Improved response of CdO nanorods towards liquefied petroleum gas (LPG): Effect of Pd sensitization

Liquefied petroleum gas (LPG) sensors have been fabricated using cadmium oxide nanorods obtained by a chemical bath deposition (CBD) method. The response of the CdO nanorod network to LPG was improved significantly after palladium (Pd) sensitization by a dip and dry method. Before exposing for the sensing application, these films were characterized for its structural, morphological and compositional analysis using XRD, FESEM, EDX, etc. The LPG sensing properties of the unsensitized and Pd-sensitized CdO were investigated at different operating temperatures and LPG concentrations. The unsensitized CdO exhibited the maximum response of 14% at 698 K upon exposure to 0.1 vol% of LPG that was improved up to 35% at an optimum operating temperature of 548 K after the Pd sensitization. The Pd-sensitized CdO film showed more selectivity towards LPG as compared to CO2 (i.e. 3.18% for Pd-sensitized CdO and 2.8% for unsensitized CdO). Additionally, the stability of the films has been studied.