A separation method and separation device for the deep processing of nuclides

Abstract

The application discloses a separation method and a separation device for nuclide deep treatment. 12 The nanoparticles are dispersed on the surface of the ZIS nanoflower, and a CsPMo 12 / ZIS composite photocatalyst with an S-type heterojunction is successfully constructed, and then is added into nuclide waste liquid to perform a photocatalytic reduction reaction in a photocatalytic separation device. 12 In the photocatalytic process, the S-type heterojunction of the prepared CsPMo / ZIS composite photocatalyst has a strong built-in electric field driving force and a close interface contact, which is beneficial to realize efficient interface charge separation and transfer, provides a strong driving force for the generation of active species ·H, realizes efficient enrichment and separation of uranium in a high-concentration uranyl carbonate solution, and provides a new idea for efficient photocatalytic reduction of uranyl carbonate.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic functional materials technology, and more specifically, it relates to a separation method and separation device for deep processing of radionuclides. Background Technology

[0002] Nuclear energy, as a clean, stable, and efficient energy source, is a strategic pillar for my country's construction of a new energy system and the guarantee of energy security. my country's nuclear energy industry has entered a new stage of high-quality development, the fundamental guarantee of which lies in the safe and efficient management of radioactive materials throughout the entire nuclear fuel cycle. Nuclide separation technology runs through the entire process of resource recovery, waste volume reduction, and safe disposal, directly affecting the efficiency of uranium resource utilization, the long-term risks of high-level radioactive waste, and ecological security. It is a key manifestation of a country's nuclear science and technology strength and safety management level. Currently, the continuous expansion of nuclear energy scale has placed higher demands on radioactive waste management: efficient recovery of uranium resources from uranium mine wastewater must be achieved at the front end; during nuclear power plant operation, the efficient removal of nuclides such as cesium, uranium, and strontium directly affects operational safety. For example, in nuclear fuel reprocessing and uranium mining and metallurgy, large amounts of radioactive solutions containing high concentrations of carbonates are generated, such as carbonate leaching solutions and alkaline leaching mother liquors. Uranium in these systems mainly exists as the extremely stable uranyl tricarbonate complex [UO2(CO3)3]. 4- It exists in form, and its high stability (k≈2×10) 18 This presents a significant challenge to traditional adsorption and precipitation methods, which suffer from poor selectivity and low efficiency. Utilizing photocatalysis to reduce soluble U(VI) to insoluble U(IV) is a highly promising approach. However, achieving [UO2(CO3)3]... 4- The efficient reduction of uranium requires photocatalysts to possess not only a sufficiently negative reduction potential to overcome thermodynamic barriers but also to achieve efficient separation of photogenerated carriers. This presents a difficult contradiction to achieve simultaneously for single-component catalysts, placing high demands on the system construction of photocatalytic reactions. Furthermore, the uranium separation efficiency of materials in higher concentration carbonate solutions still needs improvement. Therefore, developing new technologies for the efficient reduction and separation of uranium in uranyl carbonate solutions is of dual significance for the safe disposal of nuclear waste and the recycling of uranium.

[0003] Carbonate concentration has a significant impact on the photocatalytic reduction of uranium. Firstly, carbonate concentration directly affects the complexation mode between carbonate and uranyl ions; as carbonate concentration changes, the complexation of uranyl carbonate (UO2(CO3)) with uranyl ions increases. n 2-2n The form in which carbonates exist (n=1, 2, 3) change. When the carbonate concentration is low, it may exist as a complex with a lower coordination number; while when the carbonate concentration increases, it will form a stable complex with a higher coordination number, such as [UO2(CO3)3]. 4-The high stability of these complexes significantly reduces the reactivity of uranyl ions. From an electron transfer perspective, the stable complex structure results in a more compact electron cloud distribution for uranyl ions, making them less susceptible to photogenerated electron attacks and thus hindering the reduction reaction. Simultaneously, high concentrations of carbonate adsorbate extensively on the photocatalyst surface, severely occupying the active sites. This significant reduction in active sites prevents uranyl ions from effectively contacting the catalyst surface, blocking the photogenerated charge transfer pathway and greatly shrinking the effective area for the photocatalytic reaction. From a chemical bonding perspective, the coordination bonds between carbonate and uranyl ions alter the charge distribution around the uranyl ions, leading to [UO2(CO3)3] 4- The reduction potential of uranyl carbonate is as high as -0.85 V, making reduction difficult. Therefore, developing a method to reduce uranyl carbonate under high carbonate concentration conditions is of great significance for the efficient reduction and separation of uranium in uranyl carbonate solution. Summary of the Invention

[0004] One object of the present invention is to at least solve the above-mentioned problems or defects and to provide a technical solution whose advantages will be described later.

[0005] To achieve these and other advantages of the present invention, a method for separation through deep processing of radionuclides is provided, comprising: preparing CsPMo 12 / ZIS composite photocatalyst, then added to radionuclide waste liquid and ultrasonically dispersed evenly, and then photocatalytically reduced radionuclide uranium in a photocatalytic separation device to achieve deep treatment of radionuclide uranium; Among them, CsPMo 12 The specific preparation method of / ZIS composite photocatalyst is as follows: Step 1: Add phosphomolybdic acid hydrate to anhydrous ethanol and sonicate to dissolve, forming solution A; add cesium carbonate to anhydrous ethanol and stir to dissolve, forming solution B. Slowly pour solution A into solution B while stirring, centrifuge, wash with anhydrous ethanol, and vacuum dry the obtained sample to obtain CsPMo. 12 ; Step 2: Add zinc chloride, indium chloride tetrahydrate, and thioacetamide to ethylene glycol and stir to form a homogeneous mixture. Transfer the mixture to a reaction vessel and heat to react. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample to obtain zinc indium sulfide (ZIS). Step 3: Disperse ZIS in a mixed solution of pure water and anhydrous ethanol, stir, and then add CsPMo to the mixed solution. 12 Continue stirring, then filter and collect the sample. Freeze-dry the obtained sample to obtain the S-type heterojunction CsPMo. 12 / ZIS refers to composite photocatalyst materials.

