Abstract
Self-assembled α-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 α-Fe2O3-GO NCs are composed of uniformly distributed spherical particles of ∼20 nm in size. The effect of varying magnetic field on the surface and structure of the α-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 °C) for pristine GO is limited to 8%. Attributed to p-n hetero-junction effect and electron spill-over effect, on the α-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 α-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 α-Fe2O3-GO NCs are measured and reported in-depth.
•Metal oxide-graphene oxide nanocomposites.•Microwave-Oven assisted Cost-effective and ecofriendly synthesis.•Ammonia sensors with high detection ability.•Comparison of different metal oxides gas sensors.•Gas sensing mechanism on the basis of p-n heterojunctions.