000K  utf8
1100  $c2023
1500  eng
2050  urn:nbn:de:gbv:8:3-2023-00075-9
2051  10.3390/c9010007
3000  Ofoegbu, Stanley Udochukwu
3010  Ferreira, Mário Guerreiro Silva
3010  Nogueira, Helena I. S.
3010  Zheludkevich, Mikhail
4000  Comparison of the Electrochemical Response of Carbon-Fiber-Reinforced Plastic (CFRP), Glassy Carbon, and Highly Ordered Pyrolytic Graphite (HOPG) in Near-Neutral Aqueous Chloride Media  [Ofoegbu, Stanley Udochukwu]
4209  Carbon-fiber-reinforced polymers (CFRP), being conductive, are capable of supporting cathodic oxygen reduction reactions (ORR) and thus promote galvanic corrosion when coupled to many metallic materials. Hence, understanding cathodic processes at carbon surfaces is critical to developing new strategies for the corrosion protection of multi-material assemblies. In the present work, the electrochemical responses of CFRP, glassy carbon, and HOPG (Highly Ordered Pyrolytic Graphite) have been evaluated in a quiescent 50 mM NaCl solution, and their respective activities towards ORR have been ranked. Employing the averages of the specific charges (CFRP, 129.52 mC cm−2; glassy carbon, 89.95 mC cm−2; HOPG, 60.77 mC cm−2) passed during 1 h polarization of each of the 3 carbon surfaces at −1000 mVSCE in the test media as a ranking criterion, the propensities of the 3 carbon surfaces (CFRP, GC, and HOPG) to support cathodic activities that can lead to anodic metal dissolution on galvanic coupling to metallic materials are ranked thusly; CFRP > GC > HOPG. This ranking is consistent with the trend of capacitance values obtained in this work: CFRP (19.5 to 34.5 μF cm−2), glassy carbon (13.6 to 85.5 μF cm−2), and HOPG (1.4 to 1.8 μF cm−2). A comparison of electrochemical data at potentials relevant to galvanic coupling to metals indicated that at these cathodic potential(s) the CFRP surface is the most electrochemically active of the studied carbon surfaces.These results could provide valuable insights on plausible strategies for designing carbon surfaces and carbon fiber composites with reduced activity toward ORR for corrosion protection applications or enhanced activity towards ORR for energy applications.
4950  https://doi.org/10.3390/c9010007$xR$3Volltext$534
4950  https://nbn-resolving.org/urn:nbn:de:gbv:8:3-2023-00075-9$xR$3Volltext$534
4961  https://macau.uni-kiel.de/receive/macau_mods_00003395
5051  600
5550  carbon surfaces
5550  cathodic polarization
5550  CFRP
5550  galvanic coupling
5550  multi-material combinations
5550  oxygen reduction reactions (ORR)