Prediction of Single-Wall Boron Nanotube Structures and the Effects of Hydrogenation

The unique electronic properties of boron nano tubes (BNTs) and hydrogenated BNTs (H-BNTs) lead to its potential applications in electrochemical and hydrogen storage. In the present work, the stability and electronic properties of single wall BNTs and, particularly, the effects of hydrogenation on the structural and electronic features are investigated on the basis of the first-principles electronic calculations. It is interesting to find that hydrogenation can stabilize (m,0) BNTs with m being 7-13. In addition, H-BNTs can be either metallic or semiconducting depending on the diameter. In particular, electronic properties of (m,0) H-BNTs can also be engineered by exerting strain along the axial direction, as verified in the case of strained H-BNTs where a semiconductor metal crossover was predicted at 3% tensile strain. Our results would drive more interesting studies on BNTs with different chiralities and chemical functionalizations.