عنوان مقاله [English]
The probable structures of format anion adsorbion on the 101 surface of anatase allotropy of titanium dioxide were investigated by quantum mechanical calculations in order to analyze mechanism of action of this advanced photocatalyst in this adsorption process. At the first, in order to get the optimized structures, the structures of adsorbent surface alone, adsorb species alone and adsorbent surface including adsorb species were exposure to the structural optimization calculations. These optimizations of structures were done using cluster and periodic computational methods. Results of both methods show that dissociative adsorption of formic acid on the 101 surface of anatase is more stable than associative one. Also, stability of the adsorbed formate ion is in the order of bidentate state on the surface with oxygen defency, bidentate state on the perfect surface and monodentate state on the perfect surface. The atom in molecule (AIM) and nuclear magnetic resonance (NMR) theorems were employed in order to certify the results of adsorption energy investigations. The nature of the oxygen-titanium bonds were identified using quantum theory of atoms in molecules and it was shown that they have electrostatic nature. Results of these theorems certified the former results of adsorpsion strength.