Integrating Light-Harvesting Ruthenium(II)-based Units into Three-Dimensional Metal Covalent Organic Frameworks for Photocatalytic Hydrogen Evolution

Three metal covalent organic frameworks (MCOFs), namely RuCOF-ETTA, RuCOF-TPB and RuCOF-ETTBA, were synthesized by incorporating the photosensitive Ru^II tris(2,2'-bipyridine) unit into the skeleton. Interestingly, each RuCOF contains three isostructural covalent organic frameworks that interlock together with the Ru^II centers serving as point of registry. The covalently linked network coupling with uniformly distributed Ru^II units allowed the RuCOFs to exhibit superior chemical stability, strong light-harvesting ability, and high photocatalytic activity toward hydrogen evolution (20 308 μmol g^-1 h^-1 ). This work illustrates the potential of developing versatile MCOFs-based photocatalysts from functionalized metal complex building unit and further enriches the MCOFs family.