Synergistic effect in Fe/N co-doped anatase TiO2(1 0 1) surface and the adsorption of di-, tri- and polyatomic gases: A DFT investigation

• The interaction between implanted N and Fe at the anatase TiO2(1 0 1) surface are invested by DFT.
• The formation energy calculations suggest that a large energy barrier blocks the transfer of Fe atom form surface to body.
• The electronic structures and the densities of states show that the half-metallic properties appear for the two cases.
• The relative adsorption energies of the gases on TiO2 (1 0 1) are in orders as: CO > NH3 > N2O > CO2 > CH4.
• Adsorption abilities of two surfaces are stronger to polar molecules than pure surface while weaker to non-polar ones.

The interaction of the implanted nitrogen and iron atoms on the anatase TiO2(1 0 1) surface was investigated by the first-principles calculations. Substitutional and interstitial configurations of Fe doping, with and without N atom, at different sites were considered. The formation energies of the cases were calculated, and the results suggested that a larger energy barrier blocked the transfer of Fe atom from the surface to body. A synergetic effect was observed taking place between the co-doped N and Fe atoms. A comprehensive analysis of electronic structure and state density revealed that the property of TiO2 changed from semiconductor to half-metallic. Finally, on the meliorated anatase TiO2 (1 0 1) surface (M-S (1 0 1)), the adsorption energies (ΔEads) of diatomic (CO), triatomic (N2O, CO2) and polyatomic (NH3 and CH4) gases were obtained and compared with the former experimental and theoretical results.

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