Prussian blue composite nanomaterial, and preparation method and application thereof
By loading Prussian blue hollow spheres onto MXene materials to form Prussian blue composite nanomaterials, the problems of easy stacking of MXene and poor conductivity of Prussian blue are solved, achieving efficient desalination and improved stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAN JIAOTONG LIVERPOOL UNIV
- Filing Date
- 2024-09-19
- Publication Date
- 2026-07-21
AI Technical Summary
Existing MXene materials have a layered structure that is easy to stack and oxidize, while Prussian blue analogues have poor conductivity and short cycle life, making them difficult to effectively desalinate in high-concentration brine.
Prussian blue composite nanomaterials were formed by loading Prussian blue hollow spheres onto the surface of MXene material and utilizing the high conductivity of MXene and the open framework structure of the Prussian blue hollow spheres to perform electrostatic self-assembly.
It improves the conductivity and ion transport performance of the material, enhances its desalination capacity and cycle stability, and alleviates structural distortion during charge and discharge processes.
Smart Images
Figure CN119191482B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of capacitive deionization technology, and relates to a Prussian blue composite nanomaterial, its preparation method and application. Background Technology
[0002] Capacitive deionization (CDI) is an electrochemical desalination technology. Among various seawater desalination technologies, CDI has many advantages, such as low energy consumption, low maintenance costs, long service life, and environmental friendliness. Electrode materials are an important component of CDI systems. In recent years, Faraday electrode materials have gradually replaced traditional carbon materials due to their different electroadsorption principles, exhibiting stronger electroadsorption capabilities.
[0003] MXene, as a typical Faraday material, exhibits excellent conductivity and high capacity in CDI applications. However, the layered structure of MXene is prone to stacking problems and is easily oxidized during storage. Therefore, researchers hope to improve its desalination ability and rate by modifying MXene or optimizing etching methods.
[0004] Prussian blue analogues (PBAs) are also high-capacity Faraday electrode materials. Their open framework structure and abundant sodium ion extraction / intercalation channels give PBAs a high specific surface area, uniform active sites, and tunable crystal structure. However, traditional Prussian blue analogues have poor conductivity, short cycle life, and still face many challenges when used to treat high-concentration brine.
[0005] Based on the above research, there is a need to provide a Prussian blue composite nanomaterial, which has high conductivity and fast ion transport performance, and can improve the desalination capacity, rate and cycle stability of electrode materials. Summary of the Invention
[0006] The purpose of this invention is to provide a Prussian blue composite nanomaterial, its preparation method, and its application. The Prussian blue composite nanomaterial, through the synergistic effect of Prussian blue hollow spheres and MXene, possesses high conductivity and fast ion transport performance, improving the material's desalination capacity, rate, and cycle stability. At the same time, it can also alleviate structural distortion caused by the Jan Taylor effect during charging and discharging.
[0007] To achieve this objective, the present invention adopts the following technical solution:
[0008] In a first aspect, the present invention provides a Prussian blue composite nanomaterial comprising MXene material and Prussian blue hollow spheres, wherein the Prussian blue hollow spheres are loaded on the surface of the MXene material.
[0009] This invention utilizes the high conductivity of MXene as a conductive substrate, loading Prussian blue hollow spheres onto MXene. Through the synergistic effect of the two, the composite nanomaterial possesses high conductivity and fast ion transport performance, improving the material's desalination capacity, rate, and cycle stability. Furthermore, the Prussian blue hollow sphere structure facilitates ion diffusion and can alleviate structural distortion caused by the Jan Taylor effect during charging and discharging.
[0010] Preferably, the content of Prussian blue hollow spheres in the Prussian blue composite nanomaterial is 15-75 wt%, for example, it can be 15 wt%, 30 wt%, 45 wt%, 60 wt% or 75 wt%, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0011] Preferably, the hollow volume of the Prussian blue hollow sphere accounts for 30-40% of the total volume of the Prussian blue hollow sphere, for example, it can be 30%, 32%, 34%, 36%, 38% or 40%, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0012] Secondly, the present invention provides a method for preparing Prussian blue composite nanomaterials, the method comprising the following steps:
[0013] The MXene material, Prussian blue hollow spheres, and solvent were mixed and then separated into solid and liquid components to obtain the Prussian blue composite nanomaterial.
