Influence of Zn concentration on zinc oxide nanoparticles and their anti-corrosion property

Abstract

Abstract In the present study, zinc oxide nanoparticle was synthesized through chemical precipitation method. The size effect of zinc oxide nanoparticle under zinc acetate precursor molar concentration were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman spectroscopy (FT-Raman), Ultraviolet visible spectroscopy (UV–Visible), Photoluminescence spectroscopy (PL), Field emission scanning electron microscopy (FE-SEM), High resolution transmission electron microscopy (HR-TEM) and Energy dispersive X-ray (EDAX) analysis. X-ray Diffractogram affirms the hexagonal wurtzite structure of ZnO nanoparticles. The average crystallite size was found to be 29–22 nm. The FTIR spectrum endorsed the existing functional groups on the ZnO surfaces. Raman spectroscopy deals with the molecular vibrational response of ZnO nanoparticle. Raman scattering displays a strong E2 mode at 438 cm−1 reveals the grown nanostructures have a hexagonal wurtzite phase. The surface morphology and the elemental composition of the samples were analyzed by HR-TEM, FE-SEM and EDAX. The direct optical bandgap energy was evaluated in the range of 3.10–3.14 eV. Near band edge (NBE) emission and violet emission in the PL spectrum indicates the presence of crystal defects in ZnO lattice. The anti-corrosive property of nanoscopic size (22 nm) ZnO/Epoxy nanocomposite was studied by electrochemical impedance spectroscopy (EIS) technique in both neutral and acidic medium. The acquisition of ZnO into the plain epoxy coating materially increased the charge transfer resistance Rct by 32 times in 3% NaCl solution and 11 times in 3% Oxalic acid solution compared to bare mild steel.