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Wang Z, Labat F. Modeling stoichiometric and oxygen defective TiO 2 anatase bulk and (101) surface: structural and electronic properties from hybrid DFT. J Mol Model 2023; 29:174. [PMID: 37166566 DOI: 10.1007/s00894-023-05584-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/05/2023] [Indexed: 05/12/2023]
Abstract
CONTEXT We present a periodic hybrid DFT investigation of the structural and electronic properties of both stoichiometric and oxygen-defective TiO2 anatase bulk and (101) surface, in singlet and triplet spin states. In all cases, an excellent agreement with available photoelectron spectroscopy data has been obtained, reproducing the offsets of the deep defect levels positions from the conduction band minimum of TiO2 created upon oxygen vacancy (VO) formation. For the bulk, different local structural polaronic distortions around the VO site have been evidenced depending on the spin state considered. Although a similar conclusion has been drawn for the defective surface for the nine different vacancy positions which have been considered, large migration of the twofold coordinated surface O atom has also been evidenced, up to the initial vacancy site in some cases. The very good agreement obtained with available experimental data regarding the offsets from the conduction band minimum of the deep defect levels positions both for the bulk and the (101) surface of TiO2 anatase is encouraging for the application of the proposed hybrid-based computational strategy to TiO2 surface-related processes such as TiO2-based photocatalysis in which oxygen vacancies are known to play a key role. METHODS All calculations have been performed with Crystal17, considering different hybrid functionals with both effective core pseudopotentials and all-electron atom-centered basis sets, as well as additional empirical dispersion effects with the D2 and D3 models.
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Affiliation(s)
- Zihan Wang
- Chimie ParisTech, PSL University, CNRS UMR 8060, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Group, F-75005, Paris, France
| | - Frédéric Labat
- Chimie ParisTech, PSL University, CNRS UMR 8060, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Group, F-75005, Paris, France.
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Asgari S, Mohammadi Ziarani G, Badiei A, Setayeshmehr M, Kiani M, Pourjavadi A. Electrospun Ag-decorated reduced GO-graft-chitosan composite nanofibers with visible light photocatalytic activity for antibacterial performance. CHEMOSPHERE 2022; 299:134436. [PMID: 35358565 DOI: 10.1016/j.chemosphere.2022.134436] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/15/2022] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
The treatment of water contaminated by bacteria is becoming a necessity. The nanomaterials possessing both intrinsic antibacterial properties and photocatalytic activity are excellent candidates for water disinfection. The powdered form of nanomaterials can be aggregated while embedding the nanomaterials into the NFs can overcome the limitation and enhance the photocatalytic activity and transition from UV-light to visiblelight. Here, graphene oxide (GO) was synthesized, grafted to chitosan, and decorated with silver nanoparticles (Ag NPs) to produce Ag-decorated reduced GO-graft-Chitosan (AGC) NPs. The blends of polyacrylonitrile (PAN) and AGC NPs were prepared in various concentrations of 0.5 wt%, 1.0 wt%, 5.0 wt%, and 10.0 wt% and used to fabricate the electrospun composite NFs. FTIR/ATR, UV-Vis, Raman, XRD, and SEM/EDAX analyses confirmed the successful preparation of the NPs and NFs. The cytotoxicity and antibacterial activity of the composite NFs were received in the order of composite NFs 10.0 wt%˃ 5.0 wt%˃ 1.0 wt%˃ 0.5 wt% in both conditions with/without light irradiation. Their cytotoxicity and antibacterial activity were more under light irradiation compared to the dark. The composite NFs (5.0 wt%) were distinguished as the optimum NFs with cell viability of 80% within 24 h and 60% within 48 h on L929 cells and inhibition zone diameter (IZD) of 12 mm for E. coli and 13 mm for S. aureus after 24 h under the light irradiation. The optimum composite NFs showed thermal stability up to 180 °C and tensile strength of 1.11 MPa with 21.71% elongation at break.
