▎ 摘　　要

Highly sensitive and selective tin dioxide (SnO2)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 metaloxide-semiconductor, such as SnO2, 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 SnO2 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.