Discontinuity-Enhanced Thin Film Electrocatalytic Oxygen Evolution.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Thin film electrocatalysts offer advantages over powder forms for gas evolution reactions due to better electrode contact and mass transfer.
• Cobalt manganese oxyhydroxide serves as a model system for studying oxygen evolution reaction (OER) electrocatalysts grown directly on electrodes.

Purpose of the Study:

• To investigate the impact of film discontinuity on the OER performance of thin film electrocatalysts.
• To determine if creating discontinuous films enhances OER efficiency and stability.

Main Methods:

• Fabrication of continuous and discontinuous cobalt manganese oxyhydroxide thin films on electrodes.
• Electrochemical characterization including overpotential and turnover frequency measurements.
• Operando Raman spectroscopy to study activation mechanisms during electrocatalysis.

Main Results:

• Discontinuous films exhibited significantly enhanced OER performance compared to continuous films.
• Higher edge-to-area ratios in discontinuous films led to reduced overpotentials and increased turnover frequency.
• Operando Raman spectroscopy indicated lower activation energy barriers at the film edges.

Conclusions:

• Discontinuities in thin film electrocatalysts can dramatically improve OER performance and durability.
• The enhanced performance is attributed to the increased number of active edge sites.
• This approach offers a pathway to high-performance, robust electrocatalysts for demanding gas evolution reactions.