Molybdenum Sulfide Electrocatalysis is Dramatically Influenced by Solvents Used for Its Dispersions

Transition metal dichalcogenides, especially MoS 2 and related MoS 3 , have attracted attention as potential replacement of platinum for electrochemical energy applications. These materials are typically treated before the use in solvents. It is assumed that these solvents do not influence follow-up electrochemistry. Here, we show that the oxygen reduction overpotentials as well as inherent electrochemistry of MoS 3 is dramatically influenced by solvents used, them being water, acetonitrile, dimethylformamide, or ethanol. This has a profound impact on the interpretation of the electrochemical studies and the choice of MoS x solvent treatment.