Novel Micro/Nanostructured Composites of Fe-Encapsulated Fe-N-Doped Porous Carbon Nanosheets Tangled with CNT for Efficient Electrocatalysis

The exploration of low-cost and high-efficiency multifunctional electrocatalysts for oxygen reduction reaction is of significant importance for future sustainable energy conversion systems. Herein, novel three-dimensional (3D) micro/nanostructured composites of porous two-dimensional (2D) carbon nanosheets and one-dimensional (1D) carbon nanotubes (Fe@Fe-N-CNS/CNT) are fabricated by a feasible self-sacrificial template synthetic strategy. By virtue of high specific surface area, hierarchically porous structure, uniformly dispersed active sites, and unique 1D/2D-architecture, as-fabricated Fe@Fe-N-CNS/CNT exhibits excellent ORR performance, such as outstanding stability (3 mV after 30,000 cycles) and superior methanol tolerance in alkaline media, outperforming a commercial Pt/C catalyst. Furthermore, Fe@Fe-N-CNS/CNT is employed as a cathode catalyst in primary Zn-air batteries, which demonstrates outstanding electrocatalytic activity (the maximum power density of 113 mW cm^-2) and high discharge stability (5 discharge cycles). In addition, Fe@Fe-N-CNS/CNT also presents a high ORR activity and stability in acidic media. Therefore, this feasible synthetic strategy provides inspiration for rational construction of efficient electrocatalysts for various energy systems.