Perchlorate selective electrode based on electron / ion dual-channel material and preparation method of perchlorate selective electrode

Abstract

The invention discloses a perchlorate selective electrode based on an electron / ion dual-channel material and a preparation method of the perchlorate selective electrode. The electron / ion dual-channel material is synthesized by polymerizing part of polypyrrole on the surface of Mxene and introducing long-chain alkyl substituted quaternary ammonium salt, and the material combines the dual-channel characteristics of ion enrichment and conductivity, and can significantly improve the perchlorate detection capability. Experimental results show that a perchlorate selective electrode made of the dual-channel material shows extremely high selectivity and ultra-low detection limit recognition on perchlorate, the lowest detection limit can reach 12.4 mu g / L, meanwhile, the response time is extremely short (-4s), and therefore sensitive and rapid detection on the perchlorate under the complex water body condition can be achieved. The perchlorate selective electrode provided by the invention has the characteristics of wide detection linear range, low detection limit, strong anti-interference capability, simplicity in operation, high efficiency, rapidness, low cost and the like when being used for detecting perchlorate. Therefore, the method has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical detection, and particularly relates to a perchlorate selective electrode based on an electron / ion dual-channel material and a preparation method thereof. Background Art

[0002] Perchlorate (ClO4⁻) is a strongly oxidizing anion, which has been widely used in industrial, military and other fields due to its unique chemical and physical properties. Especially in the production and use of high-energy materials such as rocket propellants, fireworks, and explosives, perchlorate plays an irreplaceable role as a key component. In recent years, with the rapid development of these technologies and products, the production and use of perchlorate have increased significantly. However, this has also led to a continuous increase in its emissions, becoming an environmental problem that cannot be ignored.

[0003] Perchlorate has excellent chemical stability and strong water solubility, resulting in extremely difficult degradation under natural conditions. Once it enters the environment through industrial wastewater discharge, propellant leakage, improper waste treatment or other means, it is easy to accumulate and spread in soil and water bodies. More severely, perchlorate is widely distributed in the environment globally. According to relevant investigations, the presence of perchlorate has been detected in surface water and groundwater in many regions, and its concentration level even exceeds the safety limit in some cases.

[0004] However, detecting perchlorate in water bodies faces many challenges, mainly manifested in: First, the extremely low limit requires the detection method to have ultra-high sensitivity and accuracy; Second, the complex chemical environment in water bodies and the interference of other anions make the selective recognition of perchlorate extremely difficult. Therefore, there is an urgent need to develop an efficient, rapid and low-cost perchlorate detection method.

[0005] Currently, the methods for perchlorate detection mainly include: electrochemical detection method, mass spectrometry method, fluorescence sensing method, ion chromatography method, etc. Among them, The electrochemical detection method has received extensive attention due to its advantages such as simple equipment, rapid response, and easy miniaturization. Through a specifically modified electrode, the aggregation of perchlorate on the electrode surface can be accurately detected. However, this detection method is sensitive to interfering ions in complex water bodies and has insufficient selectivity, which limits its application. Therefore, further improving the performance of the modified material is a feasible way to solve perchlorate sensing.

[0006] The mass spectrometry method is also known for its high sensitivity and is particularly suitable for the detection of ultra-trace perchlorate. However, this method uses expensive equipment, has high detection costs, and complex operations, making it difficult to be popularized in routine water quality monitoring or resource-limited areas.

[0007] Fluorescence sensing technology has become a research hotspot for perchlorate detection due to its high sensitivity, rapid response, and visualization characteristics. By designing specific fluorescent probes, fluorescence sensing technology can achieve highly selective detection of perchlorate and has potential value for portable applications. However, existing fluorescence sensing methods still face some problems in practical applications, such as insufficient environmental stability of the probes and limited recognition effect for interfering ions. Ion chromatography is the most commonly used method for analyzing perchlorate and other ionic substances due to its high efficiency, sensitivity, and reliability. The detection limit for perchlorate can reach the level of 10 μg / L, but this method has disadvantages such as long detection time (>30 min) and the need for sample pretreatment.