[0014] Preferably, the Prussian blue hollow spheres are first modified to obtain positively charged Prussian blue hollow spheres before being mixed with MXene material and solvent;
[0015] Preferably, the modification method includes the following steps:
[0016] Prussian blue hollow spheres, solvent, and modifier are mixed to obtain positively charged Prussian blue hollow spheres, thus completing the modification of the Prussian blue hollow spheres.
[0017] This invention first modifies Prussian blue hollow spheres to obtain positively charged Prussian blue hollow spheres, and then combines them with MXene material. This allows MXene and PBA to be electrostatically self-assembled and combined. If the modification is not performed and MXene material is directly combined with Prussian blue hollow spheres, the negatively charged Prussian blue hollow spheres and negatively charged MXene cannot be uniformly combined, which leads to a decrease in desalination capacity.
[0018] Preferably, the modifier comprises an amino-containing silane compound.
[0019] This invention uses amino-containing silane compounds for modification. Prussian blue hollow spheres exhibit positively charged -NH2 functional groups on their surface after amine modification. During the composite process, these functional groups can recombine with the surface functional groups of MXene nanosheets (such as negatively charged -OH, -F, and -O) through electrostatic forces and exist in the final composite material.
[0020] Preferably, the amino-containing silane compound includes any one or a combination of at least two of 3-aminopropyltrimethoxysilane, 3-aminopropylsilane, N-(n-butyl)-3-aminopropyltrimethoxysilane, dimethylaminopropyltrimethoxysilane, or diethylaminomethyltriethoxysilane.
[0021] Preferably, the mass ratio of the Prussian blue hollow spheres to the modifier is 1:(0.025-0.18), for example, it can be 1:0.025, 1:0.05, 1:0.1, 1:0.15, 1:0.17 or 1:0.18, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0022] The mass ratio of Prussian blue hollow spheres to modifier described in this invention affects the degree of modification. If there is too little modifier, the degree of modification will be too low, resulting in incomplete electrostatic self-assembly, uneven distribution and poor contact of components in the composite material, leading to low conductivity and low ion adsorption. If there is too much modifier, the degree of modification will be too high, resulting in excess surface modifier, affecting conductivity and redox reaction rate, and may also damage the Prussian blue structure.
[0023] Preferably, the temperature at which the Prussian blue hollow spheres, solvent, and modifier are mixed is 55-75°C, for example, 55°C, 60°C, 70°C, or 75°C, and the time is 3-5 hours, for example, 3 hours, 4 hours, or 5 hours, but not limited to the listed values. Other unlisted values within the range are also applicable.
[0024] Preferably, the method for preparing the Prussian blue hollow spheres includes the following steps:
[0025] (i) The alcohol solvent and the metal source are mixed and subjected to a solvothermal reaction to obtain the precursor;
[0026] (ii) The ferricyanide, the precursor described in step (i), and the solvent are mixed and reacted to obtain the Prussian blue hollow spheres.
[0027] This invention first involves a solvothermal reaction of an alcohol solvent and a metal source to obtain solid Prussian blue glycerate spheres, the precursor for preparing Prussian blue hollow spheres via a self-templating method. After the glycerate spheres dissolve in water, metal ions are slowly released and react with ferricyanide [Fe(CN)6]. 4-Anion exchange occurs, producing Prussian blue precipitate. As Prussian blue continues to form, the glyceryl ester is hydrolyzed, and the material gradually transforms from a solid structure to a hollow structure, ultimately yielding hollow Prussian blue spheres.
[0028] Preferably, the alcohol solvent in step (i) includes glycerol and / or isopropanol.
[0029] Preferably, the mass ratio of the alcohol solvent to the metal source in step (i) is (40-55):100, for example, it can be 40:100, 45:100, 50:100 or 55:100, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0030] Preferably, the metal source in step (i) includes a manganese source and / or a cobalt source.
[0031] Preferably, the temperature of the solvothermal reaction in step (i) is 130-150°C, for example, 130°C, 140°C or 150°C, and the time is 1-3h, for example, 1h, 2h or 3h, but not limited to the listed values. Other unlisted values within the range are also applicable.
[0032] Preferably, the ferricyanide in step (ii) comprises potassium hexacyanoferroate trihydrate.
[0033] Preferably, the temperature of the reaction in step (ii) is 80-100°C, for example, 80°C, 90°C or 100°C, and the time is 3-5h, for example, 3h, 4h or 5h, but not limited to the listed values. Other unlisted values within the range are also applicable.