[0006] Preferably, the photocatalytic separation device includes: a primary uranium solution tank, a catalytic reaction mechanism, and a uranium solution product tank. The primary uranium solution tank is connected to the catalytic reaction mechanism via an electric pump, and the catalytic reaction mechanism is connected to the uranium solution product tank via an electric pump.

[0007] Preferably, the catalytic reaction mechanism includes: a magnetic stirrer on which a photocatalytic reaction vessel is mounted, the photocatalytic reaction vessel being connected to a gas cylinder, and a light source being mounted above the photocatalytic reaction vessel.

[0008] Preferably, the radionuclide waste liquid is uranyl carbonate waste liquid.

[0009] Preferably, the uranyl carbonate waste liquid and CsPMo 12 The ratio of / ZIS composite photocatalyst is 40~60mL:10~15mg, the uranium concentration of the uranyl carbonate waste liquid is 100~120mg / L, the carbonate concentration of the uranyl carbonate waste liquid is 10~90mM, and the ultrasonic treatment is performed at 20~40kHz for 2~5min.

[0010] Preferably, in step one, the ratio of phosphomolybdic acid hydrate to anhydrous ethanol is 2-4:100mL, the ultrasonic treatment is performed at 20-40kHz for 5-10min, and the ratio of cesium carbonate to anhydrous ethanol is 240-360mg:100mL.

[0011] Preferably, in step one, the volume ratio of solution A to solution B is 1~2:1~2, and when mixing solution A and solution B, the mixture is stirred at 600~800 rpm for 6~8 hours, and the vacuum drying temperature is 60~80℃ for 12~18 hours.

[0012] Preferably, in step two, the ratio of zinc chloride, indium chloride tetrahydrate, thioacetamide, and ethylene glycol is 1-2 mmol: 2-5 mmol: 4-10 mmol: 60-100 mL, the mixture is stirred at 600-800 rpm for 30-60 min, heated to 160-200°C for 12-18 h, and freeze-dried at -10 to -20°C for 24-36 h.

[0013] Preferably, in step three, the volume ratio of ZIS to the mixed solution is 100-200 mg: 30-60 mL, the volume ratio of pure water to anhydrous ethanol is 1:1, and CsPMo... 12 The mass ratio of ZIS to ZIS is 1~9:100~200, and the mixture is stirred at 600~800 rpm for 0.1~12 h. The freeze-drying temperature is -10~-20℃, and the freeze-drying time is 12~16 h.

[0014] Preferably, the CsPMo obtained in step one... 12 The modification is carried out by means of: S11, CsPMo 12 Add phosphoric acid, heat to dissolve, then add choline solution, continue heating and stirring to obtain solution C, and continue heating. S12. Dissolve zinc nitrate in water, heat and stir to form solution D. Slowly pour solution D into solution C, heat and stir for a period of time, then gradually lower the temperature of the mixed solution, and then cool to crystallize. Freeze-dry the precipitated solid to obtain modified CsPMo. 12 .

[0015] Preferably, in S11, CsPMo 12 The ratio of phosphoric acid to choline solution is 1~2g:100~150mL:50~75mL, the phosphoric acid concentration is 60%~85%, the temperature is heated to 60~80℃, the stirring speed is 300~400rpm, and the stirring time is 1~2h. The choline solution concentration is 0.01~0.02g / L. In S12, the ratio of zinc nitrate to water is 0.1~0.2g:100~200mL, the volume ratio of solution C to solution D is 1~2:0.8~1, the heating temperature is 60~80℃, the stirring speed is 500~600rpm, and the stirring time is 0.5~1h. The freeze-drying temperature is -10~-20℃, and the freeze-drying time is 4~6h.

[0016] The present invention has the following beneficial effects: It utilizes polyoxometalate CsPMo 12 Nanoparticles were dispersed on the surface of ZIS nanoflowers to successfully construct CsPMo with an S-shaped heterostructure. 12 / ZIS composite photocatalyst, to prepare CsPMo 12 The ZIS composite photocatalyst was used for the photocatalytic reduction of uranium-containing waste liquid under a high-concentration carbonate background. During the photocatalytic process, the strong built-in electric field and tight interfacial contact of the S-type heterojunction facilitated efficient interfacial charge separation and transfer, providing a powerful impetus for the generation of the active species ·H. Compared to single-component catalysts, the composite catalyst achieved more efficient uranium reduction and separation: namely, the separation of 0.25 g / L 3-CsPMo within 60 min. 12 / ZIS reduced and separated approximately 76% of the uranium in an 80 mM sodium bicarbonate solution, yielding CsPMo with an S-type heterojunction. 12 The / ZIS composite photocatalyst has a strong reducing ability, which enables the efficient enrichment and separation of uranium in uranyl carbonate solution, providing a new approach for the efficient photocatalytic reduction of uranyl carbonate.

