ACS Sustainable Chemistry & Engineering | 2019
Space-Confined Strategy to Fe 7 C 3 Nanoparticles Wrapped in Porous Fe-/N-Doped Carbon Nanosheets forEfficient Oxygen Electrocatalysis
Abstract
The development of economical, high-efficiency, and robust bifunctional oxygen electrocatalysts toward both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is highly desirable but challenging. Herein, we develop a space-confined strategy with a sacrificial template for preparing Fe7C3 nanoparticles embedded in an interconnected porous graphene-like Fe-/N-doped carbon matrix (Fe7C3@FeNC). This approach relies on pyrolysis of precursor hybrids of an iron–ellagic acid (Fe–EA) complex and polydopamine (PDA) from the pyrocondensation polymerization of dopamine (DA) that are confined in the interlayer gaps of the sacrifice template g-C3N4. Such a functionalized configuration can avoid the uncontrollable growth of polydopamine (PDA) during the usual solution polymerization and postsynthetic removal of the template. The as-prepared Fe7C3@FeNC catalyst shows an impressive half-wave potential of 0.83 V for ORR and a low overpotential of 358 mV for reaching the current density of 10 mA cm–2 for O...