Ethanol sensing properties of networked In2O3 nanorods decorated with Cr2O3-nanoparticles

In2O3 nanorods decorated with Cr2O3 nanoparticles were synthesized by thermal evaporation of In2S3 powder in an oxidizing atmosphere followed by solvothermal deposition of Cr2O3 and their ethanol gas sensing properties were examined. The pristine and Cr2O3-decorated In2O3 nanorods exhibited responses of ~524% and ~1053%, respectively, to 500-ppm ethanol at 200 °C. The Cr2O3-decorated In2O3 nanorod sensor showed stronger electrical response to ethanol gas at 200 °C than the pristine In2O3 nanorod counterpart. The former also showed faster response and recovery than the latter. The pristine and Cr2O3-decorated In2O3 nanorod sensors showed the strongest response to ethanol gas at 250 and 200 °C, respectively. The Cr2O3-decorated In2O3 nanorod sensor showed selectivity for ethanol gas over other reducing gases. The underlying mechanism for the enhanced response, sensing speed and selectivity of the Cr2O3-decorated In2O3 nanorod sensor for ethanol gas is discussed.