Eliminating the Galvanic Corrosion Effect of Graphene Coating by an Accurate and Rapid Self‐Assembling Defect Healing Approach

• Published in: Advanced functional materials Vol. 32; no. 13
• Main Authors: Wu, Yinghao, Sun, Tian‐Yu, Ge, Tianhao, Zhao, Wenjie, Huang, Liang‐Feng
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.03.2022
• Subjects: 1H,1H,2H,2H‐perfluorooctanethiol; Atomic bonding; Bonding strength; Chemical bonds; Chemical vapor deposition; Coating effects; Corrosion; Corrosion effects; Corrosion resistance; defect healing; Defects; electronic properties; Galvanic corrosion; Graphene; Healing; Materials science; Protective coatings; Substrates
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202110264

The structural defects on graphene grown on a metal substrate via chemical vapor deposition can readily stimulate severe galvanic corrosion phenomena. For any defect passivation method that can be technologically promising for superior corrosion‐resistant graphene coatings, efficiency and accuracy are two critical but still challenging requirements. In this work, the authors design a rapid processing method (within just 15 min) that can accurately heal various structural defects of different types and sizes on graphene coating, where the hydrophobic 1H,1H,2H,2H‐perfluorooctanethiol (PFOT) molecules are self‐assembled onto the defect sites. The surface morphologies, atomic bonding states, and defect‐healing mechanism are deeply understood by comprehensive experimental characterizations and first‐principles calculations. Both weak physical PFOT‐pristine graphene bonding and strong covalent PFOT‐defect bonding are two microscopic factors that enhance defect healing efficiency and accuracy. Spatially resolved electronic and electrochemical measurements show that the defect‐healing not only effectively suppresses galvanic corrosion phenomena during both short‐term and long‐term tests, but also well preserves the superior electronic conductivity of pristine graphene. The defect healing strategy proposed here can find its wide potential applications in the fields like electro‐industry, coating, and sensors that require the graphene coatings having both superior corrosion resistance and electronic property. The detrimental inborn galvanic corrosion effect of chemical vapor deposition‐graphene coating is effectively eliminated by accurately and rapidly healing the defect sites by 1H,1H,2H,2H‐perfluorooctanethiol (PFOT) molecules, which considerably improves the anticorrosion of the metal substrate. Joint experimental characterizations and ab‐initio calculations reveal the essential role of multilateral coupling between defects, graphene/metal interface, and inhibiting PFOT molecules with high defect‐healing efficiency.