Intercalation and delamination of layered carbides and carbonitrides

Intercalation and delamination of two-dimensional solids in many cases is a requisite step for exploiting their unique properties. Herein we report on the intercalation of two-dimensional Ti₃C₂, Ti₃CN and TiNbC—so called MXenes. Intercalation of hydrazine, and its co-intercalation with N,N-dimethylformamide, resulted in increases of the c-lattice parameters of surface functionalized f-Ti₃C₂, from 19.5 to 25.48 and 26.8 Å, respectively. Urea is also intercalated into f-Ti₃C₂. Molecular dynamics simulations suggest that a hydrazine monolayer intercalates between f-Ti₃C₂ layers. Hydrazine is also intercalated into f-Ti₃CN and f-TiNbC. When dimethyl sulphoxide is intercalated into f-Ti₃C₂, followed by sonication in water, the f-Ti₃C₂ is delaminated forming a stable colloidal solution that is in turn filtered to produce MXene ‘paper’. The latter shows excellent Li-ion capacity at extremely high charging rates.