Boosting oxygen reduction reaction activity by incorporating the iron phthalocyanine nanoparticles on carbon nanotubes network

The lethargic kinetics of oxygen reduction reaction (ORR) at cathode typically desires to be catalyzed by highly competent catalysts to get better performance of fuel cell devices for efficient energy conversion. Herein, we fabricated a nanocomposite of multiwall carbon nanotubes decorated with iron phthalocyanine nanoparticles (FePcNPs@CNTs) using a single-step facile microwave strategy. The morphologies and composition of the FePcNPs and FePcNPs@CNTs were confirmed by using multiple analytical techniques. Further, these materials were taken under the ORR electrocatalytic investigations in O-2-saturated 0.1 M KOH. The results demonstrated the composite FePcNPs@CNTs to have superior ORR activity as evidenced by the significant reduction in over-potential (onset potential, +1.03 V and half-wave potential, + 0.97 V) in comparison to commercial FePc and 20% Pt/C. In addition, the electrochemistry of FePcNPs, FePcNPs@CNTs in N-2-saturated 0.1 M KOH indicated that more positive formal potential of Fe2+/Fe3+ redox couple facilitated the strong interaction between Fe2+ and O-2; weaken the O-O bond followed by 4e(-) ORR. This work confirms that bio-inspired molecules at the nanoscale can be applied to achieve 4e(-) ORR.