Barrier coating of super hydrophobically modified nano zirconia on copper: study of electrochemical anti-corrosion properties

Purpose Copper, the fifth most common metal, has been prized for architectural and aesthetic artwork because of its distinctive colour. On exposure of copper metal to air and moisture, it corrodes, and a blue-green layer appears on its surface. The purpose of this study to develop a barrier coating that can protect copper from corrosion by preventing air and moisture. Design/methodology/approach The present work investigates a durable, self-cleaning and transparent nanostructured superhydrophobic nano zirconia-based barrier coating on copper. ZrO 2 was prepared by sol-gel method and further hydrophobically modified. The nano zirconia was characterised by particle size analysis and transmission electron microscopy. Morphological characteristics of the coated surface were analysed by SEM and AFM, which revealed a nanoscale rough surface. Anti-corrosive properties of coated copper were analysed by linear polarise resistance (LPR) and electrochemical impedance spectra (EIS). Findings A contact angle in the range of 149.9°–172.3° confirmed the coating’s superhydrophobic nature. Anti-corrosive properties were analysed by LPR and EIS, which indicated corrosion resistance efficiency of 99.96%. Stability of the coating was conducted for 60 days in the air and salt solution, which revealed a 12% and 15% change in contact angle in air and salt solution, respectively. Anti-corrosive properties and coating stability studies support the potential of the coating material for copper metal protection. Originality/value Researchers have developed a variety of coating materials for corrosion protection of metal, but most of these coating materials form a thick layer on metal, which hides its lustre. Copper is known for its pink lustre, and such coating can hide or decrease its lustre. The authors proposed a sol-gel-assisted nano zirconia-based transparent barrier coating that can prevent copper from corrosion without hiding its pink lustre.