Adsorbed property of boron nitride nanotube (BNNT) device: A study of first-principles calculations

Abstract

Summary form only given. Sensors with high sensitivity and selectivity act as the role for real-time detections of a variety of industrial processes and environment. Currently, plenty of low dimensional materials, such as graphene, layered MoS2, and nanotubes, have been proposed as potential candidates of gas sensors. The nanotubes are generally porous due to their high reactivity exterior surface, which makes them sensitive to small molecular. As being important low-dimensional materials with wide band gaps, boron nitride nanotubes (BNNTs) have also received considerable interests. Despite the adsorption behavior of pure or doped BNNTs has been reported, the structure and electronic properties of adsorbed small molecule on BNNTs is still ambiguous. Here, we investigate the structure and electronic property of BNNTs device with absorbed small molecules, and then effect of physisorbed small molecules. Fig. 1 displays a BNNT device structure for gas sensors. The first-principles calculations are performed within the framework of density function theory (DFT) by using GGA-PW91. It is found that the sites of LOMO and HOMO would be changed after BNNTs absorbed the different small molecules. The energy gap of BNNTs decreases with increasing the distance between small molecule and BNNT. The adsorption effect of BNNT will be optimal as the distance between the small molecule and BNNT is from 1 to 1.5 A. The potential application of BNNT as highly sensitive gas sensor for N-based small molecules has also been discussed.