International Journal of Hydrogen Energy, Vol.45, No.30, 15380-15389, 2020
Hydrophobic octadecylamine-functionalized graphene/TiO2 hybrid coating for corrosion protection of copper bipolar plates in simulated proton exchange membrane fuel cell environment
In the present work, G-TiO2 and G-ODA-TiO2 hybrids were prepared by concurrent surface functionalization and reducing of graphene oxide (GO) using octadecylamine (ODA). The G-TiO2 and G-ODA-TiO2 powders were deposited on the copper surface by electrophoretic deposition (EPD) technique. The wettability of coatings revealed the preferable hydrophobic characteristic of G-ODA-TiO2 compared to G-TiO2 and bare copper with water contact angles of 130 degrees, 101 degrees, and 87 degrees, respectively. The anti-corrosion performance of specimens in a 0.5 M H2SO4 solution was appraised by the potentiodynamic polarization (Tafel analysis), which clearly showed that G-TiO(2)and G-ODA-TiO2 coatings can act as a great barrier for copper in the corrosive H2SO4 solution. The corrosion inhibition of G-TiO2 and G-ODA-TiO2 was about 2 and 15 times higher than bare copper. Moreover, the hydrophobic G-ODA-TiO2 coating on copper reached a much lower interfacial contact resistance (ICR) than the other samples. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.