Microstructure and interface analyses of novel external anode mortar incorporated calcined hydrotalcite nanoparticles towards an enhanced impressed current cathodic protection

Abstract

BackgroundDuring Impressed current cathodic protection (ICCP), acidification around the mortar is occurred by anodic reactions including the transfer of hydroxide to oxygen, and significantly influences the expected lifetime of the utilized external anodes. MethodsIn this study, calcined hydrotalcite (CLDH NPs) were designed by a simple and single step and were presented to stabilize the pH around anode mortar in the ICCP system. The modified ICCP system by CLDH or its external anode was evaluated by surface, mechanical, and electrochemical analyses (impedance (EIS) and potentiodynamic polarization (PDP)) besides different techniques such as X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), and scanning electron microscope (SEM) morphology at the investigated anode mortar interface. Significant findingsThe obtained results indicated that CLDH NPs enhanced the lifetime of the external anode in ICCP by decreasing the acidification around the mortar. The corrosion current (Jcorr) went down from 1.78 to 1.62 µA/cm2 due to the CLDH NPs incorporation, which indicated the impact of CLDH NPs on the electrochemical stability of the utilized mortar. Besides, the presented CLDH NPs could potentially be applied for the engineering fabrication of the anode mortars in ICCP systems.