Carbon-based Prussian blue composite material as well as preparation method and application thereof
The preparation of carbon-based Prussian blue composite materials as carbon sources by biomass materials has solved the problems of complex preparation process and inappropriate powdered materials in the prior art, and achieved efficient cesium extraction and radioactive wastewater treatment, with good industrial application prospects.
Patent Information
- Application Number
- CN202510432664.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2025-05-23
AI Technical Summary
In the process of preparing Prussian blue composites, the reaction conditions are difficult to control, complex operation, many side reactions, dangerous gas generation, and the flowability and permeability of powdered adsorbents are not suitable for industrial applications.
Carbon-based Prussian blue composite materials are prepared by immersion or domain-limited in-situ etching. Porous carbon materials are used as support, combined with complexing agents and surfactants to regulate the size and morphology of the materials, and composite materials with strong hydrophilicity and high mechanical strength are prepared.
It has achieved efficient cesium extraction and radioactive wastewater treatment, high adsorption capacity, fast adsorption rate, easy to form and good dispersion, suitable for large-scale production, and no pollutant emissions, and has good industrial application prospects.
Smart Images
Figure CN120022867A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of adsorption material development and comprehensive resource utilization, and more specifically relates to a carbon-based Prussian blue composite material and a preparation method and application thereof. Background Art
[0002] Cesium is an indispensable key mineral for the development of strategic emerging industries, and is also a key raw material supporting breakthroughs in energy conversion technology and new communication technology research. There are abundant cesium resources in liquid resources such as seawater, salt lake brine and geothermal water, which are of great industrial development value. 137 Cs is the main nuclide in radioactive wastewater. It is very easy to migrate and diffuse in the environment, causing great harm to the human body. Therefore, the development of efficient and green extraction technology is of great significance to the comprehensive utilization of resources and the treatment of radioactive wastewater.
[0003] At present, the main methods for extracting cesium at home and abroad include precipitation, solvent extraction, electrochemical method, adsorption method, etc. The precipitation method is mainly used for the analysis of cesium content and the separation and extraction of high-concentration cesium solutions; the organic reagents in the solvent extraction method are prone to environmental pollution, which limits its industrial application; the electrochemical method is an emerging ion extraction technology with high operating costs, and research is still in its infancy; the adsorption method is easy to operate, has good selectivity, can be reused, is green and environmentally friendly, and is a method with industrial application prospects. Commonly used adsorbents include heteropolyacid salts, clay, Prussian blue, etc. Among them, Prussian blue has a strong affinity for cesium, good adsorption selectivity, and high adsorption capacity, and is widely used in the extraction of cesium.
[0004] Biomass materials are widely available and are the most promising renewable energy. After activation and carbonization, porous carbon materials are prepared. Porous carbon materials have the characteristics of large specific surface area, developed pore structure, and adjustable pore size, which are very suitable for use as adsorbents. Using them to load Prussian blue can achieve better adsorption effects. However, in the preparation process of existing technologies, there are often problems such as difficult to control reaction conditions, complex operations, difficult to control products, more side reactions and products, and the generation of dangerous gas hydrocyanic acid. Summary of the invention
[0005] The purpose of the present invention is to provide a carbon-based Prussian blue composite material and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art.
[0006] To achieve the above object, the present invention provides the following solutions:
[0007] One of the technical solutions of the present invention is to provide a method for preparing a carbon-based Prussian blue composite material, comprising the following steps:
[0008] The carbon-based Prussian blue composite material is prepared by using biomass materials as carbon source through impregnation method or confined in-situ etching method.
[0009] Furthermore, the biomass material includes corrugated paper.
[0010] Furthermore, the step of preparing the carbon-based Prussian blue composite material by the impregnation method comprises:
[0011] A porous carbon material is prepared using biomass material as a raw material, and then the porous carbon material is immersed in a metal ion solution, and solid-liquid separation is performed to obtain a porous carbon loaded with metal ions;
[0012] The porous carbon loaded with metal ions is immersed in a ferrocyanide solution, and then washed and dried to obtain the carbon-based Prussian blue composite material.
