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Inico E, Saetta C, Di Liberto G. Impact of quantum size effects to the band gap of catalytic materials: a computational perspective. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:361501. [PMID: 38830369 DOI: 10.1088/1361-648x/ad53b5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 06/03/2024] [Indexed: 06/05/2024]
Abstract
The evolution of nanotechnology has facilitated the development of catalytic materials with controllable composition and size, reaching the sub-nanometer limit. Nowadays, a viable strategy for tailoring and optimizing the catalytic activity involves controlling the size of the catalyst. This strategy is underpinned by the fact that the properties and reactivity of objects with dimensions on the order of nanometers can differ from those of the corresponding bulk material, due to the emergence of quantum size effects. Quantum size effects have a deep influence on the band gap of semiconducting catalytic materials. Computational studies are valuable for predicting and estimating the impact of quantum size effects. This perspective emphasizes the crucial role of modeling quantum size effects when simulating nanostructured catalytic materials. It provides a comprehensive overview of the fundamental principles governing the physics of quantum confinement in various experimentally observable nanostructures. Furthermore, this work may serve as a tutorial for modeling the electronic gap of simple nanostructures, highlighting that when working at the nanoscale, the finite dimensions of the material lead to an increase of the band gap because of the emergence of quantum confinement. This aspect is sometimes overlooked in computational chemistry studies focused on surfaces and nanostructures.
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Affiliation(s)
- Elisabetta Inico
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, Via R. Cozzi 55, 20125 Milano, Italy
| | - Clara Saetta
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, Via R. Cozzi 55, 20125 Milano, Italy
| | - Giovanni Di Liberto
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, Via R. Cozzi 55, 20125 Milano, Italy
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2
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Vale M, Barrocas BT, Serôdio RMN, Oliveira MC, Lopes JM, Marques AC. Robust Photocatalytic MICROSCAFS ® with Interconnected Macropores for Sustainable Solar-Driven Water Purification. Int J Mol Sci 2024; 25:5958. [PMID: 38892146 PMCID: PMC11172857 DOI: 10.3390/ijms25115958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape, and morphology offer a sustainable solution to the water pollution problem by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigated the influence of pore and particle sizes of photocatalytic MICROSCAFS® on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica-titania microspheres with a controlled size and interconnected macroporosity, synthesized by an adapted sol-gel method that involves a polymerization-induced phase separation process. Photocatalytic experiments were performed both in batch and flow reactors, with this latter one targeting a proof of concept for continuous transformation processes and real-life conditions. Photocatalytic degradation of 87% in 2 h (batch) was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® performance. A scavenger study was performed, enabling an in-depth mechanistic understanding. Finally, the transformation products resulting from the MO photocatalytic degradation were elucidated by high-resolution mass spectrometry experiments and subjected to an in silico toxicity assessment.
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Affiliation(s)
- Mário Vale
- Centro de Recursos Naturais e Ambiente (CERENA), Chemical Engineering Department, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (M.V.); (B.T.B.); (R.M.N.S.)
| | - Beatriz T. Barrocas
- Centro de Recursos Naturais e Ambiente (CERENA), Chemical Engineering Department, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (M.V.); (B.T.B.); (R.M.N.S.)
| | - Rita M. N. Serôdio
- Centro de Recursos Naturais e Ambiente (CERENA), Chemical Engineering Department, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (M.V.); (B.T.B.); (R.M.N.S.)
- Centro de Desenvolvimento de Produto e Transferência de Tecnologia (CDP2T), Escola Superior de Tecnologia de Setúbal, Instituto Politécnico de Setúbal, 2910-761 Setúbal, Portugal
- Centro de Física e Engenharia de Materiais Avançados (CeFEMA), Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
| | - M. Conceição Oliveira
- Centro de Química Estrutural (CQE), Chemical Engineering Department, Institute of Molecular Sciences, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (M.C.O.); (J.M.L.)
| | - José M. Lopes
- Centro de Química Estrutural (CQE), Chemical Engineering Department, Institute of Molecular Sciences, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (M.C.O.); (J.M.L.)
| | - Ana C. Marques
- Centro de Recursos Naturais e Ambiente (CERENA), Chemical Engineering Department, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal; (M.V.); (B.T.B.); (R.M.N.S.)
