LPG sensing characteristics of electrospray deposited SnO2 nanoparticles

Highlights: • SnO₂ nanopowder was deposited on conductive substrates using ESD technique. • Solution flow rate, coating time, substrate–nozzle distance and solid/alcohol ratio were studied to optimize SnO₂ film structure. • The gas sensing properties of tin oxide films were investigated using LPG. • The sensitivity of the films was increased with operating temperature. • The best sensitivity was observed for 20 LEL LPG at 450 °C operating temperature. - Abstract: In this study, SnO₂ films were fabricated on conductive substrate such as aluminum and platinum coated alumina using electro-spray deposition (ESD) method for gas sensor applications. Solution flow rate, coating time, substrate–nozzle distance and solid/alcohol ratio were studied to optimize SnO₂ film structure. The morphology of the deposited films was characterized by stereo and scanning electron microscopy (SEM). The gas sensing properties of tin oxide films were investigated using liquid petroleum gas (LPG) for various lower explosive limit (LEL). The results obtained from microscopic analyses show that optimum SnO₂ films were evaluated at flow rate of 0.05 ml/min, at distance of 6 cm, for 10 min deposition time, for 20 gSnO₂/L_ethanol ratio and at 7 kV DC electric field. By the results obtained from the gas sensing behavior, the sensitivity of the films was increased with operating temperature. The films showed better sensitivity for 20 LEL LPG concentration at 450 °C operating temperature