Co O Nanowire Arrays toward Superior Water Oxidation Electrocatalysis in Alkaline Media by Surface Amorphization.

It is highly desirable to develop a simple, fast and straightforward method to boost the alkaline water oxidation of metal oxide catalysts. In this communication, we report our recent finding that the generation of amorphous Co-borate layer on Co O nanowire arrays supported on Ti mesh (Co O @Co-Bi NA/TM) leads to significantly boosted OER activity. The as-prepared Co O @Co-Bi NA/TM demands overpotential of 304 mV to drive a geometrical current density of 20 mA cm in 1.0 M KOH, which is 109 mV less than that for Co O NA/TM, with its catalytic activity being preserved for at least 20 h. It suggests that the existence of amorphous Co-Bi layer promotes more CoO (OH) generation on Co O surface.