[0013] Optionally, the step of preparing the porous carbon material using biomass material as raw material comprises:
[0014] The biomass material is crushed and then immersed in a water-ethanol mixed solution, and after the immersion, the solvent is removed and formed to obtain a porous carbon material precursor;
[0015] The porous carbon material precursor is subjected to carbonization treatment to obtain the porous carbon material.
[0016] Preferably, the volume proportion of ethanol in the water-ethanol mixed solution is ≥50%.
[0017] Preferably, the mass ratio of the biomass material to the water-ethanol mixed solution is 0.02-0.6.
[0018] Preferably, the immersion time in the water-ethanol mixed solution is 30-120 min.
[0019] Preferably, the desolventizing body is shaped into a cylinder, a sphere or a cube.
[0020] Preferably, the temperature of the carbonization treatment is 400-900° C., the heating rate is 1-10° C. / min, the holding time is 30-360 min, and the atmosphere is a nitrogen atmosphere.
[0021] Optionally, the mass ratio of the porous carbon material to the metal ion solution is 0.01-0.1.
[0022] Optionally, the metal ion solution includes 0.01 mol / L to saturated metal salt, 0 mol / L to saturated complexing agent and 0-5 wt.% concentration of surfactant.
[0023] Preferably, the metal salt is at least one of chloride, sulfate, carbonate, nitrate and acetate of a transition metal.
[0024] More preferably, the transition metal includes at least one of Fe, Co, Ni, Cu and Zn.
[0025] Preferably, the complexing agent is citrate.
[0026] Preferably, the surfactant is at least one of polyvinyl pyrrolidone, hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate.
[0027] Optionally, the immersion time in the metal ion solution is 0.5-24h.
[0028] In the above scheme, the solid-liquid separation operation can be carried out by suction filtration.
[0029] Optionally, the concentration of the ferrocyanide solution is from 0.01 mol / L to saturation.
[0030] Optionally, the mass ratio of the porous carbon loaded with metal ions to the ferrocyanide solution is 0.01-0.1.
[0031] Optionally, the immersion time in the ferrocyanide solution is 0.5-24h.
[0032] Optionally, the cleaning is performed using deionized water and ethanol in sequence at least once.
[0033] Optionally, the drying is vacuum drying at a temperature of 50-70° C. for 12 hours.
[0034] Furthermore, the step of preparing the carbon-based Prussian blue composite material by using the confined in-situ etching method comprises:
[0035] The biomass material is crushed and then immersed in a metal ion solution, and then subjected to desolventizing, molding and carbonization treatments in sequence to prepare a precursor material;
[0036] The precursor material is etched by an acid-ferrocyanide solution, and then cleaned and dried to obtain the carbon-based Prussian blue composite material.
[0037] Optionally, the mass ratio of the biomass material to the metal ion solution is 0.01-0.1.
[0038] Optionally, the immersion time is 30-120 min.
[0039] Optionally, the metal ion solution consists of a metal salt and a solvent, wherein the concentration of the metal salt in the metal ion solution is 0.01 mol / L to saturation; the solvent is water and ethanol, and the volume proportion of ethanol in the solvent is ≥50%.
[0040] Preferably, the metal salt is at least one of chloride, sulfate, carbonate, nitrate and acetate of a transition metal.
[0041] More preferably, the transition metal includes at least one of Fe, Co, Ni, Cu and Zn.
[0042] Optionally, the desolvent is shaped into a cylinder, a sphere or a cube.
[0043] Optionally, the temperature of the carbonization treatment is 400-900° C., the heating rate is 1-10° C. / min, the holding time is 30-360 min, and the atmosphere is a nitrogen atmosphere.
[0044] Optionally, the acid in the acid-ferrocyanide solution is at least one of acetic acid, hydrochloric acid, citric acid and trimesic acid, and the concentration is 0.01-5 mol / L.
[0045] Optionally, the concentration of ferrocyanide salt in the acid-ferrocyanide salt solution is from 0.01 mol / L to saturation.
[0046] Optionally, the etching time is 0.5-24h.
[0047] Optionally, the cleaning is performed using deionized water and ethanol in sequence at least once.
