Photoaccumulation of Long‐Lived Reactive Electrons in a Microporous Ti(IV) Oxocluster‐Based Metal–Organic Framework for Light and Dark Photocatalysis

Abstract The microporous Ti 12 oxocluster‐based metal–organic framework (MOF) MIP‐177(Ti)‐LT exhibits excellent stability and photoactivity, making it highly promising for photocatalysis. Using transient and photoinduced absorption spectroscopies, the behavior of reactive electrons in MIP‐177(Ti)‐LT across femtosecond‐to‐second timescales is investigated. The framework shows efficient charge separation and slow decay kinetics, with photogenerated charges persisting into the microsecond‐second (µs‐s) range and displaying higher yields and slower recombination than benchmark MOFs MIL‐125(Ti)‐NH 2 and UiO‐66(Zr)‐NH 2 . Photogenerated holes oxidize water with an O 2 yield of 335 µmol g −1 h −1 in the presence of electron scavengers. Under continuous irradiation, long‐lived electrons accumulate, further enhanced by a hole scavenger (methanol). Remarkably, these electrons persist over 48 h post‐excitation under argon, accompanied by a reversible white‐to‐black color change. The stored electrons remain redox‐active, efficiently reducing added O 2 and methyl viologen. Dark addition of a Pt co‐catalyst to photocharged MIP‐177(Ti)‐LT induces H 2 evolution at ≈300 µmol g −1 (≈58 C g −1 ), corresponding to an accumulated electron density of one electron per 12 Ti atoms. These results highlight the photocharging properties of MIP‐177(Ti)‐LT and its potential for sustainable photocatalytic applications.