Nickel substitution induced effects on gas sensing properties of cobalt ferrite nanoparticles

Joshi, Seema and Kamble, Vinayak B and Kumar, Manoj and Umarji, Arun M and Srivastava, Geetika (2015) Nickel substitution induced effects on gas sensing properties of cobalt ferrite nanoparticles. In: JOURNAL OF ALLOYS AND COMPOUNDS, 654 . pp. 460-466.

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Abstract

Ni2+ ion induced unusual conductivity reversal and an enhancement in the gas sensing properties of ferrites based gas sensors, is reported. The Co1-xNixFe2O4 (for x = 0, 0.5 and 1) nanoparticles were synthesized by wet chemical co-precipitation method and gas sensing properties were studied as a function of composition and temperature. The structural, morphological and microstructural characterization revealed crystallite size of in the range 10-20 nm with porous morphology consisting of nano-sized grains. The Energy Dispersive X-ray (EDX) mapping confirms homogeneous distribution of Co, Ni, Fe and O elements in the ferrites. The non-stoichiometry of the inverse spinel type ferrites and the relative concentration of Ni3+/Co3+ defects were studied using X-ray photoelectron spectroscopy. It is found that the addition of Ni2+ ions into cobalt ferrite shows preferred selectivity towards CO gas at high temperature (325 degrees C) and ethanol gas at low temperature (250 degrees C), unlike undoped cobalt ferrite or undoped nickel ferrite, which show similar response for both these gases. Moreover, an unusual conductivity reversal is observed, except cobalt ferrite due to the difference in reactivity of the gases as well as characteristic non-stoichiometry of ferrites. This behavior is highly gas ambient dependent and hence can be well-exploited for selective detection of gases. (C) 2015 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF ALLOYS AND COMPOUNDS
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Keywords:	Ferrites nanoparticles; Nickel substitution; Gas sensing properties; Co-precipitation
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	19 Nov 2015 04:45
Last Modified:	19 Nov 2015 04:45
URI:	http://eprints.iisc.ac.in/id/eprint/52746

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