Insights into adsorptive interactions between antibiotic molecules and rutile-TiO2 (110) surface (original) (raw)
Related papers
Vietnam Journal of Chemistry, 2018
We investigated the adsorption of formic, acetic, benzoic acids, phenol, nitrobenzene molecules on rutile-TiO 2 (1 1 0) surface using the density functional theory (DFT) calculations. Details of the interaction between the investigated molecules and rutile-TiO 2 (1 1 0) surface were thoroughly considered by using the charge transfer and atoms in molecules analyses. The most stable configurations have been found upon adsorption of these molecules on TiO 2 surface by employing the Perdew-Burke-Ernzerhof (PBE) functional and projector-augmented wave method approach and utilizing the periodic slab model. The adsorption processes are determined to be strong chemisorptions, characterized by high adsorption energies in the range of-18.5 to-28.8 kcal.mol-1. Stability of the adsorption configurations is significantly contributed by attractive Ti•••O electrostatic interaction and O-H•••O strong hydrogen bond. The interactions between the adsorbed molecules on the rutile-TiO 2 (1 1 0) surface are stronger for the >COOH groups than for-OH or-NO 2 groups. The results show that the TiO 2-rutile is regarded as a potential adsorption material and an efficient photocatalyst for removal of these organic compounds.
Journal of the American Chemical Society, 2005
Recent combined experimental and theoretical studies (Beck et al., Phys. Rev. Lett. 2004, 93, 036104) have provided evidence for TidO double-bonded titanyl groups on the reconstructed rutile TiO2-(011)-(2×1) surface. The adsorption of water on the same surface is now investigated to further probe the properties of these groups, as well as to confirm their existence. Ultraviolet photoemission experiments show that water is adsorbed in molecular form at a sample temperature of 110 K. At the same time, the presence of a 3σ state in the photoemission spectra and work function measurements indicate a significant amount of hydroxyls within the first monolayer of water. At room temperature, scanning tunneling microscopy (STM) suggests that dissociated water is present, and about 30 of the surface active sites are hydroxylated. These findings are well explained by total energy density functional theory calculations and Car-Parrinello molecular dynamics simulations for water adsorption on the titanyl model of TiO 2(011)-(2×1). The theoretical results show that a mixed molecular/dissociative layer is the most stable configuration in the monolayer regime at low temperatures, while complete dissociation takes place at 250 K. The arrangement of the protonated mono-coordinated oxygens in the mixed molecular/dissociated layer is consistent with the observed short-range order of the hydroxyls in the STM images.
Surface Science, 2007
The rutile (1 1 0)-aqueous solution interface structure was measured in deionized water (DIW) and 1 molal (m) RbCl + RbOH solution (pH 12) at 25°C with the X-ray crystal truncation rod method. The rutile surface in both solutions consists of a stoichiometric (1 • 1) surface unit mesh with the surface terminated by bridging oxygen (BO) and terminal oxygen (TO) sites, with a mixture of water molecules and hydroxyl groups (OH À) occupying the TO sites. An additional hydration layer is observed above the TO site, with three distinct water adsorption sites each having well-defined vertical and lateral locations. Rb + specifically adsorbs at the tetradentate site between the TO and BO sites, replacing one of the adsorbed water molecules at the interface. There is no further ordered water structure observed above the hydration layer. Structural displacements of atoms at the oxide surface are sensitive to the solution composition. Ti atom displacements from their bulk lattice positions, as large as 0.05 Å at the rutile (1 1 0)-DIW interface, decay in magnitude into the crystal with significant relaxations that are observable down to the fourth Ti-layer below the surface. A systematic outward shift was observed for Ti atom locations below the BO rows, while a systematic inward displacement was found for Ti atoms below the TO rows. The Ti displacements were mostly reduced in contact with the RbCl solution at pH 12, with no statistically significant relaxations in the fourth layer Ti atoms. The distance between the surface 5-fold Ti atoms and the oxygen atoms of the TO site is 2.13 ± 0.03 Å in DIW and 2.05 ± 0.03 Å in the Rb + solution, suggesting molecular adsorption of water at the TO site to the rutile (1 1 0) surface in DIW, while at pH 12, adsorption at the TO site is primarily in the form of an adsorbed hydroxyl group.
Journal of Physics: Condensed Matter, 2022
A variety of OH containing molecules in their different modes of adsorption onto the rutile TiO2(110) are studied by means of density functional theory. A special focus is given to ethanol, ethylene glycol and glycerol. The different species were analyzed with respect to the adsorption energy, work function, and atomic Bader charges. Our results show that dissociated adsorption is favored in all cases. Within these modes, the strongest binding is observed in the case of bidentate fully dissociated adsorption, followed by bidentate partially dissociated then the monodentate dissociated modes. The dependence is also noted upon charge transfer analysis. Species adsorbing with two dissociated OH groups show a negative charge which is roughly twice as large compared to those exhibiting only one dissociated group. In the case of molecular adsorption, we find a small positive charge on the adsorbate. The change in work functions obtained is found to be negative in all studied cases. We obs...
