  Graphene and its heterostructures exhibit interesting electronic properties
and are explored for quantum spin Hall effect(QSHE) and magnetism based device
applications. In present work, we propose a heterostructure of graphene
encapsulated by hydrogenated graphene which could be a promising candidate for
a variety of device applications. We have carried out DFT calculations on this
system to check its feasibility to be a versatile material. We found that
electronic states of multilayer pristine graphene, especially Dirac cone, an
important feature to host QSHE, can be preserved by sandwiching it by fully
hydrogenated graphene. Interference of electronic states of hydrogenated
graphene was insignificant with those of graphene. States of graphene were also
found to be stable upon application of electric field up to 2.5V/nm. For device
applications, multilayer graphene or its heterostructures are required to be
deposited on a substrate, which interacts with system opening up a gap at Dirac
cone making it less suitable for QSHE applications and hydrogenated graphene
can prevent it. Magnetization in these hydrogenated graphene sandwiched
graphene may be induced by creating vacancies or distortions in hydrogenated
graphene, which was found to have minimal effect on graphenes electronic
states, thus providing an additional degree of manipulation. We also performed
a set of calculations to explore its applicability for detecting some
molecules. Our results on trilayer graphene encapsulated by hydrogenated
graphene indicate that all these observations can be generalized to systems
with a larger number of graphene layers, indicating that multilayer graphene
sandwiched between two hydrogenated graphene is a versatile material that can
be used in QSHE, sensor devices, etc.
