Design, simulation, fabrication and testing of electrochemical NO2 gas sensor

An electrochemical amperometric sensor measures the electric current on the surface of the working electrodes and estimates the concentration of chemical or biological species. Electrochemical sensor is fast and selective but electrochemical sensing is a complex phenomenon involving both physical and chemical processes. With a view to understand the basic operation of electrochemical sensor, present study demonstrates a steady-state analysis of the current drawn in a cell of electrolyte solution with two and three electrode configuration. Simulations are carried out for 2- dimensional geometry using COMSOL Multiphysics suite. Effect of variation in cell dimensions, electrolyte concentrations and electrode dimensions on the performance of the sensor is studied. For validation of simulation result, a two electrode electrochemical cell is fabricated and tested for NO₂ gas sensing.