Sulfur-Decorated Molybdenum Carbide Catalysts for Enhanced Hydrogen Evolution

A highly active and stable electrocatalyst (MoSx@Mo2C) for hydrogen evolution is developed via the sulfur decoration of molybdenum carbide for the first time. Although the decoration of sulfur reduced the electrochemically active surface area and slightly enlarged the impedance resistance of Mo2C substrates, the turnover frequency was remarkably enhanced, resulting in a great improvement in the final hydrogen evolution reaction activity. More importantly, there is a synergistic effect between MoSx and Mo2C, making the MoSx@Mo2C catalyst exhibit an excellent activity with a small Tafel slope of 44 mV dec–1, which is among the best records for Mo2C-based catalysts.