Local grain-to-grain conductivity in an SnO-VO nanocomposite ethanol sensor.

Nanocrystalline tin oxide-vanadium oxide (SnO-VO) nanocomposite was prepared by the hydrothermal route. Morphological and conductive atomic force microscopy studies were employed to explore the properties of the interface between the grains and grain boundaries of these binary oxides. Detailed analysis of this nanocomposite revealed that the barrier height of 0.512 eV favours a pronounced sensitivity of 63.99% towards 160 ppm of ethanol at room temperature. This might also be due to the decrease in the resistance from 2000 MΩ (individual SnO) to 830 MΩ (nanocomposite). The synergistic effect, large surface area, greater number of interfaces and more conduction electrons provide a greater number of surface active sites for the nanocomposite. This leads to the nanocomposite showing better sensing performance than the corresponding individual systems.