The XRD pattern of commercial MoS2 (Figure ) shows the characteristic diffraction peaks of 2H MoS2 (98-003-9095) with high crystallinity. Raman spectrum (Figure ) shows peaks appearing at 383 and 407 cm -1 corresponding to in-plane Mo-S phonon mode (E 1 2g) and out of plane Mo-S (A1g) vibrational modes, respectively, further demonstrating the 2H phase. In addition, the peak located at 464 cm -1 corresponds to the combination of two Longitudinal Acoustic (LA) modes caused by the resonance of excitation wavelength. The other peaks represent the combination of LA modes and E 1 2g/A1g modes. To reveal the chemical state of MoS2, high resolution XPS spectra of Mo 3d and S 2p were deconvoluted. The Mo 3d spectra (Figure ) show a main doublet of Mo 3d5/2 and Mo 3d3/2 at the binding energies of 232.2 and 229.1 eV, demonstrating the Mo 4+ state. The weak doublet at 233.2 and 235.6 eV suggests slight surface oxidation to Mo 6+ . The presence of S 2-in MoS2 (Figure ) is confirmed by the doublet of S 2p3/2 and S 2p1/2 peaks at 162.8 and 163.9 eV, respectively. SEM images (Figures and) show a layered sheet-like morphology with an average lateral size of ~30 µm and a thickness of ~5 µm. Moreover, the high resolution TEM (HRTEM) image (Figure inset) clearly shows the presence of stacked multilayers with a lattice spacing of 0.62 nm which agrees well with the (002) lattice spacing of 2H MoS2. The elemental mapping of MoS2 shows homogeneous distribution of Mo and S with no impurities and a Mo: S ratio of 1:2.2 (Figure ).