Further studies on microstructural characterization and hydrogenation behaviour of graphitic nanofibres

The present study is aimed at microstructural characterization and hydrogenation behaviour of graphitic nanofibres (GNF) prepared by ethylene gas. The GNF were prepared by thermal cracking of ethylene gas at a temperature of ∼600°C for time durations of 2 h. The structural characterizations have been evaluated by X-ray diffraction and transmission electron microscopy. It was found that the typical length of GNF was in the range of ∼1 to ∼6 μm and most of GNF sample exhibits coil like configuration. The microstructural characteristics as studied by transmission electron microscopy (TEM) techniques after hydrogenation/dehydrogenation were found to consist of curved voids and were significantly different as compared to as grown GNF. The graphitic nanofibres were hydrogenated at 120 atm for 24 h and then dehydrogenated upto 1 atm. The P-C-T curves drawn based on several dehydrogenation runs have revealed the hydrogen storage capacity of present GNF as ∼15 wt%. In addition to hydrogen storage capacity, we have also investigated the desorption kinetics of GNF samples, the hydrogen was desorbed at the rate of ∼57 ml3/min.