Density functional theory study of the adsorption of toxic large molecules on nitrogen modified TiO2 anatase nanoparticles

First principles calculations were performed to study the adsorption behaviors of large organic molecules on the pristine and N-doped TiO2 anatase nanoparticles. Both oxygen and nitrogen in the molecule can react with the TiO2 nanoparticle strongly. Thus, the binding sites were located on the oxygen or nitrogen atom of the molecule, while on the TiO2 nanoparticle the binding site occurs on the fivefold coordinated titanium atoms. It was found that the adsorption on the N-doped TiO2 is more favorable in energy than the adsorption on the undoped one, indicating the high sensitivity of N-doped TiO2 nanoparticles towards molecule molecules. It means a dominant effect of nitrogen doping on the adsorption properties of pristine TiO2. The large overlaps in the PDOS spectra of the oxygen and nitrogen atoms of the molecule and titanium atom of TiO2 represent a forming Ti-O and Ti-N bonds between them.