Impetuous exfoliation of tungsten disulfide into a few-layer nanoscale form due to super active collagenase biomolecules

We report on the collagenase activated progressive, yet spontaneous exfoliation of the stacked tungsten disulfide (WS2) system into a few-layer form via interface engineering and taking advantage of diffusion of hydronium ions (H3O+) through the interfaces. As evidenced from the Raman spectra, the apparent improvement of intensity ratio (E12g -to- A1g) from a value of 0.55 to 1.5, along with the evolution of (E12g+ LA), (A1g+ LA) modes have confirmed irreversible exfoliation of the stack of WS2 layers into its nano-dimensional form. Atomic force microscopy imaging confirms the exfoliation of WS2 system down to ten layers after eight days of continuous treatment with the super active biomolecules. The passage of H3O+ ions was believed to weaken the van der Waal forces between the WS2 layers and eventually cause impetuous exfoliation. The entropy change (ΔSt) during exfoliation and up to ten layers was predicted as, 1.83 ± 0.03 mJ m−2 K−1. The saturative trends of work accomplished and entropy change beyond six days of treatment indicate occurrence of complete exfoliation and with a high yield of nanoscale WS2. The scope of understanding the development of exfoliated layers linking diffraction, spectroscopic and imaging data is immensely beneficial for exploiting hybrid 2D nanostructures with suitable surface anchoring and designing miniaturized elements.