Hierarchical utilization of raw Ti3C2Tx MXene for fast preparation of various Ti3C2Tx MXene derivatives

Due to easy re-stacking, low yield of few-layered MXenes (f-MXenes), the applications of MXenes are mainly restricted in multi-layered MXenes (m-MXenes) state. Although f-MXenes can be prepared from m-MXenes, after exfoliation process, a mass of sediments which are still essentially compact MXenes are usually directly discarded, leading to low utilization of raw m-MXenes. Herein, a classified preparation strategy is adopted to exploit the raw m-MXenes and traditional MXenes sediments, taking multi-layered Ti3C2Tx MXene as an example. Via rational delamination and subsequent treatment to Ti3C2Tx sediments, we succeed in achieving classified and large-scale preparation of various Ti3C2Tx MXene derivatives, including few-layered Ti3C2Tx (f-Ti3C2Tx) powders, f-Ti3C2Tx films, and Ti3C2Tx MXene-derived nanowires with heterostructure of potassium titanate and Ti3C2Tx. We demonstrate the necessity of “step-by-step delamination” towards traditional Ti3C2Tx sediments to improve the yield of f-Ti3C2Tx from 15% to 72%; the feasibility of “solution-phase flocculation (SPF)” to fundamentally solve the re-stacking phenomenon, and oxidation degradation issues of f-Ti3C2Tx during storage; as well as the convenience of SPF to deal with time-consuming issues of fabricating Ti3C2Tx films. What’s more, alkali-heat treatment of final Ti3C2Tx sediments turns waste into treasure of Ti3C2Tx-derived nanowires, leading to 100% utilization of raw Ti3C2Tx. The content of one-dimensional (1D) nanowires in the hybrids can be adjusted by controlling alkalization time. The 3D architecture heterostructure composed of 1D nanowires and 2D nanosheets exhibits gorgeous application potential. This work can expand preparation and application of various MXenes derivatives, promoting process of various MXenes.