From Science Daily:
A detailed description of development of the first practical artificial leaf — a milestone in the drive for sustainable energy that mimics the process, photosynthesis, that green plants use to convert water and sunlight into energy — appears in the ACS journal Accounts of Chemical Research. The article notes that unlike earlier devices, which used costly ingredients, the new device is made from inexpensive materials and employs low-cost engineering and manufacturing processes.
Daniel G. Nocera points out that the artificial leaf responds to the vision of a famous Italian chemist who, in 1912, predicted that scientists one day would uncover the “guarded secret of plants.” The most important of those, Nocera says, is the process that splits water into hydrogen and oxygen. The artificial leaf has a sunlight collector sandwiched between two films that generate oxygen and hydrogen gas. When dropped into a jar of water in the sunlight, it bubbles away, releasing hydrogen that can be used in fuel cells to make electricity.
More here.