Visible light-induced long-lived charge separation across a sensitised nanostructured TiO2–polyviologen membrane
Abstract
The preparation of a transparent nanostructured TiO2 membrane and its sensitisation to visible light by chemisorption of a tris-bipyridyl ruthenium complex is described. Also described, is the subsequent deposition of a polyviologen film on one face of the sensitised membrane. Absorption of a visible photon by a sensitiser molecule is followed by injection of an electron into the conduction band of the nanostructured TiO2 membrane and by conduction band state mediated electron transfer to a viologen oligomer. By these means, the energy of a visible photon is converted into chemical potential stored in the form of an oxidised electron donor and a reduced electron acceptor on opposite sides of a membrane.