January 23, 2013 | 4 Comments
In a series of experiments, the scientists created spherical silicon particles about 10 nanometers in diameter. When combined with water, these particles reacted to form silicic acid (a nontoxic byproduct) and hydrogen – a potential source of energy for fuel cells.
According to the study findings that appeared online in Nano Letters on Jan. 14 2013, the scientists were able to verify that the hydrogen they made was relatively pure by testing it successfully in a small fuel cell that powered a fan. Its a paper sure to get lots of attention.
If the discovery can scale with any semblance of economic sense the technological disruption is likely on its way.
The discovery is a first major success in an ongoing worldwide effort. Mark T. Swihart, UB professor of chemical and biological engineering and director of the university’s Strategic Strength in Integrated Nanostructured Systems explains, “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.”
Pointing out the obvious goes to Paras Prasad, executive director of UB’s Institute for Lasers, Photonics and Biophotonics (ILPB) and a SUNY Distinguished Professor in UB’s Departments of Chemistry, Physics, Electrical Engineering and Medicine who said, “With further development, this technology could form the basis of a ‘just add water’ approach to generating hydrogen on demand. The most practical application would be for portable energy sources.”
This work is an internationally connected effort as well. Swihart and Prasad led the study, which was completed by UB scientists, some of whom have affiliations with Nanjing University in China and Korea University in South Korea. Folarin Erogbogbo, a research assistant professor in UB’s ILPB and a UB PhD graduate, was first author.
The press release notes the speed at which the 10-nanometer silicon particles reacted with water surprised the researchers. In under a minute, these particles yielded more hydrogen than the 100-nanometer particles yielded in about 45 minutes. The maximum reaction rate for the 10-nanometer particles was about 150 times as fast.
Swihart said the discrepancy is due to geometry. As they react, the larger particles form nonspherical structures whose surfaces react with water less readily and less uniformly than the surfaces of the smaller, spherical particles, he said.
The reality today is it takes significant energy and resources to produce the super-small silicon balls. The carefully made silicon balls could help power portable devices in situations where water is available and portability is more important than low cost. Military operations, remote locations, and many other possibilities exist for early adopter markets.
The fundamentals are quite enticing. Erogbogbo said, “It was previously unknown that we could generate hydrogen this rapidly from silicon, one of Earth’s most abundant elements. Safe storage of hydrogen has been a difficult problem even though hydrogen is an excellent candidate for alternative energy, and one of the practical applications of our work would be supplying hydrogen for fuel cell power. It could be military vehicles or other portable applications that are near water.”
Swihart takes up envisioning future applications as well, saying, “Perhaps instead of taking a gasoline or diesel generator and fuel tanks or large battery packs with me to the campsite (civilian or military) where water is available, I take a hydrogen fuel cell (much smaller and lighter than the generator) and some plastic cartridges of silicon nanopowder mixed with an activator. Then I can power my satellite radio and telephone, GPS, laptop, lighting, etc. If I time things right, I might even be able to use excess heat generated from the reaction to warm up some water and make tea.”
The implications about the potential are stunning. Yet this is the very first step in the discovery. What is to come on sizing the silicon balls a bit larger or smaller, additional shaping alternatives, temperature, pressure and other environment variables and many other circumstances and specifications are yet to be explored. Where this discovery could get to remains speculative.
A no energy input to harvesting free hydrogen is about as strong a motivator as can be imagined. If the silicon ball production at mass scale is cheap enough, the disposal or recycling of the silicic acid can be marketable or a source of recoverable renewed silicon balls, and the fuel cell research makes headway – the discovery will be a disruptive technology of the highest order.
This is one to watch very carefully.