Discharge-Induced Enhancement of the Oxygen Evolution Reaction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Surface reconstruction is key to improving the oxygen evolution reaction (OER).
• Understanding potential-induced surface changes is vital for electrocatalyst development.

Purpose of the Study:

• To investigate the role of low applied potential discharge currents in the in situ electrochemical activation of nitrogen-doped nickel oxyhydroxide.
• To elucidate the mechanism by which these currents enhance OER activity.

Main Methods:

• Electrochemical characterization of nitrogen-doped nickel oxyhydroxide.
• Application of discharge currents in a low potential region.
• Analysis of surface structure changes and vacancy formation.

Main Results:

• A previously overlooked discharge current in the low potential region induces significant in situ electrochemical activation.
• This activation promotes the formation of nitrogen and oxygen vacancies by weakening the surface structure.
• Current density at 1.4 V (vs. Hg/HgO) increased by up to 31.3% after low potential discharge.

Conclusions:

• Low applied potential discharge currents are a critical factor in the in situ enhancement of OER.
• Nitrogen and oxygen vacancies formed via this mechanism significantly boost electrocatalyst activity.
• The low potential region should be a primary consideration when evaluating electrocatalyst origins of activity.