Bottom-up fabrication of nitrogen-doped mesoporous carbon nanosheets as high performance oxygen reduction catalysts.

Nitrogen-doped mesoporous carbon nanosheets (NMCNs) with uniform hexagonal structures are fabricated via the thermal treatment of polyaniline enwrapped cobalt hydroxide (Co(OH)) nanosheets and the subsequent acid etching of the resulting composites. It is found that the morphologies, poroisties and compositions of the NMCNs are greatly dependent on the ratio of the added aniline and Co(OH) nanosheets, which can in turn affect the electrochemical behavior of the NMCNs. As the electrocatalyst for oxygen reduction reaction in alkaline media, the NMCNs obtained with the aniline/Co(OH) ratio of ∼1.2 manifest excellent perfromance with the onset potential of -0.119V, the half-wave potential of -0.182V and the limiting current density of 5.06mAcm, which are superior to most of the previously reported N-doped porous carbon nanosheets.