Visible-light induced hydrogen production using a polypeptide–chlorophyll complex with α-helix conformation

Abstract

Hydrogen production was accomplished under visible-light irradiation by using a system consisting of a biomolecule (chlorophyll a), methylviologen, ethylenediaminetetraacetic acid disodium salt and Pt-loaded poly(L-glutamate) (Poly(Glu)), in aqueous decylammonium chloride (DeAC) solution. Spectroscopic studies revealed that chlorophyll a is solubilized in the hydrophobic clusters of Pt-loaded Poly(Glu)–decylammonium chloride. In the Poly(Glu)–DeAC complex, the electron transfer occurred between chlorophyll a and methylviologen leading to hydrogen production. The most noticeable result is that the rate of hydrogen evolution depends on the change from the random coil to the α-helix in conformation of Poly(Glu) induced by the cooperative binding with DeAC.