Effects of milling conditions on hydrogen storage properties of graphite

Two milling modes (shearing and impact) were applied to investigate the hydrogen storage properties of graphite. It was found that the shearing mode leads to 0.613 wt.% hydrogen absorbed in graphite, while impact mode leads to 2.718 wt.%. X-ray diffraction was used to investigate the structure of the as-milled and subsequent annealed samples. Differential scanning calorimetry was used to study thermally induced transformations in the asmilled samples. Infrared spectrometry was carried out to investigate the interaction between carbon and hydrogen atoms. Results are compared and discussed in conjunction with Laser desorption time-of-flight mass spectrometry results obtained earlier