Deciphering the photophysical kinetics, electronic configurations and structural conformations of iridium–cobalt hydrogen evolution photocatalysts

Picosecond optical and X-ray absorption spectroscopies with time- dependent density functional theory revealed the reaction pathways, electronic and structural conformations of Ir–Co hydrogen evolution photocatalysts. The dyad bearing 2-phenylpyridine ancillary ligands produced more photoreduced Co(II) than its 2-phenylisoquinoline analogue. These findings are important for designs of earth- abundant photosensitizers for photocatalytic applications.