On-chip growth of single phase Zn2SnO4 nanowires by thermal evaporation method for gas sensor application

Ternary oxide nanowires have attracted significant research attention in recent years due to their advanced physicochemical properties. The synthesis of single phase ternary oxide nanowires is, however, a challenge because of the differences in vapour conditions of the evaporative sources. Herein, we report the on-chip synthesis of single phase Zn2SnO4 nanowires for highly sensitive NO2 gas sensor applications by a thermal evaporation method. The Zn2SnO4 nanowires were obtained using a precursor mixture of ZnO, C and Sn powders. To obtain single phase Zn2SnO4 nanowires, we varied the amount of Sn in the precursor mixture, while the ZnO and C contents were fixed. The morphology, crystal structure and phase composition of the products were characterised by scanning electron microscopy and X-ray diffraction. The gas-sensing characteristics of the synthesised nanowires were tested at different temperatures, and we found that the single phase Zn2SnO4 nanowires showed superior sensitivity to NO2 gas.