Fig. 3. (a) Raman spectra and (b) frequency difference between A_1g mode and E¹_2g mode of MoS₂ nanosheets with ZnO nanopatches (process cycle: 10, 20, 30, and 40 cycles). (c) X-ray photoelectron spectroscopy (XPS) of MoS₂ nanosheets with ZnO nanopatches. (i) Mo 3d, (ii) S 2p, (iii) Zn 2p, and (iv) O 1s core level spectra of MoS₂ nanosheets with ZnO nanopatches.