Density Functional Theory Investigation on the Structural and Electronic Properties of Pristine, Vacancy, and Group IV Doped Zigzag Boron Nitride Nanotubes

Abstract

In this work, density functional theory (DFT) calculations were conducted to study the structural and electronic properties of pure, vacancy, and group IV [i.e. carbon (C), silicon (Si), and germanium (Ge) atoms] doped boron nitride nanotubes (BNNTs). The DFT computational results obtained agree well with the literature results. The calculated B−N bond distances obtained in this study are about 1.44 Å – 1.47 Å. Among seven BNNTs, the optimized B35GeN36H12 holds the lowest local energy minimum value in this study Moreover, the structure of B35CN36H12 possesses the smallest HOMO−LUMO energy (2.17 eV) among nine BNNT models considered. The boron (B) atoms hold the positive charges, and the negative charges fall on the nitrogen (N) atoms in this work. Similar results are reported to the molecular electrostatic potentials (MEPs) of studied BNNTs. The distributions of positive and negative electrostatic potentials fall on the regions of N− and B−tips of BNNT frameworks, respectively in this report. The DFT calculations reported that the spin densities were mainly concentrated in the regions around group IV elements, such as C, Si, and Ge atoms. Therefore, we believe that these computed results will provide useful information on the adsorption of hydrogen molecules on the BNNT frameworks in the future.