[0008] Due to the presence of high-concentration (g / L) interfering ions in water bodies, traditional detection methods face great challenges in accurately detecting low-concentration (μg / L) perchlorate in raw water. The detection of perchlorate in raw water not only requires high selectivity but also an extremely low detection limit, which poses extremely high requirements for detection technology. Different from easily reactive ions, the detection of perchlorate depends on weak interactions due to its non-coordinating and non-reactive nature. Therefore, it is difficult to meet the requirements for perchlorate detection, especially in complex actual water body environments. Summary of the Invention

[0009] Aiming at the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a perchlorate selective electrode based on an electron / ion dual-channel material and a preparation method thereof. To achieve the above purpose, the present invention adopts the following technical solutions: The first aspect of the present invention provides a preparation method of a perchlorate selective electrode based on an electron / ion dual-channel material, including the following steps: S1. Preparation of the ISE membrane: Dissolve dichlorophosphorus tetraphenylporphyrin chloride, tetraoctylammonium chloride, polyvinyl chloride, polytetrafluoroethylene, and dibutyl phthalate in tetrahydrofuran, stir and mix to obtain a clear solution, take the clear solution and drop-coat it on the surface of the Mxene electrode, and dry to obtain the ISE membrane electrode; S2. Preparation of the Qas-Mx@PPy material, that is, the electron / ion dual-channel material (hereinafter referred to as the dual-channel material): Ultrasonically disperse monolayer Mxene in ultrapure water to obtain a monolayer Mxene dispersion; add a long-chain alkyl-substituted quaternary ammonium salt (denoted as R-Qas, hereinafter referred to as Qas) to the monolayer Mxene dispersion, stir and react at room temperature to allow the quaternary ammonium salt molecules to insert into the Mxene interlayer through electrostatic interaction, and then add pyrrole monomer and continue to stir and react to achieve the polymerization of pyrrole on the surface of the quaternary ammonium salt-modified Mxene to obtain the Qas@Mx / PPy material, that is, the dual-channel material; S3. Preparation of perchlorate selective electrode: Disperse the prepared Qas@Mx / PPy material in ultrapure water, and ultrasonically treat it sufficiently to ensure uniform dispersion. Then, take the dispersion and drop-coat it on the surface of the ISE membrane electrode, and leave it to stand and dry at room temperature to obtain the Qas@Mx / PPy / ISE modified electrode, that is, the perchlorate selective electrode.

[0010] Preferably, in step S1, the dosage ratio of dichlorophosphorus tetraphenylporphyrin chloride, tetraoctylammonium chloride, polyvinyl chloride, polytetrafluoroethylene, dibutyl phthalate, and tetrahydrofuran is 1 - 1.5 mg: 0.6 - 0.8 mg: 30 - 35 mg: 0.2 - 0.4 mg: 60 - 70 mg: 2 - 3 mL.

[0011] Preferably, in step S1, the stirring time is 2 - 3 h.

[0012] Preferably, in step S2, the dosage ratio of monolayer Mxene, long-chain alkyl-substituted quaternary ammonium salt, and pyrrole monomer is 8 - 10 mg: 4 - 5 mg: 1.5 - 2 mg.

[0013] Preferably, the long-chain alkyl-substituted quaternary ammonium salt is selected from C6 - C12 alkyl-substituted quaternary ammonium salts, and can be, for example, C6 alkyl quaternary ammonium salt, C8 alkyl quaternary ammonium salt, C10 alkyl quaternary ammonium salt, or C12 alkyl quaternary ammonium salt.

[0014] Preferably, in step S2, the stirring reaction time is 6 - 8 h, and the continuous stirring reaction time is 10 - 12 h.

[0015] Preferably, in step S2, the drying temperature is 55 - 60 °C, and the drying time is 5 - 6 h.

[0016] Preferably, in step S2, the preparation step of the monolayer MXene is as follows: Place Ti3AlC2 in a mixed solution of concentrated hydrochloric acid, ultrapure water, and hydrofluoric acid with a volume ratio of 6:3:1, etch at 30 - 40 °C for 20 - 28 h, collect the bottom precipitate, centrifuge and wash until the pH of the precipitate is greater than 6; Add lithium chloride to the precipitate for intercalation, shake by hand until the bottom precipitate swells, and centrifuge to obtain the collected supernatant, which is the monolayer MXene.

