in situ/operando soft X-ray absorption spectroscopy (sXAS) by a flowing liquid cell

Lo-Yueh Chang^1*, Shu-Chih Haw¹

¹Nano Science Group, National Synchrotron Radiation Research Center (NSRRC), Hsinchu, Taiwan

* Presenter:Lo-Yueh Chang, email:chang.loyueh@nsrrc.org.tw

Over the past few decades, the intensity of synchrotron radiation has increased dramatically from 10⁶ to 10¹⁵ enabling significant advancements in techniques that require high photon flux. Among these, in-situ and operando experiments have become particularly important, allowing researchers to investigate materials and reactions under real-world conditions with spectroscopic and imaging precision.

Soft X-ray absorption spectroscopy (sXAS) is a highly effective technique for probing local charge transitions, electronic structures, charge symmetry, and the local chemical environment. It is particularly well-suited for investigating interface regions in complex systems due to its shallow probing depth (~10 nm). In the soft X-ray region, sXAS can probe key elements, including organic components (C, N, and O), and the L-edges of transition metals such as Fe, Co, and Ni. Typically, sXAS measurements are performed in a vacuum chamber to prevent contamination and signal attenuation from ambient conditions. However, to advance our understanding of chemical reaction mechanisms and energy transfer processes, in situ/operando measurements are increasingly essential. Based on this, we designed a flowing liquid cell that includes three electrodes that allow for the application of external potentials. The design mitigates potential X-ray damage and prevents gas accumulation during measurements.

Keywords: Soft X-ray absorption spectroscopy, liquid cell, in situ