A high-entropy prussian blue analogue, a preparation method and application thereof, and a working electrode
By preparing high-entropy Prussian blue analogs in a microchannel reactor, the problem of insufficient conductivity of Prussian blue analogs was solved, achieving high sensitivity and catalytic performance for the electrochemical detection of dopamine, avoiding the generation of highly toxic substances, and making it suitable for the field of electrochemical sensors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHIHEZI UNIVERSITY
- Filing Date
- 2023-12-05
- Publication Date
- 2026-06-23
Smart Images
Figure CN117658175B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of sensor fabrication technology, specifically relating to a high-entropy Prussian blue analogue, its preparation method and application, and a working electrode. Background Technology
[0002] Dopamine and acetylcholine are important electrochemically active molecules coexisting in the human body. Dopamine is a primary catecholamine neurotransmitter molecule with a basal concentration of approximately 0.01–1 μM. It transmits information of excitement and pleasure in the kidneys, cardiovascular system, and central nervous system, playing a crucial role in many physiological and pathological processes. However, abnormal dopamine levels may lead to tardive dyskinesia and neuroendocrine disorders, such as Parkinson's disease and schizophrenia. To overcome the health risks arising from dopamine, accurate and rapid monitoring of dopamine molecule levels is essential.
[0003] Previously, many techniques such as colorimetry, fluorescence, electrochemistry, and electrochemiluminescence have been used for the sensitive and selective detection of dopamine. Among them, electrochemical sensors have attracted widespread attention in recent years due to their advantages such as low cost, high sensitivity, and rapid response.
[0004] One class of materials that has yet to attract attention in the field of sensing materials is high-entropy Prussian blue analogues. Converting Prussian blue analogues into metal oxides or other nanoparticles can achieve better conductivity than the Prussian blue analogues themselves, but this is not an ideal solution because the pyrolysis of Prussian blue analogues typically releases highly toxic cyanides. Prussian blue analogues already possess abundant active sites, and if their conductivity is improved, they can be directly used as electrocatalysts. The construction of open-cage structures has proven effective in improving the conductivity of Prussian blue analogues, but this method requires precise process control and is difficult to scale up for mass production. Summary of the Invention
[0005] The purpose of this invention is to provide a high-entropy Prussian blue analogue, its preparation method and application, and a working electrode. The preparation method provided by this invention has simple steps, and the obtained high-entropy Prussian blue analogue shows excellent sensitivity when used for electrochemical detection of dopamine.
[0006] To achieve the above objectives, the present invention provides the following technical solution:
[0007] This invention provides a method for preparing a high-entropy Prussian blue analogue, comprising the following steps:
[0008] Five transition metal salts were dissolved in water to obtain transition metal salt solutions;
[0009] Dissolve potassium ferricyanide and a chelating agent in water to obtain a mixed solution;
[0010] The high-entropy Prussian blue analogue is obtained by subjecting the transition metal salt solution and the mixed solution to a precipitation reaction; the precipitation reaction is carried out in a microchannel reactor.
[0011] Preferably, the five transition metal salts are any five of the following: iron salts, manganese salts, nickel salts, cobalt salts, copper salts, zinc salts, chromium salts, and vanadium salts.
[0012] The molar ratio of any two of the five transition metal salts is 1:0.9 to 1.1.
[0013] Preferably, the transition metal salt includes one or more of sulfates, chlorides, nitrates, and oxalates.
[0014] Preferably, the ratio of the total molar amount of the five transition metal salts to the molar amount of potassium ferricyanide is 1:1 to 2.
[0015] Preferably, the chelating agent comprises potassium citrate or sodium citrate;
[0016] The molar ratio of potassium ferricyanide to the chelating agent is 1:1 to 3.
[0017] Preferably, the injection flow rate of the transition metal salt solution is 1–10 mL / min;
[0018] The injection flow rate of the mixed solution is 1–10 mL / min.
[0019] Preferably, the precipitation reaction is carried out at a temperature of 20–35°C;
[0020] The precipitation reaction is followed by a settling period of 24–48 hours.
