Direct observation of an ionic cobalt complex electron mediator via operando X-ray absorption spectroscopy in photocatalytic Z-scheme CO2 reduction with (CuGa)0.3Zn1.4S2 and BiVO4

Abstract

Real-time Co(II)/Co(III) redox state transitions of cobalt complex electron mediators during aqueous Z-scheme CO₂ reduction with oxide and sulfide photocatalysts were directly observed by operando X-ray absorption spectroscopy. This approach provides a general framework for advancing mechanistic understanding of ionic redox mediator-driven artificial photosynthesis.