In situ surface derivation of an Fe-Co-Bi layer on an Fe-doped Co3O4 nanoarray for efficient water oxidation electrocatalysis under near-neutral conditions

Developing high-performance water oxidation electrocatalysts working under mild conditions is highly desirable, but still remains challenging. In this communication, we report the in situ surface derivation of an Fe-Co-Bi layer (4-7 nmin thickness) on an Fe-doped Co3O4 nanowire array supported on carbon cloth (Fe-Co3O4/CC). As a 3D catalyst electrode for water oxidation, such a core-shell FeCo3O4@Fe-Co-Bi nanoarray (Fe-Co3O4@Fe-Co-Bi/CC) demonstrates superior activity over that of a Co3O4-derived nanoarray catalyst, with the need of an overpotential of 420 mV to drive a geometrical catalytic current density of 10 mA cm(-2) in 0.1 M potassium borate (pH = 9.2). Notably, this catalyst also shows good long-term stability with high turnover frequencies.