasonic treatment is performed. The stirring speed is 60 rpm to 120 rpm, and the ultrasonic frequency during constant temperature ultrasonic treatment is 40 kHz to 80 kHz.
[0018] Furthermore, the senna leaf catalyst prepared by the above-mentioned method for uranium extraction from seawater is applied in the field of uranium extraction from seawater.
[0019] Compared with the prior art, the present invention can achieve the following beneficial effects: 1. In this invention, each milligram of senna leaf catalyst can catalyze the production of uranyl peroxide tetrahydrate product by an average of 0.293-0.295 mg per day, with a uranium content of 60.0-65.6%, which is significantly better than the existing level of 0.05 mg of uranium per day and 52.0-58.5% of uranium content of existing amine oxime-based porous organic polymers. Moreover, it only requires mixing senna leaves with a sacrificial agent (methanol + NaOH solution) in proportion for 2-5 minutes at room temperature, without the need for high temperature and high pressure, organic synthesis or multi-step modification.
[0020] 2. In this invention, 5 mg of catalyst can treat 50 liters of seawater within 18-24 days, which translates to an average daily seawater treatment capacity of 0.139-0.185 kg per milligram of catalyst, far exceeding the 0.10-0.25 L / mg of existing materials. - ¹·d - ¹ The average level of catalyst preparation cost is only 10.2-16.5 yuan / kg, which is about 200 times lower than the existing MOF / COF materials (2000-3000 yuan / kg), making it economically feasible for large-scale application.
[0021] 3. In this invention, the catalytic capacity can still be maintained at ≥85% after 5-15 cycles, which is better than most existing materials (the performance decays by more than 40% after 5-10 cycles). Moreover, the catalytic product is uranyl peroxide tetrahydrate, which is stable in air, easy to recycle and reprocess, and has no secondary environmental risks.
[0022] 4. The raw material used in this invention is natural senna leaves. There are no toxic or harmful substances emitted during the entire production process, no secondary pollution, and it is easy to scale up production. It can work effectively under visible light with wavelengths of 400nm-780nm and within a wide temperature range of 0℃-35℃. It can be driven by sunlight and has good environmental adaptability. Attached Figure Description
[0023] Appendix forming part of the invention Figure 1-8 The illustrative embodiments and descriptions of the present invention are provided to further illustrate the invention and are not intended to unduly limit the scope of the invention. In the accompanying drawings: Figure 1 Scanning electron microscope (SEM) image of the senna leaf catalyst prepared in Example 1 of this invention; Figure 2 A schematic diagram illustrating the catalytic ability of the senna leaf catalyst prepared in Example 2 of this invention for uranyl ions under different pH conditions; Figure 3 Thermogravimetric analysis (TGA) spectrum of the senna leaf catalyst prepared in Example 1 of this invention; Figure 4 Transmission electron microscopy (TEM) image of the senna leaf catalyst prepared in Example 1 of this invention; Figure 5 The catalytic activity of the senna leaf catalyst prepared in Example 3 of this invention is shown in the graph of uranyl ion solutions of different concentrations. Figure 6 A schematic diagram illustrating the anti-interference ion capability of the senna leaf catalyst prepared in Example 1 of this invention; Figure 7 A schematic diagram illustrating the cyclic properties of the senna leaf catalyst prepared in Example 1 of this invention; Figure 8 Schematic diagrams showing the catalytic performance of the senna leaf catalysts prepared in Examples 1, 3, and 4 of this invention in different proportions of methanol and sodium hydroxide as sacrificial agents. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.
[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.
[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0028] The following will refer to the appendix. Figure 1-8 The invention will be described in detail with reference to the embodiments.
[0029] Example 1 A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, weigh 2.0g of clean senna leaves and prepare 3g of sacrificial agent. The mass ratio of senna leaves to sacrificial agent is 1:1.5. The sacrificial agent is a mixture of methanol and NaOH solution. The NaOH solution is 0.1M, and the volume ratio of methanol to NaOH solution is 1:2. Add the mixture to a 25mL beaker. When mixing senna leaves and sacrificial agent, use a magnetic stirring rotor for mechanical stirring and constant temperature ultrasonic treatment. After mechanical stirring at 80 rpm and constant temperature ultrasonic dispersion treatment at 60 kHz, the sacrificial agent solution fully wets the pore structure of senna leaves, so that all the added sacrificial agent is absorbed by senna leaves. After mixing senna leaves and sacrificial agent for 2 minutes, senna leaf catalyst is obtained.
