Yttrium doped ZnO nanoparticles towards corrosion protection  epoxy nanocomposite coatings in neutral and acidic medium

Abstract In the present study, synthesized pure and Yttrium (0.5, 1.0, 1.5, 2.0 and 2.5 mM) doped Zinc Oxide (YZO) nanoparticles by chemical precipitation method. The size effect of Zinc oxide nanoparticle under Yttrium acetate precursor molar concentration were investigated by various characterization techniques. X-ray diffractogram asserts the hexagonal wurtzite structure of ZnO nanoparticles. The average crystallite size was found to be 22 − 17 nm. The FTIR and Raman spectrum inscribed the chemical composition and vibrational frequencies of the synthesized samples. The hexagonal shape, surface morphology, particle size and elemental composition of the samples were analysed by FESEM, HRTEM and EDAX. The optical bandgap energy was estimated in the range of 3.148–3.175 eV. PL spectra of yttrium doped ZnO nanoparticles at various concentration exhibit a strong UV emission band and green emission band. The anticorrosive property of nanoscopic size (17 nm) YZO/epoxy nanocomposite was studied by electrochemical impedance spectroscopy (EIS) technique in both neutral and acidic medium. Epoxy/YZO nanocomposites were prepared using different loadings (0.05, 0.10 and 0.15 wt %) of yttrium doped ZnO nanoparticles. Epoxy/YZO nanocomposites were applied on mild steel substrates. The acquisition of yttrium doped ZnO into the plain epoxy coating materially increased the charge transfer resistance Rct by 3.5 times in oxalic acid solution as against epoxy/ZnO coating. The synthesized sample has also displayed excellent antimicrobial activity against gram positive and gram-negative bacteria. This encapsulates that the YZO nanoparticles are a potential eco-friendly, antibacterial and anti-corrosive fillers in coat on mild steel.