A photosynthesis-inspired supramolecular system: caging photosensitizer and photocatalyst in apoferritin

Abstract

Inspired by the bioinorganic structure of natural [FeFe]-hydrogenase ([FeFe]-H2ase) that possesses iron sulfur clusters to catalyze proton reduction to hydrogen (H2), we design a supramolecular photosystem by sequentially integrating hydrophobic ruthenium complex (as a photosensitizer) and diiron dithiolate complex (as a photocatalyst) into the inner surface or cavity of apoferritin via noncovalent interactions. This platform allows photosensitizer and catalyst to localize in a close proximity and short-distance electron transfer process to occur within a confined space. The resulted uniform core–shell nanocomposites were stable and well dispersed in water, and showed enhanced H2 generation activity in acidic solution as compared to the homogenous system without apoferritin participation.