Interfacial Donor-Acceptor Engineering in MOFs: Synergizing Self-Excitation and External Charge Utilization for...

Aiming at the core challenges in MOF photocatalysts-severe bulk charge recombination and insufficient surface active sites-this study innovatively proposes an interfacial D-A (Donor-Acceptor) system. Through a self-optimized process of nanoconfinement, irradiation decomposition, recapture, and redistribution, three PtL acceptors with different coordination environments, anchored on NH₂-MIL-125 via amide bonds like antennas, not only undergo self-excitation under light irradiation but also act as electron acceptors to capture and converge the electrons supplied by the MOF host. Furthermore, the precise tuning of the Pt-N₃ ← Pt-N₂ → Pt-S₂ coordination microenvironment was achieved, and the optimized d-band center of Pt-S₂ effectively balances the activation of water molecules and the transformation kinetics of hydrogen intermediates. Ultimately, NML-Ptbtp achieves a high hydrogen evolution rate of 901.7 mmol g^-1 _Pt h^-1 and an apparent quantum yield of 14.5% at 365 nm. This work proposes the concept of an interfacial D-A system for the first time and, through in situ experiments combined with theoretical simulations, confirms its self-excited reaction behavior and electron-acceptor-induced bifunctionality, thereby revealing a novel optimization mechanism for photogenerated charge separation and surface reaction processes.