Scientists have discovered a brand-new material with a unique atomic structure—something they weren’t even looking for.
While trying to make borophene, a promising but elusive two-dimensional material made of boron, researchers instead found a completely different compound: a 2D copper boride.
The discovery, made by scientists at Rice University and Northwestern University, was published in Science Advances.
It offers fresh insight into how boron behaves when it interacts with metals like copper and could lead to the development of a new family of two-dimensional materials.
More than ten years ago, Rice University materials scientist Boris Yakobson and his team predicted that it would be very difficult to make borophene on copper because the boron atoms would stick too tightly to the metal.
Their prediction turned out to be right—but not in the way anyone expected. Instead of forming borophene, the boron atoms formed a completely new 2D compound with copper: copper boride.
This is different from what happens with other well-known 2D materials like graphene, where atoms tend to sit on top of the metal without forming a true new structure.
In this case, the boron atoms bonded tightly with copper to create a distinct atomic pattern that had never been seen before.
Researchers have previously succeeded in making borophene on other metals like silver and gold, but copper remained a mystery.
Some scientists thought borophene might still be possible, while others believed it would instead form borides or large crystals. To find out the truth, the team used a mix of advanced imaging, spectroscopy, and theoretical modeling.
What they saw under the microscope was unexpected—zigzag atomic patterns and electronic signals that didn’t match any known version of borophene.
After extensive analysis and comparison with simulations, they concluded that the structure was not borophene at all but a new copper boride with its own unique properties.
Although this wasn’t the result they originally aimed for, the researchers say the discovery is exciting and opens the door to more exploration.
Understanding how boron bonds with different metals could lead to a wider range of 2D materials, some of which may be useful in technologies like energy storage, electronics, and even in high-performance materials for use in extreme environments.
According to Mark Hersam at Northwestern University, this copper boride may be just the beginning. He believes many more 2D metal borides can be created, offering vast potential for future innovation.
As Yakobson put it, the strange atomic images at first didn’t make sense, but eventually led to a breakthrough. “This was unexpected at first, but now it is settled—and science can move forward.”
Source: Rice University.
