Graphene Quantum Dots from Partially Unzipped Multi-Walled Carbon Nanotubes: Promising Materials for Oxygen Electrodes

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.

Photoelectrochemical Behavior of Simple Synthesized Cl-GQDs/In2O3

“…1a) displayed the interlayer spacing of 0.21 nm and 0.34 nm, which were associated with (100) and (002) lattice planes of the graphite, respectively. 33 For UV-vis spectrum in Fig. 1b, Cl-GQDs displayed three absorption bands at 192 nm, attributing to the π→π * transition of the C=C.…”

Capacitive Properties of Chlorine Doped Graphene Quantum Dots Anchored into Reduced Graphene Oxide

“…the broad diffraction peak was observed at 28°, which was associated with (002) lattice planes of the graphite. 41,42 The chemical species of elements in ClGO were analyzed by XPS. The survey spectrum of ClGO was shown in Fig.…”