Composites of NiFe-Based\nLayered Double Hydroxide\nNanosheets and Ni-Doped Carbon Nanofibers for Electrocatalytic Oxygen\nEvolution

Oxygen evolution reaction (OER) electrocatalysts play\na vital role\nin promoting electrocatalytic water splitting technology, which should\ncover low cost, superior catalytic activity, and long-term stability\nto ensure an efficient and sustainable water splitting process. Herein,\nwe fabricate a NiFe-based layered double hydroxide (NiFe-LDH) nanosheet-supported\nnickel-doped carbon nanofiber (Ni–CNF) as a highly efficient\noxygen evolution electrocatalyst (Ni–CNF/NiFe-LDH), which is\nsynthesized by electrospinning, calcination, and hydrothermal methods.\nThe cross-linked network structure of Ni–CNF markedly increases\nthe specific surface area, thereby facilitating the exposure of active\nsites. Under the synergy of highly conductive Ni–CNF and ultrathin\nNiFe-LDH nanosheets, the synthesized Ni–CNF/NiFe-LDH exhibits\noutstanding performance in the OER, requiring only a low overpotential\nof 262 mV to achieve a current density of 10 mA·cm<sup>–2</sup>. In alkaline media, the corresponding total electrolytic water electrolyzer\nrequires only 1.56 V of battery voltage at a current density of 10\nmA·cm<sup>–2</sup>.