Latest advances in in situ and operando X-ray-based techniques for the characterisation of photoelectrocatalytic systems

Abstract

In situ and operando X-ray techniques have emerged as powerful tools for unravelling the complex mechanisms underlying photoelectrochemical transformations. These techniques offer real-time insights into the dynamic processes occurring at the electrode–electrolyte interface during solar-driven water splitting and other PEC reactions. The present work aims to summarise the latest advances in in situ and operando X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) for the characterisation of photoelectrocatalytic systems and materials for the generation of solar fuels and value-added chemicals. This review highlights the recent advancements achieved using these techniques for elucidating the structural, chemical, and electronic properties of photoelectrocatalytic materials and interfaces during operation. Besides, this review provides technical guidance for performing these measurements, considering the experimental requirements for each of these spectroscopies. Further, we provide an overview of different state-of-the-art synchrotron-based techniques employed for the characterisation of photoelectrocatalytic materials, focusing on the possibilities of the studied techniques, cell designs and more relevant results.