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3
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Recio-Poo M, Morales-García Á, Illas F, Bromley ST. Tuning electronic levels in photoactive hydroxylated titania nanosystems: combining the ligand dipole effect and quantum confinement. NANOSCALE 2024. [PMID: 38618709 DOI: 10.1039/d3nr06189b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Reducing the size of titania (TiO2) to the nanoscale promotes the photoactive anatase phase for use in a range of applications from industrial catalysis to environment remediation. The nanoscale dimensions of these systems affect the magnitude of the electronic energy gap by quantum confinement. Upon interaction with aqueous environments or water vapour, the surfaces of these systems will also be hydroxylated to some degree. In turn, this affects the electronic energy levels due to the cumulative electrostatic effect of the dipolar hydroxyl (-OH) ligands (i.e. the ligand dipole effect). Using accurate density functional calculations, we investigate the combined effects of quantum confinement and the hydration-induced ligand dipole effect on a set of realistic titania nanosystems over a wide range of hydroxylation. Our detailed investigation reveals that, contrary to previous models, the ligand dipole effect does not-linearly depend on the ligand coverage due to the formation of inter-ligand OH⋯OH hydrogen bonds. To account for the resulting effects, we propose a refined model, which describes the ligand dipole effect more accurately in our systems. We show that both hydroxylation (by the ligand dipole effect) and size (by quantum confinement) have significant but distinct impacts on the electronic energy levels in nanotitania. As an example, we discuss how variations in these effects can be used to tune the highest unoccupied energy level in nanotitania for enhancing the efficiency of the hydrogen evolution reaction. Overall, we show that any specific energy shift can be achieved by a range of different combinations of nanosystem size and degree of hydroxylation, thus providing options for energy-level tuning while also allowing consideration of practical constraints (e.g. synthetic limitations, operating conditions) for photochemical applications.
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Affiliation(s)
- Miguel Recio-Poo
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Stefan T Bromley
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
- Institució Catalana de recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
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4
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García-Romeral N, Keyhanian M, Morales-García Á, Viñes F, Illas F. Understanding the Chemical Bond in Semiconductor/MXene Composites: TiO 2 Clusters Anchored on the Ti 2C MXene Surface. Chemistry 2024; 30:e202400255. [PMID: 38251957 DOI: 10.1002/chem.202400255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 01/23/2024]
Abstract
First-principles calculations on titania clusters (TiO2)n (n=5 and 10) supported on the pristine Ti2C (0001) surface were carried out to understand the properties of semiconductor/MXene composites with implications in (photo)-catalysis. The reported results reveal a high exothermic interaction accompanied by a substantial charge transfer with a concomitant, notorious, deformation of the titania nanoclusters. The analysis of the density of states analysis of the composite systems evidences a metallic character with titania related states crossing the Fermi level. The picture of the chemical bonds is completed by the analysis of X-Ray Photoelectron Spectra (XPS) features, evidencing clear shifts of the C(1s) and O(1s) related peaks relative to the isolated systems that have a quite complex origin. This detailed analysis provides insights to experimentalists interested in the design and synthesis of these systems with possible applications in catalysis.
