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 °C. Incorporation of 1.5 wt.% Pd improved the sensitivity, selectivity, response time and reduced the operating temperature from 300 °C to 230 °C for ethanol sensor. The response time of 200 ppm ethanol in air is about 10s.