[0034] Preferably, the mixing time of MXene material, Prussian blue hollow spheres and solvent is 0.5-1.5h, for example, it can be 0.5h, 1.0h or 1.5h, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0035] Preferably, the mass ratio of the MXene material to the Prussian blue hollow spheres is 1:(0.5-7), for example, it can be 1:0.5, 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6 or 1:7, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0036] Preferably, the method for preparing the MXene material includes mixing the Max material with an etching solution, separating the solid and liquid phases, and drying.
[0037] Preferably, the Max material comprises titanium aluminum carbide.
[0038] Preferably, the etching solution comprises hydrochloric acid and lithium fluoride.
[0039] As a preferred embodiment of the preparation method of the present invention, the preparation method includes the following steps:
[0040] (1) Mix Max material, hydrochloric acid and lithium fluoride, separate solid and liquid and dry to obtain MXene material;
[0041] (2) Glycerol, isopropanol, manganese source and cobalt source in a mass ratio of (5-10):(35-45):(70-80):(20-30) are stirred and mixed, and then reacted solvothermically at 130-150℃ for 1-3h. After cooling, centrifugation is performed and the mixture is washed with ethanol to obtain the precursor.
[0042] Ferric cyanide, the precursor and solvent were mixed and reacted at 80-100℃ for 3-5 h. After centrifugation and washing with ethanol and deionized water, Prussian blue hollow spheres were obtained after drying.
[0043] (3) Mix the Prussian blue hollow spheres, solvent and modifier obtained in step (2) at 55-75°C for 3-5 hours to obtain positively charged Prussian blue hollow spheres;
[0044] The mass ratio of the Prussian blue hollow spheres to the modifier is 1:(0.025-0.18);
[0045] (4) Disperse the MXene material described in step (1) in deionized water to obtain solution A. Disperse the positively charged Prussian blue hollow spheres described in step (3) in deionized water to obtain solution B. Stir and mix solution A and solution B for 0.5-1.5 h, centrifuge, wash with ethanol and deionized water, and freeze dry to obtain the Prussian blue composite nanomaterial.
[0046] The mass ratio of the MXene material to the positively charged Prussian blue hollow spheres is 1:(0.5-2.5).
[0047] Thirdly, the present invention provides a capacitive deionization device, the capacitive deionization device comprising the Prussian blue composite nanomaterial as described in the first aspect.
[0048] Compared with the prior art, the present invention has the following beneficial effects:
[0049] This invention utilizes the high conductivity of MXene as a conductive substrate and loads Prussian blue hollow spheres onto MXene. Through the synergistic effect of the two, the composite nanomaterial exhibits high conductivity and rapid ion transport performance, thereby improving the material's desalination capacity, rate, and cycle stability. Furthermore, the Prussian blue hollow sphere structure facilitates ion diffusion and can alleviate structural distortion caused by the Jan Taylor effect during charging and discharging. Attached Figure Description
[0050] Figure 1 This is a TEM image of the Prussian blue hollow sphere described in Embodiment 1 of the present invention;
[0051] Figure 2 This is a SEM image of the Prussian blue composite nanomaterial described in Example 1 of the present invention;
[0052] Figure 3 The above are the XRD patterns of the Prussian blue composite nanomaterial and Mxene material described in Example 1 of this invention.
[0053] Figure 4 EIS image of the Prussian blue composite nanomaterial described in Example 1 of this invention;
[0054] Figure 5 The CV diagram of the Prussian blue composite nanomaterial described in Example 1 of this invention;
[0055] Figure 6 This is a graph showing the change in conductivity over time of the Prussian blue composite nanomaterial described in Example 1 of the present invention during desalination. Detailed Implementation
[0056] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0057] Example 1
[0058] This embodiment provides a Prussian blue composite nanomaterial, which includes MXene material and Prussian blue hollow spheres. The Prussian blue hollow spheres are loaded on the surface of the MXene material. In the Prussian blue composite nanomaterial, the content of Prussian blue hollow spheres is 50%, and the hollow volume of the Prussian blue hollow spheres accounts for 32.5% of the total volume of the Prussian blue hollow spheres.
[0059] The preparation method of the Prussian blue composite nanomaterial includes the following steps:
[0060] (1) Preparation of MXene materials
[0061] Mix 40 mL of 9 mol / L hydrochloric acid and 3 g of lithium fluoride, and stir magnetically for 15 minutes at room temperature until completely dissolved;
[0062] 1g of titanium aluminum carbide (Ti3AlC2) powder was slowly and uniformly added to the above solution over 20 minutes. The container was sealed and magnetically stirred at 35°C for 24 hours. The solution was then centrifuged, filtered, and washed multiple times. The centrifugation speed was gradually increased from 4000 rpm until the pH value of the supernatant was greater than 6.
