Baseline Drift Improvement Through Investigating a Novel Ag Doped SnO2/ZnO Nanocomposite for Selective Ethanol Detection

The present work investigates the baseline resistance stability with a novel Ag doped SnO2/ZnO nanocomposite for ethanol detection. A facile and cost effective sol-gel spin coating technique was used to fabricate a progression series of gas sensors using Ag (2% wt.) doping in each SnO2/ZnO composites viz. SnO2 (100% wt.)/ZnO (0% wt.), SnO2 (95% wt.)/ZnO (5% wt.), SnO2 (75% wt.)/ZnO (25% wt.), and SnO2 (50% wt.)/ZnO (50% wt.) compositions. Sol-gel spin coated samples were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy to investigate the structural, elements composition, and morphological analysis, respectively. High resolution transmission electron microscopy was used for obtaining the detailed structural information of the nanocomposite. The ethanol sensing properties of the fabricated sensors were investigated in order to analyze the baseline stability along with observing the minimum (T-min) and optimum (T opt) temperature of operation. Observed tradeoff between the % response and baseline stability improvement is explained on the basis of crystallite size and agglomeration of interwoven nanograins in the structure. Analyte sensing results revealed that Ag doped SnO2 (50% wt.)/ZnO (50% wt.) composite exhibited maximum baseline resistance stability along with appreciable % response, high selectivity and appreciable response/recovery time towards ethanol detection at low operating temperature.