Synergistic Effects of Dual-Metal Catalysts for Selective Butane Detection by SnO2/Graphene Nanocomposite Sensor

Highly sensitive and selective tin dioxide (SnO
₂
)-based sensor material was wet-chemically synthesized by sonication-assisted simultaneous precipitation method, and their sensing characteristics for various environmentally important combustible and reducing gases were investigated by resistance measurements on an assembled “Taguchi-type” sensor prototype. Characteristics and morphologies of the synthesized powder were examined by thermal, physico-chemical, spectral, and optical studies and their effect(s) on sensing properties were correlated. Small amount of gold addition along with palladium in the metal-oxide-semiconductor, such as SnO
₂
, leads to enhanced sensing properties toward environmentally important and combustible gases such as liquefied petroleum gas (mainly butane), compressed natural gas (mostly methane), carbon monoxide, and hydrogen (H
₂
). A particular composition of SnO
₂
with bi-metallic catalysts (Pd and Au) exhibits excellent sensitivity and butane selectivity. Use of graphene on the final sensor prototype is improved durability in terms of prolonged shelf life by forming a semi-exchangeable coating.