Super-tiny particles of silicon react with water to produce hydrogen -- a source of energy for fuel cells -- almost instantaneously, U.S. researchers say.

University at Buffalo scientists, writing in the journal Nano Letters, reported spherical silicon particles about 10 nanometers in diameter, when combined with water, reacted to form silicic acid (a non-toxic byproduct) and hydrogen, which could be used in fuel cells to produce energy.

The hydrogen-producing reaction didn't require any light, heat or electricity, and also created hydrogen about 150 times faster than similar reactions using silicon particles 100 nanometers wide and 1,000 times faster than bulk silicon, they said.

"When it comes to splitting water to produce hydrogen, nanosized silicon may be better than more obvious choices that people have studied for a while, such as aluminum," UB chemical and biological engineering Professor Mark T. Swihart said.

The researchers verified the hydrogen they made was relatively pure by testing it successfully in a small fuel cell that powered a fan, the university release issued Wednesday.

"With further development, this technology could form the basis of a 'just add water' approach to generating hydrogen on demand," researcher Paras Prasad said. "The most practical application would be for portable energy sources."

While it takes significant energy and resources to produce the super-small silicon balls, the researchers said, the particles could help power portable devices in situations where water is available and portability is more important than low cost, such as in military operations in the field.