Dataset Information

Removal of Ampicillin by Heterogeneous Photocatalysis: Combined Experimental and DFT Study.

ABSTRACT: A long-term exposition of antibiotics represents a serious problem for the environment, especially for human health. Heterogeneous photocatalysis opens a green way for their removal. Here, we correlated the structural-textural properties of TiO₂ photocatalysts with their photocatalytic performance in ampicillin abatement. The tested nanoparticles included anatase and rutile and their defined mixtures. The nominal size range varied from 5 to 800 nm, Aeroxide P25 serving as an industrial benchmark reference. The degradation mechanism of photocatalytic ampicillin abatement was studied by employing both experimental (UPLC/MS/MS, hydroxyl radical scavenger) and theoretical (quantum calculations) approaches. Photocatalytic activity increased with the increasing particle size, generally, anatase being more active than rutile. Interestingly, in the dark, the ampicillin concentration decreased as well, especially in the presence of very small nanoparticles. Even if the photolysis of ampicillin was negligible, a very high degree of mineralization of antibiotic was achieved photocatalytically using the smallest nanoparticles of both allotropes and their mixtures. Furthermore, for anatase samples, the reaction rate constant increases with increasing crystallite size, while the degree of mineralization decreases. Importantly, the suggested degradation pathway mechanism determined by DFT modeling was in very good agreement with experimentally detected reaction products.

SUBMITTER: Belhacova L

PROVIDER: S-EPMC8399517 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Here we present a detailed ab initio study of two experimentally synthesized bismuth niobate BiNbO4 (BNO) polymorphs within the framework of density functional theory (DFT). We synthesized orthorhombic α-BNO and triclinic β-BNO using a solid-state reaction technique. The underlying Pnna and P1̄ crystal symmetries along with their respective phase purity have been confirmed from Rietveld refinement of the powdered X-ray diffraction measurements in combination with generalized gradient approximation of Perdew-Burke-Ernzerhof (GGA-PBE) based DFT simulations. The scanning electron micrographs revealed average grain sizes to be 500 nm and 1 μm for α-BNO and β-BNO respectively. The energy-dispersive X-ray spectroscopy identified the Bi, Nb, and O with proper stoichiometry. The phase purity of the as-synthesized samples was further confirmed by comparing the local density approximation (LDA) norm-conserving pseudo-potential based DFT-simulated Raman peaks with that of experimentally measured ones. The relevant bond vibrations detected in Fourier transform infrared spectroscopy were matched with GGA-PBE derived phonon density of states simulation for both polymorphs. The structural stability and the charge dynamics of the polymorphs were verified from elastic stress and born charge tensor simulations respectively. The dynamical stability of the α-BNO was confirmed from phonon band structure simulation using density functional perturbation theory with Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional. The electronic band gaps of 3.08 and 3.36 eV for α-BNO and β-BNO measured from UV-Vis diffuse reflectance measurements were matched with the sophisticated HSE06 band structure simulation by adjusting the Hartree-Fock exchange parameter. Both GGA-PBE and HSE06 functional were used to simulate complex dielectric function and its derivatives with the help of Fermi's golden rule to define the optical properties in the linear regime. All these may have provided a rigorous theoretical analysis for the experimentally synthesized α-BNO and β-BNO polymorphs.

Dataset Information

Removal of Ampicillin by Heterogeneous Photocatalysis: Combined Experimental and DFT Study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets