Ab initio Study of Aspirin Adsorption on Single-walled Carbon and Carbon Nitride Nanotubes

摘要

We use ab intio density functional theory to investigate the adsorptionproperties of acetylsalicylic acid or aspirin on a (10, 0) carbon nanotube(CNT) and a (8, 0) triazine-based graphitic carbon nitride nanotube (CNNT). Itis found that an aspirin molecule binds stronger to the CNNT with itsadsorption energy of 0.67 eV than to the CNT with 0.51 eV. The strongeradsorption energy on the CNNT is ascribed to the high reactivity of its N atomswith high electron affinity. The CNNT exhibits local electric dipole moments,which cause strong charge redistribution in the aspirin molecule adsorbed onthe CNNT than on the CNT. We also explore the influence of an external electricfield on the adsorption properties of aspirin on these nanotubes by examiningthe modifications in their electronic band structures, partial densities ofstates, and charge distributions. It is found that an electric field appliedalong a particular direction induces aspirin molecular states in the in-gapregion of the CNNT implying a potential application of aspirin detection.