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

Autor: Wan P; School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Chemical Theory and Mechanism, Chongqing University, Chongqing, 401331, China., Chen Y; School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Chemical Theory and Mechanism, Chongqing University, Chongqing, 401331, China., Tang Q; School of Chemistry and Chemical Engineering, Chongqing Key Laboratory of Chemical Theory and Mechanism, Chongqing University, Chongqing, 401331, China.
Jazyk: angličtina
Zdroj: Chemphyschem : a European journal of chemical physics and physical chemistry [Chemphyschem] 2024 Sep 16; Vol. 25 (18), pp. e202400325. Date of Electronic Publication: 2024 Jul 17.
DOI: 10.1002/cphc.202400325
Abstrakt: 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 Ti 2 CT x MXene in different aqueous environments. The results revealed the high vulnerability of the pure and vacancy-defected Ti 2 CO 2 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 surface oxidation of Ti 2 CO 2 could be prevented in the acid condition or in the neutral condition under the negative potential. Differently, the fully F- or OH-functionalized Ti 2 CF 2 and Ti 2 C(OH) 2 as well as the mixed functionalized Ti 2 C(O 0.5 OH 0.5 ) 2 and Ti 2 CO 1.12 F 0.88 are highly stable under various electrochemical conditions, which can effectively prevent close contact between water and surface Ti atoms via electronic repulsion or steric hindrance. These findings provide atomic level understanding of the aqueous stability of MXene and provide useful strategies to prevent degradation and achieve highly stable MXenes.
(© 2024 Wiley-VCH GmbH.)
Databáze: MEDLINE
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