Nanoscale “Trees” Form Artificial Water-Splitting “Forest”
What’s the Latest Development?
Scientists at the US Department of Energy’s Lawrence Berkeley National Laboratory used forests as their inspiration for a densely-packed collection of nanoscale “trees” that can convert solar energy into oxygen and hydrogen for use in fuel cells. When they absorb sunlight, the trees’ silicon trunks produce the hydrogen, and their titanium oxide branches create the oxygen. Together they do a good job of mimicking the process of photosynthesis in a way that’s more efficient and affordable than similar artificial systems, says lead scientist Peidong Yang.
What’s the Big Idea?
Many different efforts are underway to find the best ways of capturing solar energy, which could potentially provide the entire world with clean power. Artificial photosynthesis is one of the more promising technologies, but one challenge involves creating a system that will produce enough cheap hydrogen to rival fossil fuels. Both silicon and titanium oxide are abundant and effective semiconductors that, when formed into the tree structure, simulate the electron flow normally associated with natural photosynthesis. Currently the system’s conversion efficiency is less than one percent; Yang says that his team will experiment with other branch materials in hopes of improving that number.
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