Temperature Ramp Strategy for Regulating Oxygen Vacancies in NiCo O Nanoneedles Towards Enhanced Electrocatalytic Water Splitting.

Oxide-based systems often suffer from higher overpotentials compared to transition metal sulfides and phosphides for the electrochemical hydrogen evolution reaction (HER). Interestingly, the generation of oxygen vacancy/defect has been seen as the strategy for further activating transition metal oxides (NiCo O as a model system) for an electrochemical water-splitting process. Herein, we employ the temperature ramp strategy (ambient air calcination) for the generation of oxygen vacancies in NiCo O (NCO) towards the tuning of electrocatalytic enhancements.