[0030] S2: Senna leaf catalyst was mixed with seawater at a mass ratio of 1:250000 and reacted under light irradiation at a wavelength of 400nm. The reaction was carried out at 0℃ for 18 days to catalyze the production of uranyl peroxide tetrahydrate.
[0031] In this embodiment, the daily average concentration of uranyl peroxide tetrahydrate obtained by each milligram of senna leaf catalyst is 0.16~0.23 mg, the daily average seawater treatment is 0.42~0.56 L, the uranium content of the product is 60.0-65.6%, the cost of senna leaf catalyst is 10.2-16.5 yuan / kg, and it can still maintain ≥85% catalytic capacity after 5-15 cycles.
[0032] Performance testing showed that the senna leaf catalyst prepared in this embodiment has excellent performance, and the senna leaf catalyst prepared by the method in this embodiment has great application potential in the field of uranium extraction from seawater.
[0033] Figure 1 This is a scanning electron microscope (SEM) image of senna leaves prepared in Example 1. Figure 1 It can be seen that the prepared senna leaf catalyst has an irregular and disordered surface structure. The surface structure is rough and unevenly distributed, exhibiting a typical irregular and disordered wrinkled structure without obvious regular crystal form or directional arrangement characteristics. This loose and disordered surface structure is conducive to providing abundant active sites and sufficient mass transfer channels for catalytic reactions.
[0034] Figure 3 The thermogravimetric analysis (TGA) spectrum of the senna leaf catalyst prepared in Example 1 is shown below. Figure 3It can be seen that the senna leaf catalyst prepared in this embodiment begins to show a certain degree of thermal weight loss at around 200℃, indicating that the material has good thermal stability and structural tolerance, and can adapt to certain high temperature extreme conditions. This characteristic not only ensures the structural integrity of the catalyst in the industrial preparation, post-processing and molding process, but also enables it to maintain stable catalytic performance in complex practical application scenarios such as seawater, providing a reliable guarantee for subsequent large-scale production and actual water treatment applications.
[0035] Figure 4 This is a transmission electron microscope (TEM) image of the senna leaf catalyst obtained in Example 1. Figure 4 It can be clearly seen that the senna leaf catalyst prepared by the present invention exhibits a distinctly irregular microstructure with a disordered surface and an overall structure without regular crystal arrangement and oriented disordered regions, further confirming its loose and disordered structural characteristics. This provides abundant surface active sites and efficient mass transfer interfaces for catalytic reactions, which is beneficial to improving the reaction efficiency and substrate contact ability of the catalytic process.
[0036] Figure 6 This is a schematic diagram illustrating the anti-interference ion capability of the senna leaf catalyst prepared in Example 1. Figure 6 It is known that cations (such as Na) are commonly found in seawater. + K + Mg² + Ca² + In complex environments where uranyl ions coexist in large quantities, the catalytic extraction efficiency of senna leaf catalyst for uranyl ions did not decrease significantly, and it still maintained a stable and efficient uranium capture capability. This fully demonstrates that it has excellent anti-interference ion performance and can effectively resist the competitive influence of coexisting ions in actual seawater and complex water bodies. It provides an important guarantee for achieving specific identification and efficient extraction of uranyl ions in real complex water environments.
[0037] Figure 7 This is a schematic diagram illustrating the cyclicity of the senna leaf catalyst prepared in Example 1. Figure 7 It can be seen that the catalyst can maintain high catalytic activity and uranyl ion extraction efficiency after multiple cycles, and the overall performance does not show significant decay. The catalytic ability shows good stability, indicating that the prepared senna leaf catalyst has excellent recycling performance, which can effectively reduce the cost of practical application and has good potential for industrial application.
[0038] Example 2 A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, weigh 2.0g of clean senna leaves and prepare 3g of sacrificial agent. The mass ratio of senna leaves to sacrificial agent is 1:1.5. The sacrificial agent is a mixture of methanol and NaOH solution. The NaOH solution is 1M, and the volume ratio of methanol to NaOH solution is 1:1.5. Add the mixture to a 25mL beaker. When mixing senna leaves and sacrificial agent, use a magnetic stirring rotor for mechanical stirring and constant temperature ultrasonic treatment. After mechanical stirring at 60 rpm and constant temperature ultrasonic dispersion treatment at 60 kHz, the sacrificial agent solution fully wets the pore structure of senna leaves, so that all the added sacrificial agent is absorbed by senna leaves. After mixing senna leaves and sacrificial agent for 3 minutes, senna leaf catalyst is obtained.
