Iron Ore Could Be The Next Big 2D Material

You’ve been hearing all about graphene for years. This 2-dimensional version of carbon is supposed to revolutionize everything from CPUs to faster viral diagnosis. While graphene has been important in research and a limited number of consumer products, it hasn’t exactly lived up to the hype. Perhaps the next 2D material will kickstart a material revolution. It’s called hematene, and it’s made from cheap, plentiful iron ore.

Hematene has a number of things in common with graphene. Whereas graphene is essentially a thin sheet of carbon atoms, hematene is a thin sheet of iron and oxygen. It’s composed of hematite, which is the most common source of iron ore in the world. It’s one of the most common minerals on the planet. You can go dig around in the ground and probably find bits of hematite in many areas, but they won’t have the potentially amazing properties of hematene.

The team from Rice University created hematene by subjecting hematite to a process called liquid-phase exfoliation — the ore was exposed to dimethylformamide (DMF). The resulting material isn’t a single atom thick like graphene, but it’s not far away with a thickness of just three atoms (oxygen and iron). This is still considered a monolayer, though.

Changing the physical conformation of this material gave it some fascinating properties that researchers are still exploring. For example, hematene is ferromagnetic, whereas hematite is not. Hematene also shows great promise in photocatalysis. Photons generate negative and positive charges within a few atoms of the surface. By pairing hematene with titanium dioxide nanotube arrays, the team believes photons would have a more direct path to the surface. As a result, hematene could be more efficient as a solar collector than even graphene-based cells.

A transmission electron microscope image shows bi-layer and monolayer hematene. It forms randomly aligned sheets after exfoliation.

Hematene also has one important advantage over graphene. It’s held together by chemical bonds instead of the comparatively weak van der Waals interactions that keep graphene together. That means it could be used in more applications where the structure of graphene would be disrupted.

The interesting properties of hematene have led some to suggest that other iron oxide materials could be useful in 2D forms. We could be on the verge of getting a whole range of slim materials with wild properties. First, we’ll have to see if hematene can do what scientists are hoping for.

Now read: Explosions used to make large quantities of graphene