Studies on the preparation and ethanol gas sensing properties of spinel Zn0.6Mn0.4Fe2O4 nanomaterials

Zn1-xMnxFe2O4 (X = 0, 0.2 and 0.4) nanomaterials were synthesized by sol-gel citrate method and studied structural and gas sensing properties. The structural characteristics of synthesized nanomaterials were studied by X-ray diffraction measurement (XRD) and transmission electron microscope (TEM). The results revealed that the particle size is in the range of 30-35 nm for Mn-Zn ferrite with good crystallinity. The gas sensing properties were studied towards reducing gases like LPG, CH4, CO and ethanol and it is observed that Mn-Zn ferrite shows high response to ethanol at relatively lower operating temperature. The Zn0.6Mn0.4Fe2O4 nanomaterial shows better sensitivity towards ethanol at an operating temperature 300 degrees C. Incorporation of 1.5 wt.% Pd improved the sensitivity, selectivity, response time and reduced the operating temperature from 300 degrees C to 230 degrees C for ethanol sensor. The response time of 200 ppm ethanol in air is about 10s. (C) 2009 Elsevier B.V. All rights reserved.