Autologous growth of Fe-doped Ni(OH)_2 nanosheets with low overpotential for oxygen evolution reaction

摘要

Highly active and durable electrocatalysts for oxygen evolution reaction (OER) play a vital role in water splitting. Despite numerous efforts, the strategies to prepare durable and effective electrocatalysts via scalable methods still remain a great challenge. In this work, we fabricated Fe-doped Ni(OH)(2) ultrathin nanosheets (Fe-Ni-OH/Ni) via autologous growing of Ni(OH)(2) from Ni foam, and in situ electrochemical-assisted doping Fe into Ni(OH)(2). Benefiting from the unique structure with large surface areas and strong coupling effects between Fe and Ni, the optimal Fe-Ni-OH electrodes exhibit remarkable catalytic performance toward OER, which requires an overpotential of 220 mV to achieve a current density of 10 mA cm(-2) with a Tafel slope of 48.3 mV dec(-2). The Fe-Ni-OH electrodes also possess high stability even under a high current density of 500 mA cm(-2) for 600 h with an ultralow overpotential of 290 mV. Using Ni-Fe-OH electrodes as both anode and cathode for overall water splitting, only a small overpotential of 1.57 V is required to reach a current density of 10 mA cm(-2). Moreover, the high catalytic performance and scalable preparation method can meet the emergency needs for the practical application. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.