Interfacial impedance based electrochemical detection of carbon dioxide using RTIL

Current challenges in CO2 gas sensors include stable signal to noise ratio (SNR), drifting sensor performance due to environmental factors, selectivity of sensing element in varying test matrices. We performed an evaluation of materials and sensor element design to address these challenges. We report effective utilization of room temperature ionic liquids (RTILs) in developing electrochemical CO2 sensors offering unique value for commodity applications. In this study, we have characterized RTILs with different anionic groups for varying concentrations of CO2 from 400 ppm to 1000 ppm using gold electrodes and carbon paste electrodes (CPE) on printed circuit board (PCB) substrates. This analysis was carried out using electrochemical impedance spectroscopy (EIS) and helped in identification of robust performing combination of RTIL and electrode material for environmental CO2 sensing.