Effect of Noble Metals (Ag, Au, Pt, Pd) loading over the Semiconducting p-NiO/ n-MoO3 Nanocomposite for Development of Green-House Gas Sensor

Abstract

The global awareness about health and environment is rapidly increasing in a quick pace in the view of health hazards related to toxic gases that are associated with industrial and automobile exhausts. Thus, there is a requirement of gas sensors to sense such harmful especially green house gases in order to maintain the ecological balance. The nanostructured architecture of semiconducting materials have unique and attractive properties like high surface-to-volume ratio, high bandgap, low particle size, etc. which are advantageous for developing sensitive & selective gas sensors. In the present work, we describe the design and synthesis of a novel p-n type semiconducting MoO₃: NiO nanocomposite functionalized by different noble metals (Ag, Au, Pt & Pd) among which Pd incorporated MoO₃: NiO (MNPd) showed better efficiency comparatively towards Carbon dioxide (CO₂) gas. The observed response of MoO₃: NiO (MN) sensor exhibited sensitivity of S=80% whereas the Pd-loaded MoO₃: NiO (MNPd) sensor exhibited excellent sensitivity of S=96% and selectivity towards CO₂ in comparison to other interfering gases. The results explicitly confirm the effectiveness of MNPd nanocomposite engineered for high performance CO₂ gas sensor.