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Affiliation(s)
- Néstor García-Romeral
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Masoomeh Keyhanian
- Department of Physical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, 47416-95447, Iran
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Francesc Viñes
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028, Barcelona, Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028, Barcelona, Spain
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5
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Valero R, Morales-García Á, Illas F. Estimating Nonradiative Excited-State Lifetimes in Photoactive Semiconducting Nanostructures. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:2713-2721. [PMID: 38379918 PMCID: PMC10875665 DOI: 10.1021/acs.jpcc.3c08053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/09/2024] [Accepted: 01/16/2024] [Indexed: 02/22/2024]
Abstract
The time evolution of the exciton generated by light adsorption in a photocatalyst is an important feature that can be approached from full nonadiabatic molecular dynamics simulations. Here, a crucial parameter is the nonradiative recombination rate between the hole and the electron that form the exciton. In the present work, we explore the performance of a Fermi's golden rule-based approach on predicting the recombination rate in a set of photoactive titania nanostructures, relying solely on the coupling of the ground and first excited state. In this scheme the analysis of the first excited state is carried out by invoking Kasha's rule thus avoiding computationally expensive nonadiabatic molecular dynamics simulations and resulting in an affordable estimate of the recombination rate. Our results show that, compared to previous ones from nonadiabatic molecular dynamics simulations, semiquantitative recombination rates can be predicted for the smaller titania nanostructures, and qualitative values are obtained from the larger ones. The present scheme is expected to be useful in the field of computational heterogeneous photocatalysis whenever a complex and computationally expensive full nonadiabatic molecular dynamics cannot be carried out.
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Affiliation(s)
- Rosendo Valero
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona. c/Martí i Franquès 1-11, 08028 Barcelona, Spain
- Headquarters
Research Institute, Zhejiang Huayou Cobalt, 018 Wuzhen East Rd, 314599 Jiaxing, Zhejiang, China
| | - Ángel Morales-García
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona. c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Francesc Illas
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona. c/Martí i Franquès 1-11, 08028 Barcelona, Spain
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6
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Campos-Delgado J, Mendoza ME. Ternary Graphene Oxide and Titania Nanoparticles-Based Nanocomposites for Dye Photocatalytic Degradation: A Review. MATERIALS (BASEL, SWITZERLAND) 2023; 17:135. [PMID: 38203988 PMCID: PMC10780078 DOI: 10.3390/ma17010135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/20/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024]
Abstract
Advanced oxidation processes stand as green alternatives for the decontamination of waste waters. Photocatalysis is an advanced oxidation process in which a semiconductor material absorbs photon energy and triggers redox reactions capable of degrading organic pollutants. Titanium dioxide (TiO2, titania) represents one of the most popular choices of photocatalytic materials, however the UV-activation of its anatase phase and its high charge recombination rate decrease its photocatalytic activity and weaken its potential. Graphene oxide is a 2D carbon nanomaterial consisting of exfoliated sheets of hexagonally arranged carbons decorated with oxygen- and hydrogen- functional groups. Composite nanomaterials consisting of titania nanoparticles and graphene oxide have proven to enhance the photocatalytic activity of pure TiO2. In this review, we present a thorough literature review of ternary nanocomposites based on synthesized or commercial titania nanoparticles and GO (or reduced GO) particularly used for the photodegradation of dyes. GO/TiO2 has been enriched primarily with metals, semiconductors and magnetic nanomaterials, proving a superior dye degradation performance and reusability compared to bare TiO2. Ongoing challenges and perspectives are outlined.
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Affiliation(s)
- Jessica Campos-Delgado
- Instituto de Física, Benemérita Universidad Autónoma de Puebla, Av. San Claudio esq. 18 Sur, Puebla 72570, Mexico;
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7
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R Remesal E, Morales-García Á, Illas F. Role of N Doping in the Reduction of Titania Nanostructures. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:20128-20136. [PMID: 37850083 PMCID: PMC10578348 DOI: 10.1021/acs.jpcc.3c04665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/07/2023] [Indexed: 10/19/2023]
Abstract
The effect of N-doping of titania (TiO2) nanoparticles (NPs) on their reduction through neutral O vacancy (Ovac) formation is investigated using all electron density functional theory-based calculations, including hybrid density functionals, and taking the bipyramidal anatase (TiO2)84 NP as a realistic model. The location of the N dopant is systematically analyzed, including O substitution in the (TiO2)84 structure and N occupying interstitial regions. Our computational study concludes that interstitial N doping is more favorable than N substituting O atoms and confirms that the presence of N reduces the energy gap. In the N-doped NP, Ovac formation is more favored than in undoped NP but less than in the N-doped bulk, which has important consequences.
