Controllable phosphorsulfurization of uniform binary Ni-Fe nanocubes for enhanced water oxidation

Developing bimetallic electrocatalysts with unique nanostucture for oxygen evolution reaction (OER) is crucial for promoting water splitting. Herein, Ni-Fe nanocubes (NiFe NCs) have been synthesized as the templates through a self-assembly process. Then phosphorization, sulfurization or coupling process has been used to prepare different binary Ni-Fe nanocubes samples. The coupled phosphorization and sulfurization (P-S-NiFe NCs) can improve the intrinsic activity, which may be due to rough surface with rich active sites towards OER. Moreover, compared to S-NiFe, P-NiFe and S-P-NiFe NCs, P-S-NiFe NCs maintains intact cubic structure and exhibits superior OER performance with an overpotential of 270 mV to drive a current density of 10 mA cm(2). The order of phosphorization and sulfurization are the key for unique structure and excellent activity. Therefore, the controllable phosphorsulfurization treatment of binary metal-based nanostructure may be a promising strategy to prepare excellent electrocatalysts for water oxidation. (C) 2018 Elsevier B.V. All rights reserved.