[0021] The present invention also provides a high-entropy Prussian blue analog prepared by the preparation method described above, wherein the particle size of the high-entropy Prussian blue analog is 30-200 nm.
[0022] The present invention also provides the application of the high-entropy Prussian blue analogue described in the above technical solution in electrode materials.
[0023] The present invention also provides a working electrode, comprising an electrode substrate and a modification material layer covering the electrode substrate; the modification material in the modification material layer is a high-entropy Prussian blue analogue as described in the above technical solution.
[0024] This invention provides a method for preparing a high-entropy Prussian blue analogue, comprising the following steps: dissolving five transition metal salts in water to obtain a transition metal salt solution; dissolving potassium ferricyanide and a chelating agent in water to obtain a mixed solution; subjecting the transition metal salt solution and the mixed solution to a precipitation reaction to obtain the high-entropy Prussian blue analogue; the precipitation reaction is carried out in a microchannel reactor. The preparation method provided by this invention uses a microreactor to precipitate transition metal salts with potassium ferricyanide and a chelating agent, forming randomly occupied single lattices, which can provide an ideal maximum doping model. The resulting high-entropy Prussian blue analogue exhibits excellent catalytic performance due to its entropy-stable structure, synergistic effect, and continuous active regions provided by the highly disordered atomic distribution, and can be used as a modified electrode material to prepare a working electrode for electrochemical detection. Simultaneously, the high-entropy material exhibits a "cocktail" effect, which also improves the overall electrochemical performance of the material. Example results show that the high-entropy Prussian blue analogue material obtained by the method of this invention, as a modified electrode material, exhibits excellent detection sensitivity for the electrochemical detection of dopamine. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 Scanning electron microscope image of the high-entropy Prussian blue analog material (HE-V) prepared in Example 1 of the present invention;
[0027] Figure 2 X-ray diffraction pattern of the high-entropy Prussian blue analog material (HE-V) prepared in Example 1 of this invention;
[0028] Figure 3 X-ray diffraction pattern of the high-entropy Prussian blue analog material (HE-Zn) prepared in Example 2 of this invention;
[0029] Figure 4 X-ray diffraction pattern of the high-entropy Prussian blue analog material (HE-Cr) prepared in Example 3 of the present invention;
[0030] Figure 5 The X-ray diffraction patterns of the high-entropy Prussian blue analog materials prepared in Examples 1-3 of this invention are shown below.
[0031] Figure 6 The differential pulse adsorption-dissolution voltammetry curve for the electrochemical detection of dopamine using the HE-V material prepared in Example 1 of this invention;
[0032] Figure 7 The differential pulse adsorption-dissolution voltammetry curve for the electrochemical detection of dopamine using HE-Zn material prepared in Example 2 of this invention;
[0033] Figure 8 The differential pulse adsorption-dissolution voltammetry curve of the HE-Cr material prepared in Example 3 of this invention for the electrochemical detection of dopamine;
[0034] Figure 9 The differential pulse adsorption-dissolution voltammetry curves of the CuFeV-PBA material prepared in the comparative example of this invention for the electrochemical detection of dopamine are shown.
[0035] Figure 10 This is a schematic diagram of the microreactor structure involved in the present invention;
[0036] Figure 11 This is a schematic diagram of the two channels in the microreactor involved in the present invention. Detailed Implementation
[0037] This invention provides a method for preparing a high-entropy Prussian blue analogue, comprising the following steps:
[0038] Five transition metal salts were dissolved in water to obtain transition metal salt solutions;
[0039] Dissolve potassium ferricyanide and a chelating agent in water to obtain a mixed solution;
[0040] The high-entropy Prussian blue analogue is obtained by subjecting the transition metal salt solution and the mixed solution to a precipitation reaction; the precipitation reaction is carried out in a microchannel reactor.
[0041] In this invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.
[0042] This invention dissolves five transition metal salts in water to obtain transition metal salt solutions.
