Multifunctional cesium removal material with dynamic pore channel regulation and control function and specific adsorption sites, preparation method and application

Abstract

The invention provides a multifunctional cesium removal material with a dynamic pore channel regulation and control function and specific adsorption sites and a preparation method and application thereof, and the preparation method comprises the following steps: dispersing zirconium phosphate in a hydrochloric acid solution, and then adding a Prussian blue analogue to form a mixed dispersion liquid; adjusting the pH value of the mixed dispersion liquid to be neutral, carrying out a hydrothermal reaction, and centrifugally collecting a reaction product to obtain the zirconium phosphate-Prussian blue composite porous material, the zirconium phosphate and the Prussian blue analogue are compounded through a hydrothermal method, and the formed composite material has double adsorption mechanisms of dynamic pore channel regulation and control and specific adsorption sites at the same time; wherein the Prussian blue analogue provides Fe < 3 + >-CN vacancy and forms strong coordination with Cs < + >, so that the selective removal capability of Cs < + > is enhanced; zirconium phosphate changes the interlayer distance by responding to the change of the pH value, and rapid capture and controllable release of Cs < + > are achieved.

Description

Technical Field

[0001] The present invention relates to the field of environmental engineering technology, and in particular to a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, a preparation method and applications thereof. Background Art

[0002] Cesium (Cs) is a highly toxic radioactive element (e.g. 137 Cesium (Cs) is widely present in nuclear wastewater, electronic industrial wastewater, and mining wastewater. Due to its high water solubility and long half-life (approximately 30 years), cesium easily migrates in the environment and accumulates in the food chain, causing internal radiation damage to the human body and even inducing cancer. In recent years, with the increase in nuclear energy utilization and the accumulation of electronic waste, cesium contamination of water has become a global environmental problem, urgently requiring the development of efficient and low-cost removal technologies.

[0003] At present, common cesium removal materials mainly include inorganic ion exchangers (such as zeolite, titanium phosphate), organic adsorption resins, carbon-based materials, Prussian blue analogs (PBA), layered metal phosphates, etc. However, these materials are difficult to meet the three major requirements of high selectivity, dynamic adaptability and renewability at the same time, which limits their practical application. For example, anion exchangers are not suitable for Cs + High selectivity but low adsorption capacity (typically <100 mg / g) and difficulty in regeneration. Organic adsorption resins offer flexible functionalization but poor radiation resistance and are easily degraded in radioactive wastewater. PBA exhibits excellent selectivity for Cs⁺, but its microporous structure is prone to clogging and difficult to desorb and regenerate after static adsorption. Layered metal phosphates (such as zirconium phosphate) have adjustable interlayer spacing but lack specific binding sites, making them susceptible to interference from competing ions such as Na⁺ and K⁺.

[0004] How to improve the adsorption of Cs in water by adsorption materials + The selective adsorption capacity is the highest among all Cs + Problems that need to be solved urgently for adsorption materials. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the present invention provides a multifunctional cesium removal material with dynamic pore regulation function and specific adsorption sites, a preparation method and application thereof, so as to improve the adsorption of Cs in water by the adsorption material. + selective adsorption capacity.

[0006] The specific content of the invention is as follows: In a first aspect, the present invention provides a method for preparing a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, comprising: Dispersing zirconium phosphate in a hydrochloric acid solution, and then adding a Prussian blue analog to form a mixed dispersion; adjusting the pH of the mixed dispersion to neutral, performing a hydrothermal reaction, and collecting the reaction product by centrifugation to obtain a zirconium phosphate-Prussian blue composite porous material; Wherein, the Prussian blue analogue is at least one selected from copper-iron Prussian blue analogues, nickel-iron Prussian blue analogues and cobalt-iron Prussian blue analogues; In the mixed dispersion, the mass ratio of the Prussian blue analogue to the zirconium phosphate is 1:1-10.

[0007] Optionally, the temperature of the hydrothermal reaction is 65-90° C., and the reaction time is 6-24 h.

[0008] Optionally, the Prussian blue analogue is a copper-iron Prussian blue analogue, and the mass ratio of the copper-iron Prussian blue analogue to zirconium phosphate is 1:5; The temperature of the hydrothermal reaction is 80° C., and the reaction time is 12 h.

