A Photoinduced Electron Transfer System by Graphene Oxide Non-covalently Linked Porphyrin Antennae in Water

Abstract

Non-covalent interacting porphyrin/Graphene Oxide (GO) nanohybrids were formed in water and confirmed by TEM, Raman, FT-IR, XRD, UV-vis and fluorescence spectroscopy. The binding constant between porphyrin and GO is 2.38 × 10³ L mol⁻¹ calculated by Benesi-Hildebrand equation based on absorbance plot, which confirmed a robust porphyrin/GO nanohybrid formation. Fluorescence of porphyrin was effectively quenched by GO indicated the efficient photoinduced electron transfer (PET) from porphyrin moieties to GO, which porphyrin acts as energy absorbing and electron transferring antennae and GO serves as an efficient electron acceptor of the system. The photoelectrical response measurements of porphyrin/GO nanohybrid showed a rapid and reversible on/off photovoltage and photocurrent by the alternative white light. The PET from porphyrin to GO is energetically favorable deduced by calculating free Gibbs energy. Non-covalent porphyrin/GO nanohybrid may be used as photovoltaic conversion materials for photoelectronic applications.