Unveiling key mechanism of photocatalytic non-adiabatic dynamics at interfaces

Predicting how materials respond to photoexcitation at the atomic and electronic levels plays a crucial role in advancing the fields of photocatalysis and renewable energy. Non-adiabatic photoexcitation dynamics simulations of photogenerated carrier transport and reactions provide a micro-resolved means to fully understand the mechanisms of photocatalysis at interfaces. We have investigated the excited-state dynamic processes of polymer and oxide photocatalysts by non-adiabatic molecular dynamics simulation within the framework of real-time time-dependent density functional theory, to reveal the real-time microscopic processes of photogenerated charge carrier generation and migration at the catalyst/water interface, elucidating the underlying mechanisms of important excited-state processes and confirming a new pathway for photogenerated hole migration-driven photocatalytic water splitting. Notably, by studying the photoexcited dynamics at the rutile interface, we precisely resolved the entangled evolution of the excited electronic state and the non-adiabatic nuclear motion and revealed the redistribution of photogenerated carriers in the excited state as well as the strong coupling with the lattice motion. The proposed new microscopic mechanisms, especially the hole-driven photocatalytic reaction pathways, provide richer design ideas for tailoring characteristic photocatalyst materials.