CTAB mediated synthesis of ZnO nanoparticles: Structural, optical and enhanced blue-green optical emission

Abstract

In this work, a series of cetyltrimethylammonium bromide (CTAB) mediated zinc-oxides (ZnO) nanoparticles (NPs) have been synthesized using simple, economical and mass-scale productive solid-state reaction method. The different concentrations of CTAB (0%, 2%, 5% and 7%) have been used to investigate the effect of surfactant on structural and defects mediated optical emission. In structural and morphological analysis, the X-ray diffraction patterns (XRD) exhibited that CTAB assisted ZnO NPs has a hexagonal wurtzite crystalline structure and the average crystallite sizes have been found to ranging from ∼50 nm to 12 nm corresponding to different lattice planes. The scanning electron microscopy (SEM) showed non uniform grain distribution of NPs with the addition of CTAB in ZnO which clearly illustrates an improvement in the surface morphology of ZnO NPs due to re-distribution of crystalline grains. UV–visible (UV–Vis) absorption spectra show blue-shift in absorption peaks with addition of surfactants. Photoluminescence (PL) spectra have been recorded to investigate the defect mediated optical emissions. Enhanced blue-green emission peaks have been observed with increasing CTAB concentrations indicates that the prepared samples have a good crystalline structure with rarer oxygen vacancies.