Carbon dioxide adsorption of two-dimensional carbide MXenes

Abstract Two-dimensional carbide MXenes (Ti 3 C 2 T x and V 2 CT x ) were prepared by exfoliating MAX phases (Ti 3 AlC 2 and V 2 AlC) powders in the solution of sodium fluoride (NaF) and hydrochloric acid (HCl). The specific surface area (SSA) of as-prepared Ti 3 C 2 T x was 21 m 2 /g, and that of V 2 CT x was 9 m 2 /g. After intercalation with dimethylsulfoxide, the SSA of Ti 3 C 2 T x was increased to 66 m 2 /g; that of V 2 CT x was increased to 19 m 2 /g. Their adsorption properties on carbon dioxide (CO 2 ) were investigated under 0–4 MPa at room temperature (298 K). Intercalated Ti 3 C 2 T x had the adsorption capacity of 5.79 mmol/g, which is close to the capacity of many common sorbents. The theoretical capacity of Ti 3 C 2 T x with the SSA of 496 m 2 /g was up to 44.2 mmol/g. Additionally, due to high pack density, MXenes had very high volume-uptake capacity. The capacity of intercalated Ti 3 C 2 T x measured in this paper was 502 V·v –1 . This value is already higher than volume capacity of most known sorbents. These results suggest that MXenes have some advantage features to be researched as novel CO 2 capture materials.