Bioinspired functionalization of MXenes (Ti3C2TX) with amino acids for efficient removal of heavy metal ions

MXenes are a novel type of two-dimensional (2D) materials that could be obtained from etching of Al atoms in layered hexagonal ternary carbide. These 2D materials display many outstanding physicochemical properties and are potentially utilized for various applications. Although previous reports demonstrated that MXenes and MXenes-based composites could be potentially utilized for environmental applications, the adsorption performance is limited and development of facile methods for synthesis MXenes-based composites with higher adsorption capability is of great importance. In this work, we reported for the first time that MXenes-based polymeric composites (Ti3C2TX-PDOPA) could be simply fabricated via mixing of MXenes (Ti3C2TX) and levodopa (DOPA) under rather mild reaction conditions. In this reaction system, DOPA could adhere on the surface of MXenes through self-polymerization and many carboxyl groups could thus introduce during the polymerization procedure to form poly (DOPA). The resultant Ti3C2TX-PDOPA composites were utilized as adsorbents and showed higher adsorption capacity in removal heavy metal ions as compared with that of raw Ti3C2TX. More importantly, Ti3C2TX-PDOPA composites could be further functionalized with other functional materials through subsequent reaction because many reactive functional groups were introduced on MXenes and various MXenes-based composites could be fabricated.