Oxidative Stability of Nbn+1CnTz MXenes

Despite prior reports on oxidation and oxidation mitigation for Tin+1CnTz MXenes, there have been no reports on the oxidative stability of MXene dispersions outside of this family to date, including Nb-based MXenes. Here, we monitor the oxidative stability of Nbn+1CnTz MXenes by using UV-vis absorbance and XPS and demonstrate methods to mitigate oxidation. We show that the inclusion of an antioxidant (i.e., ascorbic acid) and low temperature storage improve the oxidative stability of Nbn+1CnTz MXenes. We also demonstrate that MXenes with higher "n" are more oxidatively stable. Our results suggest that the use of an antioxidant and low temperature storage may be generalized for improving the oxidative stability of all MXenes outside of the Tin+1CnTz family. This discovery shows potential for the future use of new MXenes and that MXenes with higher "n" are more favorable for long-term storage and use.