Hydrogen is an attractive fuel source because it can easily be converted into electric energy and gives off no greenhouse emissions. A group of chemists at the University of Rochester is adding to its appeal by increasing the output and lowering the cost of current light-driven hydrogen-production systems.
The work, funded by the U.S. Department of Energy, was led by chemistry professors Richard Eisenberg, Todd Krauss, and Patrick Holland, and included graduate students Zhiji Han and Fen Qiu. Their paper will be published later this month (Nov. 23) in the journal Science.
The chemists say their work advances what is sometimes considered the "holy grail" of energy scienceefficiently using sunlight to provide clean, carbon-free energy for vehicles and anything that requires electricity.
One disadvantage of current methods of hydrogen production has been the lack of durability, but the Rochester scientists were able to overcome that problem by incorporating nanocrystals. "Organic molecules are typically used to capture light in photocatalytic systems," said Krauss, who has been working in the field of nanocrystals for over 20 years. "The problem is they only last hours, or, if you're lucky, a day. These nanocrystals performed without any sign of deterioration for at least two weeks."
Richard Eisenberg, the Tracy H. Harris Professor of Chemistry, has spent two decades working on solar energy systems. During that time, his systems have typically generated 10,000 instancescalled turnoversof hydrogen atoms being formed without having to replace any components. With the nanocrystals, Eisenberg and his colleagues witnessed turnovers in excess of 600,000.
The researchers managed to overcome other disadvantages of traditional photocatalytic systems. "People have typically used catalysts made from platinum and other expensive metals," Holland said. "It would be much more sustainable if we used metals that were more ea
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University of Rochester