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

Abstract Sulfur dioxide (SO 2 ) emissions must be efficiently controlled owing to environmental demands. An interesting approach for SO 2 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][BF 4 ]) have been shown to absorb and desorb SO 2 , and the electrochemical behavior has been investigated by using nanoscale molybdenum disulfide (nano-MoS 2 )–modified electrodes. The corresponding absorption results showed that the MoS 2 -modified electrode is a good sensor for SO 2 and that the ILs have a high SO 2 absorption capacity. According to the SO 2 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 SO 2 , it was utilized to detect the SO 2 in haze. The results suggested that [EMIM][TfO] is able to absorb SO 2 from haze with a higher selectivity and capacity than [EMIM][BF 4 ]. Meanwhile, the MoS 2 -modified electrode was used to detect the concentration of SO 2 in the air, which was consistent with the official results.