Branched SnO2 nanowires on metallic nanowire backbones for ethanol sensors application

We report the synthesis of hierarchically branched semiconducting $\mathrm{Sn}{\mathrm{O}}_2$ nanowire on metallic Sb-doped $\mathrm{Sn}{\mathrm{O}}_2$ nanowires by the sequential seeding of multiple nanowire generations with Au nanoparticles as catalysts. Such semiconducting nanowire/metallic backbone complex structures increase the potential functionality of $\mathrm{Sn}{\mathrm{O}}_2$ nanowires. Branched $\mathrm{Sn}{\mathrm{O}}_2$ nanowire films are used as sensing materials for high-performance ethanol sensor fabrication. The nanowire sensors show sub-ppm sensitivity and fast response and recovery times at $300°\mathrm{C}$ . A linear equation relationship between sensitivity and the ethanol vapor concentration was observed.