High-performance carbon monoxide gas sensor based on palladium/tin oxide/porous graphitic carbon nitride nanocomposite

The palladium (Pd)/tin oxide (SnO2)/porous graphitic carbon nitride (g-C3N4) nanocomposites with different Pd and g-C3N4 contents were synthesized by a facile hydrothermal route and their applications as efficient carbon monoxide (CO) gas sensors were investigated. These nanocomposites were characterized in detail by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), micrograph techniques (FESEM and TEM), and energy dispersive X-ray spectroscopy (EDS), in order to evaluate their structural and morphological properties. On the basis of the FESEM and TEM analysis, two-dimensional porous g-C3N4 nanosheets provided a large surface area suitable for growth of SnO2 nanoparticles and formation of a heterogeneous nanocomposite. Among different weight ratios of the components of Pd/SnO2/g-C3N4 nanocomposites, 5%Pd/SnO2/5%g-C3N4 exhibited excellent CO sensing characteristics such as high response, short response/recovery times, good selectivity and stability at lower operating temperature of 125 degrees C. The outstanding gas sensing performance of these nanocomposites could be attributed to the high surface area of porous g-C3N4, the strong spillover effect of Pd nanoparticles as well as the formation of g-C3N4/SnO2 heterojunction. (C) 2019 Elsevier B.V. All rights reserved.