[0009] Optionally, the method further includes: The zirconium phosphate-Prussian blue composite porous material is immersed in a thioglycolic acid solution and allowed to stand for 2-10 hours to modify the surface of the zirconium phosphate-Prussian blue composite porous material with thiol groups, and then vacuum dried to obtain a thiol-modified zirconium phosphate-Prussian blue composite porous material.

[0010] Optionally, the concentration of the thioglycolic acid solution is 0.05~0.2 M; The mass-to-volume ratio of the zirconium phosphate-Prussian blue composite porous material to the thioglycolic acid solution is (3.5-4.5) mg / mL.

[0011] Optionally, the zirconium phosphate-Prussian blue composite porous material and the thioglycolic acid solution are allowed to react at 30-90° C. for 2-10 h.

[0012] Optionally, the zirconium phosphate is obtained by the following method: Dissolving ZrOCl2·8H2O in H3PO4 solution to form a mixed solution, refluxing the mixed solution at 100°C for 24 hours, collecting the product by centrifugation, washing with deionized water to a pH of 5-6, and vacuum drying at 60°C to obtain the zirconium phosphate; In the mixed solution, the molar ratio of H3PO4 to ZrOCl2·8H2O is 100-500.

[0013] Optionally, the water contact angle of the thiol-modified zirconium phosphate-Prussian blue composite porous material is ≤40°, and the Zeta potential is ≤-25 mV.

[0014] In a second aspect, the present invention provides a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, and the material is obtained by the preparation method described in the first aspect.

[0015] In a third aspect, the present invention provides an application of a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites. The material is obtained by the preparation method described in the first aspect above, and the material is used for the treatment of cesium in water.

[0016] Compared with the prior art, the present invention has the following advantages: The present invention provides a preparation method of a multifunctional cesium removal material with both dynamic pore regulation function and specific adsorption sites, comprising: dispersing zirconium phosphate in a hydrochloric acid solution, and then adding a Prussian blue analogue to form a mixed dispersion; adjusting the pH of the mixed dispersion to neutral, performing a hydrothermal reaction, and collecting the reaction product by centrifugation to obtain the zirconium phosphate-Prussian blue composite porous material; the present invention uses a hydrothermal method to compound zirconium phosphate with a Prussian blue analogue to form a composite material with both dynamic pore regulation and specific adsorption site dual adsorption mechanisms; wherein the Prussian blue analogue provides Fe 3+ -CN vacancy, with Cs + Forming strong coordination, strengthening Cs + Zirconium phosphate changes the interlayer spacing in response to pH changes, achieving Cs + Rapid capture and controlled release; in addition, the composite material has a wide pH range of use and can be directly used for the adsorption and removal of cesium in contaminated water bodies with a pH of 3-7. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 The figure shows the XRD characterization of the zirconium phosphate-Prussian blue composite porous material provided by the embodiment of the present invention. DETAILED DESCRIPTION

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

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

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

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

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

[0024] In a first aspect, the present invention provides a method for preparing a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, comprising: Dispersing zirconium phosphate in a hydrochloric acid solution, and then adding a Prussian blue analog to form a mixed dispersion; adjusting the pH of the mixed dispersion to neutral, performing a hydrothermal reaction, and collecting the reaction product by centrifugation to obtain the zirconium phosphate-Prussian blue composite porous material; In a specific implementation, the zirconium phosphate used in the embodiment of the present invention is α-zirconium phosphate (Zr(HPO4)2); after the zirconium phosphate is stirred and dispersed in a hydrochloric acid solution, a Prussian blue analogue (PBA) is added and stirred continuously to disperse uniformly to form a mixed dispersion; the pH value of the hydrochloric acid solution used in the dispersion process is 2-5; that is, the pH of the hydrochloric acid solution used can be 2, 3, 4 or 5; the preferred pH value of the hydrochloric acid solution is 3; the mass ratio of the Prussian blue analogue to the zirconium phosphate is 1:1-10; that is, the mass ratio of the Prussian blue analogue to the zirconium phosphate can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10; the preferred mass ratio of the Prussian blue analogue to the zirconium phosphate is 1:5; the zirconium phosphate swells in the acidic environment provided by the hydrochloric acid solution, thereby opening the layered structure of the zirconium phosphate, exposing more active sites, and protonating the surface to promote interaction with PBA (such as electrostatic attraction or coordination bond).

