Water-splitting for renewable hydrogen energy sources: a molecular level approach

Developing renewable routes to hydrogen, a sustainable fuel, is critical to achieving net-zero emissions.1 Photocatalytic devices for water-splitting integrate light harvesting, photogenerated charge separation, and catalysis into a single device and so offer a highly promising route to this end goal. However, key uncertainties remain over the kinetics underlying device function and how these kinetics depend upon materials and device design. There is, for example, significant controversy over exactly how an applied voltage or photoexcitation drives catalysis in kinetically challenging, multi-step reactions such as water splitting.2,3 Addressing these questions forms the main research question behind this project. In this project you will focus on a range of inorganic catalysts for sustainable fuel synthesis. At ICL you will use time and potential resolved UV-Vis and NIR spectroelectrochemistry to determine the spectral fingerprint of charge carriers in catalysts and photabsorbers, as well as their populations and reaction kinetics, measured under operating conditions. This information will be complemented by operando resonance Raman spectroscopy at UCL, which will give direct chemical insight into the local structure and conformation of these charged species. The combination of these structural and kinetic analyses will enable molecular design principles to be established, allowing greater insight into the factors that determine photocatalytic material and device performance. In turn, this will further the development of a crucial low carbon technology.