Multi-component supramolecular gels induce protonation of a porphyrin exciplex to achieve improved collective optical properties for effective photocatalytic hydrogen generation.

Towards mimicking natural photosystems, supramolecular gels containing two types of porphyrins were developed for photocatalysis. Protonation and J-aggregation of porphyrins within gels expand the absorption to a wide range of visible wavelengths. Porphyrin exciplex formation renders a smaller bandgap for photo-induced electron generation. These features induce effective photocatalytic hydrogen generation.