Copper molybdenum sulfide: a new efficient electrocatalyst for hydrogen production from water

A new inorganic solid state electrocatalyst for the hydrogen evolution reaction (HER) is reported. Highly crystalline layered ternary sulfide copper-molybdenum-sulfide (Cu sub(2)MoS sub(4)) was prepared by a simple precipitation method from Cu super(I) and [MoS sub(4)] super(2-) precursors. In aqueous solution and over a wide pH range (pH 0 to 7), this Cu sub(2)MoS sub(4) showed very good catalytic activity for HER with an overvoltage requirement of only ca.135 mV and an apparent exchange current density of 0.040 mA cm super(-2) (Tafel slope of ca.95 mV per decade was found irrespective of the pH value). This Cu sub(2)MoS sub(4) catalyst was found to be stable during electrocatalytic hydrogen generation. Therefore, it represents an attractive alternative to platinum.