The effect of Ag doped SnO2 nanorods and nanoparticles in desining, fabrication and sensitivity enhancement of H2S gas sensor considering ultra-violet ray and self-heating

A H2S gas sensor was fabricated by growing SnO2 nanorods on an interdigitated Ag substrate spin coating SnO2 nanoparticles. The geometry, morphology, chemical composition, optical and electrical properties were investigated by scanning electron microscopy, Energy Dispersive X-ray Spectroscopy (EDAX), X-Ray diffraction, photoluminescence spectroscopy and absorption spectroscopy. The obtained sensor was further improved by doping Ag on the SnO2 Nano-Particles and a unique method of simultaneous exposure to UV illumination and applying and electrical potential (self-heating). Our attempts lead to production of a highly sensitive sensor in the low detection range (500 ppb-10ppm) in which H2O gas interfering was also used for the first time in the gas sensing. Regarding this achievement, the sensor response and recovery times remarkably boosted in 10 ppm H2O gas from 10 and 11s in initial method to 5 and 8s in the improved method, respectively. The sensor cross-sensitivity toward C6H6, C2H5OH, CO2 and NH3 was also examined in order to determine the sensor selectivity.