[0063] The collected precipitate was added to 60 mL of deionized water, sonicated for 30 minutes until completely dissolved, centrifuged at 3000 rpm for 20 minutes, and the supernatant was collected and freeze-dried for 48 hours to obtain black flake MXene material.
[0064] (2) Preparation of Prussian Blue Hollow Spheres
[0065] Add 75.3 mg of manganese nitrate tetrahydrate and 21.8 mg of cobalt nitrate hexahydrate to 8 mL of glycerol and 40 mL of isopropanol, stir magnetically for 20 minutes, then react solvothermically at 140 °C for 2 h. After cooling to room temperature, centrifuge and wash several times with ethanol to collect the precipitate to obtain the precursor.
[0066] The precursor was added to 200 mL of ethanol and sonicated for 15 minutes until completely dissolved to obtain the first solution. 3.2 mmol of potassium hexacyanoferrate(II) trihydrate was added to 120 mL of deionized water to obtain the second solution. The second solution was added to the first solution under stirring. A straight condenser was added and the mixture was refluxed in an oil bath at 90 °C for 4 h. After centrifugation and washing with ethanol and deionized water several times, the precipitate was collected and baked at 60 °C for 2 h to obtain Prussian blue hollow sphere powder.
[0067] The mass ratio of glycerol, isopropanol, manganese nitrate tetrahydrate, and cobalt nitrate hexahydrate is 8:40:75.3:21.8.
[0068] (3) Modification of Prussian Blue Hollow Spheres
[0069] Add 5 mg of the Prussian blue hollow sphere powder described in step (2) to 50 mL of deionized water, ultrasonically disperse until completely dissolved, add 0.5 mL of 3-aminopropyltrimethoxysilane, and reflux at 65 °C for 4 h to obtain positively charged Prussian blue hollow spheres.
[0070] The mass ratio of the Prussian blue hollow spheres to 3-aminopropyltrimethoxysilane is 1:0.1;
[0071] (4) Preparation of Prussian blue composite nanomaterials
[0072] 10 mg of the MXene material described in step (1) was ultrasonically dispersed in deionized water to obtain solution A. 10 mg of the positively charged Prussian blue hollow spheres described in step (3) were dispersed in deionized water to obtain solution B. Solution A and solution B were magnetically stirred for 1 h, centrifuged, and washed multiple times with ethanol and deionized water. The precipitate was collected and freeze-dried for 48 hours to obtain the Prussian blue composite nanomaterial PBA@MXene.
[0073] The mass ratio of the MXene material to the positively charged Prussian blue hollow spheres is 1:1;
[0074] The TEM image of the Prussian blue hollow sphere is as follows: Figure 1 As shown, the SEM image is as follows: Figure 2 As shown, the EIS diagram is as follows: Figure 4 As shown, the CV diagram is as follows Figure 5 As shown, the XRD patterns of the Prussian blue composite nanomaterial and the MXene material are as follows. Figure 3 As shown.
[0075] Example 2
[0076] This embodiment provides a Prussian blue composite nanomaterial, which includes MXene material and Prussian blue hollow spheres. The Prussian blue hollow spheres are loaded on the surface of the MXene material. In the Prussian blue composite nanomaterial, the content of Prussian blue hollow spheres is 33%, and the hollow volume of the Prussian blue hollow spheres accounts for 30% of the total volume of the Prussian blue hollow spheres.
[0077] The preparation method of the Prussian blue composite nanomaterial includes the following steps:
[0078] (1) Preparation of MXene materials
[0079] Mix 40 mL of 9 mol / L hydrochloric acid and 3 g of lithium fluoride, and stir magnetically for 15 minutes at room temperature until completely dissolved;
[0080] 1g of titanium aluminum carbide (Ti3AlC2) powder was slowly and uniformly added to the above solution over 20 minutes. The container was sealed and magnetically stirred at 35°C for 24 hours. The solution was then centrifuged, filtered, and washed multiple times. The centrifugation speed was gradually increased from 4000 rpm until the pH value of the supernatant was greater than 6.
