Preparation of g–C3N4–SnO2 composites for application as acetic acid sensor

In this study, SnO2 was prepared by simple hydrothermal method and a series of g–C3N4–SnO2 composite were prepared through sonication mixing method. The materials were characterized by X-Ray Diffraction (XRD), ThermoGravimetric Analysis–Differential Scanning Calorimetry (TG-DSC), Transmission Electron Microscopy (TEM), Fourier Transform InfraRed Spectroscopy (FTIR), Nitrogen adsorption-desorption and X-ray Photoelectron Spectroscopy (XPS), respectively. The gas sensing properties of as-prepared materials were also studied. The addition of g-C3N4 in SnO2 improved gas sensitivity and selectivity of SnO2 to acetic acid vapor and also decreased the operating temperature. The results showed that the optimum operating temperature for acetic acid detection was reduced from 230 °C for pure SnO2 based sensor to 185 °C for g–C3N4–SnO2 based sensors. The g–C3N4–SnO2 based gas sensor containing 10 wt% of g-C3N4 showed the best sensitivity of 87.7–1000 ppm acetic acid. The detection limit was as low as 0.1 ppm for acetic acid. The sensitivity to 1000 ppm acetic acid was 60.9 after 30 days, which make it a potential candidate for application as an acetic acid sensor.