[0043] In this invention, the five transition metal salts are preferably any five of iron, manganese, nickel, cobalt, copper, zinc, chromium, and vanadium salts, more preferably any five of iron, nickel, cobalt, copper, zinc, chromium, and vanadium salts, and most preferably iron, nickel, cobalt, copper, and vanadium salts; the transition metal salts are preferably soluble transition metal salts; the transition metal salts preferably include one or more of sulfates, chlorides, nitrates, and oxalates, more preferably one or more of sulfates, chlorides, and nitrates; the iron salt is preferably a divalent iron salt; the manganese salt is preferably a divalent manganese salt; the nickel salt is preferably a divalent nickel salt; the cobalt salt is preferably a divalent cobalt salt; the copper salt is preferably a divalent copper salt; the zinc salt is preferably a divalent zinc salt; the chromium salt is preferably a divalent chromium salt; and the vanadium salt is preferably a trivalent vanadium salt.
[0044] In this invention, the molar ratio of any two of the five transition metal salts is preferably 1:0.9 to 1.1, more preferably 1:1 to 1.1, and most preferably 1:1.
[0045] In this invention, the total concentration of the five transition metal salts in the transition metal salt solution is preferably 0.02 to 1 mol / L, more preferably 0.04 to 0.5 mol / L, and most preferably 0.04 to 0.3 mol / L.
[0046] In this invention, potassium ferricyanide and a chelating agent are dissolved in water to obtain a mixed solution.
[0047] In this invention, the molar ratio of the total amount of the five transition metal salts to the molar amount of potassium ferricyanide is preferably 1:1 to 2, more preferably 1:1 to 1.7, and most preferably 1:1 to 1.3.
[0048] In this invention, the chelating agent preferably includes potassium citrate or sodium citrate; the molar ratio of potassium ferricyanide to the chelating agent is preferably 1:1 to 3, more preferably 1:1.5 to 3, and most preferably 1:2 to 2.5.
[0049] In this invention, the concentration of potassium ferricyanide in the mixed solution is preferably 0.02-2 mol / L, more preferably 0.04-1 mol / L, and most preferably 0.04-0.5 mol / L.
[0050] After obtaining the transition metal salt solution and the mixed solution, the present invention performs a precipitation reaction on the transition metal salt solution and the mixed solution to obtain the high-entropy Prussian blue analogue.
[0051] In this invention, the precipitation reaction is carried out in a microchannel reactor; the microchannel reactor is preferably a dual-channel microchannel reactor; the channel height of the microchannel reactor is preferably 1 mm, and the channel width is preferably 0.8 mm.
[0052] In this invention, the injection flow rate of the transition metal salt solution is preferably 1-10 mL / min, more preferably 1-8 mL / min, and most preferably 1-5 mL / min; the injection flow rate of the mixed solution is preferably 1-10 mL / min, more preferably 1-8 mL / min, and most preferably 1-5 mL / min; both the transition metal salt solution and the mixed solution are preferably injected into the microchannel reactor by an injection pump.
[0053] In this invention, the temperature of the precipitation reaction is preferably 20-35°C, more preferably 20-30°C;
[0054] In this invention, the transition metal salt solution and the mixed solution are injected into two channels of the microreactor to undergo a transient precipitation reaction, forming a multi-atom-doped high-entropy Prussian blue analog material.
[0055] In this invention, the precipitation reaction is preferably followed by a settling period; the settling time is preferably 24 to 48 hours, more preferably 30 to 45 hours; the temperature is preferably 20 to 35°C, more preferably 20 to 30°C.
[0056] In this invention, the settling process preferably includes centrifugation, washing, and drying performed sequentially; the centrifugation speed is preferably 7000-10000 rpm, more preferably 8000-9000 rpm; the time is preferably 10-20 min, more preferably 10-15 min; the washing solvent is preferably an aqueous ethanol solution; the volume ratio of ethanol to water in the aqueous ethanol solution is preferably 1:1-2, more preferably 1:1; the number of washing cycles is preferably 3-6 times, more preferably 4-5 times; the drying is preferably vacuum drying; the vacuum drying temperature is preferably 60-80℃, more preferably 65-75℃; the time is preferably 12-24 h, more preferably 15-20 h.