[0039] S2: Senna leaf catalyst was mixed with seawater at a mass ratio of 1:150000 and reacted under light irradiation at a wavelength of 550nm for 20 days at 15℃ to catalyze the production of uranyl peroxide tetrahydrate.
[0040] In this embodiment, the daily average concentration of uranyl peroxide tetrahydrate obtained by each milligram of senna leaf catalyst is 0.16~0.23 mg, the daily average seawater treatment is 0.42~0.56 L, the uranium content of the product is 60.0-65.6%, the cost of senna leaf catalyst is 10.2-16.5 yuan / kg, and it can still maintain ≥85% catalytic capacity after 5-15 cycles.
[0041] Performance testing showed that the senna leaf catalyst prepared in this embodiment has excellent performance, and the senna leaf catalyst prepared by the method in this embodiment has great application potential in the field of uranium extraction from seawater.
[0042] The scanning electron microscope (SEM) image of the senna leaf catalyst prepared in this embodiment is similar to that in Example 1, and will not be repeated here. Figure 2 This is a schematic diagram illustrating the catalytic ability of the senna leaf catalyst prepared in Example 2 for uranyl ions under different pH conditions. Figure 2 It can be seen that the senna leaf catalyst provided in this embodiment can maintain good and stable catalytic performance over a wide pH range. Even under pH conditions close to that of real seawater environment, the catalyst can still maintain efficient and stable catalytic activity, which fully demonstrates that it has excellent acid and base stability and environmental adaptability. It is not easily deactivated in complex water systems and has good practical application potential and industrialization prospects.
[0043] Example 3 A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, weigh 2.0g of clean senna leaves and prepare 2g of sacrificial agent. The mass ratio of senna leaves to sacrificial agent is 1:1. The sacrificial agent is a mixture of methanol and NaOH solution. The NaOH solution is 0.1M, and the volume ratio of methanol to NaOH solution is 1:1.2. Add the mixture to a 25mL beaker. When mixing senna leaves and sacrificial agent, use a magnetic stirring rotor for mechanical stirring and constant temperature ultrasonic treatment. After mechanical stirring at 80 rpm and constant temperature ultrasonic dispersion treatment at 60kHz, the sacrificial agent solution fully wets the pore structure of senna leaves, so that all the added sacrificial agent is absorbed by senna leaves. After mixing senna leaves and sacrificial agent for 4min, senna leaf catalyst is obtained.
[0044] S2: Senna leaf catalyst was mixed with seawater at a mass ratio of 1:100000 and reacted under light irradiation at a wavelength of 650nm for 22 days at 25°C to catalyze the production of uranyl peroxide tetrahydrate.
[0045] In this embodiment, the daily average concentration of uranyl peroxide tetrahydrate obtained by each milligram of senna leaf catalyst is 0.16~0.23 mg, the daily average seawater treatment is 0.42~0.56 L, the uranium content of the product is 60.0-65.6%, the cost of senna leaf catalyst is 10.2-16.5 yuan / kg, and it can still maintain ≥85% catalytic capacity after 5-15 cycles.
[0046] Performance testing showed that the senna leaf catalyst prepared in this embodiment has excellent performance, and the senna leaf catalyst prepared by the method in this embodiment has great application potential in the field of uranium extraction from seawater.
[0047] The scanning electron microscope (SEM) image of the senna leaf catalyst prepared in this embodiment is similar to that in Example 1, and will not be repeated here. Figure 5 This is a graph showing the catalytic activity of the senna leaf catalyst prepared in Example 3 at different concentrations of uranyl ion solutions. Figure 5 It is evident that the senna leaf catalyst prepared in this embodiment maintains excellent catalytic activity stably in environments with varying concentrations of uranyl ions. Furthermore, regardless of the uranyl ion concentration, it efficiently and selectively extracts uranyl ions. This characteristic fully demonstrates the strong recognition ability and catalytic stability of the senna leaf catalyst for uranyl ions, unaffected by fluctuations in the concentration of uranyl ions in the water. It can adapt to the complex scenarios of varying uranyl ion concentrations in actual uranium-containing water bodies, providing reliable technical support for the recovery of different types of uranium resources, including low-concentration and high-concentration uranium resources, further broadening its practical application scope and industrial value. In summary, the senna leaf catalyst provided by this invention exhibits good stability and cycling stability; after 15 cycles, its catalytic capacity remains above 85% of its original value.