Journal of Physical Chemistry C, 2007
Classical molecular dynamics simulations, supported by ab initio periodic calculations, were carried out to investigate peptide adsorption mechanisms onto a rutile (1 1 0) TiO 2 layer in the presence of water molecules. Different binding modes, comprising multiple coordination to the titanium atoms, of several conformers, simultaneously adsorbed upon the surface, were analyzed in detail. In agreement with experimental and theoretical findings, peptide carbonyl oxygens and nitrogens were found to be possible coordination atoms. Local effects were responsible of adsorption and desorption events and intermolecular interactions induced conformational changes and reorientations of the molecules with respect to the surface that produced both strongly and weakly adsorbed species.
Adsorption of bi-isonicotinic acid on rutile TiOsub 2
The Journal of Chemical Physics, 1999
Bi-isonicotinic acid ͑2,2Ј-bipyridine-4,4Ј-dicarboxylic acid͒ is the ligand of several organometallic dyes, used in photoelectrochemical applications. Therefore the atomic scale understanding of the bonding of this molecule to rutile TiO 2 (110) should give insight into the crucial dye-surface interaction. High resolution x-ray photoelectron spectroscopy ͑XPS͒, near edge x-ray absorption fine structure ͑NEXAFS͒, and periodic intermediate neglect of differential overlap ͑INDO͒ calculations were carried out on submonolayer bi-isonicotinic acid rutile TiO 2 (110). Data from multilayers is also presented to support the submonolayer results. For a multilayer, XPS shows that the carboxyl groups remain in the ͑pristine͒ protonated form, and NEXAFS show that the molecular plane is tilted by 57°with respect to the surface normal. For the submonolayer, the molecule bonds to the rutile TiO 2 (110) surface via both deprotonated carboxyl groups, with a tilt angle of 25°, and additionally an azimuthal orientation of 44°with respect to the ͓001͔ crystallographic direction. The adsorbant system was also investigated by quantum mechanical calculations using a periodic INDO model. The most stable theoretical adsorption geometry involves a twist around the molecular axis, such that the pyridine rings are tilted in opposite directions. Both oxygen atoms of each carboxyl group are bonded to five-fold coordinated Ti atoms ͑2M-bidentate͒, in excellent agreement with the experimental results.
Surface Science, 2003
The adsorption of monolayers of the pyridine-carboxylic acid monomers (isonicotinic acid, nicotinic acid, and picolinic acid) on rutile TiO 2 (1 1 0) has been studied by means of X-ray photoemission spectroscopy. An investigation of the O 1s spectra shows that the molecular carboxylic groups are deprotonated and, hence, that the molecules bind to the surface in a bidentate mode. Moreover, the binding energy of those core levels that are related to the pyridine ring atoms shift as a function of molecule relative to the substrate O 1s and Ti 3p levels, while the position of the core levels related to emission from the carboxylic group are constant relative to the substrate levels. The molecule-dependent shifts are attributed to local intermolecular interactions that determine the proximity of adjacent molecular rings and thus the core-hole screening response of the neighbouring molecules. We propose a simple molecular arrangement for each case which satisfies the known constraints.
physica status solidi (b), 2017
The accuracy of the theoretical description of materials properties in the framework of density functional theory (DFT) inherently depends on the exchange-correlation (XC) functional used in the calculations. Here we investigate the influence of the choice of a XC functional (PBE, RPBE, PW91, and PBE0) on the kinetics of the adsorption, diffusion and dissociation of water on the rutile TiO 2 (110) surface using a combined Kinetic Monte Carlo (KMC)-DFT approach, where the KMC simulations are based on the barriers for the aforementioned processes calculated with DFT. We also test how the adsorption energy of intact and dissociated water molecules changes when dispersion interactions are included into the calculations. We consider the beginning of the water layer formation varying coverage up to 0.2 monolayer (ML) at temperatures up to 180 K. We demonstrate that the dynamics of the simulated water-titania system is extremely sensitive to the choice of the XC functional.
Catalysis Today, 2013
A study has been carried out to determine the influence of bacterial adhesion onto immobilized TiO 2 on the photocatalytic efficiency for bacteria inactivation. Two bacterial strains with differences in their membrane structure (Escherichia coli and Enterococcus faecalis) have been characterized in various suspensions for adhesion to the TiO 2 catalyst and surface charge. Non-meaningful differences have been observed regarding the adhesion properties between both bacteria. In contrast, the configuration of the catalyst and the composition of the suspension impacted the extent of bacterial adhesion. The solution affected the adhesion between bacteria and catalyst due to its influence on electrostatic forces between them. Under electrostatically favourable conditions, hydrophobicity is the primary mechanism of adhesion. Under unfavourable conditions aquatic chemistry governs the bacterial adhesion process. Organic matter in combination with divalent ions leads to the highest level of adhesion. This may be due to the presence of Ca 2+ which can bridge between bacteria and catalyst. Additionally, Ca 2+ can also bridge with organic matter, which can act as source of nutrients for bacteria. Despite the solution ionic strength being low, divalent cations can contribute to the compression of the electric double layer, enhancing cellcatalyst interactions and subsequent adhesion. The bacterial adhesion observed in wastewaters might be responsible for the fact photocatalytic bacterial inactivation efficiency was not as low as expected since the main role of ions and organic matter is to act as scavengers of hydroxyl radicals.