Recent advances and perspectives of MXene sediment: Composition, morphology, properties and applications

In the past decade, MXenes have undergone rapid development in their synthesis, delamination and application. Specifically, the continuous optimization of the delamination methods has led to a great increase in the yield of single-/few-layered MXene nanosheets, but it is still far from 100%. Therefore, there always exists some MXene sediment that is difficult to be further exfoliated and generally discarded as trash in the early stage, leading to significant economic losses. Since 2020, researchers have discovered that MXene sediment possesses a series of outstanding properties, opening the door to turning MXene sediment trash to treasure. Related reports of MXene sediment have continuously increased in the past four years, but a systematic review on this topic has not been reported yet. Herein, the latest advances of MXene sediment are comprehensively summarized. Firstly, the various synthesis and delamination strategies of MXenes are briefly introduced. Subsequently, the composition and morphology, large interlayer spacing, superior rheological, electrical and mechanical properties of MXene sediment are discussed. Furthermore, the applications of MXene sediment in supercapacitors, lithium-ion batteries, electromagnetic interference shielding, electrothermal and photothermal conversion as well as sensors have been carefully summarized. Finally, some perspectives for the future development of MXene sediment are proposed. This review aims to arouse the scientific interest of researchers in MXene sediment, further boosting the comprehensive development of MXenes.