Highly ordered iron oxide-mesoporous fullerene nanocomposites for oxygen reduction reaction and supercapacitor applications

Abstract In this study, we report a facile synthetic strategy to embed ultra-small iron oxide nanoparticles within the channels of highly ordered mesoporous fullerene (C 60 ) (Fe-MFC 60 -T, where T denotes the temperature of the template synthesis). The present work is judicially designed to form the hematite phase of iron oxide (α-Fe 2 O 3 ) nanoparticles (NPs) through the subsequent calcination of Fe-MFC 60 -T. The Fe-MFC 60 -T materials were analysed comprehensively for obtaining their physico-chemical properties. Among the materials studied, Fe-MFC 60 -150 exhibits a unique doughnut-shaped morphology with a high specific surface area (∼598 m 2  g −1 ), crystalline wall structure, and well-ordered porosity. The Fe-MFC 60 -150 displays an adequate oxygen reduction reaction (ORR) activity with a positive onset potential at 0.85 V ( vs RHE) and half wave potential at 0.78 V ( vs RHE), low Tafel slope (66 mV per decade), high exchange current density (1.2 × 10 −10  A cm −2 ), and good tolerance towards methanol crossover. We also demonstrate that Fe-MFC 60 -150 is capable of delivering a specific capacitance of 112.4 F g −1  at 0.1 A g −1 . The electrochemical performance of Fe-MFC 60 -150 towards ORR and supercapacitor can be ascribed to the synergistic coupling effects between the active sites of α-Fe 2 O 3 and MFC 60.