Functionalized Metal Carbides For Energy Storage

SUMMARY

• The invention is a novel synthetic approach for surface modification of two-dimensional (2D) metal carbides (MXenes) using molten inorganic salts. Surface modification of MXenes have been hypothesized to affect material aspects ranging from structural properties to electron transport but—prior to this invention—no experimental method existed to modify surface functionalization of MXenes in a controlled manner.  This invention enables unprecedented atomic‐level control over the surface-group functionalization of MXenes with demonstrated synthesis of more than twenty new materials.
• MXenes are a class of 2D transition-metal compounds containing carbides and nitrides with several potential commercial applications. In contrast to more mature 2D materials, such as graphene and transition metal dichalcogenides, MXenes have chemically modifiable surfaces that offer additional engineerability. MXenes are typically synthesized through selective etching in aqueous solutions, which leaves the MXene surface terminated with a mixture of fluoride, oxygen, or hydroxyl (OH) functional groups.  
• This invention enables precise control over the composition, structure, and properties of MXenes, and thus opens up engineering and tuning of this commercially important substance. The inventors have demonstrated experimentally how the surface groups control interatomic distances in the MXene lattice as well as how different surface groups control electronic transport and superconductivity, and—in the process—have greatly expanded the library of MXene surface groups.

FIGURE

Schematics for etching surface reaction of MXenes in molten inorganic salts with atomic resolution electron micrograph of resulting materials.

ADVANTAGES

ADVANTAGES

• Proven synthetic method to produce previously inaccessible compounds
• Low cost synthetic approach
• Tunable electronic properties

APPLICATIONS

• Energy storage devices (i.e., supercapacitors and batteries)
• Electrocatalysis for water-splitting
• Electromagnetic interference shielding
• Composites
• Catalysts

PUBLICATIONS

• Vladislav Kamysbayev et al. ,Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes.Science369,979-983(2020).DOI:10.1126/science.aba8311