An All Solid State Electrochemical pH Sensor Based on Niobium Modified Electrode

Abstract

pH is an important chemical index. The measurement of pH is widely used in various fields. At present, the most common pH meter on the market is the glass electrode pH meter, which has many advantages, such as high accuracy, short response time and so on. However, when industrial wastewater and environmental water samples need long-time real-time monitoring, such as using glass electrode pH meter will lead to leakage of internal liquid, fragile glass and sodium difference. Therefore, it is urgent to design and develop a new type of pH meter with all solid, simple structure and no nanodeviation. In this study, an all solid state electrochemical modified pH electrode was developed based on the adsorption and storage of hydrogen by niobium. Hydrogen in hydrochloric acid was adsorbed and stored in niobium electrode by constant potential electrolysis. The results showed that the detection linear range was pH1-pH13, the response slope was −56.4 mV dec <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> , and the response time was 5 seconds. In the actual sample detection, the detection results are consistent with the glass electrode pH meter. In addition, cyclic voltammetry and electron microscopy were used to study the response mechanism.