Insights into adsorptive interactions between antibiotic molecules and rutile-TiO2 (110) surface

Abstract

Intermolecular interactions between antibiotic molecules, ampicillin (AP), amoxicillin (AX) and tetracycline (TC), and rutile-TiO2 (110) surface (r-TiO2) were thoroughly investigated using density functional theory calculations in solid state. The popular rutile-TiO2 is considered as a material for treatment of antibiotic molecules present in waste water. Calculated results revealed that in these adsorbate-adsorbent systems, significant contributions of Ti··O electrostatic interactions and important addition of O/N-H···O hydrogen bonds occur in stabilization of configurations of the most favored structures. Existence and role of adsorptive interactions are clarified by the atom-in-molecule theory, density of states and electron density transfer analyses. Adsorption of antibiotic molecules onto the r-TiO2 surface is characterized as chemisorption processes. Furthermore, the most stable configurations tend to be formed preferably in horizontal arrangement of molecules onto the material surface. The adhesive capacity of these AP, AX and TC antibiotic molecules on r-TiO2 surface is large and quantitatively evaluated.