Electrochemical properties of a 2D-molybdenum disulfide-modified electrode and its application in SO2 detection

Sulfur dioxide (SO2) emissions must be efficiently controlled owing to environmental demands. An interesting approach for SO2 concentration is the use of ionic liquids (ILs) and subsequent detection by electrochemical methods. In this study, two kinds of IL ([EMIM][TfO] and [EMIM][BF4]) have been shown to absorb and desorb SO2, and the electrochemical behavior has been investigated by using nanoscale molybdenum disulfide (nano-MoS2)-modified electrodes. The corresponding absorption results showed that the MoS2-modified electrode is a good sensor for SO2 and that the ILs have a high SO2 absorption capacity. According to the SO2 desorption results, it was shown that desorption can be completed at approximately 140 °C under vacuum. Based on the high response signal of this modified electrode to SO2, it was utilized to detect the SO2 in haze. The results suggested that [EMIM][TfO] is able to absorb SO2 from haze with a higher selectivity and capacity than [EMIM][BF4]. Meanwhile, the MoS2-modified electrode was used to detect the concentration of SO2 in the air, which was consistent with the official results.