Self‐Healing Pd(II) Cage Metallogels for Iodine Capture in Water and Heterogeneous Photocatalysis

ABSTRACT Adaptive multifunctional systems that integrate responsiveness, environmental remediation, and catalysis within a single platform remain exceptionally rare. Herein, two carbazole‐derived metal‐organic cages (MOCs) were constructed through coordination‐driven self‐assembly and subsequently transformed into fibrous metallogels ( MOC1G and MOC2G ) in mixed DMSO/H 2 O media through cooperative π−π stacking and dynamic supramolecular interactions. The resulting metallogels display reversible gel−sol transitions, interconnected nanofibrous architectures, and pronounced viscoelastic behavior. Rheological analyses revealed dominant elastic characteristics with rapid recovery after large mechanical deformation. Remarkably, the metallogels exhibit autonomous self‐healing without external stimuli, restoring their structural integrity within ∼18 min for MOC1G and ∼14 min for MOC2G after mechanical damage. Temperature‐dependent DLS and DSC studies further confirmed reversible thermally driven assembly−disassembly processes. Beyond their adaptive soft‐matter properties, the discrete MOCs demonstrated highly efficient capture of iodine species from aqueous media, achieving uptake capacities up to 3.01 g g ‒1 together with excellent selectivity and fast adsorption kinetics under both static and continuous‐flow conditions. In addition, the cages function as visible‐light‐responsive heterogeneous photocatalysts for aerobic sulfide oxidation, affording sulfoxides under mild conditions. This work establishes the first example of cage‐based metallogels that exhibit adaptive and autonomous self‐healing behavior while integrating environmental remediation and photocatalytic functionality within a single supramolecular platform.