[0048] Optionally, the drying is vacuum drying at a temperature of 50-70° C. for 12 hours.
[0049] The second technical solution of the present invention is to provide a carbon-based Prussian blue composite material, which is prepared by the above-mentioned preparation method.
[0050] The third technical solution of the present invention is to provide an application of the above-mentioned carbon-based Prussian blue composite material in extracting cesium from liquid resources and treating cesium in radioactive wastewater.
[0051] The present invention discloses the following technical effects:
[0052] Most existing Prussian blues are in powder form, and the fluidity and permeability of powder adsorbents are not suitable for industrial applications. The present invention utilizes cheap and readily available biomass materials (waste corrugated paper) as a carbon source, and synthesizes a series of carbon-based Prussian blue composite materials with porous carbon as a supporting material through an impregnation method or a confined in-situ etching method, which can be used for the efficient extraction of cesium.
[0053] The composite material provided by the invention has a simple preparation process and can be directly formed without the need for adhesives and high molecular polymers to assist in forming. The preparation cost is low and the composite material has good industrial application prospects.
[0054] The present invention adopts waste corrugated paper of biomass material as a carbon source, and provides a green synthesis route for preparing a carbon-based Prussian blue composite material by an impregnation method or a confined in-situ etching method. The preparation steps are simple and easy to operate. The synthesis speed of Prussian blue is regulated by adding a complexing agent, and its size and morphology are regulated under the action of the confined space of the carbon fiber and a surfactant (the material synthesized in the existing implementation case 1 is in the morphology of nanosheets).
[0055] The carbon-based Prussian blue composite material prepared by the invention has strong hydrophilicity, high mechanical strength and good dispersibility, and is helpful to improve the adsorption capacity and exchange rate.
[0056] The carbon-based Prussian blue composite material prepared by the present invention is used for extracting cesium from liquid resources and removing cesium from wastewater, and has the characteristics of high adsorption capacity, fast adsorption rate, etc. The adsorption capacity can reach more than 100 mg / g, and the cycle stability is good, the resource recovery rate is high, no pollutant emissions, and it is easy to mass produce, which is of great significance to the comprehensive utilization of resources and the treatment of radioactive wastewater. BRIEF DESCRIPTION OF THE DRAWINGS
[0057] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:
[0058] Figure 1 This is a physical picture of the product after desolventizing and molding in Example 1.
[0059] Figure 2 This is a physical picture of the porous carbon material in Example 1.
[0060] Figure 3 These are SEM images of the carbon-based Prussian blue composite material prepared in Example 1 at different magnifications.
[0061] Figure 4 This is the element distribution diagram of the carbon-based Prussian blue composite material prepared in Example 1.
[0062] Figure 5 This is the adsorption kinetics diagram of cesium adsorbed by the carbon-based Prussian blue composite material prepared in Example 1.
[0063] Figure 6 This is a graph showing the cyclic stability of cesium adsorption by the carbon-based Prussian blue composite material prepared in Example 1.
[0064] Figure 7 The actual picture of the material prepared in Comparative Example 1 and the state of the solution after adsorption, wherein the left picture is the actual picture and the right picture is the state of the solution after adsorption. DETAILED DESCRIPTION
[0065] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0066] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.
[0067] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.
[0068] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.
[0069] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.
[0070] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in the art and are not the focus of the present invention.
[0071] Unless otherwise specified, the raw materials and reagents used in the present invention are all commercially available products, and the purchase channels do not affect the realization of the technical effects.
[0072] Unless otherwise specified, the "normal temperature" and "room temperature" involved in the specific embodiments of the present invention refer to 20-30°C.
