Achieving colloidal stability of diluted MXene dispersions through corrosion inhibition strategy with sodium tartrate

The limited chemical and dispersive stabilities of transition metal carbides and nitrides (MXenes) significantly hinder their practical applications despite the demonstrated excellent performances. In this study, colloidally stable Ti₂CT_x- and Ti₃C₂T_x-MXene aqueous dispersions (0.1 mg·mL⁻¹) were achieved through a corrosion inhibition strategy by incorporating sodium tartrate (ST). The addition of ST (0.3 mg·mL⁻¹) effectively increased the activation energy and enthalpy for the degradation of Ti₂CT_x and Ti₃C₂T_x in aqueous solutions, largely extending their time constants to 565.5 h and 239.3 days, respectively. This strong oxidation inhibition effect of ST preserved the structural integrity and colloidal properties of both MXenes without compromising their electrical and electrochemical performances. The vacuum-filtered Ti₂CT_x and Ti₃C₂T_x film electrodes demonstrated capacitance retentions of 96.7% and 88.5% after 96 h and 24 days of aging at 25 °C, respectively. Multiscale simulations revealed that single-deprotonated ST⁻ preferentially adsorbed onto edges and defect sites of MXene nanosheets via oxygen heteroatoms on the carbonyl moiety bonding to Ti vacancies. This work offers a promising and straightforward approach to stabilize the diluted MXene aqueous dispersions, fundamentally address their oxidation issues, and meet the requirements for temporary storage.

Graphical Abstract