Covalent Bonding of Salen Metal Complexes with Pyrene Chromophores to Porous Polymers for Photocatalytic Hydrogen Evolution.

The development of low-cost and efficient photocatalysts to achieve water splitting to hydrogen (H ₂ ) is highly desirable but remains challenging. Herein, we design and synthesize two porous polymers (Co-Salen-P and Fe-Salen-P) by covalent bonding of salen metal complexes and pyrene chromophores for photocatalytic H ₂ evolution. The catalytic results demonstrate that the two polymers exhibit excellent catalytic performance for H ₂ generation in the absence of additional noble-metal photosensitizers and cocatalysts. Particularly, the H ₂ generation rate of Co-Salen-P reaches as high as 542.5 μmol g ^-1 h ^-1 , which is not only 6 times higher than that of Fe-Salen-P but also higher than a large amount of reported Pt-assisted photocatalytic systems. Systematic studies show that Co-Salen-P displays faster charge separation and transfer efficiencies, thereby accounting for the significantly improved photocatalytic activity. This study provides a facile and efficient way to fabricate high-performance photocatalysts for H ₂ production.