Shell thickness controlled core-shell FeO@CoO nanocrystals as efficient bifunctional catalysts for the oxygen reduction and evolution reactions.

Core-shell Fe3O4@CoO NCs have been demonstrated to be efficient bifunctional catalysts for the oxygen reduction (ORR) and evolution (OER) reactions. Their activities are strongly shell thickness dependent. Specifically, nanocrystals with ∼2 monolayers of CoO can exhibit a potential difference of 0.

Core@shell structured Co-CoO@NC nanoparticles supported on nitrogen doped carbon with high catalytic activity for oxygen reduction reaction.

A composite with a hierarchical structure consisting of nitrogen doped carbon nanosheets with the deposition of nitrogen doped carbon coated Co-CoO nanoparticles (Co-CoO@NC/NC) has been synthesized by a simple procedure involving the drying of the reaction mixture containing Co(NO), glucose, and urea and its subsequent calcination. The drying step is found to be necessary to obtain a sample with small and uniformly sized Co-CoO nanoparticles. The calcination temperature has a great effect on the catalytic activity of the final product.