In this study, NiO nanoparticle–decorated MoS₂ nanoflowers (MoS₂/NiO) were synthesized via a facile hydrothermal method to investigate the influence of NiO incorporation (0-12 wt%) on the structural, optical, and electronic properties of MoS₂. XRD and Rietveld refinement confirmed the hexagonal 2H-MoS₂ phase and successful integration of NiO, accompanied by lattice contraction, crystallite growth, and strain-induced structural distortion. FESEM and TEM analyses revealed well-defined MoS₂ nanoflowers with ultrathin nanosheets, with NiO nanoparticles uniformly anchored and progressively increasing surface roughness and defect density at higher loadings. Raman spectroscopy showed significant redshifts and FWHM broadening of the E₂ g ¹ and A₁ g modes, evidencing enhanced lattice disorder and phonon scattering due to NiO incorporation. UV–Vis diffuse reflectance analysis showed strong visible absorption and a systematic reduction in the indirect bandgap from 1.59 eV (pure MoS₂) to 1.30 eV (8 wt% NiO), attributed to defect-level formation and synergistic MoS₂-NiO interactions. Complementary DFT calculations further revealed bandgap narrowing, the emergence of Ni-3d states near the Fermi level, enhanced electron localization, and improved optical response in the heterostructure. The combined experimental and theoretical results establish that controlled NiO incorporation effectively tunes the microstructure, vibrational modes, electronic structure, and optical properties of MoS₂, highlighting the MoS₂/NiO nanocomposite as a promising candidate for next-generation optoelectronic, and sensing applications.
Akter et al. (Wed,) studied this question.