Two-in-one strategy to enhance the stability of Ti3C2Tx in transition metal ion solutions

Although MXenes have attracted significant attention across diverse fields, they exhibit a pronounced susceptibility to oxidation in aqueous environments, with oxidation significantly accelerated in the presence of transition metal ions (TMI) such as Fe 3+ and Cu 2+ . This limitation impedes the synthesis of transition metal compounds/MXene-based composites and their potential for functional applications. In this study, we elucidate the mechanism of accelerated oxidation of Ti 3 C 2 T x is that Fe 3+ promotes the electron loss in Ti 3 C 2 T x , thus leading to an increased production of hydroxyl radicals ( OH) to oxidize Ti 3 C 2 T x . Furthermore, a rational two-in-one strategy is provided with adding electron-rich ethylenediaminetetraacetic acid disodium zinc salt (ZnNa 2 EDTA) to enhance the stability of Ti 3 C 2 T x by defect filling and electron donation. Consequently, the production of OH is significantly reduced and thus Ti 3 C 2 T x remains well-preserved in the presence of Fe 3+ , which has also effectively enhanced the oxidation stability of Ti 3 C 2 T x in the presence of Cu 2+ . This work is expected to pave a new pathway for targeted applications with coexisting Ti 3 C 2 T x and TMI.