[0073] Example 1
[0074] The steps of preparing a carbon-based Prussian blue composite material by an impregnation method using copper sulfate as a metal salt include:
[0075] Waste corrugated paper was crushed into paper scraps by dry method in a solid sample crusher. 2 g of paper scraps were taken and immersed in a water-ethanol mixed solution for 30 min, wherein the volume ratio of water to ethanol was 1:9 and the mass ratio of paper scraps to the water-ethanol mixed solution was 0.06. After immersion, they were placed in a cylinder for desolventizing and forming. After drying (such as Figure 1 As shown), in a nitrogen atmosphere, the temperature was raised to 800°C in a tubular furnace at a heating rate of 5°C / min and then carbonized for 2h to prepare a porous carbon material;
[0076] The porous carbon material was immersed in the metal ion solution for 24 h, and the loaded Cu was obtained by filtration. 2+ The porous carbon was then immersed in a potassium ferrocyanide solution (0.15 mol / L) for 24 h, washed with deionized water and ethanol three times, placed in a vacuum drying oven, and dried at 70 ° C for 12 h to obtain a carbon-based Prussian blue composite material (such as Figure 2 shown);
[0077] The metal ion solution contains 0.15 mol / L CuSO 4 and 0.075 mol / L C 6 H 5 K 3 O 7 , the solvent is water; the mass ratio of porous carbon material to metal ion solution is 0.013; the loaded Cu 2+ The mass ratio of the porous carbon to the potassium ferrocyanide solution is 0.013.
[0078] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 1 was added to a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 140 mg / g and the adsorption rate was 70.5%.
[0079] Figure 1 This is a physical picture of the product after desolventizing and molding in Example 1.
[0080] Figure 2 This is a physical picture of the porous carbon material in Example 1.
[0081] Figure 3 These are SEM images of the carbon-based Prussian blue composite material prepared in Example 1 at different magnifications.
[0082] Figure 4 This is the element distribution diagram of the carbon-based Prussian blue composite material prepared in Example 1.
[0083] Figure 5 This is the adsorption kinetics diagram of cesium adsorbed by the carbon-based Prussian blue composite material prepared in Example 1.
[0084] Example 2
[0085] Compared with Example 1, the only difference is that the carbonization temperature is adjusted to 600°C.
[0086] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 2 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 136 mg / g.
[0087] Example 3
[0088] Compared with Example 1, the only difference is that the carbonization temperature is adjusted to 400°C.
[0089] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 3 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 130 mg / g.
[0090] Example 4
[0091] Compared with Example 1, the difference is that the metal ion solution is 0.15 mol / L CuSO 4 Solution, the solvent is water.
[0092] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 4 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 133 mg / g.
[0093] Example 5
[0094] Compared with Example 1, the difference is that 0.15 mol / L CuSO 4 Replaced with 0.15 mol / L ZnCl 2 .
[0095] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 5 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 162 mg / g.
[0096] Example 6
[0097] Compared with Example 1, the difference is that 0.15 mol / L CuSO 4 Replaced with 0.15 mol / L CuSO 4 and 0.3wt.% of hexadecyltrimethylammonium bromide mixed solution.
[0098] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 6 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 190 mg / g.
[0099] Example 7
[0100] The steps of preparing a carbon-based Prussian blue composite material by an in-situ etching method using zinc sulfate as a metal salt include:
[0101] Waste corrugated paper was crushed into paper scraps by dry method in a solid sample crusher. 1.5 g of paper scraps were taken and mixed with 0.1 mol / L ZnSO 4 The paper scraps were immersed in a solution (water and ethanol as solvent, volume ratio of 3:7) for 30 min. 4 The mass ratio of the solution is 0.06. After impregnation, it is placed in a cylinder for desolventizing and forming. After drying, it is heated to 500°C at a heating rate of 5°C / min in a tube furnace under a nitrogen atmosphere and then carbonized for 2h to prepare a porous carbon material loaded with ZnO.
[0102] The ZnO-loaded porous carbon material was slowly etched with a citric acid-potassium ferrocyanide solution (the concentration of citric acid was 0.5 mol / L, and the concentration of potassium ferrocyanide was 0.1 mol / L) for 24 h. After etching, it was washed three times with deionized water and ethanol, placed in a vacuum drying oven, and dried at 70°C for 12 h to controllably generate a carbon-based Prussian blue composite material in situ.
[0103] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 7 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 281 mg / g.
