Electrochemical Stability of MXenes in Water Based on Constant Potential AIMD Simulations.

MXene has been recently explored as promising electrocatalytic materials to accelerate the electrocatalytic process for hydrogen evolution, but their dynamic stability under electrochemical conditions remains elusive. Here we performed first-principle ab initio molecular dynamics calculations to reveal the electrochemical stability of TiCT MXene in different aqueous environments. The results revealed the high vulnerability of the pure and vacancy-defected TiCO MXene towards water attack, leading to surface oxidation of MXene under neutral electrochemical condition that formed adsorbed oxygen species to Ti and dissociated proton in solution.

The Effect of Constant Potential on the Hydrogen Evolution Reaction Activity of M CO and M NO MXenes.

Two-dimensional transition metal carbides and nitrides (MXenes) have been widely explored as electrocatalysts for hydrogen evolution reaction (HER). However, current theoretical understanding of the MXene activity mainly relies on the charge neutral method, which neglects the charge effect from the electrode potential. In this work, using hydrogen adsorption as the testing probe, we compared the HER activity of M CO and M NO MXenes via the constant potential method (CPM) and charge neutral method (CNM) computations.