|Experimental paint generates electricity.|
A research team at University of Notre Dame is developing an inexpensive "solar paint" that uses semiconducting nanoparticles to produce energy. They have incorporated power-producing nanoparticles, called quantum dots, into a spreadable compound, to make a one-coat solar paint that can be applied to any conductive surface without special equipment.
"The best light-to-energy conversion efficiency we've reached so far is 1 percent, which is well behind the usual 10 to 15 percent efficiency of commercial silicon solar cells," explains one of the scientists. "But this paint can be made cheaply and in large quantities. If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future. That's why we've christened the new paint, Sun-Believable."
Their work uses nano-sized particles of titanium dioxide coated with either cadmium sulfide or cadmium selenide.Nano titanium dioxide is already used in "self-cleaning" concrete, where it acts as a semi-conductor to convert sunlight into electrical charges that convert pollutants into relatively benign compounds.
If the solar paint can be successfully developed, it will potentially impact many building finish and cladding materials. One of our clients, for example, has developed an electrically-conductive concrete that, when used with the new paint, could draw the electricity into a structure's grid or act as a storage battery.
I caution, however, that nano technology has unknown environmental risks when used in large quantities in the exterior environment. For example, the nano particles in self-cleaning concrete accelerate the deterioration of the concrete and leach potentially harmful compounds into the soil. More, the release of nano photo-catalytic titanium dioxide could be detrimental to ecosystems if released into the environment through erosion or improper disposal.
Sun-Believable Solar Paint. A Transformative One-Step Approach for Designing Nanocrystalline Solar Cells`zMatthew P. Genovese, Ian V. Lightcap, and Prashant V. Kamat*
Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
ACS Nano, Article ASAP
Publication Date (Web): December 6, 2011
Copyright © 2011 American Chemical Society