U.S. scientists have developed what they say is the first integrated nanosystem capable of replicating the process of photosynthesis, a sort of “artificial forest” that could one day lead to the production of hydrogen that could be used to power fuel cells. Composed of nanowire structures — including silicon “trunks” and titanium oxide “branches” — the system mimics the role played by chloroplasts in promoting photosynthesis in green plants. By assembling the “trees” in a dense array, resembling a miniature forest, the network lowers sunlight reflection and provides more surface area for hydrogen-producing reactions, the scientists say. “We’ve integrated our nanowire nanoscale heterostructure into a functional system that mimics the integration in chloroplasts and provides a conceptual blueprint for better solar-to-fuel conversion efficiencies in the future,” said Peidong Yang, a chemist with the Lawrence Berkeley National Laboratory and co-author of the study, published in the journal NANO Letters. The lab of Daniel Nocera at Harvard University is doing related research into so-called artificial leaves.