CN-122016961-A - Modified electrode for detecting perfluorooctane sulfonate in electrogalvanizing solution and preparation method thereof

Abstract

The application discloses a modified electrode for detecting perfluorooctanesulfonic acid in an electrogalvanizing solution and a preparation method thereof, wherein the modified electrode comprises a working electrode, the surface of the working electrode is modified with dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework/praseodymium-based dynamic metal organic gel, the praseodymium-based dynamic metal organic gel forms a stable film layer on the surface of the electrode, the zirconium-based metal organic framework is combined with the praseodymium-based dynamic metal organic gel and bridges the dodecyl trimethyl ammonium bromide, and the dodecyl trimethyl ammonium bromide is specifically combined with the perfluorooctanesulfonic acid. According to the application, the initial electrochemical luminescence signal of the praseodymium-based dynamic metal organic gel enhancement system and the zirconium-based metal organic framework are combined through the specific combination of the dodecyl trimethyl ammonium bromide and the perfluorooctane sulfonate, so that the stability of the interface is improved, the interference of coexisting ions in the electrogalvanized solution is avoided, and the accuracy and the reliability of perfluorooctane sulfonate detection are improved.

Inventors

• HAN MINGYANG
• XU JIANCHENG
• YE JINDUI
• Ming Zhiyao
• FANG TIAN
• WANG WENCHANG
• CHEN ZHIDONG

Assignees

• 常州大学
• 宏正（福建）化学品有限公司

Dates

Publication Date

20260512

Application Date

20251215

Claims (8)

1. 1. The modified electrode is characterized by comprising a working electrode, wherein the surface of the working electrode is modified with dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework/praseodymium-based dynamic metal organic gel, the praseodymium-based dynamic metal organic gel forms a stable film layer on the surface of the electrode, the zirconium-based metal organic framework is combined with the praseodymium-based dynamic metal organic gel and bridges the dodecyl trimethyl ammonium bromide, and the dodecyl trimethyl ammonium bromide is specifically combined with perfluorooctane sulfonic acid.
2. 2. The modified electrode according to claim 1, wherein the preparation method of the dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework comprises the steps of mixing zirconium chloride with ‌ ‌ N, N-dimethylformamide and formic acid, adding trimesic acid, heating for reaction, centrifuging to remove supernatant, washing and drying to obtain the zirconium-based metal organic framework 808, adding the zirconium-based metal organic framework 808 into a dodecyl trimethyl ammonium bromide solution, stirring uniformly, centrifuging to remove supernatant, washing and drying to obtain the dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework.
3. 3. The modified electrode of claim 1, wherein the preparation method of the praseodymium-based dynamic metal organic gel comprises the steps of mixing dimethyl sulfoxide and deionized water, adding 1, 10-phenanthroline-2, 9-dicarboxylic acid and terephthalic acid, adding triethylamine under ultrasonic conditions, adding praseodymium nitrate hexahydrate, heating and stirring, centrifuging to remove supernatant, washing, and freeze-drying to obtain the praseodymium-based dynamic metal organic gel.
4. 4. A method of producing a modified electrode as claimed in any one of claims 1 to 3, comprising the steps of: S1, adding a dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework into ‌ ‌ N, N-dimethylformamide, and performing ultrasonic dispersion to obtain dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework dispersion; S2, adding praseodymium-based dynamic metal organic gel into ‌ ‌ N, N-dimethylformamide, and performing ultrasonic dispersion to obtain praseodymium-based dynamic metal organic gel dispersion; S3, the praseodymium-based dynamic metal organic gel dispersion liquid is coated on the surface of the glassy carbon electrode in a dropwise manner, and infrared drying is carried out to obtain the praseodymium-based dynamic metal organic gel/glassy carbon electrode; And S4, the dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework dispersion is dripped on the surface of the praseodymium-based dynamic metal organic gel/glassy carbon electrode, and the surface-modified dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework/praseodymium-based dynamic metal organic gel working electrode is obtained after drying.
5. 5. Use of a modified electrode according to any one of claims 1-3 for detecting perfluorooctanesulfonic acid in an electrogalvanized solution.
6. 6. The use of the modified electrode of claim 5 for detecting perfluorooctanesulfonic acid in an electrogalvanizing solution, comprising the steps of: Step one, mixing sulfuric acid and phosphate buffer solution, and adding perfluorooctane sulfonic acid to obtain perfluorooctane sulfonic acid standard solution; Step two, placing a working electrode in the perfluorooctane sulfonate standard solution, and then adding persulfate and phosphate buffer solution to perform electrochemiluminescence measurement to obtain a linear regression equation; and thirdly, mixing sulfuric acid and phosphate buffer solution, adding a sample to be detected, inserting the sample into a working electrode, then adding persulfate and phosphate buffer solution, measuring the electrochemical luminescence intensity, and obtaining the concentration of perfluorooctane sulfonic acid in the sample to be detected according to the linear regression equation.
7. 7. The use of the modified electrode of claim 6 for detecting perfluorooctanesulfonic acid in an electrogalvanized solution, wherein in the first step, the concentration of perfluorooctanesulfonic acid in the perfluorooctanesulfonic acid standard solution is 1.0X10 -13 g/L-1.0×10 -5 g/L.
8. 8. A sensor for detecting perfluorooctanesulfonic acid comprising a modified electrode according to any one of claims 1-3.

