Tribochemical reactions on FeS2 thin films

Autor: Muñoz-Cortés, Esmeralda, Nevshupa, Roman, Ares, José R., Huttel, Yves, Román García, Elisa Leonor
Rok vydání: 2019
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Resumen del trabajo presentado a Ibertriva (X Iberian Conference on Tribology / XI Iberian Vacuum Conference), celebrada en Sevilla (España) del 26 al 28 de junio de 2019.
Along the mankind's history Iron sulfide (FeS2) was used in numerous applications from firearms to jewelries, and it holds promise as a high-tech material with the use in solar cells, lithium batteries, spintronics, etc. Furthermore, it has an important role as an inexpensive, Earth-abundant, off-the-shelf catalyst effective for various heterogeneous processes including hydroliquefaction of oil shale. Combination of heterogeneous catalysis with mechanical action such as grinding, milling, rubbing, etc. is usually beneficial for increasing reaction yield and obtaining new reaction products. However, the mechanistic aspects of mechanochemical activation of pyrite are not well studied yet. This work aims to investigate tribochemical reactions on surface of FeS2 thin films prepared by sulfuration of iron. Tribochemical reactions were tracked by analyzing mass-spectra and triboemission behavior of gases, which were emitted from FeS2 due to its rubbing under high vacuum (Fig. 1). This study was complemented by ex situ characterization of mechanically affected surface zones using infrared micro-reflectance, Raman spectrometry, X-ray photoelectron spectrometry, Electron stimulated desorption and other techniques. While the main yield of thermal and electron stimulated desorption was elemental sulphur and its oxides, tribochemical reactions brought about various compounds of C, O and S: COS, CO2, CS2, where carbon originated principally from the airborne surface contamination. These findings revealed the important role of carbon in tribochemical processes of pyrite, although further studies should be carried out in order to understand the reactional pathways.
Databáze: OpenAIRE