In photosynthesis, nature relies on intensely colored pigments to absorb select wavelengths of light. Scientists at Washington University in St. Louis (WUSTL) along with several collaborating institutions point out that chlorophyll—the pigment responsible for the green color and solar absorption capacity of plants—effectively misses the middle of the visible light spectrum. This non-violet, or red, light as well as infrared light beyond the visible spectrum contain energy that is not currently utilized.
“Since plant pigments actually reject a lot of the light that falls on them, potentially there’s a lot of light you could gather that plants don’t bother with,” said University of Sheffield collaborator Neil Hunter in a WUSTL press release.
The researchers developed a self-assembling ring of proteins, which comprised both natural and synthetic materials, to absorb more of the light spectrum than chlorophyll does. In an article published in Chemical Science, the researchers describe their protein scaffolding, which carries two pigments—one natural and one artificial. “The prototypes in the Chemical Science paper both have two, but ultimately we’d like to add three, or four, or even more,” said Jonathan Lindsey, a researcher at North Carolina State University. “One of our goals is to understand to what extent the protein can be derivatized with pigments.”
Eventually, the team hopes to convert its “sun sponges” into solar antennas that are superior in their absorption capabilities to current photovoltaic technologies.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.