Journal article
Basal-Plane Functionalization of Chemically Exfoliated Molybdenum Disulfide by Diazonium Salts
Publication Details
Authors: | Knirsch, K.; Berner, N.; Nerl, H.; Cucinotta, C.; Gholamvand, Z.; McEvoy, N.; Wang, Z.; Abramovic, I.; Vecera, P.; Halik, M.; Sanvito, S.; Düsberg, G.; Nicolosi, V.; Hauke, F.; Hirsch, A.; Coleman, J.; Backes, C. |
Publisher: | AMER CHEMICAL SOC |
Publication year: | 2015 |
Journal: | ACS Nano |
Pages range : | 6018-6030 |
Volume number: | 9 |
Issue number: | 6 |
Start page: | 6018 |
End page: | 6030 |
Number of pages: | 13 |
ISSN: | 1936-0851 |
DOI-Link der Erstveröffentlichung: |
Abstract
Although transition metal dichalcogenides such as MoS2 have been recognized as highly potent two-dimensional nanomaterials, general methods to chemically functionalize them are scarce. Herein, we demonstrate a functionalization route that results in organic groups bonded to the MoS2 surface via covalent C-S bonds. This is based on lithium intercalation, chemical exfoliation and subsequent quenching of the negative charges residing on the MoS2 by electrophiles such as diazonium salts. Typical degrees of functionalization are 10-20 atom % and are potentially tunable by the choice of intercalation conditions. Significantly, no further defects are introduced, and annealing at 350 degrees C restores the pristine 2H-MoS2. We show that, unlike both chemically exfoliated and pristine MoS2, the functionalized MoS2 is very well dispersible in anisole, confirming a significant modification of the surface properties by functionalization. DFT calculations show that the grafting of the functional group to the sulfur atoms of (charged) MoS2 is energetically favorable and that S-C bonds are formed.
Although transition metal dichalcogenides such as MoS2 have been recognized as highly potent two-dimensional nanomaterials, general methods to chemically functionalize them are scarce. Herein, we demonstrate a functionalization route that results in organic groups bonded to the MoS2 surface via covalent C-S bonds. This is based on lithium intercalation, chemical exfoliation and subsequent quenching of the negative charges residing on the MoS2 by electrophiles such as diazonium salts. Typical degrees of functionalization are 10-20 atom % and are potentially tunable by the choice of intercalation conditions. Significantly, no further defects are introduced, and annealing at 350 degrees C restores the pristine 2H-MoS2. We show that, unlike both chemically exfoliated and pristine MoS2, the functionalized MoS2 is very well dispersible in anisole, confirming a significant modification of the surface properties by functionalization. DFT calculations show that the grafting of the functional group to the sulfur atoms of (charged) MoS2 is energetically favorable and that S-C bonds are formed.
Keywords
1T-polytype, basal-plane, chemical exfoliation, covalent functionalization, layered materials, molybdenum disulfide, transition metal dichalcogenides