[0017] This invention also involves CsPMo 12 To modify it, first dissolve CsPMo in concentrated phosphoric acid.12 Then, choline solution and zinc nitrate solution were added sequentially to obtain choline-substituted and zinc-doped modified CsPMo. 12 The introduced choline can form a strong electrostatic interaction with bicarbonate ions in uranyl carbonate solution, reducing HCO3-. - With [UO2(CO3)3] 4- The electrostatic repulsion generated by the competition for reaction sites promotes the catalytic reaction, while the doped zinc element can work together with indium zinc sulfide to further enhance the photocatalytic ability of the composite photocatalyst. Attached Figure Description

[0018] Figure 1 CsPMo in this invention 12 ZIS and 3-CsPMo 12 SEM images of / ZIS, 3-CsPMo 12 / ZIS HRTEM diagram and EDS element mapping diagram; Figure 2 ZIS and CsPMo in Example 2 12 UV-Vis diffuse reflectance spectra of 3-CsPMo12 / ZIS; Figure 3 CsPMo in Example 2 12 Migration path diagram of photogenerated carriers in ZIS composite materials; Figure 4 ZIS and CsPMo in Example 2 12 and 3-CsPMo 12 Photoluminescence spectrum, time-resolved photoluminescence spectrum, photocurrent density curve and electrochemical impedance spectroscopy of / ZIS; Figure 5 This is a comparison chart of the photocatalytic separation performance of various materials in uranyl nitrate solution in Application Example 1; Figure 6 For example 2, 3-CsPMo 12 / ZIS and CsPMo 12 ZIS in 20 mM HCO3 - Comparison of photocatalytic uranium separation performance at different concentrations; Figure 7 For example 4, 3-CsPMo 12 / ZIS at 20 mM HCO3 - Cyclic stability test graph at different concentrations; Figure 8 For example 3-CsPMo 12 / ZIS in different HCO3 - Photocatalytic uranium separation efficiency at various concentrations; Figure 9For example 2, 3-CsPMo 12 / ZIS and 3-CsPMo 12 / ZIS-a、3-CsPMo 12 / ZIS-b、3-CsPMo 12 / ZIS-c at 20 mM HCO3 - Comparison of photocatalytic uranium separation performance at different concentrations; Figure 10 This is a schematic diagram of the photocatalytic separation device in this invention.

[0019] Figure reference numerals: 1. Uranium solution primary pool; 2. Catalytic reaction mechanism; 21. Magnetic stirrer; 22. Photocatalytic reaction vessel; 23. Gas cylinder; 24. Light source; 3. Uranium solution product pool; 42. Electric pump. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0021] Example 1 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 3: Disperse 100 mg ZIS in a mixture of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 1 mg CsPMo to the mixture. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain the S-type heterojunction 1-CsPMo. 12 / ZIS refers to composite photocatalyst materials.

[0022] Example 2 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 3: Disperse 100 mg ZIS in a mixture of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg CsPMo to the mixture. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain the S-type heterojunction 3-CsPMo. 12 / ZIS refers to composite photocatalyst materials.

[0023] Example 3 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 3: Disperse 100 mg ZIS in a mixture of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 6 mg CsPMo to the mixture. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain the S-type heterojunction 6-CsPMo. 12 / ZIS refers to composite photocatalyst materials.

[0024] Example 4 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 3: Disperse 100 mg ZIS in a mixture of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 9 mg CsPMo to the mixture. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain the S-type heterojunction 9-CsPMo. 12 / ZIS refers to composite photocatalyst materials.

[0025] Example 5 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo.12 ; Step 2: Add 2g of CsPMo 12 Add 100 mL of 85% phosphoric acid, heat to 80 °C and stir to dissolve. Then add 50 mL of 0.02 g / L choline solution, continue heating and stirring at 300 rpm for 2 h to obtain solution C, and maintain heating for later use. Dissolve 0.2 g of zinc nitrate in 100 mL of water, heat to 80 °C and stir until homogeneous to form solution D. Slowly pour 80 mL of solution D into 100 mL of solution C, heat and stir at 600 rpm for 0.5 h, then gradually lower the temperature of the mixed solution, and then cool to crystallize. Freeze-dry the precipitated solid at -10 °C for 6 h to obtain modified CsPMo. 12 ; Step 3: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 4: Disperse 100 mg ZIS in a mixed solution of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg modified CsPMo to the mixed solution. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain 3-CsPMo. 12 / ZIS-a.

[0026] Example 6 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 2g of CsPMo 12Add 100 mL of 85% phosphoric acid, heat to 80 °C and stir to dissolve. Then add 50 mL of 0.02 g / L choline solution, continue heating and stirring at 300 rpm for 2 h to obtain solution C. Maintain heating and set aside. Gradually lower the temperature of solution C, then cool to crystallize. Freeze-dry the precipitated solid at -10 °C for 6 h to obtain modified CsPMo. 12 ; Step 3: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 4: Disperse 100 mg ZIS in a mixed solution of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg modified CsPMo to the mixed solution. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain 3-CsPMo. 12 / ZIS-b.

[0027] Example 7 A method for preparing a composite photocatalyst material includes the following steps: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 2g of CsPMo 12 Add 100 mL of 85% phosphoric acid, heat to 80 °C and stir to dissolve, obtaining solution C. Maintain heating and set aside. Dissolve 0.2 g of zinc nitrate in 100 mL of water, heat to 80 °C and stir until homogeneous to form solution D. Slowly pour 80 mL of solution D into 100 mL of solution C, heat and stir at 600 rpm for 0.5 h, then gradually lower the temperature of the mixed solution, and then cool to crystallize. Freeze-dry the precipitated solid at -10 °C for 6 h to obtain modified CsPMo. 12 ; Step 3: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 4: Disperse 100 mg ZIS in a mixed solution of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg modified CsPMo to the mixed solution. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain 3-CsPMo. 12 / ZIS-c.

