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

Abstract

A new inorganic solid state electrocatalyst for the hydrogen evolution reaction (HER) is reported. Highly crystalline layered ternary sulfide copper-molybdenum-sulfide (Cu₂MoS₄) was prepared by a simple precipitation method from Cu^I and [MoS₄]²⁻ precursors. In aqueous solution and over a wide pH range (pH 0 to 7), this Cu₂MoS₄ 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⁻² (Tafel slope of ca. 95 mV per decade was found irrespective of the pH value). This Cu₂MoS₄ catalyst was found to be stable during electrocatalytic hydrogen generation. Therefore, it represents an attractive alternative to platinum.