Enhancing the magnetism of 2D carbide MXene Ti3C2Tx by H2 annealing

The seeking of the intrinsically ferromagnetic materials has been extended to the two-dimensional transition metal carbide MXene in recent years. However, as the first synthesized member in this family, the experimental study of the magnetism on Ti3C2Tx is rare. Herein, monolayer MXene Ti3C2Tx was prepared by LiF/HCl etching method and annealed in H2. The magnetic properties of the as-prepared and annealed Ti3C2Tx were investigated. The results show that the as-prepared Ti3C2Tx exhibits the very weak paramagnetism. After H2 annealing, the significant enhancement in the saturation magnetization is observed, and the ferromagnetism appears after annealing at 500 °C. Density functional theory simulations show that Ti–C vacancy pairs created during the exfoliation and H2 annealing are the major magnetic sources.