Electrochemical gas sensors are currently widely used in environmental industries due to their superior properties such as high sensitivity and gas selectivity, fast response and reproducibility, and low power consumption. Various kinds of gas sensors have already been commercialized and produced in series and there is a continuous effort to further improve their properties.
As reported in the previous literature, several sensor electrode structures have been used in the fabrication of electrochemical sensors, but there is no description of which structure is the most suitable for generation of current.
With an attempt to design a suitable electrode structure for widely-used electrochemical gas sensors, Kim Yong Hyok, a researcher at the Faculty of Electronics, has performed a simulation analysis of the electrolyte potential and current density of the sensor using COMSOL Multiphysics.
The simulation results show that the sensor of a circular ring-shaped electrode structure has larger current density among the two types of sensors designed. He has also performed an analysis and an experiment of the current density distribution for the variation of the electrode area of sensors with the circular ring-shaped electrode structure and for the variation of the gap between the electrodes. As a result, he has found that the larger the area of working electrodes and the smaller the gap between electrodes, the larger the current density.
For more information, you can refer to his paper “Current Characteristics with Electrode Structure and Geometric Changes of Electrochemical Gas Sensor” in “Journal of The Electrochemical Society” (SCI).