Composites of NiFe-Based Layered Double Hydroxide Nanosheets and Ni-Doped Carbon Nanofibers for Electrocatalytic Oxygen Evolution

Oxygen evolution reaction (OER) electrocatalysts play a vital role in promoting electrocatalytic water splitting technology, which should cover low cost, superior catalytic activity, and long-term stability to ensure an efficient and sustainable water splitting process. Herein, we fabricate a NiFe-based layered double hydroxide (NiFe-LDH) nanosheet-supported nickel-doped carbon nanofiber (Ni–CNF) as a highly efficient oxygen evolution electrocatalyst (Ni–CNF/NiFe-LDH), which is synthesized by electrospinning, calcination, and hydrothermal methods. The cross-linked network structure of Ni–CNF markedly increases the specific surface area, thereby facilitating the exposure of active sites. Under the synergy of highly conductive Ni–CNF and ultrathin NiFe-LDH nanosheets, the synthesized Ni–CNF/NiFe-LDH exhibits outstanding performance in the OER, requiring only a low overpotential of 262 mV to achieve a current density of 10 mA·cm^–2. In alkaline media, the corresponding total electrolytic water electrolyzer requires only 1.56 V of battery voltage at a current density of 10 mA·cm^–2.