Structure and ultrafast ethanol sensing properties of In2O3-capped Zn-doped Fe2O3 nanorods

•This paper reports facile synthesis of In2O3-capped Zn-doped Fe2O3 nanorods.•The nanorods showed significantly enhanced response to ethanol gas.•The nanorods showed ultrafast response to ethanol gas.•The underlying mechanism for the enhanced sensing performance is discussed.

This paper reports the facile synthesis of In2O3-capped Zn-doped Fe2O3 nanorods along with their ethanol gas sensing properties. A two-stage process involving thermal oxidation of Fe foils and Zn powders in air and the sputter-deposition of In2O3 was used to synthesize these nanostructures. The nanorods synthesized using this method were ∼5 μm in length and 50–120 nm in diameter with a shell layer thickness of 10–15 nm. The multiple-networked In2O3-capped Zn-doped Fe2O3 nanorod sensor showed a significantly enhanced and ultrafast response to ethanol gas. The enhanced sensing performance was explained by modulation of the potential barrier height and the strong catalytic activity of In2O3 for ethanol oxidation.