The charge carrier concentration on the surface of metal oxide is
useful to detect the concentration of different gases in the atmosphere
[1]. Many metal oxides show good sensitivities towards
various gases like CO, NH3, NOx, SOx, alcohol vapor and liquefied
petroleum gas [4]. Amongst these, it has been seen that the global
warming and climate change are mainly due to the increase of
carbon dioxide (CO2) in air atmosphere. Thus, the detection
and control of CO2 concentration in environment is necessary.
Besides, CO2 sensors can be used in fields of air-quality monitoring,
agricultural production, clean energy technologies, engine
exhausts and chemical industry [5]. Hence there is a need for
development of fast and selectively detectable gas sensor to detect
the CO2.