Sensing capability and diameter-dependent electronic structure of boron nitride nanotubes

Abstract

The sensing and diameter-dependent properties of armchair Boron Nitride nanotubes (BNNTs) were scrutinized based on density functional theory (DFT) to find out their electronic structure and carbon monoxide (CO) sensing capability. Our results show that diameter increase causes a rise in the binding energy of BNNT, from 6.44 eV to 6.62 eV. An increasing trend of adsorption energies in the range of -3.25 and -3.47 kcal/mol indicates that BNNTs act weak physical adsorption upon CO verified by the analysis of the Electron localization function (ELF), however, more increase in the diameter could enhance the sensing capability of BNNT. The energy gap of the biggest BNNT is calculated as 6.20 eV wide, i.e., about 0.12 eV smaller than the smallest one which is compatible with available experimental results. The reactivity properties such as the adiabatic and vertical ionization potentials (IPs), chemical hardness, and electrophilicity index of BNNTs were also analyzed. The BNNTs exhibit strong absorption peaks -7.08 eV which can be a promising candidate for the UV light-emitting devices. The results herein reveal that BNNTs with bigger diameters can be useful for gas sensor applications.