[0028] Figure 1 CsPMo in this invention 12 ZIS and 3-CsPMo 12 SEM images of / ZIS (corresponding to a, b, and c from left to right), 3-CsPMo 12 HRTEM image (Fig. d) and EDS elemental mapping (Fig. e) of CsPMo / ZIS; as shown in Fig. a, CsPMo / ZIS is an irregular nanoparticle; as shown in Fig. b, the nanoflower structure has a large specific surface area, thus exposing more reactive sites. These two materials were placed in an aqueous solution and stirred to allow CsPMo / ZIS to react. 12 CsPMo is uniformly distributed on the ZIS surface, as shown in Figure c, forming a structure. 12 The / ZIS composite photocatalyst clearly showed lattice fringes with spacings of 0.32, 0.19, and 0.33 nm under high-resolution transmission electron microscopy (HRTEM), corresponding to the (102) and (110) planes of indium zinc sulfide and the (222) plane of cesium phosphomolybdate, respectively (Fig. d). The clear lattice fringes indicate good crystallinity of the material, which is beneficial to charge separation during the photocatalytic process. At the same time, CsPMo can be seen in the HRTEM image. 12 The crystal boundary between CsPMo and ZIS fully verifies the successful construction of the heterojunction interface engineering; energy dispersive X-ray spectroscopy (EDS) was used to analyze CsPMo. 12 The elemental composition and distribution in / ZIS were analyzed, as shown in Figure e. Zn, In, S, Cs, P, Mo and O elements are uniformly distributed in the composite material.

[0029] Figure 2 ZIS and CsPMo in Example 2 12 and 3-CsPMo 12The UV-Vis diffuse reflectance spectrum of / ZIS, from Figure 2 It can be seen that when ZIS and CsPMo 12 After compounding, CsPMo 12 The enhanced light absorption capacity of / ZIS means that the formation of the heterojunction significantly improves the catalyst's efficiency in utilizing light, generating more charge carriers to participate in the reaction under illumination.

[0030] Figure 3 CsPMo in Example 2 12 Migration path diagram of photogenerated carriers in ZIS composite materials; from Figure 3 It can be seen that ZIS and CsPMo 12 Both exhibit S-type heterojunction characteristics. Due to the difference in their work functions, after contact, electrons will diffuse from ZIS to CsPMo before reaching equilibrium. 12 Electron transfer creates a built-in electric field near the interface between the two semiconductors, leading to band bending in the semiconductor. Under illumination, some electrons in the semiconductor transition from the valence band to the conduction band, leaving holes in the valence band. Under the combined effects of the built-in electric field and band bending, CsPMo... 12 Photogenerated electrons in the conduction band tend to recombine with photogenerated holes in the ZIS valence band, while holes and electrons with stronger redox capabilities are retained, significantly improving the separation efficiency of photogenerated charges.

[0031] Figure 4 ZIS, CsPMo 12 and 3-CsPMo 12 The photoluminescence spectrum (Fig. a), time-resolved photoluminescence spectrum (Fig. b), photocurrent density curve (Fig. c), and electrochemical impedance spectroscopy (Fig. d) of ZIS are shown in Fig. a. As shown in Fig. a, ZIS exhibits a distinct fluorescence peak at 650 nm, indicating that most photogenerated charges in ZIS are highly susceptible to recombination. However, CsPMo... 12 The fluorescence peak intensity of / ZIS at this location is significantly weakened; meanwhile, 3-CsPMo 12 The fluorescence peak of / ZIS at 430 nm is also greater than that of CsPMo. 12 Weak. PL (photoluminescence spectroscopy) results indicate that 3-CsPMo 12 Charge recombination in the / ZIS composite photocatalyst was significantly suppressed, and a large number of photogenerated charges separated and migrated to the catalyst surface to participate in redox reactions. Furthermore, TR-PL (time-resolved photoluminescence spectroscopy) measurements were performed at an excitation wavelength of 317 nm, as shown in Figure b, for 3-CsPMo 12 The fluorescence lifetime of / ZIS was 3.32 ns, lower than that of ZIS (3.57 ns). This indicates that compared to ZIS, 3-CsPMo 12More photogenerated charges were effectively separated and transferred in / ZIS. Subsequently, in transient photocurrent testing (Fig. c), 3-CsPMo 12 / ZIS exhibits a stronger photocurrent response than ZIS, indicating that CsPMo 12 The heterojunction interface formed with ZIS provides better migration and separation of photogenerated charges. Meanwhile, the charge transport capabilities of the three materials were evaluated using electrochemical impedance spectroscopy (EIS) analysis. In the EIS plot, the smaller the radius of the Nyquist curve, the lower the electron transport resistance, and the easier it is for photogenerated carriers to migrate. As shown in Figure d, compared with pure ZIS, 3-CsPMo… 12 The smaller arc radius of / ZIS indicates reduced interfacial charge transfer resistance and improved electron transfer, which is beneficial for photocatalytic reactions. Pure CsPMo 12 It exhibits a smaller semi-circular diameter due to its reversible redox properties. In summary, combining the above photoelectric analysis results, the successful construction of the S-type heterojunction significantly enhances the performance of CsPMo. 12 / ZIS improves the photogenerated charge separation efficiency and transport rate, thereby largely suppressing the radiative recombination of photogenerated charges and increasing the utilization rate of photogenerated charges in the photocatalytic process, making CsPMo 12 / ZIS exhibits highly efficient photocatalytic performance.

[0032] Example 8 A separation device for deep processing of radionuclides includes: a primary uranium solution pool 1, a catalytic reaction mechanism 2, and a product uranium solution pool 3. The primary uranium solution pool 1 is connected to the catalytic reaction mechanism 2 via an electric pump 41, and the catalytic reaction mechanism 2 is connected to the product uranium solution pool 3 via an electric pump 42.

[0033] The catalytic reaction mechanism 2 includes: a magnetic stirrer 21, on which a photocatalytic reaction vessel 22 is mounted, the photocatalytic reaction vessel 22 is connected to a gas cylinder 23, and a light source 24 is mounted above the photocatalytic reaction vessel 22.

