Nb₂CT_x MXene Nanosheets for Dye Adsorption

Two-dimensional (2D) transition metal carbides (MXenes) have attracted substantial research interests due to their efficient absorption capability for pollutants in waste water. Nb2CTx MXene with a high specific surface area of about 44.69 m2·g–1 was successfully synthesized by etching Nb2AlC with hydrofluoric acid. The as-synthesized Nb2CTx MXene exhibits excellent absorption capability for both cationic dye and anionic dye, with the maximum adsorption capacity beyond 500 mg·g–1. In addition, the adsorption process of Nb2CTx MXene follows a pesuo-second-order kinetics model, and the rate-limiting step of the adsorption process is the chemisorption at the surface absorption active sites. Our findings show that Nb2CTx MXene is a promising candidate for a high efficiency adsorbent for dye removal from waste water and also sheds light on the further engineering of superior absorbents based on the MXene systems.