One day in the summer of 1980, Heinz Frei was working on his postdoctoral project at UC Berkeley, when his mentor walked up to his desk in Hildebrand Hall.

George Pimentel, the late scientist whose name now adorns the chemistry lab, had just returned from a Department of Energy solar research conference. He said he was surprised that one presentation after another had focused on ultraviolet light, which represents just a tiny fraction of the energy in sunlight.

Infrared, which makes up far more of the energy reaching the Earth, had hardly earned a mention. The real potential to exploit sunlight lay in this "long" end of the light wavelength spectrum, Pimentel told Frei, yet no one seemed to be exploring the possibility.

Would he like to set up a research group at Lawrence Berkeley National Laboratory to try?

Frei had been considering moving back to his native Switzerland. Instead, he said yes on the spot.

Without knowing it at the time, the decision would represent his first step on a long path to the development of artificial leaves, a potentially game-changing technology that can wring liquid fuels from sunlight, water and carbon dioxide.

For most of his childhood, Frei had expected to take over his parent's office supply business. But during a high school science class in his hometown of Lucerne, near Zurich, he found himself captivated by molecules.

"The fun of gaining knowledge and understanding phenomena around us, that really fired me up," he said.

Frei decided to go into chemistry rather than retail, eventually earning a doctorate at the Swiss Federal Institute of Technology. He went on to win a fellowship that allowed him to pursue the postdoc work at Berkeley.

He was specifically drawn by the chemistry department's sophisticated lasers and spectrometers, which allowed him to conduct highly controlled experiments using infrared light to induce chemical reactions.

Following his conversation with Pimentel, he began research at the Calvin Lab at Lawrence Berkeley that would help lay critical foundations for artificial photosynthesis. Notably, it allowed scientists to take advantage of a wider slice of the light spectrum to trigger chemical reactions.

The words "global warming" were rarely uttered in the early 1980s. But even then, Frei suspected that filling the atmosphere with carbon dioxide was creating a growing problem for society that his research could help to address.

"I felt that we needed to ultimately make everyday chemicals and fuels from sunlight," he said. "I believed that in the long run, at some point, renewable energy would become a real issue. It took a while."