[0025] In specific implementation, PBA is not stable in an acidic environment, and the CN⁻ ligand in the PBA structure is prone to detachment; the hydrothermal reaction will intensify this reaction, causing the PBA structure to decompose; therefore, the present invention uses an alkaline solution to neutralize the formed mixed dispersion to make the pH of the mixed dispersion reach neutral (pH≈7), and then conducts a hydrothermal reaction to complete the compounding of the Prussian blue analogue and zirconium phosphate in a neutral environment to obtain a structurally stable composite product.

[0026] In a specific implementation, the temperature of the hydrothermal reaction is 65-90°C, and the reaction time is 6-24 h; preferably, the temperature of the hydrothermal reaction is 80°C, and the reaction time is 12 h.

[0027] It should be noted that the present invention does not impose any specific requirements on the amount of hydrochloric acid used, and the amount of hydrochloric acid used can ensure uniform dispersion of the Prussian blue analogue and zirconium phosphate; the Prussian blue analogue is selected from at least one of a copper-iron Prussian blue analogue, a nickel-iron Prussian blue analogue, and a cobalt-iron Prussian blue analogue.

[0028] The present invention uses a hydrothermal method to compound zirconium phosphate with a Prussian blue analogue, and the resulting composite material has a stable structure and has both dynamic pore regulation and a dual adsorption mechanism of specific adsorption sites; wherein the Prussian blue analogue provides Fe 3 + -CN vacancy, with Cs + Forming strong coordination, strengthening Cs + The selective removal ability of Cs is achieved by changing the interlayer spacing in response to changes in pH value. + Rapid capture and controlled release.

[0029] As an example, when the Prussian blue analogue is preferably a copper-iron Prussian blue analogue, the mass ratio of the copper-iron Prussian blue analogue to zirconium phosphate is 1:5; the temperature of the hydrothermal reaction is 80° C., and the reaction time is 12 h.

[0030] In some embodiments, the method further includes: immersing the zirconium phosphate-Prussian blue composite porous material in a thioglycolic acid solution, allowing it to stand for 2-10 hours to modify the surface of the zirconium phosphate-Prussian blue composite porous material with thiol groups, and then vacuum drying to obtain a thiol-modified zirconium phosphate-Prussian blue composite porous material.

[0031] In a specific implementation, since thioglycolic acid contains both thiol (-SH) and carboxyl (-COOH) functional groups, the zirconium phosphate-Prussian blue composite porous material is immersed in a thioglycolic acid solution, and the thiol (-SH) of the thiol acetic acid combines with the zirconium phosphate-Prussian blue composite porous material. The thiol (-SH) functional group is introduced through surface modification, giving the material new interfacial chemical properties; the introduction of the thiol (-SH) group can shield the zirconium phosphate-Prussian blue composite porous material from interference from competing ions such as Na⁺ and K⁺, and enhance the specific adsorption of Cs by the zirconium phosphate-Prussian blue composite porous material. + Furthermore, some of the carboxyl (-COOH) functional groups in thioglycolic acid can also bind to the zirconium phosphate-Prussian blue composite porous material. The introduction of carboxyl (-COOH) groups can effectively improve the wettability and dispersion stability of the material in aqueous phase, reduce agglomeration, and thereby increase the effective specific surface area and active site accessibility. The resulting thiol-modified zirconium phosphate-Prussian blue composite porous material has a water contact angle of ≤40° and a zeta potential of ≤-25mV, both of which are significantly lower than those of the unthiol-modified zirconium phosphate-Prussian blue composite porous material.

[0032] It should be noted that the concentration of the thioglycolic acid solution used in the surface modification process is 0.05~0.2 mol / L, preferably 0.08–0.16 mol / L, and more preferably 0.10 mol / L; the mass volume ratio of the zirconium phosphate-Prussian blue composite porous material to the thioglycolic acid solution is (3.5–4.5) mg / mL, preferably 4.0 mg / mL.

[0033] It should be noted that the zirconium phosphate-Prussian blue composite porous material and the thioglycolic acid solution are allowed to react at 30-90°C for 2-10 hours to ensure that the thioglycolic acid is fully diffused into the pores of the material to achieve uniform modification (if the time is too short, the modification will be incomplete, and if the time is too long, agglomeration may occur).

[0034] In some embodiments, the zirconium phosphate used in the preparation process can be commercially available or can be obtained by the following methods: Dissolving ZrOCl2·8H2O in H3PO4 solution to form a mixed solution, refluxing the mixed solution at 100°C for 24 hours, collecting the product by centrifugation, washing with deionized water to a pH of 5-6, and vacuum drying at 60°C to obtain the zirconium phosphate; In the mixed solution, the molar ratio of H3PO4 to ZrOCl2·8H2O is 100-500.

