Effect of electrodeposition potential on the growth mechanism and corrosion resistance of Zn/Al layered double hydroxide film on steel substrate via electrodeposition-hydrothermal method

In situ growth of different anion-intercalated layered double hydroxide (LDH) films on steel substrates for corrosion resistance has been achieved via the electrodeposition-hydrothermal method, but its growth process remains unclear. In this study, the effects of electrodeposition potential (−1.1 to −1.4 V) on the formation and growth mechanism of Zn/Al-NO 3 − -LDH films were investigated using XRD, FTIR, and SEM techniques. The results demonstrated that weak potentials either failed to form the LDH film or caused cracks, while excessive potentials resulted in hydrogen evolution and the formation of heterogeneous ZnO. The LDH films prepared at the optimal potential of −1.3 V were dense and uniform, with an adhesion grade of 4B, exhibiting a corrosion inhibition efficiency of 80.6 % in a 3.5 wt% NaCl solution.