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)