Computational studies on the interaction of vitamin C (ascorbic acid) with nitrogen modified TiO2 anatase nanoparticles

Document Type: Original Research Paper

Authors

1 Molecular Simulation laboratory (MSL), Azarbaijan Shahid Madani University, Tabriz, Iran 2 Computational Nanomaterials Research Group (CNRG), Azarbaijan Shahid Madani University Tabriz, Iran 3 Department of Chemistry, Faculty of Basic Sciences, Azarbaijan Shahid Madani University Tabriz, Iran

Abstract

Density functional theory calculations were performed to investigate vitamin C interaction with
N-doped TiO2 anatase nanoparticles. The adsorption of vitamin C on the energy favorable fivefold
coordinated titanium sites was investigated. Various adsorption geometries of vitamin C towards
the nanoparticle were examined. Since the adsorption energies of N-doped nanoparticles are higher
than those of undoped ones, the N-doped TiO2 nanoparticles can interact with vitamin C molecule
more strongly. Besides, adsorption on the pristine nanoparticle is less favorable, whereas on the
N-doped one, the adsorption process is more energy favorable. The electronic structure analysis was
performed in view of the density of states and molecular orbitals of the considered nanoparticles with
the adsorbed vitamin C molecule. The significant overlaps between the PDOS spectra of the oxygen
atom of vitamin C molecule and titanium atom of TiO2 confirm the chemisorption of vitamin C on
the TiO2 nanoparticle. After the adsorption, the electronic densities in the HOMOs of the adsorption
systems were mainly distributed over the vitamin C molecule, while the LUMOs were dominant at
the TiO2 nanoparticle. Our calculations shed light on understanding the interaction between vitamin C
and TiO2 nanoparticles, which provides an efficient outline for future experimental studies.

Keywords