The enhanced ethanol sensing properties of multi-walled carbon nanotubes/SnO₂core/shell nanostructures

Multi-walled carbon nanotubes/SnO2 (CNT/SnO2) core/shell nanostructures were synthesized by a simple wet-chemical method. The thickness of the SnO2 shell was about 10 nm and the diameters of the SnO2 particles were 2–8 nm. Sensors based on the core/shell heterostructures exhibited enhanced ethanol sensing properties. The sensitivity to 50 ppm ethanol was up to 24.5, and the response time and recovery time were about 1 and 10 s, respectively. In addition, the fluctuation of the sensitivity was less than ± 3% on remeasurement after 3 months. These results indicate that the core/shell nanostructures are potentially new sensing materials for fabricating gas sensors.