Synthesis of g-C3N4 nanosheets decorated flower-like tin oxide composites and their improved ethanol gas sensing properties

The g-C3N4 nanosheets decorated three-dimensional (3D) hierarchical flower-like SnO2 nanocomposites were synthesized via a facile hydrothermal method by using the g-C3N4 and SnCl2 center dot 2H(2)O as the precursors. The structure and morphology of the as-synthesized samples were characterized by the X-ray powder diffraction (XRD), electron microscopy (FESEM and TEM), N-2 sorption, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometer (FT-IR) techniques. It is supposed that g-C3N4 nanosheets act as a template in the hydrothermal process, accelerating the preferential growth of SnO2 nanocrystals and preventing the agglomeration of the SnO2 nanoparticles. The gas sensing performances of the as-synthesized samples to ethanol vapor were tested, and the response of the sensor based on 3 wt.% g-C3N4 decorated SnO2 composite to 500 ppm ethanol vapor was 360 at 300 degrees C, which was much higher than that of pure flower-like SnO2 based sensor. The improved ethanol gas sensing property is proposed to relate to the good conductivity of g-C3N4, high specific surface area and interactions between g-C3N4 and SnO2. (C) 2017 Elsevier B.V. All rights reserved.