Dyes Improve Solar Technologies

A new class of photosensitizing dyes that increase the efficiency of light-driven systems has been synthesized by chemists at the University at Buffalo.

With the ability to produce two kinds of green energy—solar electricity and clean-burning hydrogen fuel—the new dyes could power everything from household appliances to hydrogen vehicles.

To produce electricity, the dyes—called chalcogenorhodamine dyes—operate as part of a Grätzel-type solar cell that converts sunlight into an electric current. When sunlight strikes the dyes, the energy knock loose electrons in the dyes that travel through the solar cell, forming the current.

Producing hydrogen begins in the same way, with sunlight striking the dye to free electrons. Instead of forming a current, the electrons flow into a catalyst, where they drive a chemical reaction that splits water into hydrogen and oxygen.

The research team from UB and the University of Rochester were able to show that chalcogenorhodamine systems produce hydrogen at unprecedented rates in laboratory tests. This is because the dyes absorb light more intensely and transfer their electrons more efficiently than conventional dyes. Their findings were published in the Journal of American Chemical Society in October 2010.

The research is anticipated to lead to the development of better commercial technologies for producing solar electricity and hydrogen on demand.

“Sunlight in one hour could power the world for a year, but we don’t tap into it for either electricity or for making solar fuels,” said Michael Detty, UB professor. “Plants use sunlight to make their own fuels. Humans don’t. We use oil. So if we want to have energy independence, it will come from solar.”

A Notice of Allowance from the US Patent and Trademark Office approving the issue of a patent to cover the dye’s composition was received by UB. The university’s Office of Science and Technology Transfer and Economic Outreach will handle licensing of the discoveries.

For more information, visit: www.buffalo.edu