High-performance electrocatalyst made from lignosulfonate nanofiber composited with manganese dioxide without carbonation process

Lignin-based electrospun nanofiber composited with MnO₂ mats is synthesized for electrocatalyst applications. Lignin-based nanofiber is produced from Sodium lignosulfonate (SLS) through electrospinning, using Polyvinyl acetate (PVA) as polymer followed by stabilization using iodine treatment. The composited process is observed by introducing KMnO₄ following with hydrothermal process, and it is compared between before and after the electrospinning process. A conductivity, specific surface area, and morphology analysis confirm that the PVA:SLS mass ratio of 15:4.5 and 15:6 showed the best choice. In addition, x-ray diffraction exhibit that the sample composited with MnO₂ either before or after electrospinning (pre- and post-electrospinning composite) has the same amorphous phase of α-MnO₂. Consequently, lignin nanofiber with PVA:SLS mass ratio of 15:4.5 composited with MnO₂ before the electrospinning process possesses has the best electrochemical properties with a current density of 1.5 mA/cm² and at potential applied of 0.4 V versus Ag/AgCl. Furthermore, the electron transferred, n occurred is 3.01, indicating the sample shows high potential to be used as an electrocatalyst following the two-electron pathway oxygen reduction reaction (ORR) mechanism.