[0035] In some embodiments, the Prussian blue analogue used in the preparation process can be commercially available or prepared by a co-precipitation method.

[0036] In the specific implementation, the preparation of copper iron Prussian blue analogues is taken as an example to illustrate the coprecipitation preparation method, which specifically includes the following steps: Dissolve Cu(NO3)2 and sodium citrate in an appropriate amount of deionized water to obtain solution A; wherein the molar ratio of Cu(NO3)2 to sodium citrate is greater than or equal to 1:5 and less than or equal to 1:1; Dissolve K3[Fe(CN)6] in an appropriate amount of deionized water to form solution B; wherein the concentration of K3[Fe(CN)6] in solution B is between 2 and 5 mM; Under nitrogen protection and the temperature controlled at 15-35 °C, solution B was added dropwise to solution A and stirred for 6-36 h. The product was centrifuged, washed with ethanol, and vacuum dried to obtain copper-iron Prussian blue analogue (CuFe / PBA).

[0037] In a second aspect, the present invention provides a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, and the material is obtained by the preparation method described in the first aspect.

[0038] In a third aspect, the present invention provides an application of a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites. The material is obtained by the preparation method described in the first aspect above. The material is used as a cesium removal material for the treatment of cesium in water bodies.

[0039] The multifunctional cesium removal material provided by the present invention has both dynamic pore regulation function and specific adsorption sites. It integrates dynamic pores and molecular recognition sites. When used for the treatment of cesium in water, Cs⁺ adsorption / desorption can be achieved by adjusting the pH of the solution, without the need for strong acid / oxidant elution, reducing the risk of secondary pollution. It solves the contradiction of "selectivity-capacity-regeneration" that traditional adsorbents cannot achieve at the same time, and provides a new strategy for nuclear wastewater treatment and resource recovery.

[0040] In order to enable those skilled in the art to more clearly understand the present invention, the following examples are used to describe in detail a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, a preparation method and an application thereof.

[0041] Example 1 10 mM ZrOCl2·8H2O was dissolved in 50 ml of 3 M H3PO4 solution, refluxed at 100 °C for 24 h, and the white precipitate was collected by centrifugation. The white precipitate was then washed with deionized water to pH = 5 and then dried in vacuum at 60 °C to obtain α-zirconium phosphate Zr(HPO4)2.

[0042] 5 mM Cu(NO3)2 and 10 mM sodium citrate were dissolved in 50 ml of deionized water to form solution A; 3.4 mM K3[Fe(CN)6] was dissolved in 50 ml of deionized water to form solution B. Solution B was then gradually added dropwise to solution A under nitrogen protection, stirred at 25°C for 24 h, and the dark brown precipitate was collected by centrifugation, washed three times with ethanol, and dried in vacuo at 60°C to obtain Prussian blue analog Cu-Fe / PBA nanocrystals. 100 mg Zr(HPO4)2 was dispersed in 50 ml of hydrochloric acid solution with a pH of 3, and 20 mg CuFe / PBA nanocrystals (the mass ratio of Prussian blue analogue to zirconium phosphate was 1:5) were added. The mixture was ultrasonically treated for 30 minutes. 5 ml of 1M NaOH solution was added to adjust the pH to 7. The mixture was then hydrothermally reacted at 80°C for 12 hours. The product was collected by centrifugation to form a zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA.

[0043] Figure 1 The XRD characterization diagram of the zirconium phosphate-Prussian blue composite porous material provided by the embodiment of the present invention is shown, in which a represents the characteristic peak of Zr(HPO4)2 and b represents the characteristic peak of CuFe / PBA; Figure 1 As shown, the present invention successfully composites Zr(HPO4)2 with Cu-Fe / PBA.

[0044] Example 2 Different from Example 1, Example 2 further immersed 0.05 g of the zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA obtained in Example 1 into 10 mL of 0.1 M thioglycolic acid solution, allowed to react at 60°C for 6 h, and vacuum dried to obtain a zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA-SH with a surface modified with thiol groups.

[0045] Using a contact angle meter, contact angle tests were performed on the materials provided in Examples 1 and 2, respectively, and the average value was taken after at least three repetitions. The test results showed that the contact angle of the zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA without thiol modification was 89°; after thiol modification, the contact angle of the zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA was reduced to 36.2°.

