Advanced non-precious electrocatalyst of the mixed valence CoOx nanocrystals supported on N-doped carbon nanocages for oxygen reduction

Taking advantage of the nitrogen （N）-participation and large surface area of N-doped carbon nanocages （NCNCs）, the COOx nanocrystals are conveniently immobilized onto the NCNCs with high dispersion. The CoOx/NCNCs hybrid exists in the mixed valence with predominant CoO over Co3O4 and demonstrates superb oxygen reduction reaction activity and stability remaining -94% current density even after operation over 100 h. These results suggest a promising strategy to develop advanced electrocatalysts with the novel NCNCs or even beyond.