[0057] The preparation method provided by this invention involves a precipitation reaction of a transition metal salt with potassium ferricyanide and a chelating agent via a microreactor, forming randomly occupied single lattices that provide an ideal maximum doping model. The resulting high-entropy Prussian blue analogue exhibits excellent catalytic performance due to its entropy-stable structure, synergistic effect, and continuous active regions provided by the highly disordered atomic distribution. It can be used as a modified electrode material to prepare a working electrode for electrochemical detection. Simultaneously, the high-entropy material possesses a "cocktail" effect, further enhancing the overall electrochemical performance of the material. The results of the examples show that the high-entropy Prussian blue analogue material obtained by the method described in this invention, when used as a modified electrode material for the electrochemical detection of dopamine, exhibits excellent detection sensitivity.
[0058] The present invention also provides a high-entropy Prussian blue analog prepared by the preparation method described above, wherein the particle size of the high-entropy Prussian blue analog is 30-200 nm, preferably 30-150 nm, and more preferably 40-100 nm.
[0059] The high-entropy Prussian blue analogues provided by this invention possess the four core effects of high-entropy materials, such as high-entropy effect, lattice distortion, slow diffusion characteristics, and "cocktail" effect. Furthermore, due to their entropy-stable structure, synergistic effect, and the continuous active regions provided by their highly disordered atomic distribution, high-entropy Prussian blue analogue materials exhibit excellent catalytic performance. When used as modified electrode materials to prepare working electrodes for the electrochemical detection of dopamine, they demonstrate excellent detection sensitivity.
[0060] The present invention also provides the application of the high-entropy Prussian blue analogue described in the above technical solution in electrode materials.
[0061] In this invention, the electrode material is preferably an electrode material for dopamine detection.
[0062] The present invention does not impose any special limitations on the application of the high-entropy Prussian blue analogue in electrode materials; any method known to those skilled in the art can be used.
[0063] The present invention also provides a working electrode, comprising an electrode substrate and a modification material layer covering the electrode substrate; the modification material in the modification material layer is a high-entropy Prussian blue analogue as described in the above technical solution.
[0064] In this invention, the method for preparing the working electrode preferably includes the following steps:
[0065] A high-entropy Prussian blue analogue was mixed with a solvent to obtain a mixed slurry;
[0066] The mixed slurry is coated onto the surface of the electrode substrate and dried to obtain the working electrode.
[0067] This invention involves mixing a high-entropy Prussian blue analogue with a solvent to obtain a mixed slurry.
[0068] In this invention, the solvent is preferably a naphthol-ethanol mixture; the volume ratio of naphthol to ethanol in the naphthol-ethanol mixture is preferably 1:10 to 30, more preferably 1:15 to 25, and most preferably 1:20.
[0069] In this invention, the concentration of high-entropy Prussian blue analogue in the mixed slurry is preferably 3-8 mg / mL, more preferably 4-6 mg / mL, and most preferably 5 mg / mL.
[0070] After obtaining the mixed slurry, the present invention coats the mixed slurry onto the surface of the electrode substrate and dries it to obtain the working electrode.
[0071] In this invention, the electrode substrate is preferably a glassy carbon electrode; the coating amount of the mixed slurry is preferably 5-15 μL, more preferably 8-12 μL, and most preferably 10 μL.
[0072] In this invention, the coating amount is limited to the above range because too little coating amount will result in insufficient conductive material on the surface of the glassy carbon electrode, failing to achieve optimal detection response capability; too much coating amount will result in an excessively thick coating layer, leading to excessively high resistance, and may also cause peeling.
[0073] In this invention, the drying is carried out in air; the present invention does not impose any special limitations on the drying process, and any method known to those skilled in the art can be used.
