A new method for creating complex nanostructures could have applications in everything from clean energy to quantum computing and new sensors.
By using a connector, or ‘intermedium’, nanoparticle to join multiple different nanoparticles the team has been able to create nanostructures from modular that would be very difficult or even impossible to make with existing crystalline growth methods.
And the team has already used the new method to create a photocatalyst – a chemical that use light to boost chemical reactions – 15 times more efficient than conventional ones, which could be a major step towards creating artificial photosynthesis-like reactions to split hydrogen and oxygen to produce hydrogen fuel or transform water and carbon dioxide into fuels.
The modular approach to designing nanostructures used by the University of Maryland team avoids the limitations in material choice and nanostructure size, shape and symmetry inherent in the crystalline growth – or epitaxial synthesis – approaches currently used by scientists.
"Our approach makes it possible to design and build higher order – more complex and materially varied – nanostructures with a specifically designed symmetry or shape," said Min Ouyang, an associate professor in the department of physics and the Maryland NanoCenter who lead a team including lead author Lin Weng.
"Such a synthesis method is the dream of many scientists in our field and we expect researchers now will use our approach to fabricate a full class of new nanoscale hybrid structures.”
The new method, published in journal Nature Communications, has been praised by the University of Delaware's Matt Doty, an associate professor of materials science and engineering, physics, and electrical and computer engineering and associate director of the UD Nanofabrication Facility.
"The work of Weng and co-authors provides a powerful new tool for the quantum engineering of complex nanostructures designed to implement novel electronic and optoelectronic functions,” he said.
“(Their) new approach makes it feasible for researchers to realize much more sophisticated nanostructure designs than were previously possible."
The team has already managed to use the method to create a nanostructure that harnesses an effect known as surface plasmon resonance, which involves the generation of high energy electrons using light, to create a super-efficient photocatalyst.
"Using our new modular synthesis strategy, our UMD team created an optimally designed, plasmon-mediated photocatalytic nanostructure that is an almost 15 times more efficient than conventional photocatalysts," said Ouyang.
Current photocatalytic methods are too inefficient to be cost effective for use in large scale water splitting applications to create clean hydrogen fuel using the light energy from solar energy farms, but the team’s findings hold great promise for future advances in the field among others.
"The ingenious nano-assemblies that Professor Ouyang and his collaborators have fabricated, which include the novel feature of a silver-gold particle that super-efficiently harvests light, bring us a giant step nearer the so-far elusive goal of artificial photosynthesis: using sunlight to transform water and carbon dioxide into fuels and valuable chemicals," said Professor Martin Moskovits of the University of California at Santa Barbara.