[0017] Preferably, the mass dosages of Ti3AlC2 and lithium chloride are the same. Preferably, in step S3, the dosage ratio of the Qas@Mx / PPy material (dual-channel material) and ultrapure water is 1.5 - 2 mg: 1.5 - 2 mL.

[0018] The second aspect of the present invention lies in providing a perchlorate selective electrode prepared by the above preparation method.

[0019] Detection mechanism: In the present invention, polypyrrole (PPy) is polymerized on the surface of Mxene, and a quaternary ammonium salt substituted with a long-chain alkyl group is introduced. By controlling the ratio of Mxene / pyrrole, precise control of the polymerization ratio of PPy is achieved, and an electron / ion dual-channel material is successfully synthesized. This material is used as an electrode modification material to fabricate a perchlorate-selective electrode, which can realize the regulation of the interlayer spacing and hydrophobicity of Mxene. Among them, the introduction of the quaternary ammonium salt substituted with a long-chain alkyl group as a pillar can effectively regulate the interlayer spacing of Mxene, further optimize the hydrophobicity of the material, and improve the ion channel structure of the material. At the same time, incompletely polymerized PPy forms an ion migration channel between the Mxene layers, which can provide a migration channel for perchlorate ions and further improve the conductivity of the material. This design significantly improves the ion / electron mobility of the material. In the constructed dual-channel structure, PPy not only serves as an electron channel to improve the longitudinal conductivity of Mxene, but also provides an effective enrichment space for perchlorate in the ion channel. This dual-channel structure design plays an important role in greatly enhancing the enrichment and improving the conductivity, thus significantly improving the detection effect of perchlorate. Coating this dual-channel material on the surface of the electrode and integrating it into a composite electrode can achieve highly sensitive and highly selective detection of perchlorate in complex water bodies.

[0020] Beneficial effects: (1) The present invention provides a perchlorate-selective electrode based on an electron / ion dual-channel material and a preparation method thereof. Experimental results show that when using the perchlorate-selective electrode based on the electron / ion dual-channel material to detect perchlorate, it exhibits extremely strong selectivity and ultra-low detection limit recognition. The lowest detection limit can reach 12.4 μg / L, and the response time is extremely fast (~4 s). Therefore, it can achieve sensitive and rapid detection of perchlorate under complex water body conditions, and thus provides a reliable and efficient solution to the technical problem of perchlorate detection in complex environments, so it has broad application prospects.

[0021] (2) The method for detecting perchlorate in the present invention has the characteristics of a wide detection linear range (50 μg / L to 10 g / L), low detection limit, strong anti-interference ability, simple operation, high efficiency, low cost, etc. It not only overcomes the deficiencies of traditional methods in detection selectivity and sensitivity, but also greatly improves the detection efficiency, providing a new idea for the detection of perchlorate. Description of the drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 SEM image of C8@Mx / PPy / ISM prepared in Example 1; Figure 2 It is: (a) EDS map of C8@Mx / PPy / ISM: (b) Mapping diagram of Ti element; (c) Mapping diagram of N element; Figure 3 XRD diagrams of different electrode modification materials (Mxene, C6@Mx / PPy, C8@Mx / PPy, C10@Mx / PPy, C12@Mx / PPy); Figure 4 EIS diagrams of different electrode modification materials: (a) Mxene; (b) Mx@PPy; (c) C8@Mx / PPy; Figure 5 Charge density diagrams of different electrode modification materials: (a) Mxene; (b) C8@Mx / PPy; Figure 6 It is: (a) Results of LOD and sensitivity of electrode modification materials prepared at different ratios of Mxene and PPy for perchlorate detection; (b) Results of LOD and sensitivity of electrode modification materials (C6@Mx / PPy, C8@Mx / PPy, C10@Mx / PPy, C12@Mx / PPy) prepared with quaternary ammonium salts of different carbon chain lengths for perchlorate detection when Mx / PPy = 5:1; Figure 7 It is: (a) Potential response result diagram when the composite electrode assembled with the C8@Mx / PPy / ISM modified electrode as the working electrode is inserted into perchlorate at different concentrations; (b) Fitting curve diagram of the potential response result to the perchlorate concentration; Figure 8 It is: (a) Selectivity result diagram of the composite electrode assembled with the C8@Mx / PPy / ISM modified electrode as the working electrode for perchlorate detection; (b) Stability result diagram. Detailed implementation manners

[0024] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present invention.

