A Red-Phosphorous-Assisted Ball-Milling Synthesis of Few-Layered Ti3C2Tx (MXene) Nanodot Composite

Layered two-dimensional (2D) early transition metal carbides (MXenes) are a new class of 2D materials with established activity for electrochemical energy conversion and storage. The use of MXenes is expected to increase by reducing their lateral size to the nanoscale. Herein, using Ti3C2Tx (T=O, OH, F) MXenes as an example, we show that m-sized MXenes can be reduced in size to approximate to 6 nm nanodots by ball-milling with red phosphorous (P). It is remarkable almost all starting MXenes were converted to nanodots with this method. The Ti3C2Tx surface O groups interacted with P strongly and chemically to drive the nanodots formation. Ti3C2Tx nanodots (TNDs) with different sizes could also be obtained by ball-milling Ti3C2Tx with other solid-state elements such as carbon, sulfur and silicon. The as-prepared TNDs and P composite was evaluated as a sodium-ion battery anode material. A good sodiation capacity (approximate to 600 mAhg(-1)) at 260 mAg(-1) and good cycle stability for 150 cycles were shown.