Fabrication and optical properties of NiO/ZnO hierarchical nanostructures

NiO/ZnO hierarchical nanostructures were synthesized by a combination of electrospinning, hydrothermal and ultraviolet (UV)-assisted deposition. Initially, ZnO nanofibers were synthesized by electrospinning method following thermal oxidation. Subsequently, ZnO hierarchical nanostructures were synthesized by hydrothermal method using ZnO nanofibers as templates. Finally, NiO nanoparticles were deposited on ZnO surface by UV-assisted deposition method. Morphology and characteristics of the material were determined by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS) and photoluminescence spectrum (PL). The results showed that the NiO/ZnO hierarchical nanostructures with high open space were obtained. NiO/ZnO crystals showed hexagonal structure of ZnO without phase formation of NiO. PL spectra of the NiO/ZnO material showed emission peaks shift towards longer wavelengths in the visible region with increasing the content of NiO nanoparticles.