Optical and electronic properties of SO2 molecule adsorbed on Si-doped (8, 0) boron nitride nanotube

•The optical properties of SO2 adsorption on Si-doped BNNTs are investigated.•Blue-shifts and red-shifts of main peaks are found in different constructions.•The speculated optical band gaps are decreased after Si doping and SO2 adsorption.•The asymmetry impurity states are mainly contributed by the Si-3p states.

The study of the optical properties of pristine BNNT, Si-doped BNNTs and SO2 molecule adsorption on Si-doped BNNTs is that, to our knowledge, few relevant research have ever been found. In this paper, the adsorption behaviors of Sulfur dioxide (SO2) molecule on Si-doped Boron nitride nanotubes (BNNTs) are investigated applying the first-principles calculations. The main contribution of this paper is that the foremost investigation for the optical properties of the pristine BNNT, Si-doped BNNTs and SO2 adsorption on Si-doped BNNTs. Additionally, the electronic properties and the structural properties are also presented. In our calculations of optical properties, the dielectric constant, the refractive index and the absorption coefficient are obtained. Comparing the pristine BNNT, our results indicate that, the blue-shifts (in the main peaks of the dielectric constant of SiB-BNNTSiB-BNNT and SO2-SiB-BNNTSO2-SiB-BNNT), and the red-shifts (in the main peaks of the refractive index of SiN-BNNTSiN-BNNT and SO2-SiN-BNNTSO2-SiN-BNNT) are appeared. Under these conditions, Si-doped BNNT and Si-doped BNNT with SO2 adsorption, the gaps are reduced both for the speculated optical band gaps and the electronic structure band gaps.

Graphical abstractThe absorption spectrums of the pristine BNNT, Si–BNNT and SO2–Si–BNNT are calculated and plotted, and the absorption coefficient of the pristine BNNT, SiB–BNNT, SO2–SiB–BNNT, SiN–BNNT, and SO2–SiN–BNNT are showed in Figs. (a) and (b).Figure optionsDownload full-size imageDownload as PowerPoint slide