engleski

Mechanochemical synthesis of fluoride-free Ti3C2

MXenes, a family of two-dimensional (2D) layered early transition metal carbides and carbonitrides, have rapidly drawn intensive research attention due to their high metallic conductivity, large theoretical specific surface area, excellent mechanical properties, and high hydrophilicity. Their general chemical formula is Mn+1XnTx (n=2- 4), where M represents a transition metal, X is carbon and/or nitrogen, and T stands for surface termination groups (–OH, –F, –O) [1]. Ti3C2Tx was the first MXene reported in 2011, and more than 25 different MXene compositions have been synthesised since then. To date, most MXenes have been prepared through the wet chemical etching methods where A-element atomic layers (e.g., aluminum) are etched from the Mn+1AXn phase (e.g., Ti3AlC2) using highly hazardous HF or LiF/HCl solutions [2]. Therefore, there is an urgent need to explore safe, reliable, and fluorine-free synthetic methods to prepare MXene. In this work, we describe several different fluoride-free mechanochemical routes for the preparation of the Ti3C2 MXene from the Ti3AlC2 MAX phase. It consists of a ball-milling of the MAX phase with LiCl or ZnCl2, followed by washing and ultrasonication in order to completely exfoliate the MXene sheets. The prepared Ti3C2 was studied by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible (UV/Vis) spectrophotometry and dynamic light scattering (DLS). The results reported here pave the way for new preparation methods for various fluoride-free MXenes as ideal candidates for many functional applications such as energy storage, catalysis, electronics, and sensors.

2D materials ; ball-milling ; mechanochemistry ; solid state

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