[0081] The collected precipitate was added to 60 mL of deionized water, sonicated for 30 minutes until completely dissolved, centrifuged at 3000 rpm for 20 minutes, and the supernatant was collected and freeze-dried for 48 hours to obtain black flake MXene material.
[0082] (2) Preparation of Prussian Blue Hollow Spheres
[0083] Add 70 mg of manganese nitrate tetrahydrate and 30 mg of cobalt nitrate hexahydrate to 5 mL of glycerol and 45 mL of isopropanol, stir magnetically for 20 minutes, then react solvothermically at 130 °C for 3 h. After cooling to room temperature, centrifuge and wash with ethanol several times to collect the precipitate to obtain the precursor.
[0084] The precursor was added to 200 mL of ethanol and sonicated for 15 minutes until completely dissolved to obtain the first solution. 3.2 mmol of potassium hexacyanoferrate(II) trihydrate was added to 120 mL of deionized water to obtain the second solution. The second solution was added to the first solution under stirring. A straight condenser was added and the mixture was refluxed in an oil bath at 100 °C for 3 h. After centrifugation and washing with ethanol and deionized water several times, the precipitate was collected and baked at 60 °C for 2 h to obtain Prussian blue hollow spheres.
[0085] The mass ratio of glycerol, isopropanol, manganese nitrate tetrahydrate and cobalt nitrate hexahydrate is 5:45:70:30;
[0086] (3) Modification of Prussian Blue Hollow Spheres
[0087] Add 5 mg of the Prussian blue hollow sphere powder described in step (2) to 50 mL of deionized water, ultrasonically disperse until completely dissolved, add 0.125 mL of 3-aminopropyltrimethoxysilane, and reflux at 75 °C for 3 h to obtain positively charged Prussian blue hollow spheres.
[0088] The mass ratio of the Prussian blue hollow spheres to 3-aminopropyltrimethoxysilane is 1:0.025;
[0089] (4) Preparation of Prussian blue composite nanomaterials
[0090] 10 mg of the MXene material described in step (1) was ultrasonically dispersed in deionized water to obtain solution A. 5 mg of the positively charged Prussian blue hollow spheres described in step (3) were dispersed in deionized water to obtain solution B. Solution A and solution B were magnetically stirred for 1.5 h, centrifuged, and washed multiple times with ethanol and deionized water. The precipitate was collected and freeze-dried for 48 h to obtain the Prussian blue composite nanomaterial.
[0091] The mass ratio of the MXene material to the positively charged Prussian blue hollow spheres is 1:0.5.
[0092] Example 3
[0093] This embodiment provides a Prussian blue composite nanomaterial, which includes MXene material and Prussian blue hollow spheres. The Prussian blue hollow spheres are loaded on the surface of the MXene material. In the Prussian blue composite nanomaterial, the content of Prussian blue hollow spheres is 67%, and the hollow volume of the Prussian blue hollow spheres accounts for 40% of the total volume of the Prussian blue hollow spheres.
[0094] The preparation method of the Prussian blue composite nanomaterial includes the following steps:
[0095] (1) Preparation of MXene materials
[0096] Mix 40 mL of 9 mol / L hydrochloric acid and 3 g of lithium fluoride, and stir magnetically for 15 minutes at room temperature until completely dissolved;
[0097] 1g of titanium aluminum carbide (Ti3AlC2) powder was slowly and uniformly added to the above solution over 20 minutes. The container was sealed and magnetically stirred at 35°C for 24 hours. The solution was then centrifuged, filtered, and washed multiple times. The centrifugation speed was gradually increased from 4000 rpm until the pH value of the supernatant was greater than 6.
[0098] The collected precipitate was added to 60 mL of deionized water, sonicated for 30 minutes until completely dissolved, centrifuged at 3000 rpm for 20 minutes, and the supernatant was collected and freeze-dried for 48 hours to obtain black flake MXene material.
[0099] (2) Preparation of Prussian Blue Hollow Spheres
[0100] Add 80 mg of manganese nitrate tetrahydrate and 20 mg of cobalt nitrate hexahydrate to 10 mL of glycerol and 35 mL of isopropanol, stir magnetically for 20 minutes, then react solvothermically at 150 °C for 1 h. After cooling to room temperature, centrifuge and wash several times with ethanol to collect the precipitate to obtain the precursor.
