Graphene Quantum Dots from Partially Unzipped Multi-Walled Carbon Nanotubes: Promising Materials for Oxygen Electrodes
М. О. Данилов, S. S. Fomanyuk, Г. И. Довбешко, Olena Gnatyuk, I. A. Rusetskyi, G. Ya. Kolbasov
Abstract
Photoluminescent graphene quantum dots (GQDs) the one- or two-layer graphene nanoparticles 1.5–3 nm in size with a blue emission have been obtained from electrochemically synthesized partially unzipped multi-walled carbon nanotubes ultrasonically treated for one hour. Various physicochemical methods including photoluminescence spectroscopy, XRD, TEM, and Raman spectroscopy, have been used to characterize the electrochemically synthesized partially unzipped multi-walled carbon nanotubes and GQDs. Two-layer oxygen electrodes were fabricated, where GQDs served as an active layer. The investigations of electrocatalytic characteristics of the oxygen electrodes fabricated of the obtained materials were carried out in a fuel half-cell with an alkaline electrolyte. The fabricated oxygen electrodes were stable for six months at a discharge current density of 200 mA cm −2 . The obtained GQDs are promising materials as a new type of catalyst carriers for oxygen electrodes of fuel cells.