Federico Pistono

Donuts and tea are the main ingredients in a MacGyver-style do-it-yourself solar cell, epxplained step-by-step in this video.

"It turns out these delicious little things contain everything we need to make a simple solar cell," said Blake Farrow, a Canadian scientist who filmed the video while visiting Prashant Kamat's lab at the University of Notre Dame.

Powdered sugar contains titanium dioxide nanoparticles, a substance that is also used in paint. When that powder is coated with an organic dye, like the colorful chemicals in pasionfruit tea, it can be used as the light-absorbing layer of a photovoltaic device.

"In dye-sensitized solar cells, colored materials like tea absorb some visible light and transfer the energy to good electron transporting materials, like white TiO₂, that cannot absorb on their own," said Farrow.

Once those electrons have been excited, they need somewhere to go. So Farrow sandwiched the TiO₂ between a clear electrode, and a graphite electrode that he fashioned by rubbing a pencil onto some glass. As a finishing touch, he added some electrolyte solution, improvised from everclear and iodine water purification tablets.

Dye-sensitized solar cells are cheaper and more durable than traditional photovoltaics, but they are less efficient. And by extracting the titanium dioxide from donuts, Farrow gives them a whole new layer of inefficiency.

Video: Blake Farrow / YouTube
Photo: House of Sims / flickr
Story via: Wired and Mitch at Chemistry Blog