October 10, 2024
Journal Article
Contribution of the Sub-Surface to Electrocatalytic Activity in Atomically Precise La0.7Sr0.3MnO3 Heterostructures
Abstract
Electrocatalytic reactions are known to take place at the catalyst/electrolyte interface. Whereas recent studies of size-dependent activity in nanoparticles and thickness-dependent activity of thin films imply that the sub-surface layers of a catalyst can contribute to the catalytic activity as well, most of these studies consider actual modification of the surfaces. In this study, we investigate the role of a catalytically active sub-surface layers by employing atomic-scale thickness control of the La0.7Sr0.3MnO3 (LSMO) films and heterostructures, without altering the catalyst/electrolyte interface. The activity of oxygen evolution reaction (OER) shows a non-monotonic thickness dependence in the LSMO films and a continuous screening effect in LSMO/SrRuO3 heterostructures, which allowed us to define an “electrochemically-relevant depth” on the order of 10 unit cells. Our study on the electrocatalytic activity of epitaxial heterostructures provides new insight in designing efficient electrocatalytic nanomaterials and core-shell architectures.Published: October 10, 2024