Matej Prijatelj, 23.3.2018 at 13:00 in F7 Seminar room

Expansion of transition metal dichalcogenides

Hella Saturnus Slovenija d.o.o., HSS – Ljubljana

Abstract:

Layered two-dimensional materials have unique physical and chemical properties due to their highly anisotropic nature.
A few of the layered crystals can be further expanded to low density / high specific surface area materials by introducing molecules to the inter planar spaces. These can be rapidly transformed to gas which inflates the layers and transforms the compact crystals to low density foam like structures. The most notable examples of expanded layered crystals are expanded vermiculite and expanded graphite. Both have numerous uses both in science and industry.
Transition metal dichalcogenides (TMDs) form layered crystals of stoichiometry MX2 (M=transition metal, X=S, Se, or Te). The best known compound, MoS₂, is an earth abundant mineral and has been used for decades as a solid lubricant and as a catalyst for petroleum desulphurization.
In this seminar I will present our results in preparation and expansion of air stable expandable MoS2 and expanded TiS₂ and TaS₂. The quality of the expanded crystals has been shown by various analytical techniques not to differ from the parent compounds and our findings show that expandable MoS2 can be considered an analogue to expandable graphite.