Oxygen-terminated M4X3 MXenes with superior mechanical strength

• Published in: Mechanics of materials 2021-09, Vol.160, p.103957, Article 103957
• Main Authors: Imani Yengejeh, Sadegh, Kazemi, Seyedeh Alieh, Wen, William, Wang, Yun
• Format: Article
• Language: English
• Subjects: 2D stiffness; Density functional theory; M4X3 MXenes; Oxygen functionalization; Super-strong materials
• ISSN: 0167-6636; 1872-7743
• DOI: 10.1016/j.mechmat.2021.103957

Two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, have gained notable attention recently because these super-strong materials have many promising applications. In this study, computational analysis is conducted to explore the in-plane elastic constants, 2D stiffness and shear modulus of oxygen terminated M4X3 MXenes by means of the density functional theory (DFT) calculations. Our results reveal that the binding site of the oxygen atoms can greatly affect the mechanical properties. The crystal orbital Hamilton population (COHP) analysis suggests that the impact of the oxygen-binding site is because the M − O bonding strength can significantly influence their mechanical stiffness. Our outcomes may, therefore, provide the theoretical foundation for the advance of MXene-based applications in mechanical engineering. [Display omitted] •2D M4X3O2 materials are super-strong materials and possess outstanding mechanical properties.•Introducing the oxygen termination groups to the surface of MXenes improve their mechanical strength.•The influence of transition metal on the mechanical properties of MXenes has been investigated.•The COHP analysis indicates that the M–O bonding strength mainly determines the mechanical strength of M4X3O2.