Brown University researchers have made a groundbreaking discovery in the world of nanotechnology, revealing the first experimental evidence of a boron buckyball molecule made from 80 boron atoms. This finding is a significant development, as it opens up new possibilities for the use of boron in various applications, potentially surpassing the capabilities of its carbon counterpart, the carbon buckyball. The research, led by Professor Lai-Sheng Wang, has been published in Chemical Science, and it marks a pivotal moment in the exploration of boron's nanostructures.
The concept of buckyballs, which are spherical molecules with unique properties, has been a cornerstone of nanotechnology. Carbon buckyballs, discovered over 40 years ago, have found applications in energy technology, medicine, and more. However, the focus has primarily been on carbon due to its electron configuration, which allows for the formation of interesting shapes. Professor Wang, a pioneer in this field, has been working for nearly three decades to explore whether boron, carbon's neighbor on the periodic table, could also form similar nanostructures.
In 2013, Wang's team successfully created a planar, one-atom-thick disc made of 36 boron atoms, known as borophene. This discovery was followed by the synthesis of a 40-atom boron cluster in 2014, which formed a hollow cage resembling a buckyball but lacking perfect spherical symmetry. The latest breakthrough, however, involves the creation of a boron buckyball made from 80 boron atoms, a structure that was previously thought to be unstable.
The researchers used photoelectron spectroscopy to gather evidence of this new nanostructure. By blasting a boron target with a high-powered laser, they knocked off a plume of boron atoms, which were then quickly cooled to form nanoclusters with various numbers of atoms. The clusters were then weighed to determine the number of atoms in each, and photoelectron spectroscopy was employed to investigate their shapes. The spectral readouts indicated a highly stable and symmetric structure, which, after further analysis, was confirmed to be the boron buckyball.
Despite the excitement surrounding this discovery, it is not without controversy. Density functional theory (DFT), the gold-standard method for determining molecular properties, suggests that the boron buckyball should not be stable. However, after an exhaustive search of possible 80-atom boron configurations, all signs pointed to the buckyball structure. Professor Wang believes that the DFT calculations may be incorrect, as they have some bond lengths wrong for the B80 buckyball, leading to incorrect predictions of its stability.
The implications of this discovery are far-reaching. If boron buckyballs can be synthesized in bulk form, they could have even more interesting properties than their carbon cousins. However, there are challenges to overcome, such as understanding the chemical reactivity of the B80 buckyball in ambient conditions. Wang's lab creates clusters in a vacuum, and it is not yet clear if boron buckyballs would be too reactive to stay intact in everyday environments.
Despite these challenges, Professor Wang remains optimistic. He points out that the synthesis of borophene took only two years, and he believes that the same could be achieved for boron buckyballs. This discovery not only expands our understanding of boron's nanostructures but also opens up new avenues for innovation in various fields, from energy technology to medicine. It is a testament to the power of scientific exploration and the endless possibilities that lie within the nanoscale world.
