Efficient overall water splitting over Mn doped Ni2P microflowers grown on nickel foam

Abstract

The efficient design of highly active, economical and stable electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline electrolyte still remains a great challenge. Herein, Mn doped Ni2P microflowers with porous feature directly grown on Ni foam have been successfully synthesized via a facile hydrothermal method and phosphorization treatment. By detailed analyzing X-ray photoelectron spectroscopy results, it can be found that the electronic structure of Ni2P can be efficiently regulated by Mn doping. As expected, the Mn-doped Ni2P microflowers with an optimal Mn/Ni ratio of 0.053 exhibit a low overpotential of 205 mV for HER and 330 mV for OER to achieve a current density of 100 mA cm−2 in 1.0 M KOH solution. Furthermore, when this electrocatalyst is adopted as both the cathode and anode for overall water splitting, a current density of 10 mA cm-2 is achieved at a cell voltage as low as 1.58 V, accompanied with high stability. © 2019 Elsevier B.V.