Effect of modified polyacrylonitrile-based carbon fiber on the oxygen reduction reactions in seawater batteries

Modified micron-sized commercial polyacrylonitrile-based carbon fiber (PAN-CF) electrodes were prepared using an electrochemical method. Such modified electrodes exhibit remarkably improved catalytic activity together with outstanding stability for oxygen reduction reactions (ORR) in seawater batteries. The effects of three solutions, including sodium hydroxide, sulfuric acid, and sodium nitrate, on the electrode electrochemical behavior were investigated and compared. The results show that the dual actions of the surface N and O functional groups will simultaneously improve the hydrophilic properties and catalytic activity of the electrode. In addition, we observed that the pyridine nitrogen- or/and pyridone-related active sites are prone to catalyzing the electrode process.