[0074] The working electrode provided by this invention is used for the electrochemical detection of dopamine and has excellent sensitivity.
[0075] To further illustrate the present invention, the high-entropy Prussian blue analogues, their preparation methods and applications, and working electrodes provided by the present invention are described in detail below with reference to the accompanying drawings and embodiments. However, these descriptions should not be construed as limiting the scope of protection of the present invention.
[0076] Example 1
[0077] A high-entropy Prussian blue analog electrode material and its preparation method comprise the following steps:
[0078] A transition metal salt solution was prepared by magnetically stirring 0.1163 g (0.0004 mol) of nickel nitrate hexahydrate, 0.0966 g (0.0004 mol) of copper nitrate trihydrate, 0.1164 g (0.0004 mol) of cobalt nitrate hexahydrate, 0.1112 g (0.0004 mol) of ferrous sulfate heptahydrate, 0.1160 g (0.0004 mol) of vanadium chloride, and 50 mL of deionized water at room temperature.
[0079] Mix 0.6585 g (0.002 mol) of potassium ferricyanide and 0.6617 g (0.00225 mol) of sodium citrate with 50 mL of deionized water to form an aqueous solution;
[0080] The two solutions were injected into the two channels of the microreactor at a rate of 1 mL / min using a syringe pump at 20 °C, then allowed to stand for 48 hours, and then centrifuged at 7000 rpm for 10 min. The solutions were washed four times with an ethanol-water solution with a volume ratio of 1:1, and finally vacuum dried at 60 °C for 24 hours to obtain the high-entropy Prussian blue analog material (HE-V).
[0081] The HE-V prepared in Example 1 was characterized using scanning electron microscopy, and the SEM images of HE-V are shown below. Figure 1 As shown. From Figure 1 It can be clearly observed that the HE-V structure consists of particles with a diameter of 50 nm that are bonded together.
[0082] The HE-V prepared in Example 1 was characterized using an X-ray diffractometer, and the X-ray diffraction pattern of HE-V was obtained as shown in the figure. Figure 2 As shown. From Figure 2 It can be seen that the HE-V material prepared in this embodiment has a crystal phase structure.
[0083] Example 2
[0084] A high-entropy Prussian blue analog electrode material and its preparation method comprise the following steps:
[0085] A transition metal salt solution was prepared by magnetically stirring 0.1163 g (0.0004 mol) of nickel nitrate hexahydrate, 0.0966 g (0.0004 mol) of copper nitrate trihydrate, 0.1164 g (0.0004 mol) of cobalt nitrate hexahydrate, 0.1112 g (0.0004 mol) of ferrous sulfate heptahydrate, 0.0545 g (0.0004 mol) of zinc chloride, and 50 mL of deionized water at room temperature.
[0086] Mix 0.6585 g (0.002 mol) of potassium ferricyanide and 1.3234 g (0.0045 mol) of sodium citrate with 50 mL of deionized water to form an aqueous solution;
[0087] The two solutions were injected into the two channels of the microreactor at a rate of 10 mL / min using a syringe pump at 35 °C, then allowed to stand for 24 hours, and then centrifuged at 10,000 rpm for 15 min. The solutions were washed five times with an ethanol-water solution with a volume ratio of 1:1, and finally vacuum dried at 80 °C for 12 hours to obtain the high-entropy Prussian blue analog material (HE-Zn).
[0088] The HE-Zn prepared in Example 1 was characterized using an X-ray diffractometer, and the X-ray diffraction pattern of HE-Zn was obtained as shown in the figure. Figure 3 As shown. From Figure 3It can be seen that the HE-Zn material prepared in this embodiment has a crystal phase structure.
[0089] Example 3
[0090] A high-entropy Prussian blue analog electrode material and its preparation method comprise the following steps:
[0091] A transition metal salt solution was prepared by magnetically stirring 0.1163 g (0.0004 mol) of nickel nitrate hexahydrate, 0.0966 g (0.0004 mol) of copper nitrate trihydrate, 0.1164 g (0.0004 mol) of cobalt nitrate hexahydrate, 0.1112 g (0.0004 mol) of ferrous sulfate heptahydrate, 0.1601 g (0.0004 mol) of chromium nitrate and 50 mL of deionized water at room temperature.
