Nalidixic Acid Adsorption on the Surface of Boron Nitride Nanocluster (B12N12): DFT Studies

Abstract

In this research study, the detection and removal of nalidixic acid by boron nitride nanocluster (B₁₂N₁₂) were investigated using the DFT, infra-red (IR), natural bond orbital (NBO) and frontier molecular orbital (FMO) computations. The calculated negative values of adsorption energy, Gibbs free energy changes, and great amounts of thermodynamic equilibrium constants demonstrated nalidixic acid adsorption on the surface of B₁₂N₁₂ was spontaneous, irreversible and experimentally feasible. The values of adsorption enthalpy changes and specific heat capacity (C_V) revealed that, the interaction of the adsorbate and adsorbent was exothermic and B₁₂N₁₂ was an ideal nanostructure for the construction of new thermal sensors for detection of nalidixic acid. The influence of temperature on the thermodynamic parameters was also investigated and the results demonstrated that, the adsorption process was more favorable at room temperature. The NBO results indicated in all of the studied configurations covalent bonds were formed between nalidixic acid and B₁₂N₁₂ and their interaction was chemisorption. The density of states (DOS) spectrums showed that, the bandgap of boron nitride nanocage after the adsorption of nalidixic acid decreased from 14.864 (eV) to 7.314 (eV), indicating that the electrical conductivity of B₁₂N₁₂ improved significantly in the adsorption process and B₁₂N₁₂ is an appropriate sensing material for developing novel electrochemical sensor to nalidixic acid determination. The important structural parameters including chemical hardness, chemical potential, dipole moment, electrophilicity and maximum charge capacity were also computed and discussed in detail.