Carbon nanotubes (CNTs) have drawn great attention since they
were found at first in1991 [1] because of their marvelous structure,
high stability,and excellent conductivity or semiconductivity [2].
Numerous studies have been devoted to investigation of stable
structures of non–carbonnanotubes.
Among these structures, the
III–V analogs of carbon nanotubes such as boron-nitride nanotubes
(BNNTs) and aluminum-nitride nanotubes (AlNNTs) are of great importance [3–5].
These nanotubes are wide-band gap semiconduc-
tors which are known by high temperature stability,considerable
thermal conductivity,low thermal expansion,resistance to chemi-
cals and gases used in semiconductor processing and reliable
dielectric properties [6].
However,the relatively large band gap
has imposed great limitations to the applications of AlNNTs and
BNNTs [7].
Unfortunately,poor solubility and difficulties of purifying
and processing have hampered the future applicationofIII–V
nanotubes [8].
Now,chemically modified (i.e.,functionalized) nano-
tubes are being extensively promoted as one of the solutions to
overcome these problems.
Chemical functionalization is a commonly used method to
tailor the physical and chemical properties of nanotubes.
It has been reported that covalent functionalizations using adatoms,
organic molecules,and functional groups can effectively change
the electronic structures [9], magnetic properties [10], and solu-
bility of nanotubes [11].
Lim et al.
reported theoretically
investigation of the functionalization of AlNNT with hydrogen,
indicating that H2 dissociation is exothermic in the surface of
AlNNT, and the dissociation barrier is rather low (0.76eV).
Recently, theoretical calculations have also shown that AlNNTs
can be functionalized by various groups (such as NO2 [13],
transition metals [14], and NH3 [4]).