2D β-tellurene: Increase sensitivity toward toxic cyanide molecules

Cyanide gases are colorless and toxic gases, which are widely used in the industry, thus efficiently detecting them has become a pressing issue. The sensitivity and selectivity of β-tellurene toward cyanide gases are reported in this work. Adsorption energy, charge transfer, and electronic properties of the cyanide gases (HCN, (CN)2, CNBr) as well as common gases (CO2, N2, CO) adsorption systems are calculated based on the density functional theory (DFT). The significantly larger adsorption energy (−0.26 eV for HCN, −0.36 eV for CNBr) and charge transfer (0.11 |e| for HCN, 0.10 |e| for CNBr) show that the tellurene is a well sensitive material for cyanide gases detection. The change of I–V curves made by gas adsorption further confirms the selectivity and sensitivity of tellurene to cyanide gases, especially the HCN. Moreover, different biaxial strains could effectively regulate the adsorption behavior of cyanide gases on tellurene, as the adsorption energy of the HCN molecule is enhanced to be −0.52 eV. Based on these results, we predict that tellurene could be a practical material to detect cyanide gases.