[0025] Example 1 A preparation method of a perchlorate selective electrode based on an electron / ion dual-channel material is as follows: S1. Preparation of the ISE membrane: Dissolve 1 mg of tetraphenylporphyrin dichlorophosphate, 0.6 mg of tetraoctylammonium chloride, 30 mg of polyvinyl chloride, 0.2 mg of polytetrafluoroethylene, and 60 mg of dibutyl phthalate in 2 ml of tetrahydrofuran, stir at room temperature for 2 h to obtain a clear solution, take 50 μL of the solution and drop-coat it onto the surface of the Mxene electrode, and dry it to obtain the ISE membrane electrode.

[0026] S2. Synthesis of the electron / ion dual-channel material, specifically the C8@Mx / PPy material here: (1) Preparation of monolayer Mxene: Etch Ti3AlC2 at 30 °C in a ratio of concentrated hydrochloric acid: ultrapure water: hydrofluoric acid = 6:3:1 for 20, collect the bottom precipitate, and wash it by centrifugation multiple times to make the pH of the precipitate greater than 6. Add an equal weight of lithium chloride for intercalation, shake by hand until the bottom precipitate swells, and the supernatant collected by centrifugation is monolayer Mxene; Weigh 10 mg of the prepared monolayer Mxene and ultrasonically disperse it in ultrapure water to ensure uniform dispersion to obtain a monolayer Mxene dispersion; (2) Add 5 mg of C8 alkyl quaternary ammonium salt to the monolayer Mxene dispersion, continuously stir and react at room temperature for 8 h to allow the quaternary ammonium salt molecules to insert into the Mxene interlayer through electrostatic interaction; then add 2 mg of pyrrole (Py) monomer and continue to react under vigorous stirring for 12 h to achieve the polymerization of pyrrole on the surface of the quaternary ammonium salt-modified Mxene. After centrifugally separating the obtained reaction product, place it in a vacuum drying oven at 60 °C for 6 h to obtain the C8@Mx / PPy material; S3. Preparation of the C8@Mx / PPy / ISE modified electrode: Weigh 2 mg of the C8@Mx / PPy material and disperse it in 2 mL of ultrapure water, ultrasonically disperse it sufficiently to ensure uniform dispersion, then take 6 μL of the dispersion and drop-coat it onto the surface of the ISE membrane electrode, and let it stand and dry at room temperature to finally obtain the C8@Mx / PPy / ISE modified electrode, that is, the target perchlorate selective electrode.

[0027] Example 2 Basically the same as Example 1, except that in step S2, the C8 alkyl quaternary ammonium salt is replaced with a C6 alkyl quaternary ammonium salt, and finally a C6@Mx / PPy / ISE modified electrode is obtained.

[0028] Example 3 Basically the same as Example 1, except that in step S2, the C8 alkyl quaternary ammonium salt is replaced with a C10 alkyl quaternary ammonium salt, and finally a C10@Mx / PPy / ISE modified electrode is obtained. Example 4 Basically the same as Example 1, except that in step S2, the C8 alkyl quaternary ammonium salt is replaced with a C12 alkyl quaternary ammonium salt, and finally a C12@Mx / PPy / ISE modified electrode is obtained. Example 5 Basically the same as Example 1, except that in step S2, 4 mg of the prepared monolayer Mxene is weighed and 2 mg of pyrrole (Py) monomer is added.

[0029] Example 6 Basically the same as Example 1, except that in step S2, 4 mg of the prepared monolayer Mxene is weighed and 2 mg of pyrrole (Py) monomer is added.

