Self-assembled α-Fe2O3-GO nanocomposites: Studies on physical, magnetic and ammonia sensing properties

Self-assembled alpha-Fe2O3-GO nanocomposites (NCs) obtained via rapid, easy and economic microwave-assisted method through the carbonization of sugar in presence of ferric nitrate in different concentrations are envisaged for physical, magnetic and ammonia (NH3) sensing measurements. The alpha-Fe2O3-GO NCs are composed of uniformly distributed spherical particles of similar to 20 nm in size. The effect of varying magnetic field on the surface and structure of the alpha-Fe2O3-GO NCs has also been investigated. Composites endow a better magnetization over the phase-pure. The highest gas response obtained for 100 ppm NH3 concentration at room-temperature (25 degrees C) for pristine GO is limited to 8%. Attributed to p-n hetero-junction effect and electron spill-over effect, on the alpha-Fe2O3 doping, the gas response is greatly improved to 80% at room-temperature. Mechanism for the enhanced sensitivity has carefully been addressed. Gas sensing activities of alpha-Fe2O3-GO NCs against various target gases are examined using computer assisted Keithley 6514 electro-source meter. Along with physical properties, magnetic and NH3 gas sensor performances of the alpha-Fe2O3-GO NCs are measured and reported in-depth.