Theoretical study of O2 adsorption and reactivity on single-walled boron nitride nanotubes

The adsorption and reactivity of O2 on perfect and defective (10, 0) boron nitride nanotubes (BNNTs) are investigated employing the density-functional theory. Our results indicate that O2 prefers to physically adsorb on perfect BNNT. The assumed dissociation of O2 on the perfect BNNT is endothermic and difficult to realize with an energy barrier of 3.25 eV. The point defects such as vacancies and Stone-wales defect on the wall of BN nanotubes reduce the oxidation resistance of the tubes. Especially, O2 is dissociated on nitrogen vacancy tube with a barrier of 0.84 eV. The electronic properties analysis indicates that chemisorbed O2 can reduce the energy-gap of BN tubes.