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: Tiny wires could provide a big energy boost

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

Tiny wires could provide a big energy boost

12 hours ago

Wearable electronic devices for health and fitness monitoring are a rapidly growing area of consumer electronics; one of their biggest limitations is the capacity of their tiny batteries to deliver enough ...

Graphene sheets enable ultrasound transmitters

12 hours ago

University of California, Berkeley, physicists have used graphene to build lightweight ultrasonic loudspeakers and microphones, enabling people to mimic bats or dolphins' ability to use sound to communicate ...

Project uses crowd computing to improve water filtration

Jul 06, 2015

Nearly 800 million people worldwide don't have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. ...

Engineering the world's smallest nanocrystal

Jul 06, 2015

In the natural world, proteins use the process of biomineralization to incorporate metallic elements into tissues, using it to create diverse materials such as seashells, teeth, and bones. However, the way ...

A stretchy mesh heater for sore muscles

Jul 03, 2015

If you suffer from chronic muscle pain a doctor will likely recommend for you to apply heat to the injury. But how do you effectively wrap that heat around a joint? Korean Scientists at the Center for Nanoparticle ...

Polymer mold makes perfect silicon nanostructures

Jul 03, 2015

Using molds to shape things is as old as humanity. In the Bronze Age, the copper-tin alloy was melted and cast into weapons in ceramic molds. Today, injection and extrusion molding shape hot liquids into ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.