Enhanced Ethanol Sensing Properties of TeO2 Nanorods Functionalized with Co3O4 Nanoparticles

TeO2 nanorods functionalized with Co3O4 nanoparticles were fabricated using thermal evaporation and hydrothermal methods. X-ray diffraction and transmission electron microscopy showed that the cores and shells were single crystal TeO2 and polycrystalline Co304, respectively. The multiple networked TeO2/Co3O4 composite nanorod sensor showed responses of 333-1,276%, response times (75-110 sec), and recovery times (20-40 sec) ethanol (C2H5OH) concentrations of 50-250 ppm at 300 degrees C. The response values are 3-10 times higher and the response and recovery times are also far shorter than those of the pristine TeO2 nanorod sensor over the same C2H5OH concentration range. The origin of the enhanced ethanol sensing properties of the composite nanorod sensor is discussed.