Heavy metals adsorption performance of Ti-MXenes synthesized via fluorinated etchants and their regeneration

Water contaminated with toxic or radioactive HMs even in small concentrations is very hazardous to human and marine life. Secretion of these metals into the aquatic environment through industrial waste has raised global concern. In the current decade, different approaches have been adopted to extract the metals pollutants from water. Adsorption is a naive and fast process, which offers an effective approach for such remediation. However, most of the conventional adsorbents exhibit low adsorption performance with a high cost and slower process. Therefore these materials need to be replaced with more efficient and advanced adsorbents. Ti-MXenes are the most versatile group of two-dimensional nanomaterials, which seizes great potential for environmental application. Owing to the large specific surface area, hydrophilicity, chemical stability, efficient mechanism, and effective adsorption towards the removal of aquatic pollutants, these MXenes are considered a thriving candidate for wastewater treatment. In this paper, the synthesis techniques of Ti-MXenes using fluorine-containing etchants vis-a-vis their adsorption performance are critically reviewed. The adsorption mechanism of the hazardous and radioactive HMs, regeneration, and reusability of the MXenes nanosheets are also precisely covered. In addition, prospects of the MXenes particularly challenges from the current research and a way forward are proposed. Hopefully, this review will provide a valuable guide to relate, discuss and expand the synthesis and application of the MXenes family. Graphical abstract