Tailored Novel Azomethine Ligand and Its Cu(II) Complex for Improving Corrosion Resistance and Charge–Discharge Performance of Ni in Acidic Media

ABSTRACT The ligand and its resulting CuL complex have been synthesized and meticulously characterized using a suite of spectroscopic and physicochemical techniques. These analyses reveal that the CuL complex exhibits an octahedral geometry, as confirmed by DFT calculations. These compounds not only are significant for their structural properties but also serve as potent and environmentally friendly corrosion inhibitors for nickel and its alloy systems. The efficacy of these inhibitors was evaluated in a 0.5‐M H 2 SO 4 solution, simulating a harsh acidic environment. Electrochemical methods such as impedance spectroscopy and Tafel analysis were employed to scrutinize the performance of the L ligand, the CuL complex, and their combined effect on the corrosion process of nickel in the specified acidic medium. The study underscores the relationship between the corrosion rate of nickel and the presence or absence of these inhibitors. The addition of these substances significantly mitigates the corrosion process, showcasing their protective capabilities. Interestingly, the inhibitory properties of the L ligand and CuL complex are influenced by temperature variations. At elevated temperatures, particularly 55°C, the efficiency of inhibition is substantially enhanced, especially when the concentration of the L ligand reaches 1 × 10 −3 M, as well CuL as additives, η = 98.5% and 99.7%. The enhancement of inhibitory efficacy as a function of temperature suggests that the additives undergo a chemisorption mechanism on the Ni surface within an acidic environment. This phenomenon is observed when these substances are introduced into the solution, leading to the formation of a protective layer that mitigates the corrosion process. Overall, the findings showed that increasing the temperature of a solution containing varying amounts of the CuL addition increases the inhibitory impact more than utilizing its ligand.