A theoretical study of small molecule adsorptions on boron nitride nanomaterials

Abstract

The structural properties, electronic properties, and gas adsorption abilities of pristine and transition metal- (TM = V, Cr, Mn, Nb, Mo, Tc, Ta, W, and Re) doped boron nitride nanotubes (BNNT) and boron nitride nanosheets (BNNS) were investigated using the density functional theory method at B3LYP/LanL2DZ level of theory. The adsorption abilities of V-, Cr-, Mn-, Nb-, Mo-, Tc-, Ta-, W-, and Re-doped BNNTs on NO molecule and V-, Nb-, and Ta-doped BNNTs on CO, NH3, and NO2 molecules were evaluated. The calculated results indicate that NO, CO, NH3, and NO2 molecules weakly interact with the pristine BNNT, whereas they show a strong adsorption ability with TM−doped BNNTs. The increase in the adsorption abilities of the TM−doped BNNTs on NO, CO, NH3, and NO2 molecules is due to the geometrical deformation on TM doping site and the charge transfer between TM−doped BNNTs and NO, CO, NH3, and NO2 molecules. In addition, the adsorption abilities of CH2O and H2 on V-, Cr-, Mn-, Nb-, Mo-, Tc-, Ta-, W-, and Re-doped BNNSs were also calculated. Electronic properties, i.e., HOMO and LUMO energies, energy gaps, density of states of the BNNT and BNNS are modified after TM doping. These observations suggest that gas adsorption and sensing ability of BNNT and BNNS could be greatly improved by introducing appropriate TM dopant. Overall, these studies suggest that TM-doped BNNTs and TM-doped BNNSs have a strong potential to be used as storage and sensing materials for small gas molecules.

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