Lanthanum oxide (La2O3), an environment friendly and highly
stable p-type semiconductor metal oxide has been used in various
applications such as gas sensors, catalysts, supercapacitors, batteries,
electromagnetic and luminescence devices and biomedicine
[6–12]. Michel and Martinez-Preciado [13] and Jinesh et al. [14]
reported use of nanostructured La2O3 and La2O3/Si layers, respectively
for CO2 sensing. The La2O3 is used to improve the CO2 sensing
of SnO2 thick film sensor and also in CO and ethanol sensing of
ZnO based sensors [15,16]. The high chemical stability, low toxicity
and presence of oxidation states La2+/La3+ of lanthanum are
responsible for pseudosupercapacitor application [17]. Recently,
Yadav et al. [8] reported specific capacitance of the 147 F g1 for
chemically deposited La2O3 electrode.