Abstract
In this work, nickel oxide nanoparticles (NiO NPs) were synthesized using ultrasonic wave-assisted green synthesis route with Delonix elata leaf extract as a reducing and capping agent. The phase structure, crystallinity, thermal and physical stability, surface morphology, and surface area of the produced NiO NPs were investigated using X-ray diffraction, field-emission scanning electron microscopy high-resolution transmission electron microscopy, thermogravimetric/differential thermal analysis, and Brunauer–Emmett–Teller analysis. The surface properties such as roughness and hardness of NiO NP-coated plates were determined using atomic force microscopy and nanoindentation techniques. The electrochemical corrosion behavior of NiO NPs was studied in the presence of an aqueous electrolyte medium, that is, 3.5% NaCl, 6 M KOH, 1 M HCl, and 1 M H2SO4. The Tafel plot showed that the corrosive nature of Zn and Mg plates significantly decreases when the plates were coated with the prepared high surface area and mesoporous NiO NPs under all electrolytes, especially in acidic medium, that is, 1 M H2SO4.