Description

Modified electrode for detecting perfluorooctane sulfonate in electrogalvanizing solution and preparation method thereof Technical Field The application relates to the technical field of organic pollutant detection, in particular to a modified electrode for detecting perfluorooctane sulfonate in electrogalvanized solution and a preparation method thereof. Background Perfluorooctane sulfonate (PFOS) has been a key additive with excellent performance in the electroplating industry by virtue of its excellent chemical stability, and is mainly used for inhibiting the generation of acid mist, improving the quality of a coating and the stability of an electroplating process. For example, in the process of electro-galvanizing and zinc-nickel alloy plating, PFOS is often used as a plating solution additive to reduce the surface tension of the plating solution and avoid pinholes, pits, and other defects in the plating layer. In addition, by reducing the surface tension of the plating solution and regulating the interface behavior, the adhesion and the carry-out of the plating solution on the surface of the workpiece can be obviously reduced, thereby improving the process efficiency and reducing the pollution risk. However, since the bond energy of the fluorocarbon bond of PFOS is as high as 486kJ/mol, the PFOS can be decomposed at a high temperature of more than 1000 ℃ and can hardly be degraded in natural environment, and the atmospheric half-life of PFOS exceeds 3.7 years, and the half-life in water and soil is longer than hundreds of years. This stability allows the PFOS to migrate globally by means of atmospheric circulation, ocean currents, etc., even PFOS residues are detected in polar bears in arctic regions, penguins bodies, and snow in remote mountains. Experimental data indicate that very low concentrations of PFOS are extremely harmful to humans, such as causing liver damage, metabolic disorders, and interference with the endocrine system in humans, and are also a powerful carcinogen. For this reason, the stockholm convention ranks PFOS and its salts as "persistent organic pollutants" prohibiting production. The Chinese government regulated the general ban of PFOS production, use and import and export in 2019, and placed it in the "New pollutant List of emphasis" in 2023. However, PFOS has been very desirable for use by those in the plating industry because of its excellent performance as a plating additive, and thus techniques and methods for effectively monitoring PFOS have become particularly urgent. Currently, various methods have been used for detection of PFOS, including gas chromatography-mass spectrometry, liquid chromatography-tandem mass spectrometry, ultra-high performance liquid chromatography, and fluorescence spectrophotometry. In these assays, where the assay water sample is a majority, the co-existing substances have less interference with PFOS detection. However, it is particularly difficult to analyze and detect PFOS in the plating solution, and the root cause is that high concentration of cations and anions will affect the detection of PFOS, and if the plating solution is subjected to pretreatment and separation, the low concentration of PFOS (usually at 10 μg/ml) will be lost, and errors will be caused in the detection of PFOS. Disclosure of Invention In order to improve the accuracy of PFOS detection, the application provides a modified electrode for detecting PFOS in an electrogalvanizing solution and a preparation method thereof. In a first aspect, the present application provides a modified electrode, which adopts the following technical scheme: A modified electrode comprises a working electrode, wherein a dodecyl trimethyl ammonium bromide-zirconium-based metal organic framework/praseodymium-based dynamic metal organic gel is modified on the surface of the working electrode, a stable film layer is formed on the surface of the electrode by the praseodymium-based dynamic metal organic gel, the zirconium-based metal organic framework is combined with the praseodymium-based dynamic metal organic gel and bridges the dodecyl trimethyl ammonium bromide, and the dodecyl trimethyl ammonium bromide is specifically combined with perfluorooctane sulfonate. By adopting the technical scheme, the modified layer of the Dodecyl Trimethyl Ammonium Bromide (DTAB) on the surface of the working electrode can be specifically combined with the hydrophobic fluorocarbon chain of the PFOS molecule and the negatively charged sulfonate through the hydrophobic long chain and the positively charged hydrophilic head of the modified layer, so that the PFOS is identified and enriched in a complex matrix in a high selectivity way, the interference of coexisting ions (such as zinc ions and sulfate ions) in the electrogalvanized solution is effectively shielded, the praseodymium ions in the praseodymium-based dynamic metal organic gel can be used for reducing a co-reactant in cooperation with zirconium oxide clusters