SiO2-derived Fe-NSC Hollow Nanosphere as an Efficient Electrocatalyst for Oxygen Reduction Reaction

초록

Recently, next-generation energy devices have attracted great attention such as metal-air batteries and fuel cells. Oxygen reduction reaction (ORR), occurred on the cathode of the system, is crucial to improve the energy devices performance because it has sluggish kinetics and high overpotential [1]. Although Pt-based catalysts showed excellent electrocatalytic performance, they have high cost, low durability, and low abundance. Pyrolyzed iron-nitrogen-doped carbon (Fe-N-C) materials have been studied to replace the Pt-based catalysts, because of their abundance, various redox property, and durability [1], [2]. In this study, single-atom Fe embedded in nitrogen- and sulfur-doped carbon (Fe-NSC) hollow nanosphere was successfully synthesized via pyrolysis and chemical etching of a SiO2 template. Fe-NSC hollow nanosphere electrocatalyst presented outstanding ORR activity and long-term durability both in alkaline and acidic solution . These outstanding ORR activities are mainly originated from Fe single atomic sites (Fe-Nx) species, C-S-C active sites, synergetic N and S doping and unique hollow structure. This work opens up a path for transition metal embedded in heteroatoms-doped carbon hollow nanosphere electrocatalysts for energy conversion and storage technologies.