Synthesis and ethanol sensing properties of CuO nanorods coated with In2O3

CuO/In2O3 core–shell nanorods were fabricated using thermal evaporation and radio frequency magnetron sputtering. X-ray diffraction and transmission electron microscopy showed that both the cores and shells were crystalline. The multiple networked CuO/In2O3 core–shell nanorod sensors showed responses of 382–804%, response times of 36–54 s and recovery times of 144–154 s at ethanol (C2H5OH) concentrations ranging from 50 to 250 ppm at 300 °C. These responses were 2.3–2.8 times higher than those of the pristine CuO nanorod sensor over the same C2H5OH concentration range. The origin of the enhanced ethanol sensing properties of the core–shell nanorod sensor is discussed.