Open AccessTermination-Property Coupling via Reversible Oxygen Functionalization of MXenes
Author(s) -
James L. Hart,
Kanit Hantanasirisakul,
Yury Gogotsi,
Mitra L. Taheri
Publication year - 2022
Publication title -
acs nanoscience au
Language(s) - English
Resource type - Journals
ISSN - 2694-2496
DOI - 10.1021/acsnanoscienceau.2c00024
Subject(s) - mxenes , surface modification , annealing (glass) , materials science , nitride , plasma , transition metal , carbide , metal , nanotechnology , chemical physics , chemistry , layer (electronics) , composite material , physics , metallurgy , quantum mechanics , catalysis , biochemistry
MXenes are a growing family of 2D transition-metal carbides and nitrides, which display excellent performance in myriad of applications. Theoretical calculations suggest that manipulation of the MXene surface termination (such as =O or -F) could strongly alter their functional properties; however, experimental control of the MXene surface termination is still in the developmental stage. Here, we demonstrate that annealing MXenes in an Ar + O 2 low-power plasma results in increased =O functionalization with minimal formation of secondary phases. We apply this method to two MXenes, Ti 2 CT x and Mo 2 TiC 2 T x (T x represents the mixed surface termination), and show that in both cases, the increased =O content increases the electrical resistance and decreases the surface transition-metal's electron count. For Mo 2 TiC 2 O x , we show that the O content can be reversibly altered through successive vacuum and plasma annealing. This work provides an effective way to tune MXene surface functionalization, which may unlock exciting surface-dependent properties.