2D Metal Carbides and Nitrides (MXenes) for Energy Storage

The family of 2D transition metal carbides, carbonitrides and nitrides has expanded rapidly since the discovery of Ti3C2 in 2011. About 20 different MXenes have been synthesized, and the structures and properties of dozens more have been theoretically predicted. The versatile chemistry of MXenes allows the tuning of properties for applications including energy storage, electromagnetic interference shielding, reinforcement for composites, water purification, gas- and biosensors, lubrication, and photo-, electro- and chemical catalysis. 2D materials have unusual electronic, mechanical and optical properties, which have led them to be extensively studied in the past decade for diverse applications. MXenes are made by selective etching of certain atomic layers from their layered precursors, such as MAX phases. MXenes can be intercalated with different metal cations, using aqueous solutions of ionic compounds, such as halide salts or metal hydroxides.