Photocatalytic and electrocatalytic pathways to sustainable fuels and chemicals: insights into reaction kinetics from optical spectroscopy

James Durrant

Professor of Photochemistry, Imperial College

Abstract

Starting with the challenge of sustainably synthesizing fuels and chemicals in transitioning to a more sustainable energy system, Durrant will introduce photo- and electrocatalytic approaches to the problem and discuss mechanistic insights gained from transient optical spectroscopy studies of key reactions, such as water splitting water to hydrogen and organic oxidations (e.g., photoreforming). The kinetic challenge for photocatalysis arises from the mismatch between the picosecond-to-nanosecond lifetimes of photoexcitations in most light-absorbing materials and the microsecond-to-second reaction timescales in chemical fuel synthesis, which is different from the challenges arising in photovoltaic solar cells. Applications of transient spectroscopy to study photocatalysis involving both organic and inorganic materials (including metal oxides and conjugated polymers) will be presented, as well as insights gained from operando spectroscopy about the function of metal oxide catalysts in water oxidation, the key kinetic and thermodynamic bottleneck for water splitting. This latter topic will be explored further to examine materials design and function, comparing water oxidation kinetics on heterogeneous and molecular iridium electrocatalysts, as well as on hematite photoelectrodes.

Bio

James Durrant is a British photochemist and professor of photochemistry at Imperial College London and Sêr Cymru Solar Professor at Swansea University. He serves as director of the center for plastic electronics. Durrant was educated at Gresham’s School in Norfolk, the University of Cambridge and Imperial College London, where he was awarded a Ph.D. in 1991 for research on photosystem II using spectroscopy. Durrant’s research focuses on a range of photochemical applications including solar cells, solar fuel production and photocatalysis, nanomaterials and plastic electronics.