Author(s): Garcia-Basabe, Yunier ; Peixoto, Gabriela F. ; Grasseschi, Daniel ; Romani, Eric C. ; Vicentin, Flávio C. ; Villegas, Cesar E. P. ; Rocha, Alexandre R. [UNESP] ; Larrude, Dunieskys G.
Date: 2020
Persistent ID: http://hdl.handle.net/11449/199541
Origin: Oasisbr
Made available in DSpace on 2020-12-12T01:42:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-09
In this work a simple approach to transform MoS2 from its metallic (1T′ to semiconductor 2H) character via gold nanoparticle surface decoration of a MoS2 reduced graphene oxide (rGO) nanocomposite is proposed. The possible mechanism to this phase transformation was investigated using different spectroscopy techniques, and supported by density functional theory theoretical calculations. A mixture of the 1T′- and 2H-MoS2 phases was observed from the Raman and Mo 3d high resolution x-ray photoelectron spectra analysis in the MoS2-rGO nanocomposite. After surface decoration with gold nanoparticles the concentration of the 1T′ phase decreases making evident a phase transformation. According to Raman and valence band spectra analyzes, the Au nanoparticles (NPs) induce a p-type doping in MoS2-rGO nanocomposite. We proposed as a main mechanism to the MoS2 phase transformation the electron transfer from Mo 4dxy,xz,yz in 1T′ phase to AuNPs conduction band. At the same time, the unoccupied electronic structure was investigated from S K-edge near edge x-ray absorption fine structure spectroscopy. Finally, the electronic coupling between unoccupied electronic states was investigated by the core hole clock approach using resonant Auger spectroscopy, showing that AuNPs affect mainly the MoS2 electronic states close to Fermi level.
Universidade Federal da Integracao Latino-Americana UNILA
Inorganic Chemistry Department Chemistry Institute Federal University of Rio de Janeiro (UFRJ)
MackGraphe-Graphene and Nanomaterial Research Center Mackenzie Presbyterian University
SENAI Innovation Institute for Virtual Production Systems
Brazilian Synchrotron Light Laboratory (LNLS) Brazilian Center for Research in Energy and Materials (CNPEM)
Departamento de Ciencias Universidad Privada Del Norte, Av. Andrés Belaunde Cdra. 10 s/n, Comas
Instituto de Física Teórica State University of Sao Paulo (UNESP)
Instituto de Física Teórica State University of Sao Paulo (UNESP)
