Electronic modulation of nickel phosphide by iron doping and its assembly on a graphene framework for efficient electrocatalytic water oxidation

Fe-doped Ni2P nanoparticles have been fabricated on wrinkled graphene (rGO@Fe-Ni2P NPs) by a facile hydrothermal reaction followed by phosphorization. By adjusting the content of iron in Fe-Ni2P, optimal OER performance is achieved (Ni/Fe = 1.67). rGO@Fe-Ni2P displays pronounced alkaline OER activity with a small overpotential (260 mV vs RHE) at a current density of 10 mA cm(2), and a low Tafel slope (35.7 mV dec(-1)) with long-term durability (17 h). The superior catalytic performance of rGO@Fe-Ni2P is attributed to the rational incorporation of iron into Ni2P, leading to a higher valence of nickel with more oxidation ability and inducing faster OER process. In addition, highly conductive graphene promotes electron transfer for oxygen generation, improves the stability of the catalyst, and provides more active sites facilitating the OER process. (C) 2020 Published by Elsevier B.V.