Structural and electronic properties of adsorbed nucleobases on Si-doped hexagonal boron nitride nanoflake: a computational study

摘要

Effect of doping on surface reactivity and molecular adsorption mechanism is a key feature for many applications, including molecular sensing, molecular recognition, and catalysis. The interaction of nucleobases (NBs) with the silicon (Si)-doped hexagonal boron nitride nanoflake (Si-(B)-hBNNF and Si-(N)-hBNNF) surfaces has been studied using electronic structure methods. A comparison between the binding energy (E-b, adsorption strength) of NBs on Si-(B)-hBNNF, Si-(N)-hBNNF, and hBNNF surfaces showed that the doping of hBNNF surface with Si atom significantly increases the binding energy values as follows: Si-(B)-hBNNF...NB>Si-(N)-hBNNF...NB>hBNNF...NB. Our results revealed that the adsorption of NBs on the Si-doped hBNNF surfaces arises through the electrostatic/partial covalent Si...N(O) interactions as well as noncovalent interactions, improving the field emission properties of the surfaces. The work function (?), HOMO-LUMO energy gap (E-g), and chemical hardness (eta) of the Si-doped hBNNF surfaces were decreased, resulting in increasing of the chemical reactivity of the adsorption complexes. Time-dependent density functional theory (TDDFT) calculations revealed that the main absorption bands respectively at 269.64nm and 283.17nm for the Si-(B)-hBNNF and Si-(N)-hBNNF surfaces are red-shifted due to the NBs adsorption. In addition, the appearance of new peaks in the visible region of the absorption spectra of the Si-(B)-hBNNF...NB and Si-(N)-hBNNF...NB complexes, indicates their promising applicability in the optical sensing of NBs and light-emitting technology.