[0030] Example 7 Basically the same as Example 1, except that in step S2, 8 mg of the prepared monolayer Mxene is weighed and 1 mg of pyrrole (Py) monomer is added.

[0031] Example 8 Basically the same as Example 1, except that in step S2, 10 mg of the prepared monolayer Mxene is weighed and 1 mg of pyrrole (Py) monomer is added.

[0032] 1. Characterization of Materials (1) SEM Characterization The C8@Mx / PPy / ISM material prepared in Example 1 was characterized by SEM, and the results are shown in Figure 1 .

[0033] Figure 1 The results in show that in the C8@Mx / PPy / ISM material, after adding quaternary ammonium salt (QAS) and polypyrrole (PPy) to its surface, the layered structure of Mxene is still retained, indicating that the process of adding alkyl quaternary ammonium salt (QAS) and polypyrrole (PPy) does not destroy the basic morphological structure of Mxene; at the same time, it is also found that the space between Mxene layers is not completely filled, thus proving the successful synthesis of the C8@Mx / PPy / ISM material and verifying the feasibility of the partial polymerization of pyrrole strategy between Mxene layers.

[0034] (2)Energy Dispersive X-ray Spectroscopy (EDS) Characterization The C8@Mx / PPy material prepared in Example 1 was characterized by EDS, and the results are shown in Figure 2 .

[0035] From Figure 2 (b) and Figure 2 (c), it can be seen that in the C8@Mx / PPy material, the mapping diagram of Ti element (characteristic element of Mxene) and the mapping diagram of N element (characteristic element of quaternary ammonium salt) can be clearly observed. This result proves that C8 alkyl quaternary ammonium salt is uniformly loaded on the surface of Mxene and forms a composite structure with polypyrrole, ensuring the uniformity and effectiveness of the charge transfer path and ion migration channel on the surface and between layers of the C8@Mx / PPy material.

[0036] (3) The electrode modification materials prepared with quaternary ammonium salts substituted by alkyl groups with different chain lengths (C6-C12) were characterized by XRD, and the results are shown in Figure 3 .

[0037] From Figure 3 the results, it can be inferred by analyzing the characteristic peaks near 6° that the interlayer spacing of Mxene gradually increases with the increase of the chain length of the alkyl-substituted quaternary ammonium salt, and the characteristic peak decreases from 6.24° to 5.78°. This change indicates the successful insertion of the alkyl quaternary ammonium salt between the Mxene layers and further verifies the technical feasibility of controllably adjusting the interlayer spacing of Mxene by adjusting the chain length of the alkyl-substituted quaternary ammonium salt.

[0038] (4) Different electrode modification materials (compared with Mxene, Mx / PPy and C8@Mx / PPy materials) were characterized by EIS, and the results are shown in Figure 4 (The diameter of the semicircle in the EIS diagram represents the resistance of the material). From Figure 4 the results, it can be seen that compared with Mxene, the resistances of Mx / PPy obtained by compounding with PPy and C8@Mx / PPy materials obtained by compounding with PPy and C8 alkyl quaternary ammonium salt are significantly reduced. This indicates that the addition of PPy (polypyrrole) improves the longitudinal conductivity of the material, and the introduction of C8 alkyl quaternary ammonium salt further optimizes the ion migration channel by regulating the interlayer spacing. This multi-level composite strategy helps to improve the overall conductivity and interfacial ion exchange performance of the obtained materials.

[0039] (5) By constructing models of different materials (Mxene, C8@Mx / PPy materials), the charge density of the materials was calculated, and the results are shown in Figure 5 .

[0040] FromFigure 5 The results clearly show the charge density distributions of different atoms. Compared with Mxene, for the C8@Mx / PPy material obtained by adding quaternary ammonium salts and polypyrrole between its layers, the atomic charge density at the Mxene interface increases significantly. This phenomenon proves that electron transfer between interfaces is achieved through the construction process of the composite material.

[0041] (6)Study the LOD and sensitivity of the electrode modification materials prepared under different ratios of Mxene and PPy for perchlorate detection. The results are shown in Figure 6 .

