From Philadelphia, at a meeting of the American Chemical Society
Instead of running fuel cells on hydrogen derived from fossil fuels, a future hydrogen economy might be driven by water and sunlight. Inspired by natural photosynthesis, chemists at Virginia Polytechnic Institute and State University in Blacksburg have devised complex molecular machines that use the sun's energy to split water and form hydrogen.
Led by Karen Brewer, the researchers made the tiny machines, called supramolecular complexes, out of three building blocks. Each block, made of a metal surrounded by organic compounds, performs its own task within the molecular machine. Two of the building blocks contain light-absorbing ruthenium atoms. When solar energy excites a single electron in each of these units, the electrons are shuttled toward the third building block. There, the metallic element rhodium collects the two electrons and delivers them to water molecules.
The collection of elec