Tailoring the electrochemical hydrogen evolution activity of Cu3P through oxophilic surface modification

Abstract The hydrogen evolution reaction in alkaline medium can be promoted by the modification of platinum group metal with oxophilic metals. Herein, an earth abundant metal was first converted to copper phosphide Cu3P and the latter was electrochemically activated by a short and simple procedure to yield an oxidized electroactive surface. Compared with the pristine Cu3P catalyst, the electrochemical activated Cu3P catalyst exhibits an HER overpotential of 155 mV at 10 mA/cm2 (90 mV decrease from Cu3P catalyst) in alkaline medium with a stability over 24 hours). XRD, XPS and EDS reveal that the oxidation occurs only on the surface of Cu3P which shows the presence of both copper phosphide and oxide species.