Electrochemical sensing of SF₆ decomposition products based on a screen printed carbon electrode

In the present work, a screen printed carbon electrode (SPCE) was used for the electrochemical detection of SF₆ decomposition products. At least 11 compounds from SF₆ decomposition gas sample were observed and identified by GC-MS. The SPCE was characterized by a scanning electron microscopy and electrochemical impedance spectroscopy. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) was used for the detection of SF₆ decomposition products. The results of GC-MS, CV and DPV reveal that SF₆ decomposition products mostly contain SO₂. The CV result shows three main peaks in 0.1 M KOH solution; a cathodic peak at -0.556 V and anodic peaks at -0.127 and 0.252 V, respectively. This is due to the reduction and oxidation products of adsorbed SO₂ on the electrode surface. The DPV also reveals three distinct peaks; one reduction peak at -0.572 V and other two oxidation peaks at -0.204 and 0.18 V. In addition, this study can also be further extended for detection of similar gases in the solution phase.