Morphological features and photoluminescence of ZnO and ZnO decorated S,N-doped few-layered graphene (ZnO–S, N-FLGs)

Abstract

Zinc oxide (ZnO) nanoparticles and ZnO decorated S, N doped few-layered graphene (1 wt%, 2 wt%, and 3 wt %) were synthesized using a simple chemical method followed by calcination. The chemical composition, morphology, lattice vibrations, and distinct structural features of the ZnO and ZnO–S,N-FLGs composites have been characterized by X-ray diffraction (XRD) and μ-Raman spectroscopy. X-ray diffraction (XRD) patterns conform that the pristine ZnO nanostructures and ZnO–S,N-FLGs composites were formed. Electron microscopic techniques (FESEM & TEM) were employed to observe the morphologies. Field emission electron microscope (FESEM) images showed that different morphologies of ZnO nanostructures were decorated on S,N-FLGs sheets. Transmission electron microscope (TEM) images exposed that ZnO different morphologies were uniformly distributed on S,N-FLGs sheets. However, the TEM images showed that nanocomposites' morphology changed significantly with increased S,N-FLGs concentration. The results showed that ZnO with different morphologies was well dispersed on the S,N doped FLGs, which serve as ZnO nanoparticle growing supports and the morphology controller. The Raman shift of the 2D peak shows the interaction between ZnO and S,N-FLGs. It was found that control of the incorporated functional groups of the S,N-FLGs with the assistance of calcination temperature during the synthesis. The morphology of ZnO, such as hexagonal, nanorods, and nanospheres (1 wt%, 2 wt%, and 3 wt% S,N-FLGs). The bandgap of all the synthesized materials was calculated by UV–vis spectroscopy (UV–vis). The photoluminescence (PL) spectra were measured at room temperature (RT). The intensity of peaks of ZnO–S, N-FLGs composites decreased compared to ZnO in PL spectra because of oxygen vacancies and defects. The intense UV emission indicates interesting optical properties were reported in detail.