Pyrene-containing conjugated organic microporous polymers for photocatalytic hydrogen evolution from water

Photoactive conjugated microporous polymers (CMPs) are emerging as porous materials capable of mediating the photocatalytic evolution of H-2 from water. In this study, we synthesized three pyrene-based CMPs (Py-F-CMP, Py-TPA-CMP, Py-TPE-CMP) through Sonogashira-Hagihara cross-couplings of 1,3,6,8-tetraethynylpyrene (Py-T, as a common monomer building block) with 2,7-dibromo-9H-fluorene (F-Br-2), tris(4-bromophenyl)amine (TPA-Br-3), and 1,1,2,2-tetrakis(4-bromophenyl)ethene (TPE-Br-4), respectively, in the presence of Pd(PPh3)(4) in DMF/Et3N. We then characterized the chemical structures, crystallinities, thermal stabilities, surface morphologies, and porosities of these three new CMPs. Brunauer-Emmett-Teller (BET) analyses and tests of photocatalytic H-2 production revealed that Py-TPA-CMP displayed the highest BET surface area (454 m(2) g(-1)), highest total pore volume (0.28 cm(3) g(-1)), highest H-2 evolution rate (19 200 mu mol h(-1) g(-1)), and highest apparent quantum yield (15.3%) when compared with those of Py-F-CMP, Py-TPE-CMP, and other organic porous materials.

Automated summary

In this study, three pyrene-based photoactive conjugated microporous polymers were synthesized and characterized, with Py-TPA-CMP exhibiting the best performance in photocatalytic H-2 production, showing high BET surface area, total pore volume, and apparent quantum yield compared to other organic porous materials.