A biodegradable polymer-assisted efficient and universal exfoliation route to a stable few layer dispersion of transition metal dichalcogenides

Quasi two-dimensional transition metal dichalcogenides (2D-TMDs) with 1-5 layers have been obtained by developing an effective and highly efficient bio-based polymer-solvent system by mild ultrasonication. The hydroxypropyl cellulose (HPC)/1-Butanol (BuOH) system was determined to be an universal polymer-solvent system to effectively exfoliate the bulk transition metal dichalcogenides (TMDs) MoS2, TiS2, WS2, NbS2 and MoSe2. The above process is significant as it is a room temperature liquid phase exfoliation method that leads to a stable dispersion of a few layer 2D-TMD having significant proportion (>50%) of exfoliated material which remains stable in suspension for several months.