[0046] The materials provided in Examples 1 and 2 were further subjected to Zeta potential testing. The results showed that at pH = 7, after thiol modification, the Zeta potential of the zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA dropped from -20 mV to -40 mV.

[0047] Example 3 10 mM ZrOCl2·8H2O was dissolved in 50 ml of 3 M H3PO4 solution, refluxed at 100 °C for 24 h, and the white precipitate was collected by centrifugation. The white precipitate was then washed with deionized water to pH = 5 and then dried in vacuum at 60 °C to obtain α-zirconium phosphate Zr(HPO4)2.

[0048] 5 mM Co(NO3)2·6H2O, 10 mM sodium citrate, and 50 ml of deionized water were mixed to form solution A. 3.4 mM K3[Fe(CN)6] was dissolved in 50 ml of deionized water to form solution B. Solution B was then gradually added dropwise to solution A under nitrogen protection, and the pH of the mixture was adjusted to a stable pH of 3.5-4 with ammonia. The reaction was allowed to proceed at room temperature for 3 h. The brown-red precipitate was collected by centrifugation, washed three times with ethanol, and dried in a vacuum at 60°C to obtain Prussian blue analog Co-Fe / PBA nanocrystals. 100 mg Zr(HPO4)2 was dispersed in 50 ml of hydrochloric acid solution with a pH of 3, 20 mg of CoFe / PBA nanocrystals were added, and ultrasonic treatment was performed for 30 minutes; 5 ml of 1M NaOH solution was added to adjust the pH to 7, and then hydrothermally reacted at 80°C for 12 hours. The product was collected by centrifugation to form a zirconium phosphate-Prussian blue composite porous material ZrP-CoFe / PBA.

[0049] Example 4 Different from Example 3, Example 4 further immersed 0.05 g of the zirconium phosphate-Prussian blue composite porous material ZrP-CoFe / PBA obtained in Example 3 into 15 mL of 0.1 M thioglycolic acid solution, allowed to react at 60°C for 6 h, and vacuum dried to obtain a surface-modified zirconium phosphate-Prussian blue composite porous material ZrP-CoFe / PBA-SH.

[0050] Using a contact angle meter, contact angle tests were performed on the materials provided in Examples 3 and 4, respectively, and the average value was taken after at least three repetitions. The test results showed that the contact angle of the zirconium phosphate-Prussian blue composite porous material ZrP-CoFe / PBA without thiol modification was 85°; after thiol modification, the contact angle of the zirconium phosphate-Prussian blue composite porous material ZrP-CoFe / PBA was reduced to 34.9°.

[0051] The materials provided in Examples 3 and 4 were further subjected to Zeta potential testing. The results showed that at pH = 7, after thiol modification, the Zeta potential of the zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA dropped from -25 mV to -41 mV.

[0052] Example 5 10 mM ZrOCl2·8H2O was dissolved in 50 ml of 3 M H3PO4 solution, refluxed at 100 °C for 24 h, and the white precipitate was collected by centrifugation. The white precipitate was then washed with deionized water to pH = 5 and then dried in vacuum at 60 °C to obtain α-zirconium phosphate Zr(HPO4)2.

[0053] 5 mM Ni(NO3)2·6H2O and 10 mM sodium citrate were dissolved in 50 ml of deionized water to form solution A. 3.4 mM K3[Fe(CN)6] was dissolved in 50 ml of deionized water to form solution B. Solution B was then gradually added dropwise to solution A under nitrogen protection. The mixture was stirred at room temperature for 24 h, and the reddish-brown precipitate was collected by centrifugation, washed three times with ethanol, and dried in vacuo at 60°C to obtain Prussian blue analog Ni-Fe / PBA nanocrystals. 100 mg Zr(HPO4)2 was dispersed in 50 ml of hydrochloric acid solution with a pH of 3, 20 mg NiFe / PBA nanocrystals were added, and ultrasonic treatment was performed for 30 minutes; 5 ml of 1M NaOH solution was added to adjust the pH to 7, and then hydrothermally reacted at 80°C for 12 hours. The product was collected by centrifugation to form a zirconium phosphate-Prussian blue composite porous material ZrP-NiFe / PBA.

