Exploring the Sensing Performance of T-Graphene, T-Boron Nitride, and Their Lateral Heterostructure for Toxic CO, NO, NO2, and SO2 Gas Molecules

Abstract

In this observation, density functional theory calculations were carried out to examine the adsorption performance of T-graphene (TG), T-boron nitride (TBN), and their heterostructure (TG-TBN) toward CO, SO₂, NO, and NO₂ gas molecules. To observe the sensing performance of the nanosheets, the adsorption energy with adsorption distance, charge transfer, electronic properties, sensitivity, and recovery time have been investigated. The gas molecules were adsorbed in the tetragonal (T) and octagonal (O) sites of the nanosheets, in which we found that the O site was more favorable. In the case of the interaction between TG and gases, low adsorption behavior has been found, but TBN and TG-TBN exhibit favorable interaction behavior with the gases. Among the four gases, SO₂ and NO₂ interact with the TBN in chemisorption energy, which are −0.911 and −1.75 eV, at the O site, respectively. During their interaction, the gases gain −0.139e and −0.428e charges from the TBN. TG-TBN shows high interaction properties with the NO and NO₂ gases with energies −1.21 and −1.35 eV, respectively. The DOS spectra show that extra electronic states are generated at the Fermi level of NO and NO₂ gas adsorption on the nanosheets. Low recovery times have been observed during the desorption; in the case of TG-TBN, the recovery times are 0.19 and 1.56 s at the T and O sites for NO and 28.32 and 41.04 s at the T and O sites for the NO₂ gas molecule. Therefore, TBN can be used as a gas sensor for SO₂ and NO₂ gases and TG-TBN can be used as a gas sensor for NO and NO₂ gas molecules.