Hydrothermal synthesis of Ni-doped hierarchically porous carbon monoliths for hydrogen storage

Hierarchically porous carbon monoliths doped with nickel nanoparticles (Ni-HPCM) have been synthesized by hydrothermal method. The obtained Ni-HPCM materials exhibit a three dimensional interconnected macroporous network (0.5-3.5 mu m), high specific surface area (620 m(2)/g), large pore volume (0.41 cm(3)/g), and narrow pore size distribution (3.9 nm). The Ni-HPCM materials present a high hydrogen storage capacity. At the pressure of 5 bar, the Ni-HPCM materials show a maximum hydrogen capacity of 4.29 and 1.69 wt% at 77 and 298 K, respectively. The enhanced hydrogen storage capacity is due to the hydrogen spillover effect, which allows the dissociation of hydrogen molecules on the surface of nickel nanoparticles and consequent adsorption of hydrogen atoms inside the channels of HPCM material. Therefore, the Ni-doped hierarchically porous carbon monoliths in the present study are potentially suitable to be used in the range of hydrogen storage.