Strain-Engineering Deformable Amorphous Metal Electrodes: Insights from Optical Imaging

Abstract Amorphous electrodes and amorphous/crystalline interfaces are garnering increasing interest in water-splitting applications. In these systems, mechanical strain—particularly at amorphous/crystalline interfaces—plays a critical role in influencing overall performance. A deeper understanding of how mechanical strain affects the catalytic activity of amorphous metals is therefore essential for optimizing their functionality. However, the impact of mechanical strain on the electrocatalytic behavior of amorphous metals has received surprisingly little attention in the literature. An optical imaging method is presented to spatially resolve local pH changes at electrode surfaces during water splitting, thereby enabling the visualization of the local hydrogen production rate. This technique is applied to investigate the electrocatalytic behavior of deformable electrodes composed of amorphous metals, which allow for exceptionally large strains and thus significant strain-engineering capabilities. The results reveal spatial nonuniformity in hydrogen production across planar electrodes, underscoring the necessity of spatially resolved measurements in electrocatalysis at small scales. The study further demonstrates the critical role of mechanical strain in modulating electrocatalytic performance, establishing this approach as a powerful tool for optimizing strain-engineered electrode materials in advanced energy conversion systems.