University of California, San Diego electrical engineers are building a forest of tiny nanowire trees in order to cleanly capture solar energy and harvest it for hydrogen fuel generation. Reporting in the journal Nanoscale, the team said nanowires, which are made from abundant natural materials like silicon and zinc oxide, also offer a cheap way to deliver hydrogen fuel on a mass scale.
The trees’ vertical structure and branches are keys to capturing the maximum amount of solar energy, according to Deli Wang, professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering. In images of Earth from space, light reflects off of flat surfaces such as the ocean or deserts, while forests appear darker. That’s because the vertical structure of trees grabs and adsorbs light while flat surfaces simply reflect it, Wang said, adding that it is also similar to retinal photoreceptor cells in the human eye.
Photo: Rapid hydrogen generation on the surface of nanotree electrodes that are submersed in water and illuminated by simulated sun light.