[0054] Example 6 Different from Example 5, Example 6 further immersed 0.05 g of zirconium phosphate-Prussian blue composite porous material ZrP-NiFe / PBA obtained in Example 5 into 12.5 mL of 0.1 M thioglycolic acid solution, allowed to react at 60°C for 6 h, and vacuum dried to obtain a surface-modified zirconium phosphate-Prussian blue composite porous material ZrP-NiFe / PBA-SH.

[0055] Using a contact angle meter, contact angle tests were performed on the materials provided in Examples 5 and 6, respectively, and the average value was taken after at least three repetitions. The test results showed that the contact angle of the zirconium phosphate-Prussian blue composite porous material ZrP-NiFe / PBA without thiol modification was 88°; after thiol modification, the contact angle of the zirconium phosphate-Prussian blue composite porous material ZrP-NiFe / PBA was reduced to 36°.

[0056] The materials provided in Examples 5 and 6 were further subjected to Zeta potential testing. The results showed that at pH = 7, after thiol modification, the Zeta potential of the zirconium phosphate-Prussian blue composite porous material ZrP-CuFe / PBA dropped from -27 mV to -43 mV.

[0057] Comparative Example 1 10 mM ZrOCl2·8H2O was dissolved in 50 ml of 3M H3PO4 solution, refluxed at 100 °C for 24 h, and the white precipitate was collected by centrifugation. The white precipitate was then washed with deionized water to pH = 5 and then dried in vacuo at 60 °C to obtain α-zirconium phosphate Zr(HPO4)2.

[0058] Comparative Example 2 5 mM Cu(NO3)2 and 10 mM sodium citrate were dissolved in 50 ml of deionized water to form solution A; 3.4 mM K3[Fe(CN)6] was dissolved in 50 ml of deionized water to form solution B; then, solution B was gradually added dropwise to solution A under nitrogen protection, stirred at 25°C for 24 hours, and the dark brown precipitate was collected by centrifugation, washed three times with ethanol, and dried in vacuo at 60°C to obtain Prussian blue analogue Cu-Fe / PBA nanocrystals.

[0059] Performance Verification: (1) Verification of adsorption performance The same mass (0.2 g) of adsorption materials prepared in Examples 1 and 2 were used for Cs + Adsorption performance test, the test water sample is 100 mL, pH = 4 containing initial Cs + The concentration was 160 mg / L and the test time was 20 minutes. The test results showed: The ZrP-CuFe / PBA provided in Example 1 had a negative effect on Cs at 20 min. + The adsorption rate reaches 100%.

[0060] The ZrP-CuFe / PBA-SH provided in Example 2 had a negative effect on Cs at 15 min. + The adsorption rate reaches 100%.

[0061] The α-zirconium phosphate Zr(HPO4)2 provided in Comparative Example 1 had a negative effect on Cs at 20 min. + The adsorption rate is only 34%.

[0062] The Prussian blue analogue Cu-Fe / PBA nanocrystals provided in Comparative Example 2 had a negative effect on Cs + The adsorption rate is only 42%.

[0063] It can be seen that compared with a single zirconium phosphate adsorption material or a single Prussian blue analog (Cu-Fe / PBA), the zirconium phosphate-Prussian blue composite porous material provided by the embodiment of the present invention has excellent Cs + Moreover, compared with the zirconium phosphate-Prussian blue composite porous material, the zirconium phosphate-Prussian blue composite porous material with surface modified thiol groups has a better adsorption capacity for Cs + The adsorption capacity is further increased.

[0064] Furthermore, the adsorption rate constants of Cs⁺ were fitted for the adsorption materials prepared in Examples 1 and 2. It was found that the adsorption rate constant of Cs⁺ by the thiol-modified ZrP-CuFe / PBA was increased by 2.1 times compared with that of the ZrP-CuFe / PBA provided in Example 1.

[0065] Furthermore, the test water sample was 1L, pH = 3 and 7, containing initial Cs + The concentration was 160 mg / L, the initial K + The concentration mg / L is 200 mg / L, the initial Na + The concentration of the solution was 200 mg / L. Under the condition that the other test conditions remained unchanged, the adsorption materials provided in Examples 1 and 2 and Comparative Examples 1 and 2 were used to perform Cs + Adsorption test results showed that: When the pH value of the test water sample is 3, the ZrP-CuFe / PBA provided in Example 1 has a negative effect on Cs + The adsorption rate reaches 90%; The ZrP-CuFe / PBA-SH provided in Example 2 had a negative effect on Cs at 15 min. + The adsorption rate reached 94%.

