Nanoscale coatings improve stability and efficiency of devices for renewable fuel generation

Nov 28, 2013 by Mick Kulikowski
Nanoscale coatings improve stability and efficiency of devices for renewable fuel generation
A graphic representation of how atomic layer deposition can aid renewable hydrogen fuel generation. Two papers published in Proceedings of the National Academy of Sciences show how atomic layer deposition can make water-splitting devices more stable and more efficient.

(Phys.org) —Splitting water into its components, two parts hydrogen and one part oxygen, is an important first step in achieving carbon-neutral fuels to power our transportation infrastructure – including automobiles and planes.

Now, North Carolina State University researchers and colleagues from the University of North Carolina at Chapel Hill have shown that a specialized coating technique can make certain water-splitting devices more stable and more efficient. Their results are published online this week in two separate papers in the Proceedings of the National Academy of Sciences.

Atomic layer deposition, or "ALD," coats three-dimensional structures with a precise, ultra-thin layer of material. "An ALD coating is sort of like the chocolate glaze on the outside of a Klondike bar – just much, much thinner," explains Dr. Mark Losego, research assistant professor of chemical and biomolecular engineering at NC State and a co-author on the work. "In this case, the layers are less than one nanometer thick – or almost a million times thinner than a human hair."

Although extremely thin, these coatings improve the attachment and performance of surface-bound molecular catalysts used for water-splitting reactions in hydrogen-fuel-producing devices.

In the first paper, "Solar water splitting in a molecular photoelectrochemical cell," the researchers used ALD coatings on nanostructured water-splitting cells to improve the efficiency of electrical current flow from the molecular catalyst to the device. The findings significantly improved the hydrogen generating capacity of these molecular-based solar water-splitting cells.

In the second paper, "Crossing the divide between homogeneous and heterogeneous catalysis in water oxidation," the researchers used ALD to "glue" molecular catalysts to the surface of water-splitting electrodes in order to make them more impervious to detachment in non-acidic water solutions. This improved stability at high pH enabled a new chemical pathway to water splitting that is one million times faster than the route that had been previously identified in acidic, or low pH, environments. These findings could have implications in stabilizing a number of other molecular catalysts for other renewable energy pathways, including the conversion of carbon dioxide to hydrocarbon fuels.

"In these reports, we've shown that nanoscale coatings applied by ALD can serve multiple purposes in water-splitting technology, including increasing hydrogen production efficiency and extending device lifetimes," Losego said. "In the future, we would like to build devices that integrate both of these advantages and move us toward other fuels of interest, including methanol production."

Explore further: Researchers create a low-cost, long-lasting water splitter made of silicon and nickel

Related Stories

Improving performance of a solar fuel catalyst

Oct 04, 2012

(Phys.org)—Hydrogen gas that is created using solar energy to split water into hydrogen and oxygen has the potential to be a cost-effective fuel source if the efficiency of the catalysts used in the water-splitting ...

Recommended for you

Nanoparticle technology triples the production of biogas

8 hours ago

Researchers of the Catalan Institute of Nanoscience and Nanotechnology (ICN2), a Severo Ochoa Centre of Excellence, and the Universitat Autònoma de Barcelona (UAB) have developed the new BiogàsPlus, a technology which allows ...

Research unlocks potential of super-compound

10 hours ago

Researchers at The University of Western Australia's have discovered that nano-sized fragments of graphene - sheets of pure carbon - can speed up the rate of chemical reactions.

User comments : 0