Microwave-Assisted Efficient Intercalation for Fast Fabrication of High-Quality and Large-Size Single-Layer Ti 3 C 2 T x Nanosheets.

A novel microwave-assisted intercalation (MAI) strategy is proposed for fast and efficient intercalation of layered MXene to prepare large-size single-layer MXene. After LiF-HCl etching of Ti 3 AlC 2 , the as-prepared multi-layer Ti 3 C 2 T x (M-T) are intercalated with Li 3 AlF 6 as an intercalator and ethylene glycol (EG) as a solvent under microwave irradiation for 5 min. Furthermore, the dispersed high-quality large-sized single-layer Ti 3 C 2 T x (S-T) nanosheets with a thickness of 1.66 nm and a large lateral size over 20 µm are achieved with a yield of over 60% after a further ultrasonic delamination followed by electrostatic precipitation, acid washing, and calcination. In addition, Pd/S-T composite catalyst, which is constructed with Pd nanoparticles supported on the as-prepared S-T nanosheets, exhibits an excellent performance for rapid and efficient selective hydrogenation of nitroarenes with H 2 under a mild condition. At room temperature, full conversion of nitrobenzene and 100% aniline selectivity are achieved over Pd/S-T catalyst in 20 min with 0.5 MPa of H 2 pressure. This work provides a novel method for facile, fast, and large-scale preparation of single-layer MXene and develops a new approach for constructing efficient nanocatalytic systems.