  A description is given of a three-dimensional box-shaped graphene (BSG)
nanostructure formed/uncovered by mechanical cleavage of highly oriented
pyrolytic graphite (HOPG). The discovered nanostructure is a multilayer system
of parallel hollow channels located along the surface and having quadrangular
cross-section. The thickness of the channel walls/facets is approximately equal
to 1 nm. The typical width of channel facets makes about 25 nm, the channel
length is 390 nm and more. The investigation of the found nanostructure by
means of a scanning tunneling microscope (STM) allows us to draw a conclusion
that it is possible to make spatial constructions of graphene similar to the
discovered one by mechanical compression, bending, splitting, and shifting
graphite surface layers. The distinctive features of such constructions are the
following: simplicity of the preparation method, small contact area between
graphene planes and a substrate, large surface area, nanometer cross-sectional
sizes of the channels, large aspect ratio. Potential fields of application
include: ultra-sensitive detectors, high-performance catalytic cells,
nanochannels for DNA manipulation, nanomechanical resonators, electron
multiplication channels, high-capacity sorbents for hydrogen storage.
