Water refineries?(rk film began to form on the electrode f...)

After analyzing the electrode, the researchers concluded that a cobalt-phosphate mixture, possibly combined with phosphate, had deposited as a film.

Nocera and Kanan believe the film is the catalyst that helps break apart the water molecules to create oxygen gas. The protons (hydrogen nuclei) released from the process pick up electrons and convert back into hydrogen at a partner electrode.

Nocera and Kanan also found evidence that the catalyst seems to refresh itself, a mechanism that would make maintenance of such oxygen-extracting systems far simpler than alternatives, although that finding needs confirmation from additional experiments.

"The simplicity of this process is amazing," said Luis Echegoyen, director of NSF's Chemistry Division. "Using common and affordable elements, and a glass of water, these chemists may have given us a future way to efficiently obtain oxygen by splitting water."

Despite the straightforward experimental setup, the exact mechanism driving the reactions is still unknown. For direct conversion of solar energy into hydrogen and oxygen, researchers will need to study the new research results and incorporate the mechanisms into a larger system that also cleanly produces hydrogen.

Nocera is a member of NSF's Powering the Planet, a partnership that NSF forged between MIT, Caltech and several other institutions as an NSF Chemical Bonding Center in 2005. In his role as a co-investigator with the center, Nocera has been pursuing sustainable energy technology through a broader effort to learn from, and apply, the lessons of photosynthesis and other natural processes.

"When we support fundamental research we never know where that investment will lead. In this instance, it may lead to new opportunities for sustainable energy," said Tony Chan, assistant
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