Binder free construction of hollow hierarchical Mn-Co-P nanoarrays on nickel foam as an efficient bifunctional electrocatalyst for overall water splitting

Constructing bifunctional electrocatalysts with high efficiency, low cost and excellent durability is of great significance for overall water splitting. The structural design of non-noble metal electrocatalysts is essential for tuning their electrocatalytic properties. Hierarchical nanostructures with hollow architectures can provide rich active sites and transmission channels. In this work, hollow hierarchical Mn-Co-P nanoarrays on a nickel foam substrate are successfully fabricated via a facile two-step hydrothermal synthesis, followed by phosphorization. The resultant hollow hierarchical Mn-Co-P nanoarrays not only exhibit outstanding overall water splitting electrocatalytic activity with a low overpotential of 250 mV for the oxygen evolution reaction (OER) and 63 mV for the hydrogen evolution reaction (HER) and a full cell voltage of 1.57 V at 10 mA cm(-2) current density, but also present extraordinary stability in 1.0 M KOH, resulting from the high surface areas and rapid electron transfer ability of hollow hierarchical nanoarrays. These binder free constructed hollow hierarchical Mn-Co-P nanoarrays with high efficiency and good durability are a promising bifunctional electrocatalyst for practical application in overall water splitting.