[0092] Mix 0.6585 g (0.002 mol) of potassium ferricyanide and 1.3234 g (0.0045 mol) of sodium citrate with 50 mL of deionized water to form an aqueous solution;
[0093] The two solutions were injected into the two channels of the microreactor at a rate of 1 mL / min using a syringe pump at 25 °C, then allowed to stand for 24 hours, and then centrifuged at 8000 rpm for 13 min. The solutions were washed 6 times with an ethanol-water solution with a volume ratio of 1:1, and finally vacuum dried at 60 °C for 12 hours to obtain the high-entropy Prussian blue analog material (HE-Cr).
[0094] The HE-Cr prepared in Example 1 was characterized using an X-ray diffractometer, and the X-ray diffraction pattern of HE-Cr was obtained as shown in the figure. Figure 4 As shown. From Figure 4 It can be seen that the HE-Cr material prepared in this embodiment has a crystal phase structure.
[0095] X-ray diffraction analysis was performed on the high-entropy Prussian blue analog materials prepared in Examples 1-3, and the obtained XRD patterns are as follows: Figure 5 As shown. From Figure 4 It can be seen that the high-entropy Prussian blue analog materials (HE-V, HE-Zn and HE-Cr) prepared by this invention exhibit obvious monoclinic Prussian blue characteristic peaks, indicating that the high-entropy Prussian blue analog materials have high crystallinity and are single-phase structures.
[0096] Comparative Example
[0097] A high-entropy Prussian blue analog electrode material and its preparation method comprise the following steps:
[0098] A transition metal salt solution was prepared by magnetically stirring 0.1611 g (0.00067 mol) of copper nitrate trihydrate, 0.1853 g (0.0004 mol) of ferrous sulfate heptahydrate, 0.1049 g (0.00067 mol) of vanadium chloride and 50 mL of deionized water at room temperature.
[0099] Mix 0.6585 g (0.002 mol) of potassium ferricyanide and 0.6617 g (0.00225 mol) of sodium citrate with 50 mL of deionized water to form an aqueous solution;
[0100] The two solutions were injected into the two channels of the microreactor at a rate of 1 mL / min using a syringe pump at 20 °C, then allowed to stand for 48 hours, and then centrifuged at 7000 rpm for 10 min. The solutions were washed three times with an ethanol-water solution with a volume ratio of 1:1, and finally vacuum dried at 60 °C for 24 hours to obtain the high-entropy Prussian blue analog material (CuFeV-PBA).
[0101] Application Example 1
[0102] 5 mg of the high-entropy Prussian blue analog material (HE-V) obtained in Example 1 was dispersed in a mixed solution of naphthol and ethanol at a volume ratio of 1:20. The mixture was sonicated for 30 min to obtain a mixed slurry with a concentration of 5 mg / mL of high-entropy Prussian blue analog material (HE-V). 10 μL of the slurry was evenly coated onto a glassy carbon electrode (GCE) with a diameter of 0.6 mm. The glassy carbon electrode was then dried in air to obtain HE-V / GCE.
[0103] Using HE-V / GCE as the working electrode, platinum wire as the auxiliary electrode, Ag / AgCl as the reference electrode, and a 0.1M mixture of acetic acid and sodium acetate (NaAC-HAC) as the electrolyte, a three-electrode system was constructed. Differential pulse adsorption-dissolution voltammetry was used to test the HE-V material prepared in Example 1 using a Shanghai Chenhua electrochemical workstation (CHI 760E). During the test, a voltage of 1.2V was applied for 120 seconds, while the solution was continuously stirred magnetically. The sedimentation potential of dopamine was measured, and the current-time curve of the HE-V material was obtained as shown below. Figure 6 As shown.
