Michigan Technological University, scientists have replaced expensive ($1,500 an ounce) platinum in solar cells with low-cost 3D graphene.

Regular graphene is a two-dimensional form of carbon. Yun Hang Hu, the Charles and Caroll McArthur Professor of Materials Science and Engineering at MTU, and his team invented a way to synthesize a 3D version, with a honeycomb-like structure.

The 3D graphene had excellent conductivity and high catalytic activity, raising the possibility that it could be used for energy storage and conversion.

In tests, a counter electrode made from 3D graphene converted 7.8 percent of the sun’s energy into electricity, nearly as much as a conventional solar cell using costly platinum (8 percent).

Synthesizing the 3D honeycomb graphene is neither expensive nor difficult, said Hu, and making it into an electrode posed no special challenges.

The research has been funded by the American Chemical Society Petroleum Research Fund and the National Science Foundation