Artificial leaves produce energy from polluted water

(new version) - A new feature has been added to the world's first real 'artificial leaf', making it more suitable for people living in developing countries and areas. Remote areas with power, cable scientists in New Orleans on April 8. It makes artificial leaves able to heal the damage that occurs during energy production.

Dr. Daniel G. Nocera described this success at the 245th National Conference and Exhibition of the American Chemical Society.

Nocera, the lead researcher, said 'artificial leaves' mimic the ability of real leaves to produce energy from sunlight and water. However, this device is not a reconstruction of the complex structure of real leaf photosynthesis, it is actually a catalytic silicon-coated film. Embedded in a water bottle and exposed to sunlight, the catalysts in this device will destroy water into its components hydrogen and oxygen. Air bubbles escaping from this device will be collected and used as a fuel to produce electricity in fuel cells.

'Amazingly, some of the catalysts we developed for use in these artificial leaf devices can actually heal themselves , ' Nocera said. 'They are a kind of' living catalyst '. This is a new finding that eases stress on one of the concerns about the initial use of artificial leaves in developing countries and other remote areas. "

Nocera, Professor Patterson Rockwood, on energy at Harvard University, explained that artificial leaves seem to be able to have their first application in providing 'personalized' electricity to private homes in areas. lack of traditional power stations and power transmission systems. Less than a liter of water will be enough to supply about 100 watts of electricity within 24 hours a day. The previous artificial leaf version needed pure water to work because then, the bacteria would form biofilms on the surface of the leaf that stopped production.

"Self-healing allows artificial leaves to run on contaminated and unclean water sources found in nature ," Nocera said. We found a way to adjust the conditions, so that part of the catalyst fell off, preventing the bacteria from reaching the smooth surface of the leaves to form on the biofilm. The catalyst can then be re-welded and re-established.

Nocera said there are currently about 3 billion people living in areas that do not have access to traditional electricity distribution and production systems. That amount will increase by billions more in the coming decades. About 1 billion people living in the developing world do not have access to clean water. Therefore, an existing need is an artificial leaf-like device that is compatible with local conditions.

'It's like providing' fast food 'form , Nocera said. 'We are interested in creating many cheap ones, which may not be the most effective, but can accomplish the job. This is like going from big computers to personal laptops. This is personal energy '.

Previous equipment used expensive, rare metals and other materials, including complex wiring and large production costs. In contrast, Nocera's artificial leaves use cheaper materials and incorporate a design - also called a 'buried joint' - that is simple and may not be expensive to mass produce. And artificial leaves have the advantage through solar panels. These sheets are usually expensive and only produce energy during the day. Hydrogen and oxygen of artificial leaves, on the other hand, can be kept and used at night.

"Many researchers are designing complex and expensive energy production devices, and it's hard to see them being applied on a large scale ," he said. 'Our device is simple, cheaper and it works. And with that, I think we are changing the story in this area. '

The team's top priority is to develop the device to integrate the technology of converting hydrogen into a liquid fuel that can be used to run traditional generators or even run cars. .

Nocera received the support of the National Science Foundation, the Ministry of Energy and the Air Force Office of Scientific Research.