Chemists at the University at Buffalo have synthesized a new class of photo sensitizing dyes that greatly increase the efficiency of light-driven systems that produce two kinds of green energy: Solar electricity and clean-burning hydrogen fuel.
On a commercial scale, these advancements could form the basis of cost-effective technologies to 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 knocks loose electrons in the dyes that travel through the solar cell, forming the current.
The mechanism for producing hydrogen begins the same way: Sunlight strikes the dyes, freeing electrons. But instead of forming a current, the electrons flow into a catalyst, where they drive a chemical reaction that splits water into its basic elements: hydrogen and oxygen.