Reduced graphene oxide-carbon black composite supported iron phthalocyanine as a high-efficiency and stable catalyst for oxygen reduction reaction

Abstract

It has been found that only catalytic sites are situated on the surfaces or sub-surfaces of supports to accelerate oxygen reduction reaction (ORR) rates, whereas those situated within the interior regions of supports do not actually participate in catalysis ORR. Therefore, catalyst support technology has been regarded as another effective tactic for improving the catalytic activities of catalysts. In the present study, ORR catalysts supported by composite materials were created by uniformly mixing super-conducting carbon black with tetra-β-(8-quinolinoxy) iron phthalocyanine-loaded reduced graphene oxides (rGO). The morphologic structures of the prepared material were investigated using AFM, SEM, FTIR, UV, XPS, and Raman spectroscopic methods. The catalytic activities and stabilities toward the ORR in alkaline electrolyte were assessed using CV and LSV processes. The experimental results demonstrated that insertions of the carbon black (CB) nanospheres between the rGO sheets not only impeded the stacking of the rGO nanosheets, but also achieved the full utilization of the synergistic effects between them. The improved electrochemical catalytic activities of the tetra-β-(8-quinolinoxy) iron phthalocyanine (TQFePc) via CB/rGO hybrid support were mainly attributed to the strong π-π interaction between the TQFePc molecules and the rGO nanosheets, as well as the novel 3D sandwiched graphene/carbon nanosphere/graphene structures.