  Hydrogen-based fuel cells are promising solutions for the efficient and clean
delivery of electricity. Since hydrogen is an energy carrier, a key step for
the development of a reliable hydrogen-based technology requires solving the
issue of storage and transport of hydrogen. Several proposals based on the
design of advanced materials such as metal hydrides and carbon structures have
been made to overcome the limitations of the conventional solution of
compressing or liquefying hydrogen in tanks. Nevertheless none of these systems
are currently offering the required performances in terms of hydrogen storage
capacity and control of adsorption/desorption processes. Therefore the problem
of hydrogen storage remains so far unsolved and it continues to represent a
significant bottleneck to the advancement and proliferation of fuel cell and
hydrogen technologies. Recently, however, several studies on graphene, the
one-atom-thick membrane of carbon atoms packed in a honeycomb lattice, have
highlighted the potentialities of this material for hydrogen storage and raise
new hopes for the development of an efficient solid-state hydrogen storage
device. Here we review on-going efforts and studies on functionalized and
nanostructured graphene for hydrogen storage and suggest possible developments
for efficient storage/release of hydrogen at ambient conditions.
