Graphene oxide guiding the constructing of nickel-iron layered double hydroxides arrays as a desirable bifunctional electrocatalyst for HER and OER

It is accepted that the electrocatalytic activity is correlated to the morphology. Here, graphene oxide guiding nickel and iron layered double hydroxides hybrid arrays (GO-FeNi-LDH) are firstly fabricated by one-step electro-deposition method. The pretty 3D arrays with sheets vertically growing on nickel foam (NF) are highlighted by controlling the quantity of GO. Furthermore, the electron transfer from Ni, Fe to graphene is detected, making the metals and graphene in high valence and electron-rich state, respectively. The optimal GO-FeNi-LDH presents pretty morphology, defects, electron interactions and good conductivity. Therefore, to achieve 10 and 100 mA cm(-2), it requires the overpotentials of 119, 210, 285 and 303 mV for HER and OER and excellent durability. Noticeably, the optimal GO-NiFe-LDH needs a cell voltage of 1.48 V to drive 10 mA cm(-2) for the whole water splitting, which are lower than that of most of advanced electrocatalysts, endowing it in first-rank electrocatalyst. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.