Site-projected electronic structure of two-dimensional Ti3C2 MXene: the role of the surface functionalization groups. Issue 45 (2nd November 2016)

• Record Type: Journal Article
• Authors: Magne, Damien; Mauchamp, Vincent; Célérier, Stéphane; Chartier, Patrick; Cabioc'h, Thierry
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 45(2016)
• Page Start: 30946
• Page End: 30953
• Publication Date: 2016-11-02
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp05985f
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The role of the surface groups in chemical bonding in two dimensional Ti3 C2 is evidenced at the nano-object level. Abstract : The role of the surface groups T (T = OH, O or F) in the chemical bonding in two-dimensional Ti3 C2 T x MXene is directly evidenced combining electron energy-loss spectroscopy in a transmission electron microscope and simulations based on density functional theory. By focusing on the 1s core electrons excitations of the C and (F, O) atoms, the site projected electronic structure is resolved. The Electron Energy-Loss Near Edge Structures (ELNES) at the C-K edge are shown to be sensitive to the chemical nature and the location of the T-groups on the MXene's surface and thereby allow for the characterization of the MXene's functionalization on the nanometre scale. In addition, the ELNES at the C and F-K edges are shown to be determined by the hybridizations of these atoms with the Ti d bands: these edges are thus relevant probes of the Ti d density of states close to the Fermi level which is of particular interest since it drives most of the Ti3 C2 T x electronic properties. Finally, the crucial role in the MXene's functionalization of the etchant used for its synthesis is evidenced by locally determining the [O]/[F] concentration ratio using the corresponding K edges. This ratio is shown to be drastically increased from 1.4 to 3.5 when using HF or LiF/HCl respectively.