Synthesis and enhanced ethanol sensing properties of α-Fe2O3/ZnO heteronanostructures

alpha-Fe2O3/ZnO heteronanostructures were synthesized via a three-step process. XRD, SEM, TEM and EDS analyses indicated that their diameters and lengths were similar to 40 nm and 0.35-1.2 mu m, respectively, in which the largest thickness of ZnO shells was about 10 nm. The heteronanostructures exhibited a dramatic improvement in ethanol sensing characteristics compared to the pure alpha-Fe2O3 nanorods. Based on the space-charge layer model, such enhanced sensing properties were attributed to small thickness of ZnO shell. Our results demonstrate that One-dimensional (1D) metal oxide heteronanostructures, whose shell thickness is comparable to Debye length, are very promising materials for fabricating gas sensors with good performances. (C) 2009 Elsevier B.V. All rights reserved.