After all the hubbub around graphene, the race is on to find more wonder materials—ones that might be even more promising than the Nobel Prize-honoured, 2D carbon lattice.
Earlier this month we reported on a type of sodium bismuthate that had earned itself the nickname “3D graphene” and pointed toward a future of hard drives with ten times their current capacity. Now, another long-theorized nanomaterial looks set to take on graphene on the 2D plane: borophene.
To be clear, borophene hasn’t actually been made yet. But physical chemists at Brown University have made one unit of a boron cluster, called B36, and detailed its interesting structure on a supercomputer. The university claims this demonstrates “that a boron-based competitor to graphene is a very real possibility.”
Borophene is made of boron atoms, arranged in a flat disk with a hexagonal hole. Image: Wang Lab/Brown University
Boron is next to carbon (which graphene is made of) in the periodic table, but no one has previously demonstrated experimentally how it could be arranged in a similar one-atom-thick sheet. Professor Lai-Sheng Wang and lead author Zachary Piazza headed up a team that assembled experimental evidence of how borophene might work, and published their findings in Nature Communications.
Graphene is well-known for its honeycomb, or “chicken wire” structure. “However, boron cannot form graphene-like structures with a honeycomb hexagonal framework because of its electron deficiency,” the researchers explained. “Computational studies suggest that extended boron sheets with partially filled hexagonal holes are stable; however, there has been no experimental evidence for such atom-thin boron nanostructures.”
Until now; they showed a two-dimensional boron lattice can be made out of a triangular pattern with hexagonal holes. Their results, they wrote, present “the first experimental evidence that single-atom layer boron sheets with hexagonal vacancies are potentially viable.”
So what does it mean? They only physically made one of the symmetrical 36-boron-atom clusters, not yet a whole graphene-like sheet. But if this precursor structure could be extended into borophene, it’s expected to be a material to rival graphene in terms of the qualities it will possess. It would be strong and two-dimensional, and possibly even more conductive than graphene. As CleanTech reports, “That quality means that borophene could find itself being of more use, in some regards, than graphene.”
Before it can steal graphene’s crown, of course, it actually has to get made. But thanks to this research, that prospect is looking ever more feasible.