pH, Nanosheet Concentration, and Antioxidant Affect the Oxidation of Ti3C2Txand Ti2CTxMXene Dispersions Academic Article uri icon

abstract

  • AbstractThe chemical stability of 2D MXene nanosheets in aqueous dispersions must be maintained to foster their widespread application. MXene nanosheets react with water, which results in the degradation of their 2D structure into oxides and carbon residues. The latter detrimentally restricts the shelf life of MXene dispersions and devices. However, the mechanism of MXene degradation in aqueous environment has yet to be fully understood. In this work, the oxidation kinetics is investigated of Ti3C2Tx and Ti2CTx in aqueous media as a function of initial pH values, ionic strengths, and nanosheet concentrations. The pH value of the dispersion is found to change with time as a result of MXene oxidation. Specifically, MXene oxidation is accelerated in basic media by their reaction with hydroxyl anions. It is also demonstrated that oxidation kinetics are strongly dependent on nanosheet dispersion concentration, in which oxidation is accelerated for lower MXene concentrations. Ionic strength does not strongly affect MXene oxidation. The authors also report that citric acid acts as an effective antioxidant and mitigates the oxidation of both Ti3C2Tx and Ti2CTx MXenes. Reactive molecular dynamic simulations suggest that citric acid associates with the nanosheet edge to hinder the initiation of oxidation.

published proceedings

  • ADVANCED MATERIALS INTERFACES

altmetric score

  • 2.85

author list (cited authors)

  • Zhao, X., Vashisth, A., Blivin, J. W., Tan, Z., Holta, D. E., Kotasthane, V., ... Green, M. J.

citation count

  • 95

complete list of authors

  • Zhao, Xiaofei||Vashisth, Aniruddh||Blivin, Jackson W||Tan, Zeyi||Holta, Dustin E||Kotasthane, Vrushali||Shah, Smit A||Habib, Touseef||Liu, Shuhao||Lutkenhaus, Jodie L||Radovic, Miladin||Green, Micah J

publication date

  • October 2020

publisher