Gas sensing properties of (MoO3)0.4(V2O5)0.6 microsheets: Effect of Pd sensitization

The (MoO3)0.4(V2O5)0.6 microsheets have been successfully prepared onto the glass substrates using chemical spray pyrolysis (CSP) deposition method at optimized substrate temperature of 400 °C. The structural characterization using XRD confirm that both MoO3 and V2O5 exhibit an orthorhombic crystal structure. The two-dimensional FE-SEM micrograph shows the more porous distribution due to the random orientation of microsheets on the film surface. The EDAX analysis of Pd-sensitized (MoO3)0.4(V2O5)0.6 microsheets confirm the presence of Pd, Mo, V and O on the surface of microsheets. Selectivity study show the sensitive and selective response to NO2 gas than NH3, H2S, CO, CO2, SO2 gases at operating temperature of 200 °C. Before Pd-sensitization (MoO3)0.4(V2O5)0.6 microsheets show the NO2 gas response of 80% whereas Pd-sensitized (MoO3)0.4(V2O5)0.6 microsheets exhibit an enhanced response of 115% at 200 °C for 100 ppm NO2 gas concentration. The spill-over gas sensing mechanism reactions based on the chemisorption process at different operating temperatures is discussed to explain how Pd affect on the NO2 gas sensing properties of (MoO3)0.4(V2O5)0.6 microsheets.