Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MIT researchers harness viruses to split water

12.04.2010
Crucial step toward turning water into hydrogen fuel

A team of MIT researchers has found a novel way to mimic the process by which plants use the power of sunlight to split water and make chemical fuel to power their growth. In this case, the team used a modified virus as a kind of biological scaffold that can assemble the nanoscale components needed to split a water molecule into hydrogen and oxygen atoms.

Splitting water is one way to solve the basic problem of solar energy: It's only available when the sun shines. By using sunlight to make hydrogen from water, the hydrogen can then be stored and used at any time to generate electricity using a fuel cell, or to make liquid fuels (or be used directly) for cars and trucks.

Other researchers have made systems that use electricity, which can be provided by solar panels, to split water molecules, but the new biologically based system skips the intermediate steps and uses sunlight to power the reaction directly. The advance is described in a paper published on April 11 in Nature Nanotechnology.

The team, led by Angela Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering, engineered a common, harmless bacterial virus called M13 so that it would attract and bind with molecules of a catalyst (the team used iridium oxide) and a biological pigment (zinc porphyrins). The viruses became wire-like devices that could very efficiently split the oxygen from water molecules.

Over time, however, the virus-wires would clump together and lose their effectiveness, so the researchers added an extra step: encapsulating them in a microgel matrix, so they maintained their uniform arrangement and kept their stability and efficiency.

While hydrogen obtained from water is the gas that would be used as a fuel, the splitting of oxygen from water is the more technically challenging "half-reaction" in the process, Belcher explains, so her team focused on this part. Plants and cyanobacteria (also called blue-green algae), she says, "have evolved highly organized photosynthetic systems for the efficient oxidation of water." Other researchers have tried to use the photosynthetic parts of plants directly for harnessing sunlight, but these materials can have structural stability issues.

Belcher decided that instead of borrowing plants' components, she would borrow their methods. In plant cells, natural pigments are used to absorb sunlight, while catalysts then promote the water-splitting reaction. That's the process Belcher and her team, including doctoral student Yoon Sung Nam, the lead author of the new paper, decided to imitate.

In the team's system, the viruses simply act as a kind of scaffolding, causing the pigments and catalysts to line up with the right kind of spacing to trigger the water-splitting reaction. The role of the pigments is "to act as an antenna to capture the light," Belcher explains, "and then transfer the energy down the length of the virus, like a wire. The virus is a very efficient harvester of light, with these porphyrins attached.

"We use components people have used before," she adds, "but we use biology to organize them for us, so you get better efficiency."

Using the virus to make the system assemble itself improves the efficiency of the oxygen production fourfold, Nam says. The researchers hope to find a similar biologically based system to perform the other half of the process, the production of hydrogen. Currently, the hydrogen atoms from the water get split into their component protons and electrons; a second part of the system, now being developed, would combine these back into hydrogen atoms and molecules. The team is also working to find a more commonplace, less-expensive material for the catalyst, to replace the relatively rare and costly iridium used in this proof-of-concept study.

Thomas Mallouk, the DuPont Professor of Materials Chemistry and Physics at Pennsylvania State University, who was not involved in this work, says, "This is an extremely clever piece of work that addresses one of the most difficult problems in artificial photosynthesis, namely, the nanoscale organization of the components in order to control electron transfer rates."

He adds: "There is a daunting combination of problems to be solved before this or any other artificial photosynthetic system could actually be useful for energy conversion." To be cost-competitive with other approaches to solar power, he says, the system would need to be at least 10 times more efficient than natural photosynthesis, be able to repeat the reaction a billion times, and use less expensive materials. "This is unlikely to happen in the near future," he says. "Nevertheless, the design idea illustrated in this paper could ultimately help with an important piece of the puzzle."

Belcher will not even speculate about how long it might take to develop this into a commercial product, but she says that within two years she expects to have a prototype device that can carry out the whole process of splitting water into oxygen and hydrogen, using a self-sustaining and durable system.

Source: "Biologically templated photocatalytic nanostructures for sustained light-driven water oxidation" Yoon Sung Nam, Andrew P. Magyar, Daeyeon Lee, Jin-Woong Kim, Dong Soo Yun, Heechul Park, Thomas S. Pollom Jr, David A. Weitz and Angela M. Belcher. Nature Nanotechnology, April 11, 2010

Funding: The Italian energy company Eni, through the MIT Energy Initiative (MITEI)

Jen Hirsch | EurekAlert!
Further information:
http://www.mit.edu

More articles from Life Sciences:

nachricht Quasi-sexual gene transfer drives genetic diversity of hot spring bacteria
29.05.2015 | Carnegie Institution

nachricht Scientists use unmanned aerial vehicle to study gray whales from above
29.05.2015 | NOAA National Marine Fisheries Service

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Lasers are the key to mastering challenges in lightweight construction

Many joining and cutting processes are possible only with lasers. New technologies make it possible to manufacture metal components with hollow structures that are significantly lighter and yet just as stable as solid components. In addition, lasers can be used to combine various lightweight construction materials and steels with each other. The Fraunhofer Institute for Laser Technology ILT in Aachen is presenting a range of such solutions at the LASER World of Photonics trade fair from June 22 to 25, 2015 in Munich, Germany, (Hall A3, Stand 121).

Lightweight construction materials are popular: aluminum is used in the bodywork of cars, for example, and aircraft fuselages already consist in large part of...

Im Focus: Solid-state photonics goes extreme ultraviolet

Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.

In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to...

Im Focus: Advance in regenerative medicine

The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.

Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Quasi-sexual gene transfer drives genetic diversity of hot spring bacteria

29.05.2015 | Life Sciences

First Eastern Pacific tropical depression runs ahead of dawn

29.05.2015 | Earth Sciences

Donuts, math, and superdense teleportation of quantum information

29.05.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>