New Nanocrystals to Aid Solid Lighting and Carbon Sequestration

Experts at the US Department Of Energy's (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) recently reported the creation of a new class of nanocrystals, perfectly able to store carbon dioxide. The non-toxic, magnesium oxide particles can also emit blue light very effectively, and their creators hope to be able to use the two traits in creating devices that would help mitigate global warming and climate change at a global level.

At the Berkeley Lab's Molecular Foundry, researchers managed to use an organometallic chemical synthesis route to gain the ability to tune the size of the bulk form of magnesium oxide to just a few nanometers. The white and inexpensive mineral, which is used in its rough form to insulate cables and help athletes maintain a grip on the objects they use, thus becomes a nanocrystal composite that glows with a bluish tint when ultraviolet wavelengths are shone on it.

The mechanism used for generating the nanocrystals varies considerably from both a regular generating technique (involving high temperatures that make the end-result unfit for this type of applications) and from vapor phase methods, which are very expensive and cause the resulting nanoparticles to remain attached to a substrate, ScienceDaily informs.

“We’ve discovered a fundamentally new, unconventional mechanism for nicely controlling the size of these nanocrystals, and realized we had an intriguing and surprising candidate for optical applications. This efficient, bright blue luminescence could be an inexpensive, attractive alternative in applications such as bio-imaging or solid-state lighting,” the Berkeley Lab Molecular Foundry Inorganic Nanostructures Facility Director Delia Milliron says. The Foundry is the lab's nanoscience research center.

Until now, experts working in solid-state lighting technologies, where semiconductor materials give off the glow, have only been able to produce green and red light sources. Finding a sustainable and powerful enough blue source was paramount, as the three colors are combined to give the white light we are accustomed to. Now, this may be made possible by the new research.

Also, “These nanocrystals will serve as a test system for modeling the kinetics of dissolution and mineralization in a simulated fluid-rock reservoir, allowing us to probe a key pathway in carbon dioxide sequestration. The geological minerals that fix magnesium into a stable carbonate are compositionally complex, but our nanocrystals will provide a simple model to mimic this intricate process,” Berkeley Labs’ Energy Frontier Research Center (EFRC) team member and staff scientist Jeff Urban adds. He is also appointed in the Inorganic Nanostructures Facility.

Details of the new paper, entitled “Size-controlled synthesis and optical properties of monodisperse colloidal magnesium oxide nanocrystals,” appear in the latest issue of the journal Angewandte Chemie International Edition.