Abstract: Based on the density-functional theory(DFT) and the first-principle method, the electronic distribution and the density of states(DOS) of the armchair (5, 5) and zigzag (8, 0) single-walled carbon nanotubes (SCNTs) grafted by hydroxyl were calculated. First a geometry optimization of SCNTs is performed by using BLYP function in DMol3 program, then the variations of electronic distribution and DOS are calculated by adopting the CASTEP program. It has been found that the electronic structure of the SCNTs due to the graft changes significantly, namely, the electron density of states near Fermi level, the delocalized degree of the highest occupied molecular orbital (HOMO), and accordingly the transport properties of SCNTs decrease as the number of grafted hydroxyl groups increase.

Key words: Carbon nanotubes, Density-functional theory, Electronic structure, Density of states, Hydroxyl functional group