A novel two-dimensional accordion-like titanium carbide (MXene) for adsorption of Cr(VI) from aqueous solution

Herein, we report on a novel two-dimensional (2D) material application, which shows that an accordion-like layered Ti₃C₂ nanomaterial (MXene) with an excellent adsorption capacity of Cr(VI) from aqueous solution was prepared by etching Al layer from Ti₃AlC₂ phase in hydrofluoric acid (HF) solution. Ti₃C₂ nanopowders were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the physical property of as-obtained samples was studied by UV-Vis diffuse reflectance spectra (DRS). After HF treatment, Ti₃AlC₂ not only has a phase transition from one crystal to another, but surprisingly, its microstructure is also undergoing an obvious change. Ti₃C₂ with product of change possesses an accordion-like multilayer structure, and a relatively higher specific surface area (SSA) than untreated Ti₃AlC₂. Then, accordion-like Ti₃C₂ with a high SSA provides abundant active sites for pollutant removal and functionalization. Accordion-like Ti₃C₂ nanomaterial exhibits a stable adsorption capacity, and 1g as-prepared accordion-like Ti₃C₂ powders can remove about 80mg potassium dichromate. Therefore, the results suggest that 2D MXenes are promising as an effective nanoadsorbent in heavy metal removal from the wastewater.