Influence of substrate morphology on alcohol sensing behaviour of p-type Co3O4

Abstract An eco-friendly approach was adopted to fabricate porous MgAl 2 O 4 ceramic substrate for designing a gas sensor. The active alcohol sensing component Co 3 O 4 nanoparticles (Co 3 O 4 NPs) were coated on dense and porous MgAl 2 O 4 substrates using a wet chemical based dip coating technique followed by annealing in air at 400 °C. The morphology of the Co 3 O 4 NPs found to be different for the porous and dense substrate. The Co 3 O 4 NPs coated MgAl 2 O 4 substrate-based sensor exhibited better alcohol sensitivity at low-temperature as compared to dense substrate counterpart. The porous substrate offers more active sites for gas adsorption and subsequent surface reaction leading to good sensitivity.