Self-Assembled Naphthalimide-Substituted Porphyrin Nanowires for Photocatalytic Hydrogen Evolution

A linear 5,15-di(naphthalimide) substituted porphyrin ZnD(p-NI)PP is facilely self-assembled into nanowires in solid with well-defined morphology through the synergistic pi-pi stack interactions of both porphyrin and naphthalimide skeletons. The self-assembled porphyrin nanowires feature broadened light absorption, efficient separation and transfer of photogenerated charges, and enhanced photostability. As a consequence, the ZnD(p-NI)PP produced 108 times higher H-2 production rate (eta H-2 = 5.40 mmol g(-1) h(-1)) than the control 5,15-diphenylporphyrin (ZnDPP) (eta H-2 = 0.05 mmol g(-1) h(-1)) and 3.6-fold higher than the ZnT(p-NI)PP (eta H-2 = 1.50 mmol g(-1)h(-1)) which bears four NI units and self-assembled into nanospheres in the solid. Additionally, the photocatalytic system of ZnD(p-NI)PP produced hydrogen evolution up to 50 h, while the hydrogen evolution of the ZnDPP photocatalytic system reached a plateau after 20 h.