Synthesis of g-C3N4 nanosheet modified SnO2 composites with improved performance for ethanol gas sensing

The composites of SnO2 have attracted much interest in the last few years due to their excellent sensing properties. A series of composites were prepared with two-dimensional (2D) g-C3N4 nanosheet modified SnO2 by a simple hydrothermal method in this work. The as-prepared composites were characterized by the techniques of powder X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), transmission electron microscopy ( TEM), energy dispersive X-ray spectroscopy (EDS), N-2 sorption and X-ray photoelectron spectroscopy (XPS). The gas sensing measurement results indicated that the sensor based on g-C3N4/SnO2 composite showed high sensitivity and excellent selectivity for detection of ethanol vapor. At 500 ppm of ethanol vapor, the response value (R-a/R-g) of 5 wt% 2D g-C3N4 modified SnO2 was 240 at 300 degrees C. Therefore, the g-C3N4/SnO2 composites have a great potential ethanol gas sensing application.