Integrated Ni2P nanosheet arrays on three-dimensional Ni foam for highly efficient water reduction and oxidation

The large-scale synthesis of efficient nonprecious bifunctional electrocatalysts for overall water splitting is a great challenge for future renewable energy conversion systems. Herein, Ni2P nanosheet arrays directly grown on three-dimensional (3D) Ni foam (NiP/NF) are fabricated by hydrothermal treatment of metallic Ni foam with H2O2 solution and subsequent phosphidation with NaH2PO2. The NiP/NF as electrocatalyst exhibits superior activities for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Most importantly, employing both as the cathode and anode for an alkaline water electrolyzer, NiP/NF only requires a cell voltage of 1.63 V to reach a current density of 10 mV cm(-2), together with stronger durability. Preliminary catalytic information suggests that the tailored 3D superstructure and integrated electrode configurations afford improved active sties and enhanced electron/mass transfer, responding for the outstanding activity and stability. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.