Carbon dioxide adsorption of two-dimensional carbide MXenes

Abstract

Abstract Two-dimensional carbide MXenes (Ti3C2T x and V2CT x ) were prepared by exfoliating MAX phases (Ti3AlC2 and V2AlC) powders in the solution of sodium fluoride (NaF) and hydrochloric acid (HCl). The specific surface area (SSA) of as-prepared Ti3C2T x was 21 m2/g, and that of V2CT x was 9 m2/g. After intercalation with dimethylsulfoxide, the SSA of Ti3C2T x was increased to 66 m2/g; that of V2CT x was increased to 19 m2/g. Their adsorption properties on carbon dioxide (CO2) were investigated under 0–4 MPa at room temperature (298 K). Intercalated Ti3C2T x had the adsorption capacity of 5.79 mmol/g, which is close to the capacity of many common sorbents. The theoretical capacity of Ti3C2T x with the SSA of 496 m2/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 Ti3C2T 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 CO2 capture materials.