Uniquely Monodispersing NiFe Alloyed Nanoparticles in Three-Dimensional Strongly Linked Sandwiched Graphitized Carbon Sheets for High-Efficiency Oxygen Evolution Reaction

Oxygen evolution reaction (OER) is known to have a significant role in renewable energy. Herein, we report a low-cost, highly active, and superbly durable three-dimensional (3D) sandwiched NiFe/C arrays grown on Ni foam by a general procedure. This special structure, with both graphitized carbon and Ni foam, possesses a huge specific surface area, high electroconductivity, and a porous structure, effectively enhancing electrocatalytic activities for OER. Furthermore, the sandwiched structure with coupled graphitized carbon sheets encapsulating the outside can hinder active materials from agglomeration and falling off during long-term operation, leading to outstanding durability, even in large temperature ranges.