Electrochemical Activation of Nickel Oxide Incorporated Aluminum-Zinc Alloy Matrix as an Efficient Sacrificial Anode in Marine Environments

Abstract

For cathodic protection of steel, the aluminium-zinc alloy sacrificial anodes incorporated with nickel oxide nanoparticles were fabricated. The metallurgical properties of Al-Zn sacrificial anodes enhanced substantially through the infiltration and uniform dispersion of nickel oxide nanoparticles into an Al-Zn matrix. Such effective and uniform presence of nano nickel oxide inside the interior mass of the anodes was characterized by electrochemical techniques. The anodes showed considerably low polarization, steady and high active open circuit potential and substantially decreased self-corrosion during galvanic exposure for prolonged periods. The presence of nickel oxide nanoparticles in the anode matrix caused effective destruction of the passive aluminia film, which facilitated enrichment of galvanic performance of the anode. The anode had high resistance against biofouling also.

Effect of Alloy Elements on the Performance of Al Sacrificial Anode

“…(3) As the Ga content in aluminum alloy increases, the negative potential shift value gradually decreases, and the best Ga content for negative potential shift effect is around 0.03%. (5) Bi is more effective than Pb in activating aluminum alloy by forming Solid solution to destroy oxide film. (6) Pb is beneficial for the negative shift of open circuit potential and working potential, but when the content of Ga is high, Pb promotes the positive shift of potential.…”

“…Al-Bi-Ga series alloys have the advantages of negative electrode potential, flat polarization curve, and no obvious passivation trend. They are generally used as anode materials for Aluminium-air battery, and are mainly used for civil electric power sources and offshore power free areas, such as navigation lights [1][2][3][4][5]. At present, research on the Al-Bi-Ga series alloys mainly focuses on their electrochemical performance in alkaline media environments, while there is little research on their electrochemical performance in seawater, freshwater, and soil [6][7][8][9].…”