A facile and efficient strategy to gram-scale preparation of composition-controllable Ni-Fe LDHs nanosheets for superior OER catalysis

Abstract

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 0.24V at a current density of 20mA/cm2. 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.