Activating the Basal Planes and Oxidized Oxygens in Layer-Structured Na0.6 CoO2 for Boosted OER Activity.

With the CoO2 slabs consisting of Co4 O4 cubane structure, layered Nax CoO2 are considered promising candidates for oxygen evolution reaction (OER) in alkaline media given their earth-abundant and structural advantages. However, due to the strong adsorption of intermediates on the large basal planes, Nax CoO2 cannot meet the activity demands. Here, a novel one-pot synthesis strategy is proposed to realize the high solubility of iron in Nax CoO2 in an air atmosphere. The optimist Na0.6 Co0.9 Fe0.1 O2 exhibits enhanced OER activity compared to their pristine and other reported Fe-doped Nax CoO2 counterparts. Such an enhancement is mainly ascribed to the abundant active sites on the activated basal planes and the participation of oxidized oxygen as active sites independently, which breaks the scaling relationship limit in the OER process. This work is expected to contribute to the understanding of the modification mechanism of Fe-doped cobalt-based oxides and the exploitation of layer-structured oxides for energy application.