Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Harnessing the energy of the Sun: New technique improves artificial photosynthesis

This discovery will make it possible to improve photoelectrochemical cells.

In the same way that plants use photosynthesis to transform sunlight into energy, these cells use sunlight to drive chemical reactions that ultimately produce hydrogen from water. The process involves using a light-sensitive semi-conducting material such as cuprous oxide to provide the current needed to fuel the reaction. Although it is not expensive, the oxide is unstable if exposed to light in water. Research by

Adriana Paracchino and Elijah Thimsen, published May 8, 2011 in the journal Nature Materials, demonstrates that this problem can be overcome by covering the semiconductor with a thin film of atoms using the atomic layer deposition (ALD) technique.

Under the supervision of Professor Michael Grätzel in EPFL's Laboratory of Photonics and Interfaces, the two scientists achieved this remarkable feat by combining techniques used at the industrial scale, and then applying them to the problem of producing hydrogen. With their process, cuprous oxide can be simply and effectively protected from contact with water, making it possible to use it as a semiconductor. The advantages are numerous: cuprous oxide is abundantly available and inexpensive; the protective layer is completely impermeable, regardless of the roughness of the surface; and the process can easily be scaled up for industrial fabrication.

A promising technique

The research team developed the technique by "growing" layers of zinc oxide and titanium oxide, one atom-thick layer at a time, on the cuprous oxide surface. By using the ALD technique, they were able to control the thickness of the protective layer down to the precision of a single atom over the entire surface. This level of precision guarantees the stability of the semiconductor while preserving all of its hydrogen-producing efficiency. The next step in the research will be to improve the electrical properties of the protective layer.

Using widely available materials and techniques that can be easily scaled up brings the "green" photoelectrochemical production of hydrogen closer to the industrial interest.

Source : Highly active oxide photocathode for photoelectrochemical water reduction, Adriana Paracchino, Vincent Laporte, Kevin Sivula, Michael Grätzel and Elijah Thimsen, Nature Materials, 8 mai 2011. DOI: 10.1038/NMAT3017


Adriana Paracchino,, +41 21 693 36 93
Nicolas Guerin,, +41 21 693 21 05 or +41 78 646 28 65

Adriana Paracchino | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>