Facile preparation of large-scale α-Fe2O3 nanorod/SnO2 nanorod composites and their LPG-sensing properties

α-Fe2O3 nanorods (NRs) with length and diameter of 300 and 50 nm, and SnO2 NRs with length and diameter of 30 and 10 nm, respectively, were prepared through hydrothermal treatment method. Morphologies of α-Fe2O3 and SnO2 NRs and their composites with different weight ratios were studied by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The SEM and TEM images showed SnO2 NRs attached on (branch onto) the surface of the α-Fe2O3 NRs. Liquefied petroleum gas (LPG)-sensing properties of films with bare α-Fe2O3, SnO2 NRs, and their composite NRs were investigated. The composite of 75 wt% α-Fe2O3/25 wt% SnO2 exhibits the highest response to LPG at optimum operating temperature of 370 °C. The improvement in the gas-sensing characteristics of the composite NRs compared with bare NRs is attributed to the formation of hetero-junctions in α-Fe2O3 NRs/SnO2 NRs and to their porous structure.