[0042] From Figure 6 (a)The results show that when Mx / pyrrole = 5:1, the obtained material has the lowest LOD and the highest sensitivity for perchlorate detection.

[0043] (7)Study the LOD and sensitivity of the electrode modification materials (C6@Mx / PPy, C8@Mx / PPy, C10@Mx / PPy, C12@Mx / PPy) prepared under different quaternary ammonium salts with different carbon chain lengths when Mxene / pyrrole = 5:1 for perchlorate detection. The results are shown in Figure 6 .

[0044] From Figure 6 (b)The results show that the C8@Mx / PPy material has the lowest detection limit and the highest sensitivity for perchlorate, that is, C8 is the optimal carbon chain length of the alkyl-substituted quaternary ammonium salt.

[0045] Therefore, the C8@Mx / PPy material is used as the electrode modification material for the final perchlorate detection in subsequent experiments.

[0046] (8)Analytical performance of the modified electrode Assemble the C8@Mx / PPy / ISE modified electrode as the working electrode into a composite electrode, and insert it into perchlorate solutions with different concentrations (10 - 6.3 M, 10 -6 M, 10 -5 M, 10 -4 M, 10 -3 M, 10 -2 M, 10 -1 M) for detection, record the corresponding electrode potentials under different concentrations of perchlorate, and realize the detection of perchlorate by fitting the potential data under different concentrations of perchlorate. The results are shown in Figure 7 .

[0047] From Figure 7From the results in (a), it can be seen that as the perchlorate concentration increases, the potential on the electrode surface gradually decreases, which may be attributed to the decrease in the electrode surface potential caused by more perchlorate adsorbed on the electrode surface. The results also show that there is a good linear relationship between the potential response of the C8@Mx / PPy / ISE modified electrode as the working electrode for detecting perchlorate and the concentration within the range of 50 μg / L to 10 g / L. The potential responses at different perchlorate concentrations were plotted against the corresponding perchlorate concentrations to obtain a linear fitting curve (see Figure 7 Figure (b)), y = -58.01x + 73.4, with R 2 = 0.995 and a minimum detection limit of 12.4 μg / L. This indicates that the C8@Mx / PPy / ISE modified electrode has a wide linear range and a low detection limit. The reasons may be as follows: the high electrochemical activity of Mxene, the precise regulation of the layer spacing by quaternary ammonium salts, and the dual optimization of the electron channels and ion channels by the partial polymerization strategy of polypyrrole. (9) Selectivity of the modified electrode for perchlorate, i.e., anti-interference analysis Since there may be various interfering substances during the water body detection process, which may affect the detection results, in this experiment of the present invention, 5 equivalents of Br - , NO3 - , NO2 - , H2PO4 - , HCO3, HSO3 - , CH3COO - , CO3 2- , SO4 2- , Cl - , ClO - , ClO2 - , ClO3 - , I - , SCN - were respectively added to the same solution, and the anti-interference performance of the C8@Mx / PPy / ISM modified electrode was detected by measuring the potential difference before and after adding the interfering ions. The results are shown in Figure 8 .

[0048] From Figure 8 the results in (a), it can be seen that the presence of 5 equivalents of the above different interfering ions has no obvious effect on the potential on the electrode surface, which is much lower than that of ClO4 - , indicating that the C8@Mx / PPy / ISM modified electrode has excellent selectivity, i.e., anti-interference performance for ClO4 - , which may be attributed to the interlayer hydrophobicity and ion channel characteristics regulated by alkyl-substituted quaternary ammonium salts.

[0049] (10) Stability of the modified electrode for perchlorate detection FromFigure 8 (b)As can be seen from the results, during the 30-day long-term storage, the potential change difference of the C8@Mx / PPy / ISM modified electrode for perchlorate is very small, which proves that the C8@Mx / PPy / ISM modified electrode has good stability. This improvement in stability may be attributed to the quaternary ammonium salt increasing the layer spacing and inhibiting the aggregation of Mxene, as well as the polymerization of polypyrrole on the surface of Mxene providing antioxidant protection.

