A new spinel compound, Ba0.25Sr0.25Fe2.5O4, developed for use in gas sensing applications

Abstract

In this article, nanoscale materials of the spinel type Ba0.25Sr0.25Fe2.5O4 have been successfully prepared using the solvothermal method, with sodium acetate as a protective agent and polyvinylpyrrolidone (PVP) to control the size and shape of the particles. The structural, morphological, and gas sensing characteristics of the sample have been thoroughly examined. It has been confirmed that the compound Ba0.25Sr0.25Fe2.5O4 exhibits a crystallite size of 32 nm, a fully cubic structure, and significant porosity, as established by the Williamson–Hall method. The electrical properties have revealed the semiconductor-type (n) behavior of our compound. The results of the ethanol, acetone, and H2S detection tests highlighted a particularly pronounced sensitivity of Ba0.25Sr0.25Fe2.5O4.Gas detection tests were conducted on the prepared compound by varying the concentrations of ethanol, acetone, and H2S gases (500 ppb, 1 ppm, 5 ppm, 10 ppm, 20 ppm, 40 ppm, 80 ppm, 100 ppm). The compound Ba0.25Sr0.25Fe2.5O4 demonstrated very good reactivity towards the three gases, even at very low concentrations, with respective optimal operating temperatures of 200 °C, 200 °C and 120 °C. Furthermore, the response and recovery time values for these three gases were found to be very short.