Fig. 1: Scheme illustrations.
a Representations of the hydrogen bonds involved in stabilizing the Fe-O2 species of the active sites of hemoglobins, the Cu-OOH intermediate of Cu-dependent lytic polysaccharide monooxygenases, and the Cu-OOH species of artificial Cu proteins. b Functionalization of graphene, carbon nanotube and fullerene with the NP group by the 1,3-dipolar cycloaddition reaction. c Schematic illustration of the construction of the NP second sphere on Co-N4 and the second sphere effect in stabilizing the *OOH intermediate toward 2e– ORR pathway.
