Water-soluble photocatalysts based on porphyrin-carbon dot conjugates produce H₂ under visible light irradiation

Herein, we report visible-light-induced hydrogen generation from aqueous protons utilizing a novel hybrid photocatalytic nanomaterial comprising porphyrin-carbon dot conjugates. Amide coupling between metallated tetra-carboxyphenyl porphyrins (MTCPPs) and nitrogen doped carbon dots (NCDots) was performed to afford M-TCPP-NCDots hybrids, which were applied in hydrogen evolution photocatalysis under visible irradiation. H₂ was obtained in the presence of appropriate sacrificial electron donors and with no additional metallic co-catalysts. It is noteworthy that the covalent attachment as well as the zinc-metallation of the porphyrin moiety were proved vital for the efficiency of the present system. The present study constitutes an innovative approach for artificial photosynthesis avoiding the use of costly materials such as noble metals.