Hybrid Density Functional Study of Structural and Electronic Properties of Functionalized \ce{Ti_{n+1}X_n} (X= C, N) monolayers

Abstract

Density functional theory simulations with conventional (PBE) and hybrid (HSE06) functionals were performed to investigate the structural and electronic properties of MXene monolayers, \ce{Ti_{n+1}C_n} and \ce{Ti_{n+1}N_n} ($n$ = 1--9) with surfaces terminated by O, F, H, and OH groups. We find that PBE and HSE06 give similar results. Without functional groups, MXenes have magnetically ordered ground states. All the studied materials are metallic except for \ce{Ti_{2}CO_{2}}, which we predict to be semiconducting. The calculated density of states at the Fermi level of the thicker MXenes ($n$ $⩾$ 5) is much higher than for thin MXenes, indicating that properties such as electronic conductivity and surface chemistry will be different. In general, the carbides and nitrides behave differently with the same functional groups.

8 figures

References in corpus (5)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Two Dimensional Atomic Crystals
• VO2: A Novel View from Band Theory
• Electronic structure and magnetism in two-dimensional hexagonal 5d transition metal carbides, Tan+1Cn (n=1,2,3)

Cited by in corpus (22)

• Electronic properties and applications of MXenes: a theoretical review
• OH terminated two-dimensional transition metal carbides and nitrides (MXenes) as ultralow work function materials
• Monolayer MXenes: promising half-metals and spin gapless semiconductors
• Superior Structural, Elastic and Electronic Properties of 2D Titanium Nitride MXenes Over Carbide MXenes: A Comprehensive First Principles Study
• Effect of mixed surface terminations on the structural and electrochemical properties of two-dimensional Ti3C2T2 and V2CT2 MXenes multilayers
• Nearly Free Electron States in MXenes
• 2D titanium carbonitrides and their hydroxylated derivatives: Structural, electronic properties and stability of MXenes Ti3C2-xNx and Ti3C2-xNx(OH)2
• Manipulation of electronic and magnetic properties of M${}_2$C (M=Hf, Nb, Sc, Ta, Ti, V, Zr) monolayer by applying mechanical strains
• Effect of Surface Termination on the Lattice Thermal Conductivity of Monolayer Ti3C2Tz MXenes
• Chemical bonding in carbide MXene nanosheets
• Electronic Structure of Beta-Ta Films from X-ray Photoelectron Spectroscopy and First-principles Calculations
• Superconductivity of monolayer Mo${}_2$C: the key role of functional groups
• Dirac points with giant spin-orbit splitting in the electronic structure of two-dimensional transition-metal carbides
• Interfacial charge transfer and interaction in the MXene/TiO2 heterostructures
• Theoretical Prediction of the Robust Intrinsic Half-Metallicity in Ni2N MXene with Different Types of Surface Terminations
• Local chemical bonding and structural properties in Ti3AlC2 MAX phase and Ti3C2Tx MXene probed by Ti 1s X-ray absorption spectroscopy
• Exfoliation of Ti${}_2$C and Ti${}_3$C${}_2$ Mxenes from Bulk Phases of Titanium Carbide: A Theoretical Prediction
• Fermiology and Band Structure of Oxygen-Terminated Ti3C2Tx MXene
• Fermiology of two-dimensional titanium carbide and nitride MXenes
• MXene's Surface Functionalization Patterns and Their Impacts on Magnetism
• Surface termination dependence of electronic and optical properties in Ti${}_2$CO${}_2$ MXene monolayers
• Activated Layered Magnetism from Bulk TiN