Fig. 7: OER mechanism.
From: Non-covalent ligand-oxide interaction promotes oxygen evolution
a Surface free-energy diagram of CoO2 and Co-PH respective to the surface saturated with hydrogen adsorption (Had) on bridge O (Obri) and OH adsorption (OHad) on coordinatively unsaturated sites. b The structures of different surface phases on Co-PH, and adsorbates of surface phases are highlighted by light blue circles on the top views. c The top view (upper) and side view (under) of charge density differences of Co-PH that surface saturated with Had and OHad, that is, Had + OHad (OH*). The purple isosurfaces represent an increase in the total charge density, and the orange isosurfaces represent a decrease in the total charge density. d The reaction-free-energy diagrams for OER on CoO2 and Co-PH at 0 VRHE. Insets are the corresponding enlarged models. The yellowish, gray, brown, red, and pink balls represent metal Co and C, N, O, and H, respectively.
