Tian Yumiao, Hou Pengfei, Zhang Huiwen, Xie Yu, Chen Gang, Li Quan, Du Fei, Vojvodic Aleksandra, Wu Jianzhong, Meng Xing
Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun, China.
Key Laboratory of Material Simulation Methods & Software of Ministry of Education, College of Physics, Jilin University, Changchun, China.
Nat Commun. 2024 Nov 21;15(1):10099. doi: 10.1038/s41467-024-54455-z.
Significant efforts have been devoted to investigating the oxidation of MXenes in various environments. However, the underlying mechanism of MXene oxidation and its dependence on the electrode potential remain poorly understood. Here we show the oxidation behavior of MXenes under the working conditions of electrochemical processes in terms of kinetics and thermodynamics by using constant-potential ab initio simulations. The theoretical results indicate that the potential effects can be attributed to the nucleophilic attack of water molecules on metal atoms, similar to that taking place in the Oxygen Evolution Reaction. Building upon these findings, we deduced the oxidation potential of the common MXenes, and proposed antioxidant strategies for MXene. Finally, we demonstrated that MBenes, the boron analogs of MXenes, may undergo a similar nucleophilic attack in water and inferred that molecule-induced Walden inversion is widely present in material reconstructions. This work contributes to a fundamental understanding MXene stability at the atomic level, and promotes the transition in materials discovery from trial-and-error synthesis to rational design.
人们已经付出了巨大努力来研究MXenes在各种环境中的氧化情况。然而，MXene氧化的潜在机制及其对电极电位的依赖性仍然知之甚少。在此，我们通过恒电位从头算模拟，从动力学和热力学角度展示了MXenes在电化学过程工作条件下的氧化行为。理论结果表明，电位效应可归因于水分子对金属原子的亲核攻击，这与析氧反应中发生的情况类似。基于这些发现，我们推导了常见MXenes的氧化电位，并提出了MXene的抗氧化策略。最后，我们证明了MXenes的硼类似物MBenes在水中可能会发生类似的亲核攻击，并推断分子诱导的瓦尔登反转在材料重构中广泛存在。这项工作有助于在原子水平上对MXene稳定性有基本的理解，并推动材料发现从试错合成向合理设计的转变。
