Rapid and reversible semi-solidification of MXene nanosheets via efficient capture for industrial applications

MXene (Ti₃C₂T_x) nanosheets produced through wet etching are typically obtained as low-concentration (<1 wt%) aqueous dispersions, leading to challenges like easy oxidation, high storage and transportation costs, and difficulties in direct processing. Here, we introduce a rapid and efficient technique to capture and semi-solidify single-layer MXene nanosheets using an erasable capture agent, transforming low-concentration MXene dispersions into high-solid-content (>85 wt%) semi-solids within minutes. This approach preserves the intrinsic properties of the MXene, imparts long-term stability, and enables reversible redispersibility. Importantly, the capture agent is fully removable without special treatment and can be recycled. Moreover, the method generalizes to other MXene compositions (e.g., Ti₂CT_x) and hydrophilic two-dimensional materials such as graphene oxide. Devices fabricated from semi-solid MXene stored for extended periods exhibit excellent functionalities including infrared stealth, Joule heating, electrochemical energy storage, and electromagnetic interference shielding. This rapid capture and semi-solidification strategy significantly streamlines the transition from MXene synthesis to practical applications, paving the way for industrial-scale utilization of MXene. © 2024 Elsevier Ltd