Synthesis of SiO2/Fe3O4 nanomaterial and its application as cataluminescence gas sensor material for ether

SiO2 capped Fe3O4 microspheres with a diameter of about 500 nm, were synthesized by the hydrolyzation of tetraethyl orthosilicate (TEOS). The scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) were employed to characterize the as-prepared samples. Ether, a common volatile organic compound, was selected as a model to investigate the cataluminescence sensing properties of the SiO2/Fe3O4 microspheres in the current work. Results indicated that the as-prepared SiO2/Fe3O4 microspheres exhibited outstanding cataluminescence (CTL) properties such as the stable intensity, high signal/noise values, short response and recovery time. After optimization, the ether sensor system could cover a linear detection range of 10-3000 ppm (R = 0.9967, n = 7) and the detection limit of about 6.7 ppm (S/N = 3), which was below the standard permitted concentrations. Furthermore, the ether sensor system showed outstanding selectivity to ether compared with other eleven kinds of common volatile organic compounds (VOCs). The performance of the SiO2/Fe3O4 microspheres based ether sensor system suggested the promising application of the SiO2/Fe3O4 nanomaterials as a novel and highly efficient CTL sensing material. (C) 2012 Elsevier B.V. All rights reserved.