[0034] Working principle: The uranyl carbonate waste liquid to be treated in the primary uranium solution pool 1 is pumped into the photocatalytic reaction vessel 22 of the catalytic reaction unit 2 by electric pump 41. After the composite photocatalyst is added and evenly dispersed, nitrogen gas is introduced through gas cylinder 23 to form an oxygen-free atmosphere. Then, the magnetic stirrer 21 is turned on to carry out the dark reaction. After the dark reaction is completed, the light source 24 is turned on to carry out the photoreaction. After the photoreaction is completed, the resulting reaction liquid is pumped into the uranium solution product pool 3 by electric pump 42 to complete the photocatalytic reduction of the uranyl carbonate waste liquid.

[0035] A separation method for deep processing of radionuclides, comprising: In such Figure 10In the photocatalytic separation device shown, 40L of uranyl carbonate waste liquid with a uranium concentration of 100mg / L (bicarbonate concentration of 10mM) from the primary uranium solution cell 1 is pumped into the photocatalytic reactor 22 via electric pump 41. Then, 10g of 3-CsPMo is added to the photocatalytic reactor 22. 12 The ZIS-a composite photocatalyst was ultrasonically treated at 20 kHz for 5 min to disperse it evenly. Argon gas was bubbled through gas cylinder 24 for 1 h, and magnetic stirrer 21 was started for stirring. Argon gas was continuously introduced during the reaction, and stirring was carried out continuously at 200 rpm for 5 h to ensure that the adsorption-desorption equilibrium was reached and the dark reaction was completed. Then, the reaction solution after the dark reaction was completed was irradiated with a 300 W xenon lamp as the light source 23 for 60 min. The reaction solution after the reaction was completed was then pumped into the uranium solution product pool 3 through electric pump 42. During the process, 0.5 mL of the reaction solution was drawn up with a syringe every 10 min of illumination, and then filtered through a 0.22 μm polyethersulfone pinhole membrane to collect the clear solution. The clear solutions collected at different time points were subjected to a colorimetric reaction with azoarsine III. Finally, the absorbance value of the colorimetric solution at a wavelength of 651.8 nm was measured using a UV spectrophotometer. Then, according to the standard curve of uranium concentration, the absorbance value of the solution was converted into the residual U(VI) concentration in the solution, and the residual U(VI) concentration in the solution was found to be 0.21 mg / L, with a uranium separation efficiency of 99.79%. Among them, 3-CsPMo 12 The preparation method of / ZIS-a composite photocatalyst material is as follows: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 2g of CsPMo 12 Add 100 mL of 85% phosphoric acid, heat to 80 °C and stir to dissolve. Then add 50 mL of 0.02 g / L choline solution, continue heating and stirring at 300 rpm for 2 h to obtain solution C, and maintain heating for later use. Dissolve 0.2 g of zinc nitrate in 100 mL of water, heat to 80 °C and stir until homogeneous to form solution D. Slowly pour 80 mL of solution D into 100 mL of solution C, heat and stir at 600 rpm for 0.5 h, then gradually lower the temperature of the mixed solution, and then cool to crystallize. Freeze-dry the precipitated solid at -10 °C for 6 h to obtain modified CsPMo. 12 ; Step 3: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 4: Disperse 100 mg ZIS in a mixed solution of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg modified CsPMo to the mixed solution. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain 3-CsPMo. 12 / ZIS-a refers to composite photocatalyst materials.

[0036] Example 9 A separation method for deep processing of radionuclides, comprising: In such Figure 10 In the photocatalytic separation device shown, 40L of uranyl carbonate waste liquid with a uranium concentration of 100mg / L (bicarbonate concentration of 80mM) from the primary uranium solution cell 1 is pumped into the photocatalytic reactor 22 via electric pump 41. Then, 10g of 3-CsPMo is added to the photocatalytic reactor 22. 12 The ZIS-a composite photocatalyst was ultrasonically treated at 20 kHz for 5 min to disperse it evenly. Argon gas was bubbled through gas cylinder 24 for 1 h, and magnetic stirrer 21 was started for stirring. Argon gas was continuously introduced during the reaction, and stirring was carried out continuously at 200 rpm for 5 h to ensure that the adsorption-desorption equilibrium was reached and the dark reaction was completed. Then, the reaction solution after the dark reaction was completed was irradiated with a 300 W xenon lamp as the light source 23 for 60 min. The reaction solution after the reaction was completed was then pumped into the uranium solution product pool 3 through electric pump 42. During the illumination process, 0.5 mL of the reaction solution was drawn up with a syringe every 10 min, and then filtered through a 0.22 μm polyethersulfone pinhole membrane to collect the clear solution. The clear solutions collected at different time points were subjected to a colorimetric reaction with azoarsine III. Finally, the absorbance value of the colorimetric solution at a wavelength of 651.8 nm was measured using a UV spectrophotometer. Then, according to the standard curve of uranium concentration, the absorbance value of the solution was converted into the residual U(VI) concentration in the solution, and the residual U(VI) concentration in the solution was found to be 14.55 mg / L, with a uranium separation efficiency of 84.45%. Among them, 3-CsPMo 12 The preparation method of / ZIS-a composite photocatalyst material is as follows: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 2g of CsPMo 12 Add 100 mL of 85% phosphoric acid, heat to 80 °C and stir to dissolve. Then add 50 mL of 0.02 g / L choline solution, continue heating and stirring at 300 rpm for 2 h to obtain solution C, and maintain heating for later use. Dissolve 0.2 g of zinc nitrate in 100 mL of water, heat to 80 °C and stir until homogeneous to form solution D. Slowly pour 80 mL of solution D into 100 mL of solution C, heat and stir at 600 rpm for 0.5 h, then gradually lower the temperature of the mixed solution, and then cool to crystallize. Freeze-dry the precipitated solid at -10 °C for 6 h to obtain modified CsPMo. 12 ; Step 3: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 4: Disperse 100 mg ZIS in a mixed solution of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg modified CsPMo to the mixed solution. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain 3-CsPMo. 12 / ZIS-a refers to composite photocatalyst materials.

