Vattenoxidation på titandioxidytor genom uppkonvertering av synligt ljus

Research Project, 2018 – 2021

More than 99% of all renewable energy resources available close to the Earth's surface are available in the form of solar radiation. Thus a sustainable energy supply for the future should utilize these solar photons, to make electricity as well as fuels. Importantly, we must rely on the visible part of the solar spectrum, where the irradiance is highest. This proposal seeks to address this challenge, and realize the generation of a chemical fuel - hydrogen gas - from absorption of visible by molecules coupled to an inorganic semiconductor catalyst, like TiO2, utilizing the so called triplet-triplet annihilation upconversion process. Already in 1972 Fujishima and Honda showed that holes in the valence band of a TiO2 electrode can split water, but that UV-light is required to drive the process. In this project, we will explore the possibility to use Visible-to-UV triplet triplet annihilation photon upconversion to activate the titandium dioxide. Our first systems will be based on Ir-complexes which have a strong and easily tunable absorption to collect the light and transfer their energy to various pyrene-derivatives which emit UV-light and thus can activate the TiO2. In the subsequent steps we will design molecules that match the energy requirements more carefully, and also investigate how we best can couple the molecular process to the semiconductor based water oxidation process. The project will rely on optical spectroscopic and electrchemical characterization methods.