Template conversion of MoO3 to MoS2 nanoribbons: synthesis and electrochemical properties

Author(s)

Vieira, Luciana ^{[1, 2]} ; Martins Neto, Jose de Ribamar ^[3] ; Ferreira, Odair Pastor ^[4] ; Torresi, Roberto Manuel ^[3] ; Cordoba de Torresi, Susana Ines ^[3] ; Alves, Oswaldo Luiz ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Lab Solid State Chem LQES, Inst Chem, Campinas, SP - Brazil

^[2] Fraunhofer Inst Interfacial Engn & Biotechnol IGB, Straubing Branch, Bio Elect & Chemocatalysis BioCat, Schulgasse 11a, D-94315 Straubing - Germany

^[3] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Sao Paulo - Brazil

^[4] Univ Fed Ceara, Lab Mat Funcionais Avancados LaMFA, Dept Fis, Fortaleza, Ceara - Brazil

• Document type: Journal article
• Source: RSC ADVANCES; v. 8, n. 53, p. 30346-30353, 2018.
• Web of Science Citations: 3

Abstract

Hydrothermally synthesized -MoO3 nanoribbons were converted to MoS2 whilst retaining the same morphology by a solid-gas reaction at 800 degrees C in a H2S/H-2/N-2 atmosphere. In order to keep the nanoribbon morphology from the oxide in the sulfide, it was crucial to have a H2S stream during the whole heating process. Thereby, the first layer of sulfide is formed as soon as the oxide is activated avoiding coalescence of the nanoribbons. Afterwards, the sulfidization takes place from the outer shell to the inner core of the nanoparticles. Both -MoO3 and MoS2-NR were investigated for the electrochemical intercalation of lithium-ions. The electrochemical insertion and removal of lithium in the molybdenum oxide are accompanied by a change of color, which was measured by in situ UV-Vis. Spectroelectrochemical experiments showed a distinguished electrochromic behavior with a significant potential-dependent change in absorbance at 660 nm upon Li+ insertion. Analysis of in situ voltammetry revealed the presence of three active sites for lithium insertion in the MoO3-NRs, which are accompanied by only two chromophores in the same potential range. Voltammetric measurements of the MoS2 nanoribbons presented a reversible reduction of MoS2 to LixMoS2, followed by Mo and Li2S, which can be further reduced to Li and S at more negative potentials. Such sulfide materials are highly promising for lithium batteries. This template synthesis is a simple method to obtain high purity MoS2 nanoparticles with a controlled morphology of nanoribbons. (AU)

• FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
• Grantee: Roberto Manuel Torresi
• Support Opportunities: Research Projects - Thematic Grants