Enhanced ethanol gas sensing performance of the networked Fe2O3-functionalized ZnO nanowire sensor

초록

ZnO nanowires functionalized with Fe2O3 nanoparticles were synthesized by a two-step process consisting of the thermal evaporation of a mixture of ZnO and graphite powders in an oxidizing atmosphere and solvothermal deposition of Fe2O3 and their ethanol gas sensing properties were examined. The Fe2O3-functionalized ZnO nanowires with diameters of 50-200 nm and lengths of 10 to 30 μm. The diameters of the nanoparticles Fe2O3 ranged from 10-30 nm. The Fe2O3-functionalized ZnO nanowire sensor showed significantly stronger response to ethanol gas than the pristine ZnO nanowire counterpart. The former also showed more rapid response than the latter. Both the pristine and Fe2O3-functionalized ZnO nanowire sensors showed the strongest response to ethanol gas at 200°C. The enhanced sensing performance of the Fe2O3-functionalized ZnO nanowire sensor towards ethanol gas is due to a combination of the modulation of the interface potential barrier and the depletion layer width, the catatytic activity of Fe2O3 for ethanol oxidation and the creation of active adsorption sites by incorporation of Fe2O3.