[0066] When the pH value of the test water sample is 7, the ZrP-CuFe / PBA provided in Example 1 has a negative effect on Cs + The adsorption rate reached 93%; The ZrP-CuFe / PBA-SH provided in Example 2 had a negative effect on Cs at 15 min. + The adsorption rate reaches 95%.

[0067] It can be seen that compared with single zirconium phosphate and single Prussian blue analogue, the composite material formed by zirconium phosphate and Prussian blue analogue has a better effect on the Cs + In terms of adsorption, it has a wider pH application range and has good Cs adsorption under pH=3-7 conditions. + adsorption effect, which is conducive to expanding the application of this type of adsorbent in different polluted water bodies.

[0068] (2) Desorption performance verification The adsorbent materials (provided in Examples 1-6) whose adsorption performance has been verified were subjected to desorption treatment. Desorption only requires adding the used adsorbent materials to a 0.5 mol / L HNO3 solution and desorbing them for 1 hour before continued use. After 5 cycles, the adsorption capacity can still be maintained at above 95%.

[0069] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0070] For simplicity of description, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the present invention is not limited by the order of the actions described, as certain steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in this specification are preferred embodiments, and the actions and components involved are not necessarily required for the present invention.

[0071] The above is a detailed introduction to a multifunctional cesium removal material, preparation method and application of the present invention, which has both dynamic pore regulation function and specific adsorption sites. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, characterized in that: include: Dispersing zirconium phosphate in a hydrochloric acid solution, and then adding a Prussian blue analog to form a mixed dispersion; After adjusting the pH of the mixed dispersion to neutral, a hydrothermal reaction is performed, and the reaction product is collected by centrifugation to obtain a zirconium phosphate-Prussian blue composite porous material; Wherein, the Prussian blue analogue is at least one selected from copper-iron Prussian blue analogues, nickel-iron Prussian blue analogues and cobalt-iron Prussian blue analogues; In the mixed dispersion, the mass ratio of the Prussian blue analogue to the zirconium phosphate is 1:1-10.

2. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 65-90°C, and the reaction time is 6-24 hours.

3. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 1, characterized in that: The Prussian blue analogue is a copper-iron Prussian blue analogue, and the mass ratio of the copper-iron Prussian blue analogue to zirconium phosphate is 1:5; The temperature of the hydrothermal reaction is 80° C., and the reaction time is 12 h.

4. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 1, characterized in that: The method further comprises: The zirconium phosphate-Prussian blue composite porous material is immersed in a thioglycolic acid solution and allowed to stand for 2-10 hours to modify the surface of the zirconium phosphate-Prussian blue composite porous material with thiol groups, and then vacuum dried to obtain a thiol-modified zirconium phosphate-Prussian blue composite porous material.

5. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 1, characterized in that: The concentration of the thioglycolic acid solution is 0.05-0.2 mol / L; The mass volume ratio of the zirconium phosphate-Prussian blue composite porous material to the thioglycolic acid solution is (3.5-4.5) mg / mL.

6. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 1, characterized in that: The zirconium phosphate-Prussian blue composite porous material and the thioglycolic acid solution are allowed to react at 30-90° C. for 2-10 hours.

7. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 1, characterized in that: The zirconium phosphate is obtained by the following method: dissolving ZrOCl2·8H2O in H3PO4 solution to form a mixed solution, refluxing the mixed solution at 100°C for 24 hours, collecting the product by centrifugation, washing with deionized water to a pH of 5-6, and vacuum drying at 60°C to obtain the zirconium phosphate; In the mixed solution, the molar ratio of H3PO4 to ZrOCl2·8H2O is 100-500.

8. The method for preparing the multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites according to claim 4, characterized in that: The water contact angle of the thiol-modified zirconium phosphate-Prussian blue composite porous material is less than or equal to 40°, and the zeta potential is less than or equal to -25 mV.

9. A multifunctional cesium removal material with both dynamic pore regulation function and specific adsorption sites, characterized in that: The material is obtained by the preparation method according to any one of claims 1 to 9.

10. Application of a multifunctional cesium removal material having both dynamic pore regulation function and specific adsorption sites, characterized in that: The material is obtained by the preparation method according to any one of claims 1 to 9, and the material is used as a cesium removal material for the treatment of cesium in polluted water.

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