Optimizing the surface state of cobalt-iron bimetallic phosphide via regulating phosphorus vacancies

Herein, we successfully regulated phosphorus vacancies in Co0.68Fe0.32P through Ar-plasma treatment. The Ar-plasma treated Co0.68Fe0.32P exhibits a delicate surface state where the surface Co and Fe ions show an unusual electron loss. The unique surface state enhances the oxygen evolving performance of the phosphide.