Herein, the vertical thin nickel-iron layered double hydroxide nanosheets grown on the hills -like nickel framework (NiFe LDH/Ni@NF) are employed for the oxygen evolution reaction (OER), securing at the low overpotentials of 197 and 270 mV to obtain the current densities of 20 and 100 mA cm(-2), respectively, with a Tafel slope of 73.34 mV dec(-1). The electrodeposited nickel film induces the NiFe LDH nanosheets grow vertically and thinly. As well, the nickel abundant interfaces and inner space makes this catalyst effective for OER. It was further served as the OER electrode in a water splitting system coupled the Pt/C cathode, and a cell voltage was at 1.52 and 1.67 V to achieve the current density of 10 mA cm(-2) and 50 mA cm(-2). In addition, the water electrolyzer can suffer a long time of 24 h at 50 mA cm(-2), showing the feasibility in a practical unbiased alkaline water splitting system. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.