Journal Article

Synthesis of Large‐Area MXenes with High Yields through Power‐Focused Delamination Utilizing Vortex Kinetic Energy

Zhang, Chenhao, Fan, Runze, Ji, Peiyi, Sheng, Jie, Liao, Qingliang, Fu, Xueli, Li, Hui, Lai, Huirong, Cheng, Weihua, Zhang, Qingxiao

2022

Overview

Evaluating the delamination process in the synthesis of MXenes (2D transition metal carbides and nitrides) is critical for their development and applications. However, the preparation of large defect‐free MXene flakes with high yields is challenging. Here, a power‐focused delamination (PFD) strategy is demonstrated that can enhance both the delamination efficiency and yield of large Ti3C2Tx MXene nanosheets through repetitive precipitation and vortex shaking processes. Following this protocol, a colloidal concentration of 20.4 mg mL–1 of the Ti3C2Tx MXene can be achieved after five PFD cycles, and the yield of the basal‐plane‐defect‐free Ti3C2Tx nanosheets reaches 61.2%, which is 6.4‐fold higher than that obtained using the sonication–exfoliation method. Both nanometer‐thin devices and self‐supporting films exhibit excellent electrical conductivities (≈25 000 and 8260 S cm‐1 for a 1.8 nm thick monolayer and 11 µm thick film, respectively). Hydrodynamic simulations reveal that the PFD method can efficiently concentrate the shear stress on the surface of the unexfoliated material, leading to the exfoliation of the nanosheets. The PFD‐synthesized large MXene nanosheets exhibit superior electrical conductivities and electromagnetic shielding (shielding effectiveness per unit volume: 35 419 dB cm2 g–1). Therefore, the PFD strategy provides an efficient route for the preparation of high‐performance single‐layer MXene nanosheets with large areas and high yields. A new method for the preparation of large 2D Ti3C2Tx MXene nanosheets is reported. The method is based on conventional etching followed by repetitive precipitation and vortex shaking process, which efficiently transfer the mechanical energy for exfoliation. Consequently, large defect‐free sheets that show an excellent electromagnetic shielding performance are produced with high yields.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley
• Subject: 2D Ti3C2Tx MXene / Conductivity / Defects / Energy / Etching / fluid–solid coupling simulation / Graphene / Industrial production / large nanosheets / liquid‐phase delamination / Methods / power‐focused delamination / Sediments / Shear stress / Ultrasonic imaging / Vortices