[0048] Example 4 A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, weigh 2.0g of clean senna leaves and prepare 4g of sacrificial agent. The mass ratio of senna leaves to sacrificial agent is 1:2. The sacrificial agent is a mixture of methanol and NaOH solution. The NaOH solution is 0.1M, and the volume ratio of methanol to NaOH solution is 1:1. Add the mixture to a 25mL beaker. When mixing senna leaves and sacrificial agent, use a magnetic stirring rotor for mechanical stirring and constant temperature ultrasonic treatment. After mechanical stirring at 80 rpm and constant temperature ultrasonic dispersion treatment at 60kHz, the sacrificial agent solution fully wets the pore structure of senna leaves, so that all the added sacrificial agent is absorbed by senna leaves. After mixing senna leaves and sacrificial agent for 5min, senna leaf catalyst is obtained.
[0049] S2: Senna leaf catalyst was mixed with seawater at a mass ratio of 1:50000 and reacted under light irradiation at a wavelength of 780nm for 24 days at 35℃ to catalyze the production of uranyl peroxide tetrahydrate.
[0050] In this embodiment, the daily average concentration of uranyl peroxide tetrahydrate obtained by each milligram of senna leaf catalyst is 0.16~0.23 mg, the daily average seawater treatment is 0.42~0.56 L, the uranium content of the product is 60.0-65.6%, the cost of senna leaf catalyst is 10.2-16.5 yuan / kg, and it can still maintain ≥85% catalytic capacity after 5-15 cycles.
[0051] The scanning electron microscope image of the senna leaf catalyst prepared in this embodiment is similar to that in Example 1, and will not be repeated here. Performance testing shows that the senna leaf catalyst prepared in this embodiment has excellent performance. The senna leaf catalyst prepared by the method in this embodiment has great application potential in the field of uranium extraction from seawater.
[0052] Figure 8 The diagram shows the catalytic performance of the senna leaf catalyst in Examples 1, 3, and 4 with different ratios of methanol and sodium hydroxide as sacrificial agents. As can be seen from the diagram, when the volume ratio of methanol to sodium hydroxide is 1:1.5, the catalytic activity of the catalyst reaches its optimal level, and the extraction efficiency and reaction stability of uranyl ions are both at the best level. It can effectively achieve the catalytic extraction of uranyl ions, and the overall catalytic process meets the process requirements for industrial application and can be directly applied to actual production scenarios.
[0053] Example 5 A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, weigh 2.0g of clean senna leaves and prepare 10g of sacrificial agent. The mass ratio of senna leaves to sacrificial agent is 1:5. The sacrificial agent is a mixture of methanol and NaOH solution. The NaOH solution is 0.05M, and the volume ratio of methanol to NaOH solution is 1:2. Add the mixture to a 25mL beaker. When mixing senna leaves and sacrificial agent, use a magnetic stirring rotor for mechanical stirring and constant temperature ultrasonic treatment. After mechanical stirring at 60 rpm and constant temperature ultrasonic dispersion treatment at 40kHz, the sacrificial agent solution fully wets the pore structure of senna leaves, so that all the added sacrificial agent is absorbed by senna leaves. After mixing senna leaves and sacrificial agent for 2min, senna leaf catalyst is obtained.
[0054] S2: Senna leaf catalyst was mixed with seawater at a mass ratio of 1:250000 and reacted under light irradiation at a wavelength of 400nm. The reaction was carried out at 0℃ for 18 days to catalyze the production of uranyl peroxide tetrahydrate.
[0055] In this embodiment, the daily average concentration of uranyl peroxide tetrahydrate obtained by each milligram of senna leaf catalyst is 0.16~0.23 mg, the daily average seawater treatment is 0.42~0.56 L, the uranium content of the product is 60.0-65.6%, the cost of senna leaf catalyst is 10.2-16.5 yuan / kg, and it can still maintain ≥85% catalytic capacity after 5-15 cycles.
[0056] The scanning electron microscope image of the senna leaf catalyst prepared in this embodiment is similar to that in Example 1, and will not be repeated here. Performance testing shows that the senna leaf catalyst prepared in this embodiment has excellent performance. The senna leaf catalyst prepared by the method in this embodiment has great application potential in the field of uranium extraction from seawater.
