DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effect of surface functional groups on MXene conductivity

Journal Article · · Journal of Chemical Physics
DOI: https://doi.org/10.1063/5.0141589 · OSTI ID:1975355

In this work, we report the in-plane electron transport in the MXenes (i.e., within the MXene layers) as a function of composition using the density-functional tight-binding method, in conjunction with the non-equilibrium Green’s functions technique. Our study reveals that all MXene compositions have a linear relationship between current and voltage at lower potentials, indicating their metallic character. However, the magnitude of the current at a given voltage (conductivity) has different trends among different compositions. For example, MXenes without any surface terminations (Ti3C2) exhibit higher conductivity compared to MXenes with surface functionalization. Among the MXenes with –O and –OH termination, those with –O surface termination have lower conductivity than the ones with –OH surface terminations. Interestingly, conductivity changes with the ratio of –O and –OH on the MXene surface. Our calculated I–V curves and their conductivities correlate well with transmission functions and the electronic density of states around the Fermi level. The surface composition-dependent conductivity of the MXenes provides a path to tune the in-plane conductivity for enhanced pseudocapacitive performance.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Energy Frontier Research Center (EFRC) (United States). Fluid Interface Reactions, Structures and Transport (FIRST)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC05-00OR22725; AC02-05CH11231
OSTI ID:
1975355
Journal Information:
Journal of Chemical Physics, Vol. 158, Issue 19; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (46)

Effects of functional groups and anion size on the charging mechanisms in layered electrode materials journal December 2020
Screening MXenes for novel anode material of lithium-ion batteries with high capacity and stability: A DFT calculation journal December 2021
Two-dimensional titanium carbonitrides and their hydroxylated derivatives: Structural, electronic properties and stability of MXenes Ti3C2−xNx(OH)2 from DFTB calculations journal November 2013
Tailoring Electronic and Optical Properties of MXenes through Forming Solid Solutions journal October 2020
Proton Redox and Transport in MXene-Confined Water journal December 2019
Hybrid density functional study of structural and electronic properties of functionalized Ti n + 1 X n ( X = C , N) monolayers journal June 2013
Role of Surface Structure on Li-Ion Energy Storage Capacity of Two-Dimensional Transition-Metal Carbides journal April 2014
Effect of surface functionalization on the electronic transport properties of Ti 3 C 2 MXene journal September 2015
Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes journal July 2020
Two-Dimensional Transition Metal Carbides journal January 2012
Parameter Calibration of Transition-Metal Elements for the Spin-Polarized Self-Consistent-Charge Density-Functional Tight-Binding (DFTB) Method:  Sc, Ti, Fe, Co, and Ni journal May 2007
An Improved Self-Consistent-Charge Density-Functional Tight-Binding (SCC-DFTB) Set of Parameters for Simulation of Bulk and Molecular Systems Involving Titanium journal December 2009
Advances in Density-Functional Calculations for Materials Modeling journal July 2019
Effect of Synthesis on Quality, Electronic Properties and Environmental Stability of Individual Monolayer Ti 3 C 2 MXene Flakes journal November 2016
Two-dimensional transition metal carbides and/or nitrides (MXenes) and their applications in sensors journal November 2021
Surface Functionalization of 2D MXenes: Trends in Distribution, Composition, and Electronic Properties journal March 2021
Control of MXenes’ electronic properties through termination and intercalation journal January 2019
Effects of Synthesis and Processing on Optoelectronic Properties of Titanium Carbonitride MXene journal March 2019
Toward the Physical Interpretation of Inductive and Resonance Substituent Effects and Reexamination Based on Quantum Chemical Modeling journal October 2017
Distinguishing electronic contributions of surface and sub-surface transition metal atoms in Ti-based MXenes journal February 2020
Superior structural, elastic and electronic properties of 2D titanium nitride MXenes over carbide MXenes: a comprehensive first principles study journal July 2018
Vacancy-mediated lithium adsorption and diffusion on MXene journal September 2019
Semiempirical Quantum Mechanical Methods for Noncovalent Interactions for Chemical and Biochemical Applications journal April 2016
Tuning of anisotropic electrical conductivity and enhancement of EMI shielding of polymer composite foam via CO2-assisted delamination and orientation of MXene journal July 2021
Boosting electrosynthesis of ammonia on surface-engineered MXene Ti3C2 journal June 2020
Fermiology of two-dimensional titanium carbide and nitride MXenes journal July 2021
Pre-Sodiated Ti 3 C 2 T x MXene Structure and Behavior as Electrode for Sodium-Ion Capacitors journal January 2021
Guidelines for Synthesis and Processing of Two-Dimensional Titanium Carbide (Ti 3 C 2 T x MXene) journal September 2017
Two-Dimensional Nanocrystals Produced by Exfoliation of Ti3AlC2 journal August 2011
High electrical conductivity and breakdown current density of individual monolayer Ti3C2T MXene flakes journal April 2021
Pillared Structure Design of MXene with Ultralarge Interlayer Spacing for High-Performance Lithium-Ion Capacitors journal January 2017
Surface Termination Dependent Work Function and Electronic Properties of Ti 3 C 2 T x MXene journal December 2018
Commentary: The Materials Project: A materials genome approach to accelerating materials innovation journal July 2013
Scalable Manufacturing of Free‐Standing, Strong Ti 3 C 2 T x MXene Films with Outstanding Conductivity journal April 2020
Structural and Electronic Properties and Stability of MX enes Ti 2 C and Ti 3 C 2 Functionalized by Methoxy Groups journal June 2013
DFTB+, a software package for efficient approximate density functional theory based atomistic simulations journal March 2020
Chemical Origin of Termination-Functionalized MXenes: Ti 3 C 2 T 2 as a Case Study journal August 2017
Are MXenes Promising Anode Materials for Li Ion Batteries? Computational Studies on Electronic Properties and Li Storage Capability of Ti 3 C 2 and Ti 3 C 2 X 2 (X = F, OH) Monolayer journal September 2012
Non-equilibrium Green's functions in density functional tight binding: method and applications journal June 2008
Unraveling the Charge Storage Mechanism of Ti 3 C 2 T x MXene Electrode in Acidic Electrolyte journal August 2020
Alkali Metal Intercalation in MXene/Graphene Heterostructures: A New Platform for Ion Battery Applications journal January 2019
Novel Electronic and Magnetic Properties of Two-Dimensional Transition Metal Carbides and Nitrides journal December 2012
Computational Insights into Charge Storage Mechanisms of Supercapacitors journal September 2020
2D metal carbides and nitrides (MXenes) for energy storage journal January 2017
Flexible and conductive MXene films and nanocomposites with high capacitance journal November 2014
pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes journal July 2019

Figures / Tables (9)


Similar Records

Pseudocapacitive Storage in Nanolayered Ti2NTx MXene Using Mg-Ion Electrolyte
Journal Article · 2019 · ACS Applied Nano Materials · OSTI ID:1527333

Understanding the MXene Pseudocapacitance
Journal Article · 2018 · Journal of Physical Chemistry Letters · OSTI ID:1493989

Computational Screening of MXene Electrodes for Pseudocapacitive Energy Storage
Journal Article · 2018 · Journal of Physical Chemistry. C · OSTI ID:1558549