[0050] (11)Detection and analysis of actual water samples To test the application potential of the material in actual water bodies, the C8@Mx / PPy / ISM modified electrode was integrated into a sensor of an ion-selective electrode, and tap water, Xiangjiang water, and wastewater from a fireworks factory (diluted 1000 times) were selected for testing. The test results are shown in Table 1 below.

[0051] Table 1

[0052] As can be seen from the results in Table 1, the recovery rate of the C8@Mx / PPy / ISM modified electrode in actual water bodies is between 97.90% and 102.20%. After multiple repeated tests, the RSD of the test results is lower than 6.89%. This indicates that the material has good actual detection stability, which fully verifies the ability of the C8@Mx / PPy / ISM modified electrode to detect perchlorate in highly complex actual water samples and has broad application prospects. The present invention is not limited to the above specific embodiments. Those of ordinary skill in the art, starting from the above concepts and without creative labor, can make various transformations, all of which fall within the protection scope of the present invention.

Claims

1. A method for preparing a perchlorate selective electrode based on an electron / ion dual channel material, characterized in that: The following steps are involved: S1. Preparation of ISE membrane: dissolve tetraphenylporphyrin dichlorophosphine chloride, tetraoctyl ammonium chloride, polyvinyl chloride, polytetrafluoroethylene and dibutyl phthalate in tetrahydrofuran, stir and mix to obtain a clear solution, drop the clear solution onto the surface of the Mxene electrode, and dry to obtain an ISE membrane electrode; S2. Synthesis of electron / ion dual channel materials: Ultrasonic dispersion of a monolayer of Mxene in ultrapure water to obtain a monolayer of Mxene dispersion; adding an alkyl-substituted quaternary ammonium salt to the monolayer of Mxene dispersion, stirring and reacting at room temperature, and then adding a pyrrole monomer, continuing to stir and react, to obtain an electron / ion dual-channel material; S3. Preparation of perchlorate selective electrode: The prepared electron / ion dual channel material is dispersed in ultrapure water to obtain a dispersion, and then the dispersion is drop-coated on the surface of the ISE membrane electrode and allowed to stand and dry at room temperature to obtain a perchlorate selective electrode.

2. The method for preparing a perchlorate selective electrode based on an electron / ion dual channel material according to claim 1, characterized in that: In step S1, the dosage ratio of tetraphenylporphyrin dichlorophosphine chloride, tetraoctyl ammonium chloride, polyvinyl chloride, polytetrafluoroethylene, dibutyl phthalate, and tetrahydrofuran is 1-1.5 mg: 0.6-0.8 mgs: 30-35 mg: 0.2-0.4 mg: 60-70 mg: 2-3 ml; the stirring time is 2-3 h.

3. The method for preparing a perchlorate selective electrode based on an electron / ion dual channel material according to claim 1, characterized in that: The long-chain alkyl-substituted quaternary ammonium salt is selected from C6-C12 alkyl-substituted quaternary ammonium salts.

4. The method for preparing a perchlorate selective electrode based on an electron / ion dual channel material according to claim 1, characterized in that: In step S2, the monolayer Mxene, the long-chain alkyl-substituted quaternary ammonium salt, and the pyrrole monomer are used in a ratio of 8-10 mg: 4-5 mg: 1.5-2 mg.

5. The method for preparing a perchlorate selective electrode based on an electron / ion dual channel material according to claim 1, characterized in that: In step S2, the stirring reaction time is 6 to 8 h, and the stirring reaction time is continued for 10 to 12 h.

6. The method for preparing a perchlorate selective electrode based on an electron / ion dual channel material according to claim 1, characterized in that: In step S2, the drying temperature is 55-60°C and the drying time is 5-6 hours.

7. The method for preparing a perchlorate selective electrode based on an electron / ion dual channel material according to claim 1, characterized in that: In step S3, the electron / ion dual-channel material and ultrapure water are used in a ratio of 1.5-2 mg: 1.5-2 mL.

8. A perchlorate selective electrode based on an electron / ion dual channel material, characterized in that: Prepared by the preparation method according to any one of claims 1 to 7.

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