Synergistically boosting the oxygen evolution reaction activity of NiOOH nanosheets by Fe doping

Electrochemical water splitting to generate oxygen and hydrogen is a key process for several energy storage and conversion devices. Developing low-cost, robust, efficient, and earth-abundant electrochemical catalysts for the oxygen evolution reaction (OER) is therefore holding a paramount position. Herein, we report the doping process to prepare two-dimensional Fe-doped NiOOH nanosheets with the tuneable molar ratio of Fe ranging from 0 to 0.4 by using a single-pot synthetic approach. Among the obtained nanomaterials, the Ni0.7Fe0.3OOH nanosheets/C exhibited greatly enhanced electrocatalytic performance toward OER in alkaline media (1.0 M KOH), with an overpotential of 265 mV to afford 10 mA cm−2 current density. The current density produced at fixed overpotential (300 mV) for Ni0.7Fe0.3OOH was 56.5 mA cm−2 which was 22.6, 6.27, 4.18 and 5.13 times higher than those of NiOOH, Ni0.9Fe0.1OOH, Ni0.8Fe0.2OOH and Ni0.6Fe0.4OOH nanosheets /C, respectively. Moreover, the nanosheets were able to retain excellent performance for over 15 h without obvious degradation. The Tafel slope for Ni0.7Fe0.3OOH was 44.8 mV/decade. Therefore, this approach has opened a new possibility for designing highly efficient catalyst-based active sites.