Utilization of Group V and VI 2H-MX2 Transition Metal Dichalcogenides (M = Mo, W; Nb; X = S, Se Te) in chemical sensors, thermal-optical coatings, and structural nanocomposites require direct chemical modification of the chalcogenide basal surface. Current hybridization strategies rely on extreme reduction processes to drive a transformation from the inert 2H to the reactive 1T phase, followed by functionalization with small, organic thiols. However, conversion back to the 2H phase is incomplete, resulting in heterogeneous materials that degrade over time. Here in, we demonstrate an alternative method for direct hybridization of Group VI 2H-MX2 TMDs via alkyl organometallic reagents and Group V 2H-MX2 with Lewis acid-base donor-acceptor chemistry. The functionalized 2H-MX2 TMDs can be transferred to non-polar solvents (THF, CHCl3, CH2Cl2), and show enhanced stability from oxidation and degradation. Finally, the developed chemistries are tolerant to –ene and –yne pendant groups, facilitating post-functionalization modification via thiol-ene click chemistry or UV initiated -ene cross-linking allowing for the development of robust nanocomposites. The TMD-organic interface is robust and post-synthetic cross-linking allows for stable composites in ambient atmospheres while maintaining the unique few-to-monolayer optoelectronic properties. Modulation of the optical and mechanical properties of NbS2, NbSe2 and MoS2 is demonstrated.

Basally modified layered transition metal dichalcogenides for optically active responsive composites

2019 Spring National Meeting

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