Rational interface engineering of Cu₂S-CoO/CF enhances oxygen evolution reaction activity

Interface engineering is the most direct and efficient way to enhance the oxygen evolution reaction (OER) activity of transition-metal sulfides (TMSs). However, present methods of engineering nano-interfaces remain to be improved. Here, we present a nitrate-pyrolysis method to create a sulfide-oxide interface on Cu2S for the first time. Specifically, a CoOx decorated Cu2S nanowire array on Cu foam (Cu2S-CoOx/CF) is prepared successfully, and the XPS result demonstrates the interfacial connection between Cu2S and CoOx. To afford a current density of 25 mA cm-2, Cu2S-CoOx/CF needs an overpotential of 255 mV, lower than that of Cu2S/CF (354 mV) and CoOx/CC (378 mV). These results indicate that the introduction of the sulfide-oxide interface is an efficient means to enhance the OER activity of Cu2S. And this paper should provide a novel route for more explorations in interface engineering for TMSs.