[0104] Example 8
[0105] The steps of preparing a carbon-based Prussian blue composite material by an in-situ etching method using iron nitrate as a metal salt include:
[0106] Waste corrugated paper was crushed into paper scraps by dry method in a solid sample crusher. 1.5 g of paper scraps were taken and mixed in 0.1 mol / LFe(NO 3 ) 3 The paper scraps were immersed in a solution (water and ethanol as solvent, volume ratio of 3:7) for 30 min. 3 ) 3 The mass ratio of the solution was 0.06. After impregnation, it was placed in a cylinder to remove the solvent and form. After drying, it was heated to 400°C in a tube furnace at a heating rate of 5°C / min in a nitrogen atmosphere and then carbonized for 2h to prepare the loaded Fe 2 O 3 porous carbon materials;
[0107] The Fe-loaded substrate was slowly etched by hydrochloric acid-potassium ferrocyanide solution (hydrochloric acid concentration was 0.1 mol / L, potassium ferrocyanide concentration was 0.1 mol / L). 2 O 3The porous carbon material was etched for 24 h, washed with deionized water and ethanol three times, placed in a vacuum drying oven, and dried at 70 °C for 12 h to controllably generate a carbon-based Prussian blue composite material in situ.
[0108] 0.05 g of the carbon-based Prussian blue composite material prepared in Example 8 was placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorption capacity was 265 mg / g.
[0109] Comparative Example 1
[0110] The steps of preparing copper ferrocyanide material by coprecipitation method include:
[0111] Prepare 0.1 mol / L K 4 Fe(CN) 6 and 0.1 mol / L CuSO 4 solution, CuSO 4 The solution was slowly dripped into K 4 Fe(CN) 6 After 12 hours of reaction in the solution, the copper ferrocyanide material (an analogue of Prussian blue) was obtained by centrifugal drying.
[0112] Comparative Example 2
[0113] The steps of preparing zinc ferrocyanide material by coprecipitation method include:
[0114] Prepare 0.1 mol / L K 4 Fe(CN) 6 and 0.1 mol / L ZnSO 4 solution, ZnSO 4 The solution was slowly dripped into K 4 Fe(CN) 6 After the reaction in the solution for 12 hours, the zinc ferrocyanide material (an analogue of Prussian blue) was obtained by centrifugal drying.
[0115] Test example
[0116] 0.05 g of the materials prepared in Example 1 and Comparative Example 1 were placed in a 100 mg / L cesium-containing solution and adsorbed for 12 h. The adsorbed materials were then desorbed in a potassium chloride solution and washed with water for several times before being directly used in the next adsorption process. The cycle was repeated 5 times. The stability and regeneration performance of the materials in Example 1 were as follows: Figure 6 shown.
[0117] Depend on Figure 6 It can be seen that the adsorption rate of cesium by the material prepared in Example 1 is maintained above 70%, indicating that the material has good stability and recycling performance.
[0118] Figure 7The actual picture of the material prepared in Comparative Example 1 and the state of the solution after adsorption, wherein the left picture is the actual picture, and the right picture is the state of the solution after adsorption. It can be seen from the figure that the material is in powder form, and the solution after adsorption is difficult to clarify, not easy to separate and recycle, difficult to recover, and poor in industrial application. The impregnation method of the present invention is a molded material that is easy to recycle and reuse.
[0119] The carbon-based Prussian blue composite material synthesized in the embodiment of the present invention can be directly formed without the need for a binder and a high molecular polymer, and has good industrial application prospects.
[0120] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.
[0121] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a carbon-based Prussian blue composite material, characterized in that the steps include: The carbon-based Prussian blue composite material is prepared by using biomass materials as carbon source through impregnation method or confined in-situ etching method.
2. The preparation method according to claim 1, characterized in that The biomass material is corrugated paper.
3. The preparation method according to claim 1, characterized in that: The step of preparing the carbon-based Prussian blue composite material by the impregnation method comprises: A porous carbon material is prepared using biomass material as a raw material, and then the porous carbon material is immersed in a metal ion solution, and solid-liquid separation is performed to obtain a porous carbon loaded with metal ions; The porous carbon loaded with metal ions is immersed in a ferrocyanide solution, and then washed and dried to obtain the carbon-based Prussian blue composite material.
