A High Surface Area Ni–Fe Layered Double Hydroxide for Electrocatalytic Water Oxidation Reaction

For water electrolysis, the energy loss at the anode is significant because water oxidationrequires four-electron transfer [1]. Therefore, it is highly desirable to design efficient oxygenevolution reaction (OER) catalysts and ensure their assembly into practical OER electrodes.Layered double hydroxides (LDHs) are anionic clays, which are made of layers of trivalent anddivalent metal cations connected to the OH- anions, with interlayer anions carbonate and nitrateinserted between the layers [2,3]. LDH has been used in a variety of areas, including but notlimited to catalysis, energy storage, drug or gene delivery, water treatment, etc [4,5]. In this study,we report a simple hydrothermal method to prepare a high surface area Ni–Fe layered doublehydroxide (LDH) assembled by nanosheets by using nickel and iron salts as the only startingmaterials.The obtained materials were characterized using scanning electron microscopy, X-raydiffraction, Fourier transform infrared spectroscopy, and BET. The NiFe-LDHs were then usedas the efficient electrocatalyst materials for water oxidation. In this condition, the componentNiFe-LDH synthesized hydrothermal method displayed improved electrocatalytic activity incomparison with other component LDHs due to the high surface area which enhanced theconductivity of the synthesized LDH. Furthermore, the Ni–Fe LDH material reported hereinmight be employed as a promising noble-metal-free water oxidation catalyst to replace the IrOxmaterial—the state-of-the-art water oxidation catalyst.

Keywords:

Water Oxidation , Layered Double Hydroxides , Electrocatalyst , H2 Generation