Synthesis of g-C3N4-Zn2SnO4 nanocomposites with enhanced sensing performance to ethanol vapor

Abstract To detect various volatile organic compounds (VOCs), the g-C3N4-Zn2SnO4 nanocomposites were synthesized via hydrothermal method, the obtained materials were characterized by XRD, SEM, TEM, EDS, UV-Vis, XPS, FT-IR and N2 adsorption-desorption isotherms, respectively. Their gas sensing properties were studied in the temperature range of 25–400 °C. The complete study regarding gas sensing measurements certified that the sensor of 6 wt% g-C3N4-Zn2SnO4 (ZSO-6) nanocomposite exhibited the response of 45–100 ppm ethanol at 290 °C, while the responses to other tested volatile organic compounds (100 ppm) were all less than 13, specifying the better selectivity of ZSO-6 to ethanol, while the selectivity of pure Zn2SnO4 to ethanol was 1.67, the response/recovery times were 15/23 s; especially, the response reached 1.5–0.01 ppm ethanol; comparing with pure Zn2SnO4 nanocubes, the specific surface area of nanocomposite was increased by the decoration of Zn2SnO4 nanocubes onto g-C3N4 sheet, the role of g-C3N4 in composites was to enhance the gas sensing response as well as the gas sensing selectivity to ethanol.