Ultrahigh oxygen evolution reaction activity in Au doped co-based nanosheets.

Oxygen evolution reaction (OER) has attracted enormous interest as a key process for water electrolysis over the past years. The advance of this process relies on an effective catalyst. Herein, we employed single-atom Au doped Co-based nanosheets (NSs) to theoretically and experimentally evaluate the OER activity and also the interaction between Co and Au. We reveal that Au-Co(OH) 2 NSs achieved a low overpotential of 0.26 V at 10 mA cm -2 . This extraordinary phenomenon presents an overall superior performance greater than state-of-the-art Co-based catalysts in a sequence of α-Co(OH) 2 < Co 3 O 4 < CoOOH < Au-Co(OH) 2 . With ab initio calculations and analysis in the specific Au-Co(OH) 2 configuration, we reveal that OER on highly active Au-Co(OH) 2 originates from lattice oxygen, which is different from the conventional adsorbate evolution scheme. Explicitly, the configuration of Au-Co(OH) 2 gives rise to oxygen non-bonding (O NB ) states and oxygen holes, allowing direct O-O bond formation by a couple of oxidized oxygen with oxygen holes, offering a high OER activity. This study provides new insights for elucidating the origins of activity and synthesizing efficient OER electrocatalysts.