[0037] Example 10 A separation method for deep processing of radionuclides, comprising: In such Figure 10 In the photocatalytic separation device shown, 40L of uranyl carbonate waste liquid with a uranium concentration of 100mg / L (bicarbonate concentration of 80mM) from the primary uranium solution cell 1 is pumped into the photocatalytic reactor 22 via electric pump 41. Then, 10g of 3-CsPMo is added to the photocatalytic reactor 22. 12The ZIS composite photocatalyst was ultrasonically treated at 20 kHz for 5 min to disperse it evenly. Argon gas was bubbled through gas cylinder 24 for 1 h, and magnetic stirrer 21 was started for stirring. During the reaction, argon gas was continuously introduced and stirred at 200 rpm for 5 h to ensure that the adsorption-desorption equilibrium was reached and the dark reaction was completed. Then, the reaction solution after the dark reaction was completed was irradiated with a 300 W xenon lamp as the light source 23 for 60 min. The reaction solution after the reaction was completed was then pumped into the uranium solution product pool 3 through electric pump 42. During the illumination process, 0.5 mL of the reaction solution was drawn up with a syringe every 10 min, and then filtered through a 0.22 μm polyethersulfone pinhole membrane to collect the clear solution. The clear solutions collected at different time points were subjected to a colorimetric reaction with azoarsine III. Finally, the absorbance value of the colorimetric solution at a wavelength of 651.8 nm was measured using a UV spectrophotometer. Then, according to the standard curve of uranium concentration, the absorbance value of the solution was converted into the residual U(VI) concentration in the solution, and the residual U(VI) concentration in the solution was found to be 24.71 mg / L, with a uranium separation efficiency of 75.29%. Among them, 3-CsPMo 12 The preparation method of / ZIS composite photocatalyst material is as follows: Step 1: Add 2g of phosphomolybdic acid hydrate to 100mL of anhydrous ethanol and sonicate at 20kHz for 5min to form solution A; add 240mg of cesium carbonate to 100mL of anhydrous ethanol and stir for 20min to form solution B. Slowly pour solution A into solution B and stir at 600rpm for 6h. Wash three times with anhydrous ethanol by centrifugation. Dry the obtained sample under vacuum at 60℃ for 12h to obtain CsPMo. 12 ; Step 2: Add 1 mmol zinc chloride, 2 mmol indium chloride tetrahydrate, and 4 mmol thioacetamide to 60 mL ethylene glycol and stir at 600 rpm for 30 min to form a homogeneous mixture. Transfer the mixture to a 100 mL Teflon reactor and heat to 160 °C for 12 h. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample at -10 °C for 24 h to obtain ZIS. Step 3: Disperse 100 mg ZIS in a mixture of 15 mL pure water and 15 mL anhydrous ethanol. Stir at 600 rpm for 20 min, then add 3 mg CsPMo to the mixture. 12 Continue stirring for 12 hours, then filter and collect the sample. Freeze-dry the obtained sample at -10℃ for 12 hours to obtain the S-type heterojunction 3-CsPMo. 12 / ZIS refers to composite photocatalyst materials.

[0038] It should be noted that current research reports on the photocatalytic reduction and separation of uranium in carbonate solutions all use sodium bicarbonate as a solute to achieve a carbonate background. Therefore, this invention also continues to use bicarbonate ions as a carbonate background.

[0039] Subsequent application examples aim to verify the performance of the composite photocatalyst through small-scale laboratory experiments.

[0040] Application Example 1 CsPMo prepared in Examples 1-4 12 / ZIS composite photocatalyst and CsPMo 12 ZIS is used to promote the efficient photocatalytic reduction and separation of uranium under anaerobic and high carbonate concentration conditions. The specific method is as follows: At a concentration of 100 mg·L⁻¹ in 40 mL -1 The reaction mixture was placed in a uranyl nitrate solution, and then 10 mg of photocatalyst was added to the solution. The mixture was sonicated at 20 kHz for 2 min to ensure uniform dispersion of the catalyst. The reaction mixture was placed in a photocatalytic reaction device. To ensure an argon atmosphere, argon (Ar) gas was bubbled into the reaction mixture for 5 min to eliminate interference from other gases. Ar was continuously introduced during the subsequent reaction. The reaction was carried out in the dark for 30 min under magnetic stirring at 180 rpm to ensure that the photocatalyst reached the adsorption-desorption equilibrium for U(VI). After the dark reaction was completed, the reaction solution was irradiated with a 300 W xenon lamp (Perfect Light PLS-SXE 300 / 300 UV) as the light source. Every 10 minutes of irradiation, 0.5 mL of the reaction solution was drawn up with a syringe and then filtered through a 0.22 μm polyethersulfone pinhole filter membrane to collect the clear solution. The clear solutions collected at different time points were subjected to a colorimetric reaction with azoarsine III. Finally, the absorbance value of the colorimetric solution at a wavelength of 651.8 nm was measured with a UV spectrophotometer. Then, according to the standard curve of uranium concentration, the absorbance value of the solution was converted into the concentration of residual U(VI) in the solution.