[0101] The precursor was added to 200 mL of ethanol and sonicated for 15 minutes until completely dissolved to obtain the first solution. 3.2 mmol of potassium hexacyanoferrate(II) trihydrate was added to 120 mL of deionized water to obtain the second solution. The second solution was added to the first solution under stirring. A straight condenser was added and the mixture was refluxed in an oil bath at 80 °C for 5 h. After centrifugation and washing with ethanol and deionized water several times, the precipitate was collected and baked at 60 °C for 2 h to obtain Prussian blue hollow spheres.
[0102] The mass ratio of glycerol, isopropanol, manganese nitrate tetrahydrate and cobalt nitrate hexahydrate is 10:35:80:20;
[0103] (3) Modification of Prussian Blue Hollow Spheres
[0104] Add 5 mg of the Prussian blue hollow sphere powder described in step (2) to 50 mL of deionized water, ultrasonically disperse until completely dissolved, add 1.25 mL of 3-aminopropyltrimethoxysilane, and reflux at 55 °C for 5 h to obtain positively charged Prussian blue hollow spheres.
[0105] The mass ratio of the Prussian blue hollow spheres to 3-aminopropyltrimethoxysilane is 1:0.18;
[0106] (4) Preparation of Prussian blue composite nanomaterials
[0107] 10 mg of the MXene material described in step (1) was ultrasonically dispersed in deionized water to obtain solution A. 20 mg of the positively charged Prussian blue hollow spheres described in step (3) were dispersed in deionized water to obtain solution B. Solution A and solution B were magnetically stirred for 0.5 h, centrifuged, and washed multiple times with ethanol and deionized water. The precipitate was collected and freeze-dried for 48 hours to obtain the Prussian blue composite nanomaterial.
[0108] The mass ratio of the MXene material to the positively charged Prussian blue hollow spheres is 1:2.
[0109] Example 4
[0110] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of MXene material and positively charged Prussian blue hollow spheres in step (4) of its preparation method is 1:0.2, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0111] Example 5
[0112] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of MXene material and positively charged Prussian blue hollow spheres in step (4) of the preparation method is 1:2.5, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0113] Example 6
[0114] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of MXene material and positively charged Prussian blue hollow spheres in step (4) of the preparation method is 1:3.5, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0115] Example 7
[0116] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of MXene material and positively charged Prussian blue hollow spheres in step (4) of the preparation method is 1:5, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0117] Example 8
[0118] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of MXene material and positively charged Prussian blue hollow spheres in step (4) of the preparation method is 1:7, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0119] Example 9
[0120] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of Prussian blue hollow spheres to 3-aminopropyltrimethoxysilane in step (3) of the preparation method is 1:0.01, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0121] Example 10
[0122] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the mass ratio of Prussian blue hollow spheres to 3-aminopropyltrimethoxysilane in step (3) of the preparation method is 1:0.4, which changes the adaptability of the obtained Prussian blue composite nanomaterial, the rest is the same as in Example 1.
[0123] Example 11
[0124] This embodiment provides a Prussian blue composite nanomaterial. Except for the fact that the Prussian blue composite nanomaterial is not modified in step (3) in its preparation method, so that the adaptability of the obtained Prussian blue composite nanomaterial is changed, the rest is the same as in Example 1.
[0125] Comparative Example 1
[0126] This comparative example provides a Prussian blue material, which is the same as that in Example 1 except that it does not include MXene material;
[0127] The preparation method of the Prussian blue material is the same as that in Example 1, except that steps (1) and (4) are not performed.
[0128] Comparative Example 2
[0129] This comparative example provides an MXene material, which is the same as that in Example 1 except that it does not include Prussian blue hollow spheres;
[0130] The preparation method of the MXene material is the same as that in Example 1, except that steps (2)-(4) are not performed.
[0131] Comparative Example 3
[0132] This comparative example provides a Prussian blue composite nanomaterial, which is the same as that in Example 1 except that hollow Prussian blue spheres are replaced with solid Prussian blue spheres of equal mass.
[0133] The preparation method of the Prussian blue composite nanomaterial is the same as that in Example 1, except that step (2) involves the preparation of solid Prussian blue spheres. The preparation method of the solid Prussian blue spheres includes:
[0134] (1) Add 4.5 mmol sodium citrate dihydrate to 100 mL deionized water and stir magnetically until completely dissolved. Then add 225.9 mg manganese nitrate tetrahydrate and 65.4 mg cobalt nitrate hexahydrate and stir magnetically to obtain the first solution.
