Work function based CO2 gas sensing using metal oxide nanoparticles at room temperature

The reversible interaction of CO2 gas with sensing material is very difficult to achieve at room temperature. In this work we present copper oxide nanoparticles (CuO-NPs) as CO2 gas sensitive material. The CO2 interaction with CuO-NPs is investigated with the help of capacitance based Kelvin probe measurements, reflecting the adsorption induced changes in contact potential difference or work function alterations. Moreover, cross-sensitivity to humidity and the dependency of CO2 gas sensing on nanoparticles layer thickness has also been investigated. It is shown that CuO-NPs sensing layer depicts high sensitivity to CO2 gas exposure (400-4000 ppm) at room temperature and can be effectively used for the development of low cost CO2 gas sensors. (C) 2015 Elsevier Ltd. All rights reserved.