Making Oxygen with Ruthenium Complexes

Mastering the production of solar fuels by artificial photosynthesis would be a considerable feat, either by water splitting into hydrogen and oxygen or reduction of CO2 to methanol or hydrocarbons: 2H2O + 4hν → O2 + 2H2; 2H2O + CO2 + 8hν → 2O2 + CH4. It is notable that water oxidation to dioxygen is a key half-reaction in both. In principle, these solar fuel reactions can be coupled to light absorption in molecular assemblies, nanostructured arrays, or photoelectrochemical cells (PECs) by a modular approach. The modular approach uses light absorption, electron transfer in excited states, directed long range electron transfer and proton transfer, both driven by free energy gradients, combined with proton…