[0135] (2) Add 9.6 mmol of potassium hexacyanoferrate(II) trihydrate to 100 mL of deionized water and stir magnetically for 30 minutes to obtain a second solution. Add the second solution to the first solution, stir magnetically for 10 minutes, age at room temperature for 24 hours, centrifuge, wash several times with ethanol and deionized water, collect the precipitate, and bake at 60 °C for 6 hours to obtain Prussian blue nanocube powder.
[0136] The Prussian blue composite nanomaterials prepared in Examples 1-8 and Comparative Example 3, the Prussian blue material prepared in Comparative Example 1, and the MXene material prepared in Comparative Example 2 were used as electrode materials. These materials were mixed with carbon black and polyvinylidene fluoride in an 8:1:1 ratio, respectively. The mixtures were stirred into a slurry using N-methylpyrrolidone as a solvent. The slurry was then coated onto a 2cm x 2cm area in the center of graphite paper to form a CDI electrode sheet, which was baked at 60°C for 12 hours. The CDI performance was tested using the prepared electrode sheet as the anode and activated carbon as the cathode. The electrode mass was approximately 30 mg, and the sodium chloride solution was set at approximately 1000 μS / cm. -1 The solution volume was 40 mL, the rotation speed was 100 rpm, the test voltage range was -1.4 V to 1.4 V, and the analytical electrode material was tested at a current density of 20 mAg. -1 The amount of salt desalination was measured, and the changes in current, voltage, and conductivity over time were recorded every 10 seconds. The conductivity-time curve for Example 1 during desalination is shown in the figure below. Figure 6 As shown, it exhibits excellent desalination performance.
[0137] The desalination amounts obtained from the tests are shown in Table 1:
[0138] Table 1
[0139]
[0140]
[0141] As can be seen from Table 1:
[0142] As shown in Examples 1 and Comparative Examples 1-2, the composite of MXene material and Prussian blue hollow spheres in this invention can exert a synergistic effect, resulting in Prussian blue composite nanomaterials with good desalination performance. As shown in Examples 1 and Comparative Example 3, when Prussian blue is a solid material, the ion diffusion ability decreases, and the Jan Taylor effect is severe during charging and discharging, which affects the performance of the Prussian blue composite nanomaterials. As shown in Examples 1 and Examples 4-8, the amount of Prussian blue hollow spheres loaded on the surface of MXene material in this invention also affects the interaction between the two, thus affecting the performance of the composite nanomaterials. As shown in Examples 1 and Examples 9-10, the degree of modification of Prussian blue hollow spheres affects their composite with MXene material, thus affecting the performance of the composite nanomaterials. As shown in Examples 1 and 11, if the Prussian blue hollow spheres are not modified, they cannot be electrostatically self-assembled with MXene material, thus affecting their composite.
[0143] In summary, this invention provides a Prussian blue composite nanomaterial, its preparation method, and its application. Through the synergistic effect of Prussian blue hollow spheres and MXene, the Prussian blue composite nanomaterial possesses high conductivity and fast ion transport performance, improving the material's desalination capacity, rate, and cycle stability. At the same time, it can also alleviate structural distortion caused by the Jan Taylor effect during charging and discharging.
[0144] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A Prussian blue composite nanomaterial, characterized in that, The Prussian blue composite nanomaterial comprises MXene material and Prussian blue hollow spheres, wherein the Prussian blue hollow spheres are loaded on the surface of the MXene material; The preparation method of the Prussian blue composite nanomaterial includes the following steps: MXene material, Prussian blue hollow spheres and solvent were mixed and then separated into solid and liquid components to obtain the Prussian blue composite nanomaterial. The Prussian blue hollow spheres are first modified to obtain positively charged Prussian blue hollow spheres, and then mixed with MXene material and solvent; The modification method includes the following steps: Prussian blue hollow spheres, solvent, and modifier are mixed to obtain positively charged Prussian blue hollow spheres, thus completing the modification of the Prussian blue hollow spheres. The modifier includes amino-containing silane compounds.
2. The Prussian blue composite nanomaterial according to claim 1, characterized in that, The Prussian blue composite nanomaterial contains 15-75 wt% hollow Prussian blue spheres.
3. The Prussian blue composite nanomaterial according to claim 1, characterized in that, In the Prussian blue hollow sphere, the hollow volume accounts for 30-40% of the total volume of the Prussian blue hollow sphere.
