Cheap way to 'split water' could lead to abundant clean fuel

Scientists have found an inexpensive way to produce hydrogen from water, a discovery that could lead to a plentiful source of environmentally friendly fuel to power homes and cars.

The technique, which mimics the way photosynthesis works in plants, also provides a highly efficient way to store energy, potentially paving the way to making solar power more economically viable.

Hydrogen is a clean, energy-rich fuel that many experts believe could become important as nations attempt to reduce their greenhouse gas emissions. The gas can be produced by splitting water but current techniques are expensive, use harsh chemicals and need carefully controlled environments in which to operate.

Daniel Nocera, a chemist at the Massachusetts Institute of Technology, has developed a catalyst made from cobalt and phosphorus that can split water at room temperature, a technique he describes in the journal Science. "I'm using cheap, Earth-abundant materials that you can mass-manufacture. As long as you can charge the surface, you can create the catalyst and it doesn't get any cheaper than that."

He said the discovery could have major implications for the uptake of solar photovoltaic technology. One of the reasons, he said, why solar panels have not penetrated the consumer market properly is that no one has found a way to store energy in a way that, when the Sun is not shining, people still have electricity. "You can't think about an energy economy or a global energy system only when the sun is out."

Batteries could do the job but they cannot store anywhere near as much energy per unit mass as chemical fuels. ...