Synergistic lubrication performance by incommensurately stacked ZnO-decorated reduced graphene oxide/MoS2 heterostructure

[Display omitted] •Weak interfacial interaction-driven incommensurate stacking between the graphene and MoS2.•Curved and bent structure of MoS2 nanosheets reduced the interparticle interaction.•Gr-MS-Zn heterostructure as a lubricant additive significantly reduced the friction and wear.•Formation of...

Full description

Saved in:
Bibliographic Details
Published in:Journal of colloid and interface science 2020-11, Vol.580, p.730-739
Main Authors: Chouhan, Ajay, Sarkar, Tarun K., Kumari, Sangita, Vemuluri, Srikanth, Khatri, Om P.
Format: Article
Language:English
Subjects:
Dispersion stability
Graphene
Incommensurate stacking
Interfacial interaction
Lubrication
MoS2
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •Weak interfacial interaction-driven incommensurate stacking between the graphene and MoS2.•Curved and bent structure of MoS2 nanosheets reduced the interparticle interaction.•Gr-MS-Zn heterostructure as a lubricant additive significantly reduced the friction and wear.•Formation of a Gr-MS-Zn-based surface protective tribo thin film of low shear strength.•Incommensurately stacked graphene and MoS2 nanosheets furnished excellent tribo-performance. Incommensurate stacking between two different types of two-dimensional layered materials furnished the weak interfacial interaction due to the mismatch of their lattice structure, which can be harnessed for development of new generation lubricant additives. Herein, a facile approach is presented to synthesize the ZnO-decorated reduced graphene oxide/MoS2 (Gr-MS-Zn) nanosheets. The Fourier transform infrared, X-ray photoelectron spectroscopic, Raman, and transmission electron microscopic analyses confirmed the preparation of Gr-MS-Zn heterostructure. The MoS2 nanosheets having 3–7 molecular lamellae are thoroughly distributed over the graphene skeleton via weak interfacial interaction. The curved and bent structure of MoS2 nanosheets grown over the graphene lamellae subsidized the cohesive interaction and furnished the stable dispersion of Gr-MS-Zn in the fully formulated engine oil. The minute dose of Gr-MS-Zn as a nano-additive to engine oil significantly enhanced the tribological performance between the steel-steel tribopair by decreasing the friction (37%) and the wear volume (87%). The microscopic and spectroscopic analyses revealed the formation of a Gr-MS-Zn-based surface protective tribo thin film of low shear strength. The enhanced tribo performance is collectively attributed to (a) uninterrupted supply of ultrathin Gr-MS-Zn nanosheets to tribo-interfaces, (b) stable dispersion of Gr-MS-Zn, and (c) the significantly low shear strength, arising from weak interfacial interaction between the incommensurately stacked graphene and MoS2 nanosheets.
ISSN:0021-9797
1095-7103
DOI:10.1016/j.jcis.2020.07.033