Interfacial Donor‐Acceptor Engineering in MOFs: Synergizing Self‐Excitation and External Charge Utilization for High‐Efficiency Photocatalytic Hydrogen Evolution

ABSTRACT

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 NH ₂ ‐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–N ₃ ← Pt–N ₂ → Pt‐S ₂ coordination microenvironment was achieved, and the optimized d‐band center of Pt‐S ₂ 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.