Room temperature ammonia gas sensing using polyaniline/indium oxide/onion-like carbon composite

The modification of onion-like carbons (OLCs) and conducting polymer composites with semiconductor metal oxides could enhance sensing performance at room temperature. The present study compared two microwave-assisted solution-phase methods for the synthesis of indium oxides. The first method produced indium hydroxide (In(OH)(3)) followed by its conversion to In2O3 through annealing at 400 degrees C, and the second method used a one-step method where ethanol was used as a solvent instead of water. A flexible room temperature ammonia (NH3) gas sensor was developed using a sensing layer composed of indium oxide (In2O3)/OLCs)/polyaniline (PANI) composite at relative humidity of 45%. The results showed that In2O3 materials can be successfully applied in room temperature gas sensing and further enhance the sensing response of OLC/PANI composite.