Enhanced ethanol sensing properties based on spherical-coral-like SnO2 nanorods decorated with alpha-Fe2O3 nanocrystallites

This paper reports a newly developed two-step method for the synthesis of a unique nanocomposites consisting of inner spherical-coral-like SnO2 nanorods (NRs) (lengths of 0.4-1.8 mu m and diameters of 60-200 nm) decorated by out alpha-Fe2O3 nanocrystallites (NCs) with an average grain size of similar to 20 nm. The introduction of alpha-Fe2O3 NCs on the surface of SnO2 NRs promotes the formation of heterojunction barrier at the interface of the two oxides. The gas-sensing results show that the sensor based on alpha-Fe2O3-decorated SnO2 NRs exhibit outstanding sensitivity, selectivity, and stability to ethanol vapor at a low optimum work temperature of 280 degrees C. In particular, a higher response can be obtained, by contrast, than that of pure SnO2 NRs along with greater response-recovery capacity. The significant improvement of ethanol sensing behavior may be attributed to the chemical and electronic sensibilization induced by the alpha-Fe2O3 NCs. (C) 2018 Elsevier B.V. All rights reserved.