Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Splitting Water with Sunlight

26.09.2007
Semiconductor acts as photocatalyst, storage, and separator for hydrogen and oxygen from water

Hydrogen is one of the most important fuels of the future, and the sun will be one of our most important sources of energy. Why not combine the two to produce hydrogen directly from solar energy without any detours involving electrical current? Why not use a process similar to the photosynthesis used by plants to convert sunlight directly into chemical energy?

Researchers from the German Max Planck Institute have now developed a catalyst that may do just that. As they report in the journal Angewandte Chemie, titanium disilicide splits water into hydrogen and oxygen. And the semiconductor doesn’t just act as a photocatalyst, it also stores the gases produced, which allows an elegant separation of hydrogen and oxygen.

“The generation of hydrogen and oxygen from water by means of semiconductors is an important contribution to the use of solar energy,” explains Martin Demuth (of the Max Planck Institute for Bioinorganic Chemistry in Mülheim an der Ruhr). “Semiconductors suitable for use as photocatalysts have been difficult to obtain, have unfavorable light-absorption characteristics, or decompose during the reaction.” Demuth and his team have now proposed a class of semiconductors that have not been used for this purpose before: Silicides. For a semiconductor, titanium disilicide (TiSi2) has very unusual optoelectronic properties that are ideal for use in solar technology. In addition, this material absorbs light over a wide range of the solar spectrum, is easily obtained, and is inexpensive.

At the start of the reaction, a slight formation of oxide on the titanium disilicide results in the formation of the requisite catalytically active centers. “Our catalyst splits water with a higher efficiency than most of the other semiconductor systems that also operate using visible light,” says Demuth.

One aspect of this system that is particularly interesting is the simultaneous reversible storage of hydrogen. The storage capacity of titanium disilicide is smaller than the usual storage materials, but it is technically simpler. Most importantly, significantly lower temperatures are sufficient to release the stored hydrogen.

The oxygen is stored as well, but is released under different conditions than the hydrogen. It requires temperatures over 100 °C and darkness. “This gives us an elegant method for the easy and clean separation of the gases,” explains Demuth. He and his German, American, and Norwegian partners have founded a company in Lörrach, Germany, for the further development and marketing of the proprietary processes.

Author: Martin Demuth, Max-Planck-Institut für Bioanorganische Chemie, Mülheim an der Ruhr (Germany), http://ewww.mpi-muelheim.mpg.de/bac/index_en.php

Title: A Titanium Disilicide Derived Semiconducting Catalyst for Water Splitting under Solar Radiation—Reversible Storage of Oxygen and Hydrogen

Angewandte Chemie International Edition 2007, 46, No. 41, 7770–7774, doi: 10.1002/anie.200701626

Martin Demuth | Angewandte Chemie
Further information:
http://ewww.mpi-muelheim.mpg.de/bac/index_en.php
http://pressroom.angewandte.org

Further reports about: Max Planck Institute Semiconductor Storage disilicide

More articles from Life Sciences:

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>