“Non-hydrolytic” sol–gel synthesis of molybdenum sulfides

Abstract

Non-hydrolytic sol-gel reactions provide a low temperature solution based synthetic approach to solid-state materials. In this paper, reactions between molybdenum chloride and hexamethyldisilthiane in chloroform were explored, which gave access to both MoS 2 and Mo 2 S 3 after heat treatment of as-recovered amorphous samples to 600 to 1000 C. Interesting morphologies were obtained for MoS 2 , ranging from fused spherical particles to well-defined nanoplatelets and nanoflakes. Both 2H-and 3R-MoS 2 were observed, which formed thin hexagonal and triangular platelets, respectively. The platelets exhibited thicknesses of 10 to 30 nm, which corresponds to 15 to 50 MoS 2 layers. No attempts to prevent agglomeration were made, however, well separated platelets were observed for many samples. Heating at 1000 C led to formation of Mo 2 S 3 for samples that showed well-defined MoS 2 at lower temperatures, while less crystalline samples had a tendency to retain the MoS 2 structure.

The Power of Non-Hydrolytic Sol-Gel Chemistry: A Review

“…A variety of metal sulfides were prepared by this method (Fe, Cu, Ta, Mo, etc.) [190][191][192]. Its main advantage is that it provides pure oxygen free metal sulfides.…”

3R-MoS2 in Review: History, Status, and Outlook

“…Deepak et al 39 prepared hydrothermal MoO 3 that was subsequently reacted with a H 2 S/H 2 gas mixture at 900 °C. Alternatively, Leidich et al 72 used a nonhydrolytic sol−gel synthesis that involved preparing an amorphous precursor by reaction of MoCl 5 and hexamethyldisilathiane and then subsequent heat treatment at ∼1000 °C. The authors found that a higher 3R-MoS 2 :2H-MoS 2 ratio was obtained at higher temperatures.…”

A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes

“…In another example, Ge(OEt) 4 was treated with H 2 S to form sulfide gels [ 41 ]. Interesting nanostructured sulfide materials have been obtained from molybdenum chloride and S(Si(CH 3 ) 3 ) 2 in chloroform [ 42 ]. A similar approach, that is also based on the formation of trimethylchlorosilane, has been used to generate polydimethylsiloxane (PDMS) analogous silicon-sulfur polymers [ 43 ].…”