I’ve talked before about researchers at the University of Rochester in New York using artificial photosynthesis to create hydrogen. Now, researchers in China at the Shanghai Jiao Tong University are taking a slightly different tactic to produce hydrogen by developing artificial leaves.
For several years now other scientists have been using sunlight through solar panels to generate electricity, split water via electrolysis and create hydrogen. But, the Shanghai Jiao Tong University researchers have decided to go nano scale and try to mimic the structure of a plant leaf, which in nature is very adept at using sunlight to split water into hydrogen.
According to New Scientist, “Then they dried the leaves and heated them to 500 °C to burn away most of the remaining plant material. This left a crystallised titanium dioxide framework plus many of the leaves’ natural structures. Titanium dioxide is commonly used in solar cells to enhance their efficiency, and in the leaf it catalyses the splitting of water molecules.
“The leaf retained features such as the lens-like cells at its surface, which catch light coming from any angle, and veins that help guide light deeper into the leaf. The replicas also captured very fine detail, including structures called thykaloids, which increase the surface area available for photosynthesis and are just 10 nanometres thick.”
The scientists found that leaves are twice as efficient as titanium dioxide that one can buy commercially at splitting water into hydrogen and oxygen. By mimicking this structure in leaves and materials, the researchers believe they can also create a very efficient method of producing hydrogen.