Visualizing photoinduced electron transfer during photocatalysis via ultrafast x-ray spectroscopy

Abstract 
The spatial localization of photoexcited charge carriers is a critical determinant of photochemical reactivity and mechanism. We are using time-resolved x-ray spectroscopy methods to pinpoint how electrons are redistributed within photocatalysts upon light absorption, identifying where and when electrons are localized. I will discuss molecular photocatalysts where electron localization within the ligand framework operates to trap and store electrons for later delivery to a metal active site. I will also discuss hybrid semiconductor-metal photocatalysts where charge trapping is found to mediate the directionality of interfacial charge transfer. The two examples are chosen to highlight time-resolved x-ray methods that are not currently available at the LCLS, but are planned to come online in the coming years (tender x-ray absorption and x-ray photoelectron spectroscopy of surfaces).  

Bio 
Amy Cordones-Hahn is a lead scientist in the PULSE Institute. Her research aims to understand the excited state processes that drive photochemical reactions of transition metal complexes and other materials relevant for solar energy conversion and catalysis.