skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on April 4, 2020

Title: Surface Termination Dependent Work Function and Electronic Properties of Ti 3C 2T x MXene

Abstract

MXenes, an emerging family of 2D transition metal carbides and nitrides, have shown promise in various applications, such as energy storage, electromagnetic interference shielding, conductive thin films, photonics, and photothermal therapy. Their metallic nature, wide range of optical absorption, and tunable surface chemistry are the key to their success in those applications. The physical properties of MXenes are known to be strongly dependent on their surface terminations. In this study, we investigated the electronic properties of Ti 3C 2T x for different surface terminations, as achieved by different annealing temperatures, with the help of photoelectron spectroscopy, inverse photoelectron spectroscopy, and density functional theory calculations. We find that fluorine occupies solely the face-centered cubic adsorption site, whereas oxygen initially occupies at least two different adsorption sites, followed by a rearrangement after fluorine desorption at high annealing temperatures. The measured electronic structure of Ti 3C 2T x showed strong dispersion of more than 1 eV, which we conclude to stem from Ti–O bonds by comparing it to calculated band structures. We further measured the work function of Ti 3C 2T x as a function of annealing temperature and found that it is in the range of 3.9–4.8 eV, depending on the surfacemore » composition. A comparison of the experimental work function to detailed density functional theory calculations shows that the measured value is not simply an average of the work function values of uniformly terminated Ti 3C 2 surfaces but that the interplay between the different surface moieties and their local dipoles plays a crucial role.« less

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [4];  [3];  [2]; ORCiD logo [3]; ORCiD logo [1]
  1. Humboldt Univ. of Berlin (Germany); Helmholtz-Zentrum Berlin (HZB), (Germany). German Research Centre for Materials and Energy
  2. Univ. of Pennsylvania, Philadelphia, PA (United States)
  3. Drexel Univ., Philadelphia, PA (United States)
  4. Institut für Physik &, IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin 12489, Germany; Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Korea
Publication Date:
Research Org.:
Drexel Univ., Philadelphia, PA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1508005
Grant/Contract Number:  
SC0018618
Resource Type:
Accepted Manuscript
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Name: Chemistry of Materials; Journal ID: ISSN 0897-4756
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Schultz, Thorsten, Frey, Nathan C., Hantanasirisakul, Kanit, Park, Soohyung, May, Steven J., Shenoy, Vivek B., Gogotsi, Yury, and Koch, Norbert. Surface Termination Dependent Work Function and Electronic Properties of Ti3C2Tx MXene. United States: N. p., 2019. Web. doi:10.1021/acs.chemmater.9b00414.
Schultz, Thorsten, Frey, Nathan C., Hantanasirisakul, Kanit, Park, Soohyung, May, Steven J., Shenoy, Vivek B., Gogotsi, Yury, & Koch, Norbert. Surface Termination Dependent Work Function and Electronic Properties of Ti3C2Tx MXene. United States. doi:10.1021/acs.chemmater.9b00414.
Schultz, Thorsten, Frey, Nathan C., Hantanasirisakul, Kanit, Park, Soohyung, May, Steven J., Shenoy, Vivek B., Gogotsi, Yury, and Koch, Norbert. Thu . "Surface Termination Dependent Work Function and Electronic Properties of Ti3C2Tx MXene". United States. doi:10.1021/acs.chemmater.9b00414.
@article{osti_1508005,
title = {Surface Termination Dependent Work Function and Electronic Properties of Ti3C2Tx MXene},
author = {Schultz, Thorsten and Frey, Nathan C. and Hantanasirisakul, Kanit and Park, Soohyung and May, Steven J. and Shenoy, Vivek B. and Gogotsi, Yury and Koch, Norbert},
abstractNote = {MXenes, an emerging family of 2D transition metal carbides and nitrides, have shown promise in various applications, such as energy storage, electromagnetic interference shielding, conductive thin films, photonics, and photothermal therapy. Their metallic nature, wide range of optical absorption, and tunable surface chemistry are the key to their success in those applications. The physical properties of MXenes are known to be strongly dependent on their surface terminations. In this study, we investigated the electronic properties of Ti3C2Tx for different surface terminations, as achieved by different annealing temperatures, with the help of photoelectron spectroscopy, inverse photoelectron spectroscopy, and density functional theory calculations. We find that fluorine occupies solely the face-centered cubic adsorption site, whereas oxygen initially occupies at least two different adsorption sites, followed by a rearrangement after fluorine desorption at high annealing temperatures. The measured electronic structure of Ti3C2Tx showed strong dispersion of more than 1 eV, which we conclude to stem from Ti–O bonds by comparing it to calculated band structures. We further measured the work function of Ti3C2Tx as a function of annealing temperature and found that it is in the range of 3.9–4.8 eV, depending on the surface composition. A comparison of the experimental work function to detailed density functional theory calculations shows that the measured value is not simply an average of the work function values of uniformly terminated Ti3C2 surfaces but that the interplay between the different surface moieties and their local dipoles plays a crucial role.},
doi = {10.1021/acs.chemmater.9b00414},
journal = {Chemistry of Materials},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {4}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on April 4, 2020
Publisher's Version of Record

Save / Share: