Enhanced ethanol sensing properties based on SnO2 nanowires coated with Fe2O3 nanoparticles

SnO2 nanowires were synthesized and then coated with Fe2O3 nanoparticles by a 3-step process. The SnO2 nanowires and Fe2O3 nanoparticles were synthesized by the VLS and hydrothermal methods, respectively. Using these two different materials, Fe2O3 nanoparticles were coated on the surface of the SnO2 nanowires by spin coating and thermal annealing. The gas sensing properties and sensing mechanisms of both types of sensors were examined. The sensitivities of the Fe2O3 nanoparticle-coated SnO2 sensors to ethanol gas were 1.48-7.54 times higher according to the ethanol concentration at 300 degrees C than those of the as-synthesized SnO2 nanowires. The enhanced ethanol sensing mechanisms of this sensor can be explained by the surface depletion region and potential energy barrier at the grain boundaries. (C) 2016 Elsevier B.V. All rights reserved.