Synthesis of Nanofiber Composite Based on Biomass Derived Material Conjugated with Nanocapsules of Ni-Co Oxides as an Effective Catalyst for Oxygen Reduction Reaction and Oxygen Evolution Reaction

The development of low-cost, high-performance catalysts and the use of renewable sources for use in oxygen reduction and evolution reactions have received considerable attention. In this study, using an efficient and single-stage method using nickel-cobalt oxides and a material obtained from southern cattail or karrapo (KP) as available biomass, a catalyst with nano-fiber structures was synthesized (NFKP/Ni-Co). In order to synthesize the NFKP/Ni-Co, the Ni-Co compound, by sol-gel method in the autoclave at 200°C for 12h, was loaded on the surface of KP, and finally, it was pyrolyzed at 700°C for 3h in an argon atmosphere. The structure, composition, morphology, and catalytic activity of the synthesized nanocomposites have been investigated. The TEM studies prove the formation of 20nm of nanoparticles of Ni-Co oxides on the surface of nanofibers. Here, KP acted as a boat-like platform in which Ni-Co oxides were loaded. Due to the synergistic effect between KP and Ni-Co oxides, NFKP/Ni-Co nanocomposite exhibit remarkable catalytic activity for the oxygen reduction reaction with an initial potential of -0.15V, half wave potential of -0.32V, peak current density of 0.25 mA/cm2 and limiting current density of 0.23 mA/cm2 which is comparable to commercial Pt/C catalyst.