Nanocarbon derived from ZIF-8 as an efficient electrode for oxygen reduction reaction (ORR)

초록

Metal organic frameworks (MOFs) are well-known crystalline compounds with high surface area and large pore volume. The MOFs have been extensively applied in various fields such as gas adsorption, proton conductor, drug delivery and catalysis because of its designable framework structures comprised of metal clusters and organic ligands [1-2]. Moreover, MOFs have received increasing attention for its considerable application as an oxygen reduction reaction (ORR) catalyst. In this study, ZIF-8 was adopted as a precursor for constructing nanocarbon. ZIF-8 was synthesized by solvothermal method and then carbonized to obtain nanocarbon materials. During carbonization, heteroatom sources, such as melamine, were added to increase ORR activity of nanocarbon materials. Carbonization time and temperature were carefully controlled to optimize catalytic properties. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analyses were carried out to compare the change in physical property of prepared samples between before and after carbonization. Pore characteristics of the materials were assessed form nitrogen sorption isotherms measured at 77 K. Electrochemical properties were investigated by linear-sweep voltammetry (LSV) on a potentiostat using a rotating disk electrode (RDE).