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Affiliation(s)
- Elena R Remesal
- Departament de Ciència
de Materials i Química Física & Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Ángel Morales-García
- Departament de Ciència
de Materials i Química Física & Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Francesc Illas
- Departament de Ciència
de Materials i Química Física & Institut de Química
Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
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8
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Pavan C, Santalucia R, Escolano-Casado G, Ugliengo P, Mino L, Turci F. Physico-Chemical Approaches to Investigate Surface Hydroxyls as Determinants of Molecular Initiating Events in Oxide Particle Toxicity. Int J Mol Sci 2023; 24:11482. [PMID: 37511241 PMCID: PMC10380507 DOI: 10.3390/ijms241411482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/04/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
The study of molecular recognition patterns is crucial for understanding the interactions between inorganic (nano)particles and biomolecules. In this review we focus on hydroxyls (OH) exposed at the surface of oxide particles (OxPs) which can play a key role in molecular initiating events leading to OxPs toxicity. We discuss here the main analytical methods available to characterize surface OH from a quantitative and qualitative point of view, covering thermogravimetry, titration, ζ potential measurements, and spectroscopic approaches (NMR, XPS). The importance of modelling techniques (MD, DFT) for an atomistic description of the interactions between membranes/proteins and OxPs surfaces is also discussed. From this background, we distilled a new approach methodology (NAM) based on the combination of IR spectroscopy and bioanalytical assays to investigate the molecular interactions of OxPs with biomolecules and membranes. This NAM has been already successfully applied to SiO2 particles to identify the OH patterns responsible for the OxPs' toxicity and can be conceivably extended to other surface-hydroxylated oxides.
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Affiliation(s)
- Cristina Pavan
- Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy
- "G. Scansetti" Interdepartmental Centre for Studies on Asbestos and Other Toxic Particulates, University of Torino, 10125 Torino, Italy
- Louvain Centre for Toxicology and Applied Pharmacology, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - Rosangela Santalucia
- Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy
- Nanostructured Interfaces and Surfaces (NIS) Interdepartmental Centre, University of Torino, 10125 Torino, Italy
| | - Guillermo Escolano-Casado
- Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy
- Nanostructured Interfaces and Surfaces (NIS) Interdepartmental Centre, University of Torino, 10125 Torino, Italy
| | - Piero Ugliengo
- Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy
- Nanostructured Interfaces and Surfaces (NIS) Interdepartmental Centre, University of Torino, 10125 Torino, Italy
| | - Lorenzo Mino
- Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy
- Nanostructured Interfaces and Surfaces (NIS) Interdepartmental Centre, University of Torino, 10125 Torino, Italy
| | - Francesco Turci
- Department of Chemistry, University of Torino, Via Giuria 7, 10125 Torino, Italy
- "G. Scansetti" Interdepartmental Centre for Studies on Asbestos and Other Toxic Particulates, University of Torino, 10125 Torino, Italy
- Nanostructured Interfaces and Surfaces (NIS) Interdepartmental Centre, University of Torino, 10125 Torino, Italy
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Recio-Poo M, Morales-García Á, Illas F, Bromley ST. Crystal properties without crystallinity? Influence of surface hydroxylation on the structure and properties of small TiO 2 nanoparticles. NANOSCALE 2023; 15:4809-4820. [PMID: 36786054 DOI: 10.1039/d3nr00141e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Titania (TiO2) nanoparticles (NPs) are widely employed in applications that take advantage of their photochemical properties (e.g. pollutant degradation, photocatalysis). Here, we study the interrelation between crystallinity, surface hydroxylation and electronic structure in titania NPs with 1.4-2.3 nm diameters using all electron density functional theory-based calculations. We show how the distribution of local coordination environments of the atoms in thermally annealed quasi-spherical non-crystalline NPs converge to those in correspondingly sized faceted crystalline anatase NPs upon increasing hydroxylation. When highly hydroxylated, annealed NPs also possess electronic energy gaps with very similar energies and band edge orbital characters to those of the crystalline anatase NPs. We refer to the crystallite-mimicking non-crystalline annealed NPs as "crystalikes". Small stable crystalike NPs could allow for photochemical applications of titania in the size range where crystalline anatase NPs tend to become thermodynamically unfavoured (<3-5 nm). Our work implies the anatase crystal structure may not be as essential as previously assumed for TiO2 NP applications and generally suggests that crystalikes could be possible in other nanomaterials.
