Rice University theorists show flat boron form would depend on metal substrates
Rice University scientists have theoretically determined that the properties of atom-thick sheets of boron depend on where those atoms land.
Calculation of the atom-by-atom energies involved in creating a sheet of boron revealed that the metal substrate - the surface upon which two-dimensional materials are grown in a chemical vapor deposition (CVD) furnace - would make all the difference.
Theoretical physicist Boris Yakobson and his Rice colleagues found in previous work that CVD is probably the best way to make highly conductive 2-D boron and that gold or silver might be the best substrates.
But their new calculations show it may be possible to guide the formation of 2-D boron by tailoring boron-metal interactions. They discovered that copper, a common substrate in graphene growth, might be best to obtain flat boron, while other metals would guide the resulting material in their unique ways.
The Rice team's results appear today in the journal Angewandte Chemie.
"If you make 2-D boron on copper, you get something different than if you made it on gold or silver or nickel," said Zhuhua Zhang, a Rice postdoctoral researcher and lead author of the paper. "In fact, you'd get a different material with each of those substrates."
In chemical vapor deposition, heated gases deposit atoms on the substrate, where they ideally form a desired lattice. In graphene and boron nitride, atoms settle into flat hexagonal arrays regardless of the substrate. But boron, the researchers found, is the first known 2-D material that would vary its structure based on interactions with the substrate.
Perfectly flat boron would be a grid of triangles with occasional hexagons where atoms are missing. The researchers ran calculations on more than 300 boron-metal combinations. They found the pattern of atoms in a copper surface match up nicely with 2-D boron and the strength of their interactions would help keep the boron flat. A nickel substrate would work nearly as well, they found.
On gold and silver, they determined weak atomic interactions would allow the boron to buckle. In an extension, they theorized that naturally forming, 12-atom icosahedrons of boron would assemble into interconnected sheets on copper and nickel, if the boron supply were high enough.
One remaining downside to 2-D boron is that, unlike graphene, it will remain difficult to separate from its substrate, which is necessary for use in applications.
But that strong adhesion may have a side benefit. Further calculations suggested boron on gold or nickel may rival platinum as a catalyst for hydrogen evolution reactions in applications like fuel cells.
"In 2007 we predicted the possibility of pure boron fullerenes," Yakobson said. "Seven years later, the first one was observed in a laboratory. This time, with the enormous attention researchers are giving to 2-D materials, I'd hope some lab around the world will make 2-D boron much sooner."
Co-authors of the paper are graduate student Yang Yang and Rice postdoctoral researcher Guoying Gao. Yakobson is Rice's Karl F. Hasselmann Professor of Materials Science and NanoEngineering and a professor of chemistry.
The Department of Energy Office of Basic Energy Sciences supported the research.
Read the abstract at http://onlinelibrary.
This news release can be found online at http://news.
Follow Rice News and Media Relations via Twitter @RiceUNews
Yakobson Research Group: http://biygroup.
Rice Department of Materials Science and NanoEngineering: https:/
George R. Brown School of Engineering: http://engr.
Wiess School of Natural Sciences: http://naturalsciences.
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,888 undergraduates and 2,610 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for best quality of life and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance.
David Ruth | EurekAlert!
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences