|May 04, 2007|
Cell splits water to produce hydrogen from sunlight
|Engineers at Washington University in St. Louis have developed a unique photocatlytic cell that splits water to produce hydrogen and oxygen in water using sunlight and the power of a nanostructured catalyst. |
Pratim Biswas has developed a unique photocatlytic cell that splits water to produce hydrogen and oxygen using sunlight and the power of a nanostructured catalyst. The discovery provides a new, low cost and efficient option for hydrogen production and can be used for a variety of distributed energy applications. The technique will be demonstrated at a poster session May 6, 2007 at the International Symposium on Energy and Environment, held at Washington University in St. Louis.
The engineering group is developing novel methodologies for synthesis of nanostructured films with superior opto-electronic properties. One of the methods, which sandwiches three semiconductor films into a compact structure on the nanoscale range, is smaller, more efficient and more stable than present photocatalytic methods which require multiple steps and can take from several hours to a day to complete.
The discovery provides a new low cost and efficient option for hydrogen production and can be used for a variety of distributed energy applications.
Pratim Biswas, Ph.D., the Stifel and Quinette Jens Professor and Chair of the Department of Energy, Environmental and Chemical Engineering, and his graduate student Elijah Thimsen, recently have developed the well-controlled, gas phase process , and have demonstrated it for synthesizing a variety of oxide semiconductors such as iron and titanium dioxide films in a single step process . It is based on a simple, inexpensive flame aerosol reactor (FLAR) and consists of four mass flow controllers to regulate process gases, a standard bubbler to deliver a precursor, a metal tube that acts as a burner and a water-cooled substrate holder.
"We put these films in water and they promote some reactions that split water into hydrogen and oxygen," said Biswas. "We can use any oxide materials such as titanium dioxide, tungsten oxide and iron oxide in nanostructures sandwiched together that make very compact structures. The process is direct and takes only a few minutes to fabricate. More important, these processes can be scaled up to produce larger structures in a very cost effective manner in atmospheric pressure processes."
For the first time in the United States, the presidents of 13 premier universities from Asia and the Middle East will gather for the International Symposium on Energy and Environment at Washington University in St. Louis May 4-7 to discuss ways their institutions are addressing global energy and environmental concerns. These institutions include Peking, Fudan, Indian Institute of Technology-Bombay, National Taiwan, Tsinghua and Yonsei universities.
The symposium is sponsored by Washington University's McDonnell International Scholars Academy. For more information on the academy, please visit http://mcdonnell.wustl.edu/.
"We are privileged to host the first meeting of the partner universities of the McDonnell International Scholars Academy here in St. Louis," said Chancellor Mark S. Wrighton. "The 20 university partners in the Academy engage more than 200,000 of the world's most talented students, and it will be rewarding to have so many outstanding academic leaders addressing the global challenges associated with energy and environment. The symposium is intended to identify opportunities to develop collaborative education and research programs involving Washington University and its international partners."
Key speakers will include the former United States Ambassador to the United Nations, the president of the National Academy of Sciences and Monsanto Company's top executive.
Organizers hope the meeting will result in new collaborative research and education projects facilitated by the McDonnell Academy. A preliminary program and details of the program are available at http://www.eer.wustl.edu.