Q: What initially drew you to the APS?

Michael: I first started using the APS as a graduate student at Northwestern. One of the main reasons I chose to go there was its proximity to Argonne and the opportunity to do X-ray measurements at a synchrotron.

I worked with Lin Chen, who had built much of her career around developing time-resolved X-ray spectroscopy techniques. Through that work, I transitioned from tabletop optical laser experiments into synchrotron-based measurements and became interested in both the science and the experimental approach.

What stood out to me was the ability to directly observe how molecular systems evolve after light excitation. That combination of electronic and structural insight made synchrotron experiments at the APS a natural fit for the kinds of questions I wanted to pursue.
 

Q: Can you describe the research you’ve conducted at the APS? 

Michael: My work at the APS has focused on using X-ray spectroscopy to study how molecular systems respond to light, particularly in the context of solar energy conversion and artificial photosynthesis. Much of this involves transition metal complexes, where we’re interested in how electronic structure and atomic geometry change following photoexcitation.

Early in my work, I focused on steady-state X-ray absorption measurements to understand electronic and structural properties in systems containing metals such as copper, iron, and platinum, including under applied electrochemical conditions.

A major part of my research has involved time-resolved X-ray absorption, in which we use a laser pulse to excite a system and then probe how it evolves using X-rays. This allows us to track charge transfer processes and structural changes, such as distortions in coordination geometry, as they occur on short timescales.
 

Q: What role did the APS play in enabling or advancing your work? 

Michael: The APS played a foundational role in enabling this work. It hosted the first time-resolved X-ray spectroscopy beamline, which meant that, at the time I was doing my graduate research, these experiments could not be performed elsewhere.

That capability allowed us to directly observe how excited states evolve in molecular systems, including both electronic changes and structural distortions following light absorption.

More broadly, the development of time-resolved techniques at the APS served as a starting point for much of the work that followed, including experiments now performed at X-ray free-electron lasers.
 

Q: Has anything unexpected come out of your work with the APS, either in your results or in the process itself?

Michael: One thing that has changed over time is the reliability of the experiments themselves. Early on, the techniques were still being developed, and it wasn’t always clear whether an experiment would work. Now, the measurements are much more established, and the focus has shifted toward how the samples behave.

That has led to a range of unexpected results. Some systems show dynamics that are more complex than anticipated, while others behave very differently from what prior experience would suggest. In some cases, experiments that were originally considered exploratory have produced some of the most interesting findings.

These experiences have reinforced the importance of remaining open to results that don’t match expectations, especially as we study more complex systems.
 

Q: What impact has your research at the APS had on your work so far? What are you excited about exploring next?

Michael: My current research builds directly on the work I began as a graduate student, but the focus has shifted from simple model systems to more complex and functional ones. The long-term goal has been to understand processes relevant to artificial photosynthesis, such as charge transfer, multi-electron reactions, and catalytic activity.

We’re now able to study systems that more closely resemble real-world photoelectrochemical processes, including combining light excitation with electrochemical control. This makes it possible to probe intermediates involved in reactions like water splitting or carbon dioxide reduction.

Looking ahead, I’m excited to continue to expand these approaches to more complex systems as experimental capabilities improve.