A novel gas sensor based on Ag/Fe2O3 core-shell nanocomposites

In this communication, Ag/Fe2O3 nanocomposites were successfully synthesized by reduction of silver nitrate with NaBH4 and subsequent coating of Fe2O3 by a simple Pechini sol-gel method. Synthesized powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Gas sensing properties of Ag/Fe2O3 nanocomposites and pristine Fe2O3 were studied at different temperature and in the presence of different gases. It was found that Ag/Fe2O3 sensor even can detect 500 ppb NO2 gas at 150 degrees C, whereas pristine Fe2O3 sensor showed no significant response to NO2. The possible mechanisms of NO2 sensing by Ag/Fe2O3 are discussed in detail. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.