Three-dimensional Fe, N-doped carbon nanosheets on interconnected carbon skeletons as a highly efficient and stable electrocatalyst for oxygen reduction reaction

Metal-nitrogen doped carbon is a class of promising catalysts to replace Pt to catalyze the oxygen reduction reaction (ORR). Herein, a novel three-dimensional (3D) Fe-N-C nanosheets grown on interconnected carbon skeletons is fabricated by a facile route, i.e., in situ polymerization of aniline to obtain polyaniline nanosheets on 3D melamine foams and subsequent pyrolysis of the composites. The catalyst exhibits comparable catalytic activity but superior long-term stability to the commercial 20% Pt/C for the ORR in alkaline electrolyte in terms of the onset potential (1.01 V vs. RHE) and the half wave potential (0.86 V vs. RHE). The outstanding catalytic performance was ascribed to the populated active sites taking advantage of the large surface area, the superior electro-conductivity and the facilitated mass transportation by virtue of the unique hierarchically interconnected porous carbon structure. This work is expected to provide a new avenue to fabricate 3D interconnected porous composites for energy conversion and storage.