Synthesis of In2O3-ZnO core-shell nanowires and their application in gas sensing

Heteronanostructures are very promising gas sensor materials due to their high surface area and hybrid properties. In2O3-ZnO core-shell nanowires are synthesized via two-step growth process. The as-deposited shell is made up of grainy polycrystalline ZnO coated on the single crystalline In2O3 core. The sensing properties of pristine In2O3 and In2O3-ZnO core-shell nanowires are investigated for different gases. In2O3-ZnO core-shell nanowires are found to possess better response towards the CO, H-2 and ethanol while pristine In2O3 nanowires has shown a superior response towards the NO2. The high sensitivity and dynamic repeatability have shown in these sensors reveal that the core-shell nanowires are promising as sensitive and reliable chemical sensors. The gas sensing mechanism of these heterostructured nanowires is discussed in detail. (C) 2011 Elsevier B.V. All rights reserved.