Researchers from Texas A&M University have done research that has the potential of opening a floodgate of nanomaterials known as MXenes, and they have found a simple, inexpensive mean of preventing the material's rapid degradation. They published their study in the journal Matter.
Ranging from energy storage to water purification, two-dimensional MXene nanosheets have promise in applications. However, MXenes have an Achilles' heels: they rapidly degrade when kept in the open.
As the team from Texas A&M suggests, the solution to this issue involves exposing MXenes to anything in a family of compounds best represented by a natural dietary supplement such as vitamin C.
The researchers wrote in the paper which described their findings that self-stable MXenes become possible and engineering-grade MXene-based materials can become a practical reality. In 2011, the team at Drexel University discovered MXenes, sheets of materials only a few atoms thick that are mostly composed of layers of metals like titanium interleaved by carbon and nitrogen.
Because of their nano-thickness and the variety of elements they can be composed of (other nanomaterials like graphene contain only carbon), these materials tend to have new properties indeed, like high electrical conductivity and high catalytic activity. An associate professor, Dr. Micah Green, was the leader of the team and he has joint appointments in the Artie McFerrin Department of Chemical Engineering and the Department of Materials Science and Engineering at Texas A&M.
As the researchers discovered, exposing a typical MXene to a solution of sodium L-ascorbate stopped the nanosheet from degrading. Also, several related compounds, such as vitamin C worked. According to the researchers, the effect lasts. Also, they noted that the team made the discovery about a year ago, and the treated MXenes are still stable.
The researchers attempted to investigate further the phenomenon that leads to the enhanced stability by completing molecular dynamics simulations of the interactions between the MXenes and the antioxidants. The team discovered that the ascorbate molecules appear to associate with the MXene nanosheet, preventing it from interacting with water molecules and as a result, shielding it from oxidation.
The researchers are excited since their technique appears to work with a variety of different MXenes. The Matter paper focuses on the most common MXene (Ti3C2Tx). However, other types of MXenes are even more unstable. So much so that people have doubted whether those materials could ever find applications. Through this method, that could change. At present, the team is exploring the stability of these additional MXenes using the same approach. They hope that everybody who works on MXenes, including people in the industry will use their strategy to protect their materials.
