Pattern-enhanced Resonant Soft X-ray Scattering for Operando monitoring of electrochemical solid-liquid interfaces

TL;DR

This paper introduces a new X-ray technique to study chemical and structural changes at solid-liquid interfaces with high precision and efficiency.

Contribution

The novel method uses engineered nanopatterns to enhance X-ray scattering for operando electrochemical interface analysis.

Findings

Ni line-grating nanopatterns effectively modulate X-ray illumination to enhance scattering signals.

The method reveals oxidation gradients and structural dynamics at electrode-electrolyte interfaces.

Finite-element simulations confirm the technique's ability to model electrocatalytic changes.

Abstract

Unveiling interfaces at sub-nanometer scales is essential for advancing the understanding of complex chemical transformations. However, characterizing solid-liquid interfaces with high dimensional sensitivity and temporal resolution remains challenging, due to their dynamic nature and inaccessibility by conventional probes. Here we present an approach, Pattern-enhanced Resonant Soft X-ray Scattering, to overcome the challenges. Rooted in a “sample-as-optics” philosophy, this technique utilizes precisely engineered line-grating nanopatterns to modulate near-field X-ray illumination, coherently enhancing scattering signals from the line-gratings. We implement the method using Ni line-grating nanopatterns in electrochemical water oxidation. The periodic nanostructures serve as diffractive optical elements to reveal the Ni oxidation gradients and structural dynamics at the electrode-electrolyte interfaces. Finite-element simulations corroborate the observed trends by modeling variations in compositions and structures during electrocatalysis. Through integrating advanced sample design with coherent wave nature of soft X-rays, our approach opens accessible pathways to operando exploring chemical evolution and sub-nanometer dimensional variations simultaneously in electrochemical systems. This non-destructive method is efficient and element-specific, making it valuable for probing chemical and dimensional dynamics with appropriate modeling.

Understanding interfaces at sub-nanometer scales is vital for complex chemical reactions. Here, the authors advance Pattern-enhanced Resonant Soft X-ray Scattering, enabling efficient operando probing of chemical and structural dynamics at solid-liquid interfaces.

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