[0041] Application Example 2 The CsPMo obtained in Examples 2 and 5-7 12 / ZIS composite photocatalyst and CsPMo 12 ZIS is used to promote the efficient photocatalytic reduction and separation of uranium under anaerobic and high carbonate concentration conditions. The specific method is as follows: At a concentration of 100 mg·L⁻¹ in 40 mL -1In a uranyl nitrate solution, 0.8 mmol of sodium bicarbonate (at which point the bicarbonate concentration is 20 mM) was added, and then 10 mg of photocatalyst was added to the above solution. The solution was sonicated at 20 kHz for 2 min to ensure uniform dispersion of the catalyst. The reaction solution was placed in a photocatalytic reaction device. To ensure an argon atmosphere, argon (Ar) gas was bubbled into the reaction solution for 5 min to eliminate interference from other gases. Ar was continuously introduced during the subsequent reaction. The reaction was carried out in the dark for 30 min under magnetic stirring at 180 rpm to ensure that the photocatalyst reached the adsorption-desorption equilibrium for U(VI). After the dark reaction was completed, the reaction solution was irradiated with a 300 W xenon lamp (Perfect Light PLS-SXE 300 / 300 UV) as the light source. Every 10 minutes of irradiation, 0.5 mL of the reaction solution was drawn up with a syringe and then filtered through a 0.22 μm polyethersulfone pinhole filter membrane to collect the clear solution. The clear solutions collected at different time points were subjected to a colorimetric reaction with azoarsine III. Finally, the absorbance value of the colorimetric solution at a wavelength of 651.8 nm was measured with a UV spectrophotometer. Then, according to the standard curve of uranium concentration, the absorbance value of the solution was converted into the concentration of residual U(VI) in the solution.

[0042] Application Example 3 Following the method of Application Example 2, the 3-CsPMo prepared in Example 2 was used. 12 The / ZIS composite photocatalyst was used to perform photocatalytic reduction of uranium at different bicarbonate concentrations (10~90mM).

[0043] Application Example 4 Following the method of Application Example 2, the 3-CsPMo prepared in Example 2 was used. 12 / ZIS composite photocatalyst, in 20 mM HCO3 - Cyclic stability tests were conducted at the specified concentrations.

[0044] Figure 5 This is a comparative graph showing the photocatalytic separation performance of various materials in uranyl nitrate solution in Application Example 1 of this invention; all prepared catalysts exhibit a certain level of uranyl ion (UO2) activity. 2+ Adsorption capacity is limited; however, under light irradiation, the surface charge of the catalyst is rearranged, leading to an decrease in the adsorbed UO2. 2+ It detaches. In the subsequent photocatalytic process, ZIS and CsPMo... 12 It exhibits a weak uranium reduction ability, but when the two are combined, its photocatalytic uranium reduction ability is significantly improved, 3-CsPMo 12 / ZIS exhibited the best uranium reduction capability, indicating that the construction of the S-type heterojunction significantly enhanced the photocatalytic performance of the catalyst, which is consistent with the conclusions of the photoelectric experiment.

[0045] Figure 6 For example 2, 3-CsPMo 12 / ZIS and CsPMo 12 ZIS in 20 mM HCO3 - A comparison chart of the performance of photocatalytic uranium separation at different concentrations; from Figure 6 It can be seen that, compared with pure ZIS and CsPMo 12 In comparison, the composite catalyst exhibited the best uranium reduction performance.

[0046] Furthermore, compared with various photocatalytic materials in the prior art, when extracting uranium from uranyl carbonate solution under an argon atmosphere, the present invention can handle higher uranium and carbonate concentrations with less time while achieving similar uranium separation efficiency (as shown in Table 1), demonstrating the superior performance of the 3-CsPMo prepared by the present invention. 12 / ZIS's ability to separate uranium from uranyl carbonate solution is also significantly higher than that of various existing photocatalytic materials.

[0047] Table 1 Material Uranium concentration Bicarbonate concentration reaction time Separation efficiency <![CDATA[3-CsPMo 12 / ZIS]]> 100 mg / L 60 mmol / L 60 min 95% <![CDATA[Carboxyl-g-C3N4]]> 23.8 mg / L 10 mmol / L 50 min 100% <![CDATA[Carboxyl-g-C3N4-CdS hydrogel]]> 23.8 mg / L 2 mmol / L 150 min 80% γ-FeOOH hydrogel 100 mg / L 2 mmol / L 120 min 92.3% <![CDATA[TiO2@PCN]]> 0.023 mg / L 2 mmol / L 210 min 95.8% Figure 7 For example 4, 3-CsPMo 12 / ZIS at 20 mM HCO3 - Cyclic stability test plot at concentration; from Figure 7 It can be seen that 3-CsPMo 12 The / ZIS maintained a uranium reduction rate of over 84% after four cycles, indicating that 3-CsPMo 12 / ZIS has good reusability and structural stability.

[0048] Figure 8 For example 3-CsPMo 12 / ZIS in different HCO3 - Photocatalytic uranium separation efficiency diagram at various concentrations; from Figure 8 It can be seen that 3-CsPMo 12 / ZIS showed higher HCO3 - The efficiency at certain concentrations, even at 80 mM HCO3 - Under the given conditions, it can also photocatalytically separate about 76% of uranium, which fully demonstrates that the construction of the S-type heterostructure significantly enhances the uranium separation efficiency of 3-CsPMo. 12 / ZIS's ability to photocatalytically separate uranium from uranyl carbonate solution.

[0049] Figure 9 For example 2, 3-CsPMo 12 / ZIS and 3-CsPMo 12 / ZIS-a、3-CsPMo 12 / ZIS-b、3-CsPMo 12 / ZIS-c at 20 mM HCO3 - A comparison chart of the performance of photocatalytic uranium separation at different concentrations; from Figure 9 As can be seen, Example 5, through the analysis of CsPMo 12 To modify it, first dissolve CsPMo in concentrated phosphoric acid. 12 Then, choline solution and zinc nitrate solution were added sequentially to obtain choline-substituted and zinc-doped modified CsPMo. 12 The introduced choline can form a strong electrostatic interaction with bicarbonate ions in uranyl carbonate solution, reducing HCO3-. - With [UO2(CO3)3] 4- The electrostatic repulsion generated by the competition for reaction sites promotes the catalytic reaction. The doped zinc element can also interact with indium zinc sulfide to further enhance the photocatalytic activity of the composite photocatalyst. (3-CsPMo) 12 / ZIS-a significantly enhances the uranium reduction ability of uranyl carbonate solution at high concentrations; Example 6 only affects CsPMo. 12 Choline modification was performed to obtain 3-CsPMo 12 / ZIS-b in high HCO3 - At the specified concentration, the reduction effect on uranium in uranyl carbonate solution was slightly worse than in Example 5, but still significantly better than in Example 2; Example 7 only reduced CsPMo 12 3-CsPMo was prepared by zinc doping modification. 12 / ZIS-c in high HCO3 - At the specified concentration, the reduction effect on uranium in uranyl carbonate solution was slightly greater than in Example 2, but significantly different from that in Example 5.

