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.