Cerium Modified Nanocrystalline SmFeO3 for Ethanol Sensing

Presently, detection of ethanol has become essential in various fields due to its adverse effects on human beings. For selective detection of ethanol, chemiresistive gas sensors are widely investigated. Modified ABO3 type perovskites have shown their potential in the fabrication of chemiresistive gas sensors. In present work, SmFeO3 perovskite oxide based thick films were fabricated and surface modified with cerium by simple dipping technique. The structural properties of the samples were studied by Field EEmission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray spectrometer (EDS). The results of FE-SEM indicate that average grain size was in nano range and Ce-modified SmFeO3 films were comparatively more porous than pure SmFeO3 film. This porous nature of film favors gas sensing mechanism. The results of EDS suggest that Ce was deposited on the surface of SmFeO3 films. The gas response of pure SmFeO3 film was tested towards LPG, CO2, NH3, H2, C2H5OH, Cl2, and H2S gases and observed that SmFeO3 film exhibited good response to ethanol (C2H5OH). Among modified samples, Ce-modified SmFeO3 film (dipping time 5 min) exhibited excellent ethanol sensing properties such as , maximum response (16.87 at 1000C ), response time (24 sec), recovery time (34 sec), excellent stability, and good selectivity towards ethanol. Thus Ce-modified SmFeO3 is a potential material in the fabrication of ethanol sensor. The impacts of Ce modification on the gas sensing performance of the SmFeO3 sensor ware discussed in detail.