[0050] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A separation method for deep processing of radionuclides, characterized in that, include: Preparation of CsPMo 12 / ZIS composite photocatalyst, then added to radionuclide waste liquid and ultrasonically dispersed evenly, and then photocatalytically reduced radionuclide uranium in a photocatalytic separation device to achieve deep treatment of radionuclide uranium; Among them, CsPMo 12 The specific preparation method of / ZIS composite photocatalyst is as follows: Step 1: Add phosphomolybdic acid hydrate to anhydrous ethanol and sonicate to dissolve, forming solution A; add cesium carbonate to anhydrous ethanol and stir to dissolve, forming solution B. Slowly pour solution A into solution B while stirring, centrifuge, wash with anhydrous ethanol, and vacuum dry the obtained sample to obtain CsPMo. 12 ; Step 2: Add zinc chloride, indium chloride tetrahydrate, and thioacetamide to ethylene glycol and stir to form a homogeneous mixture. Transfer the mixture to a reaction vessel and heat to react. After cooling, collect the sample by centrifugation, wash the sample with pure water and anhydrous ethanol, and then freeze-dry the obtained sample to obtain zinc indium sulfide (ZIS). Step 3: Disperse ZIS in a mixed solution of pure water and anhydrous ethanol, stir, and then add CsPMo to the mixed solution. 12 Continue stirring, then filter and collect the sample. Freeze-dry the obtained sample to obtain the S-type heterojunction CsPMo. 12 / ZIS refers to composite photocatalyst materials.

2. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, The photocatalytic separation device includes: a primary uranium solution tank, a catalytic reaction mechanism, and a uranium solution product tank. The primary uranium solution tank is connected to the catalytic reaction mechanism via an electric pump, and the catalytic reaction mechanism is connected to the uranium solution product tank via an electric pump.

3. The separation method for deep processing of radionuclides as described in claim 2, characterized in that, The catalytic reaction mechanism includes: a magnetic stirrer on which a photocatalytic reaction vessel is mounted, the photocatalytic reaction vessel is connected to a gas cylinder, and a light source is mounted above the photocatalytic reaction vessel.

4. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, The radionuclide waste liquid is uranyl carbonate waste liquid.

5. The separation method for deep processing of radionuclides as described in claim 4, characterized in that, The uranyl carbonate waste liquid, CsPMo 12 The ratio of / ZIS composite photocatalyst is 40~60mL:10~15mg, the uranium concentration of the uranyl carbonate waste liquid is 100~120mg / L, the carbonate concentration of the uranyl carbonate waste liquid is 10~90mM, and the ultrasonic treatment is performed at 20~40kHz for 2~5min.

6. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, In step one, the ratio of phosphomolybdic acid hydrate to anhydrous ethanol is 2-4:100mL, and the mixture is sonicated at 20-40kHz for 5-10 minutes. The ratio of cesium carbonate to anhydrous ethanol is 240-360mg:100mL.

7. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, In step one, the volume ratio of solution A to solution B is 1~2:1~2. When mixing solution A and solution B, stir at 600~800 rpm for 6~8 hours, and vacuum dry at 60~80℃ for 12~18 hours.

8. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, In step two, the ratio of zinc chloride, indium chloride tetrahydrate, thioacetamide, and ethylene glycol is 1-2 mmol: 2-5 mmol: 4-10 mmol: 60-100 mL. The mixture is stirred at 600-800 rpm for 30-60 min, heated to 160-200 °C for 12-18 h, and then freeze-dried at -10 to -20 °C for 24-36 h.

9. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, In step three, the ratio of ZIS to the mixed solution is 100-200 mg: 30-60 mL, and the volume ratio of pure water to anhydrous ethanol is 1:

1. CsPMo 12 The mass ratio of ZIS to ZIS is 1~9:100~200, and the mixture is stirred at 600~800 rpm for 0.1~12 h. The freeze-drying temperature is -10~-20℃, and the freeze-drying time is 12~16 h.

10. The separation method for deep processing of radionuclides as described in claim 1, characterized in that, The CsPMo obtained in step one 12 The modification is carried out by means of: S11, CsPMo 12 Add phosphoric acid, heat to dissolve, then add choline solution, continue heating and stirring to obtain solution C, and continue heating. S12. Dissolve zinc nitrate in water, heat and stir to form solution D. Slowly pour solution D into solution C, heat and stir for a period of time, then gradually lower the temperature of the mixed solution, and then cool to crystallize. Freeze-dry the precipitated solid to obtain modified CsPMo. 12 ; In S11, CsPMo 12 The ratio of phosphoric acid to choline solution is 1~2g:100~150mL:50~75mL, the phosphoric acid concentration is 60%~85%, the temperature is heated to 60~80℃, the stirring speed is 300~400rpm, and the stirring time is 1~2h. The choline solution concentration is 0.01~0.02g / L. In S12, the ratio of zinc nitrate to water is 0.1~0.2g:100~200mL, the volume ratio of solution C to solution D is 1~2:0.8~1, the heating temperature is 60~80℃, the stirring speed is 500~600rpm, and the stirring time is 0.5~1h. The freeze-drying temperature is -10~-20℃, and the freeze-drying time is 4~6h.

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