Boron carbide nanoclusters as H₂ and N₂ gases nanosensors: theoretical investigation

Interactions between boron carbide nanoclusters (B₁₆C₁₆ and B₂₄C₂₄) and H₂ and N₂ molecules have been investigated using the structural and electronic properties of the adsorbate/cluster complexes derived from density functional theory. The adsorption energies of the most stable configurations have been calculated to be about -0.13, -0.66 eV for H₂ and N₂ adsorbed on the B₁₆C₁₆ surface and -1.05, -3.80 eV for H₂ and N₂ adsorbed on the B₂₄C₂₄ surface, respectively. Moreover, the interaction between H₂ and the B₁₆C₁₆ has induced dramatic changes to the cluster electronic properties, so that the HOMO/LUMO gap of the cluster decreases to its original value. It has been shown that this phenomenon has led to an increment in the electrical conductivity of the cluster at a definite temperature. Thus, this work suggests that the B₁₆C₁₆ and B₂₄C₂₄ nano-cages function selectively as a gas sensor device for H₂ and N₂ molecules. (author)