[0057] Example 6 A method for preparing a senna leaf catalyst for uranium extraction from seawater includes the following steps: S1: At room temperature, weigh 2.0g of clean senna leaves and prepare 8g of sacrificial agent. The mass ratio of senna leaves to sacrificial agent is 1:4. The sacrificial agent is a mixture of methanol and NaOH solution. The NaOH solution is 1M, and the volume ratio of methanol to NaOH solution is 1:1. Add the mixture to a 25mL beaker. When mixing senna leaves and sacrificial agent, use a magnetic stirring rotor for mechanical stirring and constant temperature ultrasonic treatment. After mechanical stirring at 120 rpm and constant temperature ultrasonic dispersion treatment at 80kHz, the sacrificial agent solution fully wets the pore structure of senna leaves, so that all the added sacrificial agent is absorbed by senna leaves. After mixing senna leaves and sacrificial agent for 5min, senna leaf catalyst is obtained.
[0058] S2: Senna leaf catalyst was mixed with seawater at a mass ratio of 1:50000 and reacted under light irradiation at a wavelength of 780nm for 24 days at 35℃ to catalyze the production of uranyl peroxide tetrahydrate.
[0059] In this embodiment, the daily average concentration of uranyl peroxide tetrahydrate obtained by each milligram of senna leaf catalyst is 0.16~0.23 mg, the daily average seawater treatment is 0.42~0.56 L, the uranium content of the product is 60.0-65.6%, the cost of senna leaf catalyst is 10.2-16.5 yuan / kg, and it can still maintain ≥85% catalytic capacity after 5-15 cycles.
[0060] The scanning electron microscope image of the senna leaf catalyst prepared in this embodiment is similar to that in Example 1, and will not be repeated here. Performance testing shows that the senna leaf catalyst prepared in this embodiment has excellent performance. The senna leaf catalyst prepared by the method in this embodiment has great application potential in the field of uranium extraction from seawater.
[0061] Comparative Example Professor Ma Shengqian and Professor Sun Qi's research group published their work in *ACS Central Science* (DOI: ) in 2021. 10.1021 / acscentsci.1c00906 A novel report describes a metallo-oxime-based porous organic polymer (POP1-AO) for uranium extraction from seawater. This material utilizes an adsorption method to treat seawater, and under laboratory conditions (processing capacity 18.93 L), the adsorption equilibrium time reaches 56 days, significantly longer than the 18-24 days of this invention. The yield of uranium per unit area is 0.05 mg / g. - ¹·d - ¹, only the senna leaf catalyst of this invention (0.293-0.295 mg·g) - ¹·d - ¹) is about 1 / 6 of that. In addition, the literature does not specify the uranium purity of the product. In summary, POP1-AO has defects such as low processing efficiency, long reaction cycle and unclear product purity. Compared with the present invention, it has significant gaps in uranium extraction efficiency, reaction rate and engineering practicality, and is difficult to meet the actual needs of efficient seawater uranium extraction.
[0062] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.
[0063] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A method for preparing a senna leaf catalyst for uranium extraction from seawater, characterized in that: Includes the following steps: S1: At room temperature, senna leaves and a sacrificial agent are mixed in a certain mass ratio to obtain a senna leaf catalyst; wherein the sacrificial agent is a mixture of methanol and NaOH solution; S2: Senna leaf catalyst is mixed with seawater and reacted under light of a certain wavelength to catalyze the production of uranyl peroxide tetrahydrate.
2. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S1, the mass ratio of senna leaves to sacrificial agent is 1:5-1:
1.
3. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S1, senna leaves are mixed with a sacrificial agent for 2-5 minutes to obtain a senna leaf catalyst.
4. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S1, the volume ratio of methanol to NaOH solution is 1:2 to 1:
1.
5. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S1, the concentration of NaOH is 0.05M-1M.
6. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S2, senna leaf catalyst is mixed with seawater at a mass ratio of 1:250000-1:50000.
7. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S2, the reaction is carried out under light irradiation with wavelengths of 400-780 nm to catalyze the production of uranyl peroxide tetrahydrate.
8. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S2, the reaction conditions are 0℃-35℃, and the reaction time is 18-24 days.
9. The method for preparing senna leaf catalyst for uranium extraction from seawater according to claim 1, characterized in that: In S1, when senna leaves are mixed with the sacrificial agent, they are mechanically stirred by a magnetic stirring rotor and subjected to constant temperature ultrasonic treatment; the stirring speed is 60 rpm to 120 rpm; the ultrasonic frequency during constant temperature ultrasonic treatment is 40 kHz to 80 kHz.
10. The application of the senna leaf catalyst prepared by the method for preparing uranium extraction from seawater according to any one of claims 1-9 in the field of uranium extraction from seawater.