Chapter 11 - Copper oxide as a corrosion inhibitor

Abstract

Degradation due to corrosion of the metallic materials has an adverse impact on several industries. Consequently, it causes a huge fiscal drain across the globe. Hence, there emerges a dire need for shielding the metals and alloys prone to corrosive degradation. This has impelled the researchers to design and develop sustainable additives that can act as efficient corrosion inhibitors in a practicable approach to mitigate the corrosion reaction. In this regard, several inorganic anticorrosive materials acting as corrosion inhibitors have been developed. Copper(I) oxide, Cu2O, and copper(II) oxide, CuO, are the two principal oxides of copper and have been found to act as corrosion inhibitors. CuO possesses a high surface area, high chemical stability, and superior catalytic activity, as well as acting as a p-type semiconductor. These properties of CuO make it a potential metal oxide for application in several areas such as batteries, solar cell, sensors, catalysis, and also as a corrosion inhibitor. The corrosion protection capability of CuO depends upon the dispersibility, concentration, charge, and the entire corrosive environment. Similarly, Cu2O is also an active semiconductor which has also been explored and used as corrosion-inhibiting materials on several substrates. In this chapter, the corrosion-inhibiting properties of inorganic CuO as well as Cu2O as anticorrosive materials for various corrosive environments have been overviewed. CuO and Cu2O facilitate the anticorrosive film formation on the targeted metals or metallic materials and encumber corrosive degradation of substrates exposed to aggressive media. The mechanisms of corrosion inhibition behavior exhibited by these metal oxides in diverse corrosive media have been comprehensively discussed. The knowledge of surface chemistry plays a key role in describing the mechanistic actions of inorganic corrosion inhibitors on metal surfaces in a corrosive environment. A detailed explanation of the mechanisms of corrosion and its inhibition by these oxides of copper has been explained, which can furthermore assist in developing a highly efficient corrosion inhibitor utilizing these inorganic materials. Further innovations in designing the metal oxide and composites might find potential application as superior corrosion inhibitors.