[0104] from Figure 6 As can be seen, the high-entropy Prussian blue analogue material (HE-V) exhibits an extremely high response current for the electrochemical detection of dopamine, and its sensitivity can be calculated to be 2399.15 μA·mM. -1 ·cm -2 This demonstrates that high-entropy Prussian blue analogues (HE-V) exhibit excellent sensitivity in the electrochemical detection of dopamine.
[0105] Application Example 2
[0106] 5 mg of the high-entropy Prussian blue analog material (HE-Zn) obtained in Example 2 was dispersed in a mixed solution of naphthol and ethanol at a volume ratio of 1:20. The mixture was sonicated for 30 min to obtain a mixed slurry with a concentration of 5 mg / mL of high-entropy Prussian blue analog material (HE-Zn). 12 μL of the slurry was evenly coated onto a glassy carbon electrode (GCE) with a diameter of 0.6 mm. The glassy carbon electrode was then dried in air to obtain HE-Zn / GCE.
[0107] A three-electrode system was constructed using HE-Zn / GCE as the working electrode, platinum wire as the auxiliary electrode, Ag / AgCl as the reference electrode, and a 0.1M mixture of acetic acid and sodium acetate (NaAC-HAC) as the electrolyte. Differential pulse adsorption-stripping voltammetry was used to test the HE-Zn material prepared in Example 1 using a Shanghai Chenhua electrochemical workstation (CHI 760E). During the test, a voltage of 1.2V was applied for 120 seconds, while the solution was continuously stirred magnetically. The sedimentation potential of dopamine was measured, and the current-time curve of the HE-Zn material was obtained as shown below. Figure 7 As shown.
[0108] from Figure 7 As can be seen, the high-entropy Prussian blue analogue material (HE-Zn) exhibits an extremely high response current for the electrochemical detection of dopamine, with a calculated sensitivity of 2222.22 μA·mM. -1 ·cm -2 This indicates that high-entropy Prussian blue analogues (HE-Zn) exhibit excellent sensitivity in the electrochemical detection of dopamine.
[0109] Application Example 3
[0110] 5 mg of the high-entropy Prussian blue analog material (HE-Cr) obtained in Example 3 was dispersed in a mixed solution of naphthol and ethanol at a volume ratio of 1:20. The mixture was sonicated for 30 min to obtain a mixed slurry with a concentration of 5 mg / mL of high-entropy Prussian blue analog material (HE-Cr). 8 μL of the slurry was evenly coated onto a glassy carbon electrode (GCE) with a diameter of 0.6 mm. The glassy carbon electrode was then dried in air to obtain HE-Cr / GCE.
[0111] A three-electrode system was constructed using HE-Cr / GCE as the working electrode, platinum wire as the auxiliary electrode, Ag / AgCl as the reference electrode, and a 0.1M mixture of acetic acid and sodium acetate (NaAC-HAC) as the electrolyte. Differential pulse adsorption-dissolution voltammetry was used to test the HE-V material prepared in Example 1 using a Shanghai Chenhua electrochemical workstation (CHI 760E). During the test, a voltage of 1.2V was applied for 120 seconds, while the solution was continuously stirred magnetically. The sedimentation potential of dopamine was measured, and the current-time curve of the HE-Cr material was obtained as shown below. Figure 8 As shown.
[0112] from Figure 8 As can be seen, the high-entropy Prussian blue analogue material (HE-Cr) exhibits an extremely high response current for the electrochemical detection of dopamine, with a calculated sensitivity of 1188.96 μA·mM. -1 ·cm -2 This indicates that high-entropy Prussian blue analogues (HE-Cr) exhibit excellent sensitivity in the electrochemical detection of dopamine.
[0113] Comparative application examples
[0114] 5 mg of the intermediate-entropy Prussian blue analog material (CuFeV-PBA) obtained in the comparative example was dispersed in a mixed solution of naphthol and ethanol with a volume ratio of 1:20. The mixture was sonicated for 30 min to obtain a mixed slurry with a concentration of 5 mg / mL of intermediate-entropy Prussian blue analog material (CuFeV-PBA). 10 μL of the slurry was evenly coated onto a glassy carbon electrode (GCE) with a diameter of 0.3 mm. The glassy carbon electrode was then dried in air to obtain CuFeV-PBA / GCE.
