MOF-Directed Fabrication of Nickel/Cobalt Bimetallic Phosphides as Robust Electrocatalyst for Oxygen Evolution Reaction

The construction of efficient and stable non-noble metal electrocatalysts for oxygen evolution reaction (OER) is a major challenge via water splitting to make H-2 fuel. Herein, we report the hybrids of NiCo bimetallic phosphides (denoted as NixCoy-P) through a one-step phosphidation strategy derived from nanosheets NiCo metal-organic frameworks (NixCoy-BDC). The unique hierarchical porous structure, heterogeneous (Ni2P and Co2P) composition and carbon framework of the NixCoy-P hybrids were characterized by scanning electron microscope, X-ray diffraction and transmission electron microscope, which endowed handy ion diffusion path, synergistically active sites and high conductivity for OER. The as-fabricated Ni1Co1-P catalyst exhibited more excellent OER activity than other phosphides (Ni-P, Ni3Co1-P, Ni1Co3-P and Co-P). More remarkably, the Ni1Co1-P supported on Ni foam (NF) exhibits low overpotential (eta(35)) of 300 mV at a current density of 35 mA cm(-2), small Tafel slope of 71 mV dec(-1) and excellent stability for OER in 1.0 M KOH solution. This work provides a general strategy to design more efficient multi-metallic component OER electrocatalysts. (C) 2020 The Electrochemical Society (ECS). Published on behalf of ECS by IOP Publishing Limited.