Arrays of tree-like nanowires consisting of Si trunks and TiO2 branches facilitate solar water-splitting in a fully integrated artificial photosynthesis system
Lawrence Berkeley National Laboratory (Berkeley Lab) scientists have developed the first fully integrated nanosystem for artificial photosynthesis, in which solar energy is directly converted into chemical fuels.
“Similar to the chloroplasts in green plants that carry out photosynthesis, our artificial photosynthetic system is composed of two semiconductor light absorbers, an interfacial layer for charge transport, and spatially separated co-catalysts,” says Peidong Yang, a chemist with Berkeley Lab’s Materials Sciences Division, who led this research.
“To facilitate solar water- splitting in our system, we synthesized tree-like nanowire heterostructures, consisting of silicon trunks and titanium oxide branches. Visually, arrays of these nanostructures very much resemble an artificial forest.
“In natural photosynthesis, the energy of absorbed sunlight produces energized charge-carriers that execute chemical reactions in separate regions of the chloroplast,” Yang says. “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.”