[0115] A three-electrode system was constructed using CuFeV-PBA / GCE as the working electrode, platinum wire as the auxiliary electrode, Ag / AgCl as the reference electrode, and a 0.1M mixture of acetic acid and sodium acetate (NaAC-HAC) as the electrolyte. Differential pulse adsorption-stripping voltammetry was used to test the HE-V material prepared in Example 1 using a Shanghai Chenhua electrochemical workstation (CHI 760E). During the test, a voltage of 1.2V was applied for 120 seconds, while the solution was continuously stirred magnetically. The sedimentation potential of dopamine was measured, and the current-time curve of the CuFeV-PBA material was obtained as shown below. Figure 9 As shown.
[0116] from Figure 9 As can be seen, the high-entropy Prussian blue analog material (CuFeV-PBA) exhibits a responsive current for the electrochemical detection of dopamine, and its sensitivity can be calculated to be 230.00 μA·mM. -1 ·cm -2 .
[0117] contrast Figures 6-9 It is evident that the high-entropy Prussian blue analog electrode material prepared in this invention is a modified electrode material, which exhibits excellent sensitivity in the electrochemical detection of dopamine. This demonstrates that multi-atom-doped high-entropy Prussian blue analogs have a promising application prospect as electrode materials for dopamine detection.
[0118] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A method for preparing a high-entropy Prussian blue analogue, characterized in that, Includes the following steps: Five transition metal salts were dissolved in water to obtain transition metal salt solutions; Dissolve potassium ferricyanide and a chelating agent in water to obtain a mixed solution; The transition metal salt solution and the mixed solution were subjected to a precipitation reaction to obtain the high-entropy Prussian blue analogue; the precipitation reaction was carried out in a microchannel reactor. The particle size of the high-entropy Prussian blue analogue is 30~200nm; The five transition metal salts are iron salts, nickel salts, cobalt salts, copper salts, and vanadium salts; the iron salts are divalent iron salts, the nickel salts are divalent nickel salts, the cobalt salts are divalent cobalt salts, the copper salts are divalent copper salts, and the vanadium salts are trivalent vanadium salts. The total concentration of the five transition metal salts in the transition metal salt solution is 0.04~0.3 mol / L; The concentration of potassium ferricyanide in the mixed solution is 0.04~0.5 mol / L; The injection flow rate of the transition metal salt solution is 1~10 mL / min; The injection flow rate of the mixed solution is 1~10 mL / min.
2. The preparation method according to claim 1, characterized in that, The molar ratio of any two of the five transition metal salts is 1:0.9~1.
1.
3. The preparation method according to claim 1 or 2, characterized in that, The transition metal salts include one or more of sulfates, chlorides, nitrates, and oxalates.
4. The preparation method according to claim 1, characterized in that, The ratio of the total molar amount of the five transition metal salts to the molar amount of potassium ferricyanide is 1:1~2.
5. The preparation method according to claim 1, characterized in that, The chelating agent includes potassium citrate or sodium citrate; The molar ratio of potassium ferricyanide to the chelating agent is 1:1~3.
6. The preparation method according to claim 1, characterized in that, The precipitation reaction is carried out at a temperature of 20~35℃; The precipitation reaction is followed by a settling period of 24-48 hours.
7. The high-entropy Prussian blue analogue prepared by the preparation method according to any one of claims 1 to 6, characterized in that, The particle size of the high-entropy Prussian blue analogue is 30~200nm.
8. The application of the high-entropy Prussian blue analogue of claim 7 in electrode materials.
9. A working electrode, characterized in that, It includes an electrode substrate and a modification material layer covering the electrode substrate; the modification material in the modification material layer is a high-entropy Prussian blue analogue as described in claim 7.