Metal-metallic oxide pH electrode and method for making same

Abstract

The invention provides a metal-metal oxide pH electrode and a preparation method thereof. The method comprises the following steps of: using a chemically stable metal filament is used as a basal body, removing the original oxide film on the surface of the metal filament by mechanical polishing and chemical cleaning, and forming a IrOx (x=1 to 3) active oxide film sensitive to hydrogen ion on the treated metal filament surface with the thermal decomposition method. Comparing with glass pH electrode and conventional metal-metal oxide pH electrode, the inventive metal-metal oxide pH electrode has the advantages of simples preparation method, low cost, easiness for batch production, high mechanical strength, low fracture liability, small volume, high sensitivity of pH measurement, and rapid response speed, wide response range; and is suitable for pH measurement of low-temperature solution with wide pH range, particularly solution below zero degree (such as anti-freezing fluid and refrigerating fluid).

Description

technical field [0001] The invention belongs to the technical field of electrode material and sensor manufacturing, and more specifically relates to a metal-metal oxide pH electrode and a preparation method thereof. Background technique [0002] The detection of pH has extensive practical application value in many fields such as environmental protection, ocean, medicine, medicine, food, light industry, textile, papermaking, agriculture, soil, petrochemical, chemical industry, metallurgy, machinery and so on. The pH meter is an indispensable experimental tool in the detection of pH. [0003] At present, the traditional glass pH electrode is mainly used to detect the pH value of the solution. It generally uses a very thin glass membrane as a sensitive membrane for hydrogen ions, so its glass membrane is very fragile and easily broken. With the increasingly wide range of fields that need to measure pH value, the adaptability of glass electrodes to different environments must b...

AI Technical Summary

Problems solved by technology

Electrochemical cyclic voltammetry is the most widely used method to study the preparation of iridium oxide pH electrodes, but this method has the disadvantages of high preparation cost, complicated process conditions, and inability to carry out mass production; and the preparation of iridium oxide pH electrodes by electrodeposition There are relatively few studies. Generally, conductive substrates such as graphite, Ti, and Pt are used. The electroplating solution is chloroiridic acid, chloroiridic acid salt, and iridium chloride solution. The preparation cost is lower than that of Ir wire electrochemical cyclic voltammetry, but electroplating The liquid is relatively complex, and the process conditions are not easy to control

E~pH response sensitivity is shown as super Nernst response (>59mV / pH); sputtering deposition method to prepare iridium oxide pH electrode is another method that has been studied more, and the response results have good reproducibility, but the standard Electrode potential drift and anti-oxidation / reduction substance interference are greatly affected by sputtering process parameters

In addition, although cheap substrates can be used as substrates, sputtering equipment and targets are still relatively expensive; the iridium oxide film prepared by thermal oxidation has good adhesion, good pH electrode stability, and hydration and aging effects The post-response sensitivity change is small, which is a better method for preparing iridium oxide pH electrode, and the IrCl in the thermal oxidation method 3 The preparation process of the thermal decomposition method is simple, the substrate material can be cheap, the electrode manufacturing cost is low, and it can be mass-produced, but at present, IrCl 3 The iridium oxide pH electrode made by thermal decomposition method has poor stability and narrow linear range

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