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Affiliation(s)
- Shadi Asgari
- Department of Chemistry, Faculty of Physics and Chemistry, Alzahra University, Tehran, P.O. Box, 1993893973, Iran; School of Chemistry, College of Science, University of Tehran, Tehran, Iran
| | - Ghodsi Mohammadi Ziarani
- Department of Chemistry, Faculty of Physics and Chemistry, Alzahra University, Tehran, P.O. Box, 1993893973, Iran.
| | - Alireza Badiei
- School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
| | - Mohsen Setayeshmehr
- Department of Biomaterials, Tissue Engineering and Nanotechnology, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mahsa Kiani
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
| | - Ali Pourjavadi
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
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Mirković M, Filipović S, Kalijadis A, Mašković P, Mašković J, Vlahović B, Pavlović V. Hydroxyapatite/TiO2 Nanomaterial with Defined Microstructural and Good Antimicrobial Properties. Antibiotics (Basel) 2022; 11:antibiotics11050592. [PMID: 35625236 PMCID: PMC9137706 DOI: 10.3390/antibiotics11050592] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/14/2022] [Accepted: 04/26/2022] [Indexed: 12/04/2022] Open
Abstract
Due to the growing number of people infected with the new coronavirus globally, which weakens immunity, there has been an increase in bacterial infections. Hence, knowledge about simple and low-cost synthesis methods of materials with good structural and antimicrobial properties is of great importance. A material obtained through the combination of a nanoscale hydroxyapatite material (with good biocompatibility) and titanium dioxide (with good degradation properties of organic molecules) can absorb and decompose bacteria. In this investigation, three different synthesis routes used to prepare hydroxyapatite/titanium dioxide nanomaterials are examined. The morphology and semiquantitative chemical composition are characterized by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX). The obtained materials’ phase and structural characterization are determined using the X-ray powder diffraction method (XRD). The crystallite sizes of the obtained materials are in the range of 8 nm to 15 nm. Based on XRD peak positions, the hexagonal hydroxyapatite phases are formed in all samples along with TiO2 anatase and rutile phases. According to SEM and TEM analyses, the morphology of the prepared samples differs depending on the synthesis route. The EDX analysis confirmed the presence of Ti, Ca, P, and O in the obtained materials. The IR spectroscopy verified the vibration bands characteristic for HAp and titanium. The investigated materials show excellent antimicrobial and photocatalytic properties.
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Affiliation(s)
- Miljana Mirković
- Department of Materials, University of Belgrade, “Vinča” Institute of Nuclear Sciences—National Institute of the Republic of Serbia, 11000 Belgrade, Serbia;
- Correspondence:
| | - Suzana Filipović
- Institute of Technical Sciences of SASA, KnezMihailova 35/IV, 11000 Belgrade, Serbia;
| | - Ana Kalijadis
- Department of Materials, University of Belgrade, “Vinča” Institute of Nuclear Sciences—National Institute of the Republic of Serbia, 11000 Belgrade, Serbia;
| | - Pavle Mašković
- Faculty of Agronomy in Čačak, University of Kragujevac, Cara Dušana 34, 32012 Čačak, Serbia; (P.M.); (J.M.)
| | - Jelena Mašković
- Faculty of Agronomy in Čačak, University of Kragujevac, Cara Dušana 34, 32012 Čačak, Serbia; (P.M.); (J.M.)
| | - Branislav Vlahović
- Department of Mathematics and Physics, North Carolina Central University, Durham, NC 27707, USA;
- NASA University Research Center for Aerospace Device Research and Education and NSF Center of Research Excellence in Science and Technology Computational Center for Fundamental and Applied Science and Education, Durham, NC 27707, USA
| | - Vladimir Pavlović
- Department for Physics and Mathematics, Faculty of Agriculture, University of Belgrade, 11000 Belgrade, Serbia;
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Dispersion of Defects in TiO2 Semiconductor: Oxygen Vacancies in the Bulk and Surface of Rutile and Anatase. Catalysts 2020. [DOI: 10.3390/catal10040397] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Oxygen deficiency (O-vacancy) contributes to the photoefficiency of TiO2 semiconductors by generating electron rich active sites. In this paper, the dispersion of O-vacancies in both bulk and surface of anatase and rutile phases was computationally investigated. The results showed that the O-vacancies dispersed in single- and double-cluster forms in the anatase and rutile phases, respectively, in both bulk and surface. The distribution of the O-vacancies was (roughly) homogeneous in anatase, and heterogenous in rutile bulk. The O-vacancy formation energy, width of defect band, and charge distribution indicated the overlap of the defect states in the rutile phase and thus eased the formation of clusters. Removal of the first and the second oxygen atoms from the rutile surface took less energy than the anatase one, which resulted in a higher deficiency concentration on the rutile surface. However, these deficiencies formed one active site per unit cell of rutile. On the other hand, the first O-vacancy formed on the surface and the second one formed in the subsurface of anatase (per unit cell). Supported by previous studies, we argue that this distribution of O-vacancies in anatase (surface and subsurface) could potentially create more active sites on its surface.
