Enhanced ethanol sensing properties based on SnO_2 nanowires coated with Fe_2O_3 nanoparticles

摘要

SnO_2 nanowires were synthesized and then coated with Fe_2O_3 nanoparticles by a3-step process. The SnO_2 nanowires and Fe_2O_3 nanoparticles were synthesized by the VLS and hydrothermal methods, respectively. Using these two different materials, Fe_2O_3 nanoparticles were coated on the surface of the SnO_2 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 Fe_2O_3 nanoparticle-coated SnO_2 sensors to ethanol gas were 1.48-7.54 times higher according to the ethanol concentration at 300℃ than those of the as-synthesized SnC_2 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.