Electrodeposited copper nanoparticles in ionic liquid microchannels electrode for carbon dioxide sensor

The modification of sensing surfaces is of great importance in many practical applications for various gas detections. High sensitivity is desired for the sensing surfaces of gas sensors, especially in a viscous electrolyte (e.g., room temperature ionic liquid), which has a relatively slow diffusion of analyte gas to electrode surface compared to conventional aqueous solvents. The enhancement of sensing surface sensitivity can be achieved in various strategies from chemical to electrochemical modification. In this work, ionic liquid (IL) based microchannels electrode surface was modified by electrodeposition of copper nanoparticles (CuNPs) and used for real-time carbon dioxide (CO2) sensing application via long-term chronoamperometry. The as-prepared IL-based CuNPs-microchannels electrode was characterized by optical microscope, energy dispersive X-ray analysis (EDX) and scanning electron microscope (SEM). The IL-based CuNPs-microchannels electrode sensors demonstrated excellent performance (high sensitivity and fast response time) for CO2 sensing with good linearity from 2.4% - 11% with the detection limits of 0.14%.