SnO2 nanowires decorated by insulating amorphous carbon layers for improved room-temperature NO2 sensing

Abstract

We fabricated gas sensors by decorating amorphous carbon layers on the surfaces of SnO2 nanowires. Pretreatment and functionalization were not required for the synthesis of the SnO2-based nanocomposite, requiring only short few-second processing times. A sensing mechanism is proposed to explain the room-temperature (24 degrees C) operation of the gas sensor. The amorphous carbon not only increased the surface area, but also provided electronic effects improving the NO(2 )gas sensing likely by supplying electrons to the SnO2 and/or changing the conducting channel width inside the SnO2 by carrier transfer. The optimized gas sensor, having high response and high selectivity, can be utilized for room-temperature NO2 gas sensing applications.