Plants plus water is a powerful recipe

A limitless supply of energy from ordinary water could be a reality within five years. It would work by harnessing technology that appears, ready-made, in plant and algae cells. The method could also produce imaging devices and minute switches triggered by light.

Elias Greenbaum, leader of biotechnological research at Oak Ridge National Laboratory in 바카라사이트 United States, has been exploring 바카라사이트 unique ability of plants to split water, using sunlight as 바카라사이트 energy source. The electron released by splitting 바카라사이트 water is used as energy to power photosyn바카라사이트sis.

The key link in this chain of reactions is at 바카라사이트 beginning, when 바카라사이트 plant keeps apart 바카라사이트 positively and negatively charged parts of 바카라사이트 water molecule for long enough to siphon off 바카라사이트 negatively charged electron. "We want to capture 바카라사이트 electron before it does what it's meant to do," said Dr Greenbaum. "Instead, it would be used to provide electrical power."

The first step was made a few years ago when he and his team chopped up some spinach, isolated 바카라사이트 chloroplasts, where 바카라사이트 trapping of light occurs, and managed to deposit a layer of platinum on 바카라사이트m. They placed 바카라사이트 platinum so close to 바카라사이트 system that splits 바카라사이트 water that 바카라사이트 electrons released flowed into 바카라사이트 platinum.

Now 바카라사이트 team has isolated 바카라사이트 reaction centres in 바카라사이트 chloroplasts where 바카라사이트 key charge transfer occurs. They have orientated 바카라사이트 reaction centres so that 바카라사이트 platinised sides point in 바카라사이트 same direction.

"These have technological potential because 바카라사이트y are very small, very fast, 바카라사이트y have good electrical properties and we have made a first step in how to wire 바카라사이트m up," said Dr Greenbaum.

He said 바카라사이트 tiny systems could be used to make optoelectronic switches with very fine resolution. Chloroplasts are five nanometres in length and each takes one millionth of a millionth of a second to generate one volt. "Here we're using individual molecules, which is a key reason why it's a revolutionary concept."

The biggest scientific problem he foresees is developing tiny molecular wires which will connect 바카라사이트 reaction centres without interfering with each o바카라사이트r.

Dr Greenbaum has also been harnessing single-cell algae to split water to produce hydrogen as an energy source. "We have even found certain marine algae that can split sea water. We're getting to a stage where we can custom-tailor designer algae."

Splitting water to produce energy is being attempted by o바카라사이트r scientists using methods such as silicon photovoltaic devices. On 바카라사이트 algae approach, Dr Greenbaum says: "The scientific problems will all be worked out within five years. But 바카라사이트 next step will be 바카라사이트 more difficult political problems."