Electrochimica Acta, Vol.225, 303-309, 2017
A facile and efficient strategy to gram-scale preparation of composition-controllable Ni-Fe LDHs nanosheets for superior OER catalysis
High-efficient catalysts for oxygen evolution reaction (OER) are crucial to energy storage and conversion between electricity and chemicals. This work proposes a facile co-reduction and subsequent co-oxidation strategy to gram-scale preparation of composition-controllable LDHs nanosheets by a case study of Ni-Fe LDHs. Different from the traditional coprecipitation method, this process does not need heating and pH control. More importantly, our method can make sure that the Ni-Fe proportion in the LDHs products is well consistent with that in the mother solution. Furthermore, the electrocatalytic OER results strongly demonstrate that the as-prepared Ni-Fe LDHs possess a top-scale activity toward OER in alkaline media, typically for the Ni6Fe4-LDH nanosheets with water oxidation overpotential as low as 0.24 V at a current density of 20 mA/cm(2). Besides, it presents excellent stability during the endurance test. Therefore, the co-reduction and subsequent co-oxidation strategy is an highly efficient way to LDHs nanosheets for electrochemical applications. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords:oxygen evolution reaction;pre-coreduction/sub-cooxidation;electrocatalyst;gram-scale;layered double hydroxides