4. The preparation method according to claim 3, characterized in that: The steps of preparing the porous carbon material using the biomass material as raw material include: crushing the biomass material and immersing it in a water-ethanol mixed solution, removing the solvent and molding it after the immersion to obtain a porous carbon material precursor; carbonizing the porous carbon material precursor to obtain the porous carbon material; and / or, The mass ratio of the porous carbon material to the metal ion solution is 0.01-0.1; and / or, The metal ion solution comprises 0.01 mol / L to saturated metal salt, 0 mol / L to saturated complexing agent and 0-5 wt.% surfactant; and / or, The immersion time in the metal ion solution is 0.5-24h; and / or, The concentration of the ferrocyanide solution is 0.01 mol / L to saturation; and / or, The mass ratio of the porous carbon loaded with metal ions to the ferrocyanide solution is 0.01-0.1; and / or, The immersion time in the ferrocyanide solution is 0.5-24h; and / or, The cleaning is performed by using deionized water and ethanol to clean at least once in sequence; and / or, The drying is vacuum drying at a temperature of 50-70° C. for 12 hours.
5. The preparation method according to claim 4, characterized in that: The volume proportion of ethanol in the water-ethanol mixed solution is ≥50%; and / or, The mass ratio of the biomass material to the water-ethanol mixed solution is 0.02-0.6; and / or, The immersion time in the water-ethanol mixed solution is 30-120 min; and / or, The desolventizing body is shaped into a cylinder, a sphere or a cube; and / or, The carbonization treatment temperature is 400-900°C, the heating rate is 1-10°C / min, the holding time is 30-360min, and the atmosphere is nitrogen atmosphere; and / or, The metal salt is at least one of chloride, sulfate, carbonate, nitrate and acetate of a transition metal; the transition metal includes at least one of Fe, Co, Ni, Cu and Zn; and / or, The complexing agent is citrate; and / or, The surfactant is at least one of polyvinyl pyrrolidone, hexadecyltrimethylammonium bromide and sodium dodecylbenzenesulfonate.
6. The preparation method according to claim 1, characterized in that: The step of preparing the carbon-based Prussian blue composite material by using the confined in-situ etching method comprises: The biomass material is crushed and then immersed in a metal ion solution, and then subjected to desolventizing, molding and carbonization treatments in sequence to prepare a precursor material; The precursor material is etched by an acid-ferrocyanide solution, and then cleaned and dried to obtain the carbon-based Prussian blue composite material.
7. The preparation method according to claim 6, characterized in that: The mass ratio of the biomass material to the metal ion solution is 0.01-0.1; and / or, The immersion time is 30-120 min; and / or, The metal ion solution is composed of a metal salt and a solvent, wherein the concentration of the metal salt in the metal ion solution is 0.01 mol / L to saturation; the solvent is water and ethanol, and the volume proportion of ethanol in the solvent is ≥50%; and / or, The desolventizing body is shaped into a cylinder, a sphere or a cube; and / or, The carbonization treatment temperature is 400-900°C, the heating rate is 1-10°C / min, the holding time is 30-360min, and the atmosphere is nitrogen atmosphere; and / or, The acid in the acid-ferrocyanide solution is at least one of acetic acid, hydrochloric acid, citric acid and trimesic acid, and the concentration is 0.01-5 mol / L; and / or, The concentration of ferrocyanide salt in the acid-ferrocyanide salt solution is 0.01 mol / L to saturation; and / or, The etching time is 0.5-24h; and / or, The cleaning is performed by using deionized water and ethanol to clean at least once in sequence; and / or, The drying is vacuum drying at a temperature of 50-70° C. for 12 hours.
8. The preparation method according to claim 7, characterized in that: The metal salt is at least one of chloride, sulfate, carbonate, nitrate and acetate of a transition metal; the transition metal includes at least one of Fe, Co, Ni, Cu and Zn.
9. A carbon-based Prussian blue composite material, characterized in that: The carbon-based Prussian blue composite material is prepared by the preparation method according to any one of claims 1 to 8.
10. Use of the carbon-based Prussian blue composite material according to claim 9 for extracting cesium from liquid resources and treating cesium in radioactive wastewater.