'Artificial leaf' eyed as holy grail in energy research

VANCOUVER: Turbo-charging photosynthesis - by which plants and bacteria turn sunlight into food and energy - in an "artificial leaf" could yield a vast commercial power source, scientists said.

Photosynthesis "unfortunately not very efficient," Anne Jones, assistant professor and biochemist at Arizona State University, told the American Association for the Advancement of Science meeting in Vancouver this weekend.

"In fact, all of our current fossil fuels are products of this process," she said. But photosynthesis efficiency "could be boosted to increase food yields or sustainable biofuel production."

The world's energy consumption is expected to surge by 100 percent in the next 40 years.

That is expected even as oil and gas reserves are being used up, according to researchers, who are weighing a range of approaches to harness the power of photosynthesis to power engines.

Scientists said that given the low efficiency of photosynthesis, the top theoretical yield for squeezing energy out of the process with major crops such as wheat or sugar beets would be about five percent.

But if efficiency could be forced up by even a few percentage points, they could be sitting on major biofuel production potential. (AFP)

'Artificial leaf' turns sunlight into fuel: US study

WASHINGTON: US scientists have developed an "artificial leaf" that converts sunlight into a chemical fuel that could be stored and used later, according to a study published Friday.

When placed in a container of water, the silicon solar cell -- with catalytic materials on each side -- generates oxygen bubbles on one side and hydrogen bubbles on the other, which can be separated and collected.

The gases could then be fed into a fuel cell that recombines them into water while producing an electric current, according to lead researcher Daniel Nocera, of the Massachusetts Institute of Technology (MIT).

The device is the subject of a paper in the journal Science co-authored by six researchers from Sun Catalytix, a solar-energy firm founded by Nocera.Nocera says the "leaf" is made entirely of abundant, inexpensive materials.The sheet of semiconducting silicon is coated on one side with a cobalt-based catalyst, which releases the oxygen, and on the other with a nickel-molybdenum-zinc alloy, which separates the hydrogen.

"I think there's going to be real opportunities for this idea" Nocera said in a statement accompanying the article."You can't get more portable, you don't need wires, it's lightweight, and it doesn't require much in the way of additional equipment, other than a way of catching and storing the gases that bubble off."

The device will not be ready for commercial production, however, until systems are developed that can collect, store and use the gases, he said."It's a step," Nocera said. "It's heading in the right direction." (AFP)