On the improvement of Ethanol sensing by Co3O4 loaded SnO2 nanoparticles

Undoped and Co3O4-loaded (5, 10, and 15 at.%) SnO2 nanoparticles were prepared by a simple co-precipitation method. X-ray diffraction (XRD) study confirmed the presence of tetragonal phase of SnO2 and cubic stage of Co3O4 in accumulation to this the preferred orientation and texture coefficient were derived. The texture coefficient of (200) plane increases with parallel decrease in (110) plane, which indicate the development of voids like vacancies along (110) direction. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analyses recognized the uniform dispersion of spherical shaped nanoparticles. EDS analysis confirmed the impurity absence in the prepared samples. UV-Vis absorption analysis confirmed that the optical band gap will get red shifted from bulk which is due to the agglomeration of nanoparticles and also due to the influences of Co3O4. The absorption peaks broadens after loading Co3O4 which indicate the surface related defects in the samples. The refractive indices derived from the band gap values had confirmed the fiber-optic sensor working under the leaky mode operation. Vibrating sample magnetometer (VSM) results confirmed the behavior of ferromagnet in pure SnO2 and antiferromagnet stage in Co3O4 loaded SnO2. The undoped SnO2 with room temperature ferromagnetism (RTFM) shows better sensitivity. The sensitivity of SnO2 and Co3O4 loaded SnO2 samples were 0.076 and 0.084, respectively. The enhanced sensitivity of Co3O4 loaded SnO2 was due to the high catalytic activity of Co3O4.