LAUSR

Abstract The binary Ag-Fe-doped Co 2 P (Ag-Fe-Co 2 P) nanospheres have been prepared as bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using Ag-Fe-Co hydroxides nanospheres as precursors. XRD and XPS confirm the formation of Ag-Fe-Co 2 P. SEM and TEM demonstrate that Ag-Fe-Co 2 P has uniform nanospherical morphology composed of vertical nanosheets, which imply the more exposed active sites for water splitting. For HER measurements in 1 M KOH, Ag-Fe-Co 2 P with the overpotential of only 41 mV to drive current density of 10 mA cm −2 . Remarkably, to achieve current density of 100 mA cm −2 for OER, Ag-Fe-Co 2 P requires overpotential of 220 mV, which is obviously less than that of Fe-Co 2 P. Furtherly, when Ag-Fe-Co 2 P was used as the electrocatalyst for both cathode and anodic, a cell voltage of 1.53 V was able to reach 100 mA cm −2 in 1.0 M KOH, outperforming most reported nonprecious electrocatalysts. The obvious enhancement in activity of Ag-Fe-Co 2 P for HER and OER derived from its high conductivity, electron-donating ability and augmented accessibility of active sites. Therefore, designing multiple metal doped transition metal phosphides with unique nanostructure may be a promising way for efficient overall water splitting.