Detection of acetylene dissolved in transformer oil using SnO2/rGO nanocomposite gas sensor

The operation conditions of oil immersed power transform will affect the safety and stability of power system directly. As one of the main fault characteristic gases dissolved in transformer oil, acetylene (C2H2) gas can effectively reflect the discharge faults which occur in oil-paper insulation system. Monitoring its content of C2H2 gas has a great significance in diagnosis and evaluation the running state of transformer. In this paper, tin oxide (SnO2) and reduced graphene oxide (rGO) nanocomposite based C2H2 gas sensor was developed. The gas sensing material was synthesized by a facile hydrothermal method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM). Then, the gas sensing properties of as-synthesized nanomaterials were tested by exposing to different concentration of C2H2 gas with a temperature range of 100-300 degrees C and its gas sensing mechanism of C2H2 gas was discussed. The characterization results indicated that the SnO2 and SnO2/rGO were succeed synthesized. Under the optimum operating temperature (180 degrees C) of SnO2/rGO, it exhibited a low detection limit (1 mu L/L), high response (50 ppm, 13.2) and good linearity (1-10 mu L/L). The gas sensing mechanism for the better sensing properties to C2H2 gas was explained based on superhigh surface areas and heterojunction between SnO2 and rGO. This results highlight SnO2/ rGO can effective enhance the C2H2 gas sensing properties for monitoring the dissolved C2H2 gas in transformer oil with high performances.