N, S-doped nanocabon as a highly efficient and durable electro-catalyst for oxygen reduction reaction

초록

Developing economical and commercially available materials to replace precious and nondurable platinum based catalysts is a very important issue in contemporary oxygen reduction reaction (ORR). Metal organic frameworks (MOFs), as an alternative candidate for ORR in fuel cells, are widely investigated because of its designable framework structures comprised of metal cluster and organic ligands. In this study, nano-structured carbons were prepared from ZIF-8 carbonization. During carbonization, proper amount of thiourea was added to form l N, S-doped nanocarbon. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analyses were carried out to compare the change in physical properties after carbonization. Porous structures of the materials were investigated by nitrogen adsorption isotherms at 77 K. Electrochemical properties were investigated by linear-sweep voltammetry (LSV) and cyclic voltammetry (CV) on a potentiostat using a rotating disk electrode (RDE). The N, S-doped nanocarbon showed high and stable electro-catalytic performance for ORR. The enhanced ORR activity as an electro-catalyst might be attributed to the high surface area and abundant active site of N, S-doped nanocarbon.