Pyrene-based metal-organic frameworks (MOFs) and hydrogen-bonded organic frameworks (HOFs) for photocatalytic...

Pyrene-based metal-organic frameworks (MOFs) and hydrogen-bonded organic frameworks (HOFs) have emerged as a distinctive class of photoactive crystalline materials for photocatalytic applications. The exceptional photophysical properties of pyrene, including strong visible-light absorption, long-lived excited states, high carrier mobility, and a strong tendency for π-π stacking, enable the construction of porous frameworks with tunable photoactive functions. This review provides a systematic overview of recent advances in the design, synthesis, and photocatalytic applications of pyrene-based MOFs and HOFs. Fundamental concepts such as light harvesting, exciton migration, charge separation, and energy transfer are discussed alongside key design strategies, including linker engineering, metal node selection, and supramolecular assembly. The fabrication of pyrene-based frameworks and their composites is summarized, highlighting methods such as stacking engineering, host-guest encapsulation, and self-assembly. Their applications in hydrogen evolution, CO₂ reduction, H₂O₂ generation, organic pollutant degradation, and organic transformations are critically evaluated, with an emphasis on structure-property relationships and mechanistic insights. Finally, current challenges, including limited charge separation, structural instability, and insufficient catalytic efficiency, are discussed, and future directions such as heterostructure engineering, thin-film processing, nanoscale and interfacial design, defect and donor-acceptor modulation, and combined in situ-theoretical characterization are proposed. This review aims to provide a comprehensive design idea for the rational design and application of pyrene-based photoactive frameworks in sustainable photocatalysis.