One of the most important applications of nanomaterials is
related to environmental aspects. In this context, different
nano-materials have been used to detect toxic gases and
solvents.1–3 Previous studies have focused in the detection
of CO2, CO, SO2, O2, O3, H2, Ar, NH3 and H2O.4–11 Other
studies have focused in sensing inert gases such as Ar or
N2.10 When building a gas sensor, it is important to bare in
mind the selectivity for detecting a specific gas in different
environments. Other requirements are the sensitivity, selectivity and reversibility operating at different temperatures.In addition, it is also important to note that these sensors should be compact and of low costs. To date, a wide variety of sensors has been fabricated based on semiconducting oxides, metal oxides, metal nanoparticles, metal complexes, organic polymers and carbon nanotubes