MXenes and MXene-based Materials for the Removal of Water Pollutants: Challenges and Opportunities

Two-dimensional MXenes with their attractive applicability and unique properties such as eco-friendly features, large surface area, remarkable chemical stability, high thermal/electrical conductivity, exclusive sorption-reduction capacity, and hydrophilicity can be employed as promising candidates for water treatment; they can be mostly deployed for the elimination of various hazardous pollutants with high sorption selectivity, efficient reduction capability, and suitable degradation potentials. However, several important physicochemical parameters (e.g., pH, temperature, and water quality) can influence the adsorption performance of MXenes. Additionally some important challenging issues regarding the toxicity, degradability, storage, and large scale/commercial production of MXenes are still need to be evaluated. The aggregation of MXenes is also a critical challenge, which can reduce the adsorption activity and surface area of these materials; the surface chemistry of MXenes and related mechanisms of contaminants removal by these materials should be analytically and systematically evaluated. Importantly, the environmental risks of MXene-based structures should also be broadly analyzed. This review delineates the pros and cons and critical issues pertaining to the deployment of MXenes endowed with their superior surface area, high selectivity/sensitivity, recyclability, and attractive mechanical properties for removing hazardous pollutants (e.g., antibiotics, dyes, pesticides, heavy metals, pharmaceutical compounds, and radionuclides) from water and wastewater.