Synthesis, characterizations and improved gas-sensing performance of SnO₂ nanospike arrays

Using a tin-oleate complex as the precursor and the capping agent, we successfully synthesized ultrafine SnO₂ nanospike arrays with diameter 6-15 nm and length 150 nm, growing along the [001] direction from a simple hydrothermal route. The as-obtained SnO₂ products were characterized by X-ray powder diffraction, scanning electronic microscopy, transmission electron microscopy, UV-vis absorption spectrum, photoluminescence and Raman spectroscopy. As-synthesized SnO₂ nanospike arrays exhibited improved gas sensing performance as compared to bulk SnO₂ due to the small grain size-distribution and specific surface properties. The detection limits of the sensor were found to be down to 0.5 ppm for acetone, ethanol and 1.0 ppm for methanol with response time as short as 5 s.