4. A method for preparing the Prussian blue composite nanomaterial as described in any one of claims 1-3, characterized in that, The preparation method includes the following steps: MXene material, Prussian blue hollow spheres and solvent were mixed and then separated into solid and liquid components to obtain the Prussian blue composite nanomaterial. The Prussian blue hollow spheres are first modified to obtain positively charged Prussian blue hollow spheres, and then mixed with MXene material and solvent; The modification method includes the following steps: Prussian blue hollow spheres, solvent, and modifier are mixed to obtain positively charged Prussian blue hollow spheres, thus completing the modification of the Prussian blue hollow spheres. The modifier includes amino-containing silane compounds.
5. The preparation method according to claim 4, characterized in that, The amino-containing silane compound includes any one or a combination of at least two of 3-aminopropyltrimethoxysilane, 3-aminopropylsilane, N-(n-butyl)-3-aminopropyltrimethoxysilane, dimethylaminopropyltrimethoxysilane, or diethylaminomethyltriethoxysilane.
6. The preparation method according to claim 4, characterized in that, The mass ratio of the Prussian blue hollow spheres to the modifier is 1:(0.025-0.18).
7. The preparation method according to claim 4, characterized in that, The Prussian blue hollow spheres, solvent, and modifier are mixed at a temperature of 55-75°C for 3-5 hours.
8. The preparation method according to claim 4, characterized in that, The method for preparing the Prussian blue hollow spheres includes the following steps: (i) The alcohol solvent and the metal source are mixed and reacted with a solvothermal agent to obtain the precursor; (ii) The ferricyanide, the precursor described in step (i), and the solvent are mixed and reacted to obtain the Prussian blue hollow spheres.
9. The preparation method according to claim 8, characterized in that, The alcohol solvent in step (i) includes glycerol and / or isopropanol.
10. The preparation method according to claim 8, characterized in that, The mass ratio of the alcohol solvent to the metal source in step (i) is (40-55):
100.
11. The preparation method according to claim 8, characterized in that, The metal source in step (i) includes a manganese source and / or a cobalt source.
12. The preparation method according to claim 8, characterized in that, The temperature of the solvothermal reaction in step (i) is 130-150℃, and the time is 1-3h.
13. The preparation method according to claim 8, characterized in that, The ferricyanide in step (ii) includes potassium hexacyanoferroate trihydrate.
14. The preparation method according to claim 8, characterized in that, The reaction in step (ii) is carried out at a temperature of 80-100℃ for 3-5 hours.
15. The preparation method according to claim 4, characterized in that, The mixing time for MXene material, Prussian blue hollow spheres and solvent is 0.5-1.5 h.
16. The preparation method according to claim 4, characterized in that, The method for preparing the MXene material includes mixing the MAX material with an etching solution, separating the solid and liquid phases, and drying.
17. The preparation method according to claim 16, characterized in that, The MAX material includes titanium aluminum carbide.
18. The preparation method according to claim 16, characterized in that, The etching solution includes hydrochloric acid and lithium fluoride.
19. The preparation method according to claim 4, characterized in that, The preparation method includes the following steps: (1) Mix MAX material, hydrochloric acid and lithium fluoride, separate solid and liquid and dry to obtain MXene material; (2) Glycerol, isopropanol, manganese source and cobalt source in a mass ratio of (5-10):(35-45):(70-80):(20-30) are stirred and mixed, and then reacted in a solvothermal manner at 130-150℃ for 1-3h. After cooling, the mixture is centrifuged and washed with ethanol to obtain the precursor. Ferric cyanide, the precursor and solvent were mixed and reacted at 80-100℃ for 3-5 h. After centrifugation and washing with ethanol and deionized water, Prussian blue hollow spheres were obtained after drying. (3) Mix the Prussian blue hollow spheres, solvent and modifier obtained in step (2) at 55-75°C for 3-5 hours to obtain positively charged Prussian blue hollow spheres; The mass ratio of the Prussian blue hollow spheres to the modifier is 1:(0.025-0.18); (4) Disperse the MXene material described in step (1) in deionized water to obtain solution A, disperse the positively charged Prussian blue hollow spheres described in step (3) in deionized water to obtain solution B, stir and mix solution A and solution B for 0.5-1.5 h, centrifuge, wash with ethanol and deionized water, and freeze dry to obtain the Prussian blue composite nanomaterial. The mass ratio of the MXene material to the positively charged Prussian blue hollow spheres is 1:(0.5-2.5).
20. A capacitor deionization device, characterized in that, The capacitor deionization device includes the Prussian blue composite nanomaterial as described in any one of claims 1-3.