Scientists have raided the photosynthetic structures of leaves to figure out the most efficient way to use solar energy to turn water into hydrogen fuel. The Artificial Inorganic Leaf, or AIL, potentially represents a major step towards a hydrogen-powered world.

A team of Chinese researchers from the State Key Lab of Matrix Composites at Shanghai Jiaotong University unveiled AIL today at the annual meeting of the American Chemical Society in San Francisco. They explained that their goal was to replicate natural light-harvesting techniques that plants have developed for photosynthesis. In turn, that solar energy can be used as a sustainable, relatively inexpensive way to convert water into hydrogen, creating a clean energy source whose only byproduct is water vapor. The researchers, led by Tongxiang Fan, argued that this represents the most promising alternative to the current carbon-based economy.

So how did the scientists do it? Take a deep breath, because this is more than a bit involved:


The scientists first infiltrated the leaves of Anemone vitifolia - a plant native to China - with titanium dioxide in a two-step process. Using advanced spectroscopic techniques, the scientists were then able to confirm that the structural features in the leaf favorable for light harvesting were replicated in the new TiO2 structure. Excitingly, the AIL are eight times more active for hydrogen production than TiO2 that has not been "biotemplated" in that fashion. AILs also are more than three times as active as commercial photo-catalysts. Next, the scientists embedded nanoparticles of platinum into the leaf surface. Platinum, along with the nitrogen found naturally in the leaf, helps increase the activity of the artificial leaves by an additional factor of ten.

Initial results indicate AIL is far more efficient in its light-harvesting than any previously developed system. Fan and his colleagues will continue to study the structures of leaves in hopes of finding ways not only to replicate nature's techniques but also to improve upon them.

[American Chemical Society]