Jellyfish-like few-layer graphene nanoflakes: Synthesis, oxidation, and hydrothermal N-doping

Few-layer graphene nanoflakes with the bent edges, diameter of 15-40 nm and thickness of 6-7 graphene layers have been synthesized using MgO-templated CVD growth. Their oxidation by nitric acid led to the high oxygen content of 18 at.%, a third of which was attributed to carboxylic groups. Oxidized nanoflakes were post-doped by nitrogen groups using hydrothermal treatment at 220 degrees C with ammonia and urea water solutions resulting in corresponding nitrogen content of 7 and 5 at.%. Synthesized and treated materials were characterized by XPS, Raman spectroscopy and electron microscopy. (C) 2018 Elsevier B.V. All rights reserved.