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, H2 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.