Sensitivity Study of Nanocrystalline Fe3BO6 Sensor for Methane Gas Detection

Abstract

The iron borate Fe<inf>3</inf>BO<inf>6</inf> with functionalized properties in a nanostructure is an important material useful for electrodes, gas sensors, and biological probes. In this paper, we studied the X-ray diffraction pattern, field-emission electron microscopy, and methane (CH<inf>4</inf>) gas sensing properties of synthesized Fe<inf>3</inf>BO<inf>6</inf> nanocrystallites in a shape of nanoplates and nanobars from an iron borate glass 40Fe<inf>2</inf>O<inf>3</inf>-60B<inf>2</inf>O<inf>3</inf> by annealing it in microwave for 15 min at 823 and 1023 K, respectively, in air. The temperature dependent sensitivity for CH<inf>4</inf> (1000 ppm) illustrates a maximum value of 43% at an operating temperature 525 K for the 1023 K annealed sample. The sensitivity is found to be varied from 9% to 39% when the CH<inf>4</inf> gas concentration is increased from 50 to 1000 ppm. Thus, the sample has a reasonably good sensitivity for methane. Furthermore, the sensor exhibits fast response (1 min) and a good recovery time (1.6 min) as compared with other oxide materials. © 2001-2012 IEEE.