Low operating temperature toluene sensor based on novel α-Fe2O3/SnO2 heterostructure nanowire arrays

Abstract

In this work, we reported a novel toluene sensor based on α-Fe₂O₃/SnO₂ heterostructure nanowires arrays, which were synthesized via combining an ultrasonic spray pyrolysis (for the SnO₂ nanowires arrays) method and the subsequent hydrothermal strategy (for the α-Fe₂O₃ nanorod branches). Various techniques were employed for the characterization of the structure and morphology of the as-obtained products. The results revealed that α-Fe₂O₃ nanorod branches grew on SnO₂ nanowire arrays with an average length of about 800 nm. As a proof-of-concept demonstration of the function, such novel heterostructure nanowires arrays were used as the sensing material for gas sensors. As expected, the heterostructure composites exhibited good sensing performances for toluene, superior to a single component (SnO₂ nanowires arrays). For example, the response of the α-Fe₂O₃/SnO₂ composites was up to 5 times higher than that of the primary SnO₂ nanowire arrays at 90 °C.