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Effects of Water Intercalation and Tribochemistry on MoS 2 Lubricity: An Ab Initio Molecular Dynamics Investigation
Author(s) -
Levita Giacomo,
Righi Maria C.
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201601143
Subject(s) - intercalation (chemistry) , molecular dynamics , lubricity , chemical physics , ab initio , molecule , adsorption , materials science , ab initio quantum chemistry methods , work (physics) , enhanced data rates for gsm evolution , computational chemistry , chemistry , inorganic chemistry , thermodynamics , composite material , organic chemistry , physics , telecommunications , computer science
To date, no clear conclusion has been reached on the atomistic mechanisms that govern the observed decrease of lubricating capabilities of MoS 2 in humid environments. Based on ab initio molecular dynamic calculations, we show that intercalated water molecules hinder the sliding motion of both regular and defective layers considerably, with the velocities decaying exponentially with time. However, in the presence of an applied load and exposed edge terminations, water is rapidly removed from the interface and is adsorbed on the edges either in undissociated form or as OH/H fragments. These outcomes suggest that the interlayer slipperiness can be reduced by the presence of water even in the absence of any chemical oxidation. Our work could help to set up more dedicated experiments to further tackle a technologically relevant issue for the applications of MoS 2 ‐based lubricants.