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Elahifard MR, Behjatmanesh-Ardakani R, Ahmadvand S, Abbasi B, Abbasi B. A mechanistic study of photo-oxidation of phenol and AB92 by AgBr/TiO2. RESEARCH ON CHEMICAL INTERMEDIATES 2019. [DOI: 10.1007/s11164-019-03867-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Ahmadvand S, Elahifard M, Jabbarzadeh M, Mirzanejad A, Pflughoeft K, Abbasi B, Abbasi B. Bacteriostatic Effects of Apatite-Covered Ag/AgBr/TiO2 Nanocomposite in the Dark: Anomaly in Bacterial Motility. J Phys Chem B 2019; 123:787-791. [DOI: 10.1021/acs.jpcb.8b10710] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
| | - Mohammadreza Elahifard
- Chemical Engineering Department, Faculty of Engineering, Ardakan University, Ardakan 89518-95491, Iran
| | - Mehdi Jabbarzadeh
- Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112, United States
| | - Amir Mirzanejad
- Chemical Engineering Department, Faculty of Engineering, Ardakan University, Ardakan 89518-95491, Iran
| | | | - Bahman Abbasi
- Department of Mechanical Engineering, Oregon State University, Corvallis, Oregon 97333, United States
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Elahifard MR, Meidanshahi RV. Photo-Deposition of Ag Metal Particles on Ni-Doped TiO2 for Photocatalytic Application. PROGRESS IN REACTION KINETICS AND MECHANISM 2017. [DOI: 10.3184/146867817x14821527549130] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ni-doped TiO2 and Ag-deposited@Ni-doped TiO2 photocatalysts were prepared using the co-precipitation technique and characterised using X-ray powder diffraction, scanning electron microscopy and Brunauer–Emmett-Teller analysis. Our results confirmed the presence of Ni atoms in the TiO2 bulk structure and Ag° metal particles deposited on the surface. The Ni impurity generates defect midgap states in the TiO2 band structure, providing visible light (VL) absorption, which are responsible for photocatalytic activity under VL conditions. Against this advantage, Ni changes the indirect band gap of pure anatase to the direct band gap which may dramatically suppress the photocatalytic activity of Ni-doped TiO2. Moreover, Ni may provide a centre of electron–hole (e–h) recombination which enhances the negative effect of Ni impurity on TiO2 photo-efficiency. These drawbacks were overcome by deposition of Ag° on the Ni-doped TiO2 which sinks the photo-excited electrons, quenching e–h recombination. This improvement yields three times more photo-efficiency in the decolourisation of Acid Blue 92. Although Ag@Ni-doped anatase shows a higher adsorption constant ( Kads) than Ag@Ni-doped rutile, both catalysts surprisingly present the same rate constant ( k).
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Affiliation(s)
| | - Reza Vatan Meidanshahi
- Arizona State University, School of Electrical, Computer and Energy Engineering, Tempe, AZ, 85281, USA
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Long M, Cai W. Advanced nanoarchitectures of silver/silver compound composites for photochemical reactions. NANOSCALE 2014; 6:7730-7742. [PMID: 24922110 DOI: 10.1039/c3nr06302j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Silver/silver compound (SSC) composites have received much attention as a type of potential materials in photochemical reactions due to their high efficiency, facile syntheses and availability of raw materials. This article reviews the state-of-the-art progress on the advanced nanoarchitectures of SSC composites. We begin with a survey on the general synthetic strategies for SSC composites, and then step into relatively detailed methods for size and morphology tunable two-component and more delicate multi-component SSC nanostructures. In addition, the electronic structure-related mechanisms of such materials and the recent studies on their stability are summarized. This review also highlights some perspectives on challenges related to the SSC composites and the possible research in the future.
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Affiliation(s)
- Mingce Long
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China.
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Azimzadehirani M, Elahifard M, Haghighi S, Gholami M. Highly efficient hydroxyapatite/TiO2 composites covered by silver halides as E. coli disinfectant under visible light and dark media. Photochem Photobiol Sci 2013; 12:1787-94. [DOI: 10.1039/c3pp50119a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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