Promoting the Oxygen Evolution Activity of Perovskite Nickelates through Phase Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Perovskite oxides are promising electrocatalysts for the oxygen evolution reaction (OER).
• Traditional methods for enhancing OER activity in perovskites offer limited improvements.
• Tuning perovskite properties often involves doping, site ordering, strain, or oxygen vacancies.

Purpose of the Study:

• To introduce crystal phase engineering via amorphization as a novel strategy to enhance OER performance in perovskite oxides.
• To investigate the self-adaptive process induced by amorphous structures in perovskite oxides for improved OER activity.
• To demonstrate the superior OER performance of amorphous LaNiO3 compared to crystalline counterparts.

Main Methods:

• Crystal phase engineering through amorphization of perovskite LaNiO3.
• Fabrication of amorphous and epitaxial crystalline LaNiO3 films.
• Electrochemical characterization of OER activity using techniques like current density measurements.

Main Results:

• Amorphous LaNiO3 exhibits a 9-fold increase in current density compared to epitaxial crystalline LaNiO3.
• The amorphous structure induces a self-adaptive process that enhances OER performance.
• Achieved a record current density of 1038 μA cm⁻² at 1.6 V vs RHE for OER.

Conclusions:

• Amorphization is a highly effective strategy for boosting OER performance in perovskite oxides.
• The self-adaptive nature of amorphous structures offers a new pathway for catalyst design.
• This approach provides a novel protocol for developing advanced electrocatalysts for clean energy applications.