Selective ethanol gas sensing behavior of mesoporous n-type semiconducting FeNbO₄ nanopowder obtained by niobium-citrate process

다국어 초록 (Multilingual Abstract)

Beyond the most investigated mesoporous silica and carbon based materials, metal oxides have attracted considerable interest due to their more diverse electronic functionality, which includes gas sensing activities, semiconductor characteristics and magnetic properties. In this paper, we describe the fabrication, characterization and application of mesoporous FeNbO<SUB>4</SUB> nanopowder for ethanol gas sensing application. FeNbO<SUB>4</SUB> nanopowder was synthesized via the niobium-citrate complex method, without using any surfactant and size selection medium. Thermal stability and structure of the nanopowder was analyzed by thermogravimetric analysis (TG/DTA) and X-ray diffraction analysis (XRD). Structural analysis confirmed the formation of FeNbO<SUB>4</SUB> with monoclinic structure. The particle size, electrical and optical properties were also systemically investigated by means of transmission electron microscopy (TEM), impedance and diffused reflectance spectra. Nitrogen adsorption isotherms of the FeNbO<SUB>4</SUB> were type IV with hysteresis loops of type H<SUB>3</SUB> indicating well-defined pore structure with mesoporous nature. The sensing characteristics of FeNbO<SUB>4</SUB> nanopowder such as sensitivity, operating temperature and response time, were studied in the presence of ethanol (C<SUB>2</SUB>H<SUB>5</SUB>OH). Experimental result confirmed that a higher response to ethanol at relatively lower operating temperature of 200 <SUP>o</SUP>C.