The environmental gas monitoring and controlling is an important issue for our safety and health. Many investigations have been focused on the development of suitable gas-sensitive materials for hazardous chemical vapors detection. Hydrogen cyanide (HCN) is a colorless, extremely poisonous liquid that boils slightly above the room temperature at 26 °C. The most important route of poisoning is through inhalation which inhibits the consumption of oxygen by body cells [1]. HCN is usually produced on an industrial scale and it can play a key role in the origin of life on Earth. Thus, it seems necessary to monitor and control important pollutants such as HCN molecule in environmental systems.
The discovery of carbon nanotubes (CNTs) [2] has caused intense interest in the study of gas sensors [3] and [4]. This extreme sensitivity can be theoretically explained by the conductivity change of the nanotube before and after the adsorption process of the toxic gases. After the synthesis of carbon fullerene C60 [5], the fullerene and fullerene-like cages shown can be used in sensors [6] and [7]. Among fullerene-like cages, boron nitride sodalite like cage (BN)n are isoelectronic to carbon fullerenes. They have excellent properties such as heat resistance in air, large band gap, and structural stability [8], [9] and [10]. Seifert et al. [11] have theoretically investigated structures of (BN)n sodalite like cages and showed that B12N12, B16N16 and B28N28 are magic and B12N12 appears to be more stable than the others. Oku et al. [12] successfully synthesized B12N12 sodalite like cage by laser desorption time-of-flight mass spectrometry. Recently, Beheshtian et al. [13] have theoretically shown that B12N12 sodalite like cage can be a potential sensor for NO2 detection. Therefore, development of a gas sensor with high sensitivity toward HCN using B12N12 sodalite like cage is of great interest.
Some kinds of HCN sensors have been presented by different research groups. Zhang et al. [14] have theoretically shown that Si-doped boron nitride nanotubes (BNNTs) serving as a potential chemical sensor for HCN. Also, Al-doped graphenes are proposed as potential HCN sensor by Rastegar et al. [15]. Furthermore, Beheshtian et al. [16] showed that unlike pristine aluminum nitride nanotubes (AlNNTs), the Al-rich AlNNT is a good strategy for improving the sensitivity of these tubes toward HCN molecules. The above results show that the doping is an appropriate method for improving the sensitivity of pristine nanotubes and nano-structured materials toward HCN molecules. On the other hand improving the sensing performance of pristine nanotubes toward various desired molecules through doping is too expensive. In the present study we attempted to find a high sensitive pristine nano-structured material for HCN detection in environmental systems without manipulating its structure. Therefore, the interaction of HCN molecule with B12N12 sodalite like cage was investigated using density functional theory (DFT) calculations based on analysis of structural parameters, adsorption energies, net charge transfers, electronic densities of states (DOSs), etc.