Amirali Abbasi; Jaber Jahanbin Sardroodi
Abstract
Density functional theory investigations were conducted in order to study the effects of the adsorption of thiophene on the structural and electronic properties of TiO2 anatase nanoparticles. The ability of pristine and N-doped TiO2 anatase nanoparticles to recognize toxic thiophene was surveyed in detail. ...
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Density functional theory investigations were conducted in order to study the effects of the adsorption of thiophene on the structural and electronic properties of TiO2 anatase nanoparticles. The ability of pristine and N-doped TiO2 anatase nanoparticles to recognize toxic thiophene was surveyed in detail. It was found that thiophene molecule is chemisorbed on the N-doped anatase nanoparticles in S site geometries with large adsorption energy and small distance. By including van der Waals (vdW) interactions between thiophene molecule and TiO2, we found that the adsorption on the N-doped TiO2 is energetically more favorable than the adsorption on the pristine one, suggesting that the nitrogen doping can energetically facilitate the thiophene adsorption on the N-doped nanoparticle. The order of adsorption energy is Parallel(S site)>Perpendicular(S site)>Perpendicular (H site). The interaction between thiophene and N-doped TiO2 can induce substantial variations in the HOMO/LUMO molecular orbitals of the nanoparticle, changing its electrical conductivity, which is helpful for designing the novel sensor and remover devices. Charge analysis based on Mulliken charges reveals that charge is transferred from thiophene molecule to TiO2 nanoparticle.
Zahra Sarteep; Azadeh Ebrahimian Pirbazari; Mohammad Ali Aroon
Abstract
Hydrothermally synthesized TiO2 nanoparticles containing different amounts of silver were characterized by X-Ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM/EDX) techniques. XRD results showed prepared ...
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Hydrothermally synthesized TiO2 nanoparticles containing different amounts of silver were characterized by X-Ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM/EDX) techniques. XRD results showed prepared samples include 100% anatase phase. The presence of silver in TiO2 nanoparticle network was established by XRD, SEM/EDX and FT-IR techniques. The photocatalytic performance of the prepared catalysts was tested for the degradation of 2,4-dichlorophenol (2,4-DCP) under visible light.. The experiments demonstrated that 2,4-DCP was effectively degraded in the presence of Ag/TiO2 samples. It was confirmed that the presence of Ag on TiO2 catalysts could enhance the photocatalytic degradation of 2,4-DCP in aqueous suspension. It was found that an optimal dosage of 1.68 wt% Ag in TiO2 achieved the fastest 2,4-DCP degradation (95% after 180 min irradiation) under the experimental conditions. On the basis of various characterizations of the photocatalysts, the reactions involved to explain the photocatalytic activity enhancement due to Ag doping include a better separation of photogenerated charge carriers. GC-MS analysis showed the major intermediates of 2,4-DCP degradation are simple acids like oxalic acid, acetic acid, etc. as the final products.