A carbon dioxide gas sensor based on cobalt oxide containing barium carbonate

A CO2 gas sensor based on a metal oxide semiconductor was prepared using spinel-type Co3O4 as a sensing material. The sensing properties of the prepared Co3O4 were tested at various concentrations (500-10000 ppm) of CO2 gas at the operating temperatures of 150 and 200 degrees C that are relatively low temperatures compared to those of the conventional semiconductor gas sensors. We confirmed metal carbonate species created by the reaction between Co3O4 and CO2 through X-ray photoelectron spectroscopy analysis before and after exposure to CO2. In addition, barium carbonate (BaCO3) was doped into Co3O4 in order to improve the stability of the sensor response as well as the performance of sensor to CO2 under different humid conditions. (C) 2017 Elsevier B.V. All rights reserved.