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Affiliation(s)
- Miguel Recio-Poo
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Stefan T Bromley
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
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10
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Maleki F, Di Liberto G, Pacchioni G. pH- and Facet-Dependent Surface Chemistry of TiO 2 in Aqueous Environment from First Principles. ACS APPLIED MATERIALS & INTERFACES 2023; 15:11216-11224. [PMID: 36786774 PMCID: PMC9982820 DOI: 10.1021/acsami.2c19273] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
TiO2 is a relevant catalytic material, and its chemistry in aqueous environment is a challenging aspect to address. Also, the morphology of TiO2 particles at the nanoscale is often complex, spanning from faceted to spherical. In this work, we study the pH- and facet-dependent surface chemistry of TiO2/water interfaces by performing ab initio molecular dynamics simulations with the grand canonical formulation of species in solution. We first determined the acid-base equilibrium constants at the interface, which allows us to estimate the pH at the point of zero charge, an important experimental observable. Then, based on simulated equilibrium constants, we predict the amount of H+, OH-, and adsorbed H2O species present on the surfaces as a function of the pH, a relevant aspect for water splitting semi-reactions. We approximated the complex morphology of TiO2 particles by considering the rutile (110) and (011), and anatase (101), (001), and (100) surfaces.
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11
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Apostolova I, Apostolov A, Wesselinowa J. Band Gap Tuning in Transition Metal and Rare-Earth-Ion-Doped TiO 2, CeO 2, and SnO 2 Nanoparticles. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:145. [PMID: 36616055 PMCID: PMC9824300 DOI: 10.3390/nano13010145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
The energy gap Eg between the valence and conduction bands is a key characteristic of semiconductors. Semiconductors, such as TiO2, SnO2, and CeO2 have a relatively wide band gap Eg that only allows the material to absorb UV light. Using the s-d microscopic model and the Green's function method, we have shown two possibilities to reduce the band-gap energy Eg-reducing the NP size and/or ion doping with transition metals (Co, Fe, Mn, and Cu) or rare earth (Sm, Tb, and Er) ions. Different strains appear that lead to changes in the exchange-interaction constants, and thus to a decrease in Eg. Moreover, the importance of the s-d interaction, which causes room-temperature ferromagnetism and band-gap energy tuning in dilute magnetic semiconductors, is shown. We tried to clarify some discrepancies in the experimental data.
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Affiliation(s)
| | - Angel Apostolov
- University of Architecture, Civil Engineering and Geodesy, Hristo Smirnenski Blvd. 1, 1046 Sofia, Bulgaria
| | - Julia Wesselinowa
- Sofia University “St. Kliment Ohridski”, J. Bouchier Blvd. 5, 1164 Sofia, Bulgaria
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12
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Allès M, Remesal ER, Illas F, Morales‐García Á. Structural and Electronic Properties of Metal/Oxide Nanostructures from First‐Principles: Ru
13
Supported on (TiO
2
)
84
as a Case Study. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Miquel Allès
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona c/Martí i Franquès 1‐11 Barcelona 08028 Spain
| | - Elena R. Remesal
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona c/Martí i Franquès 1‐11 Barcelona 08028 Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona c/Martí i Franquès 1‐11 Barcelona 08028 Spain
| | - Ángel Morales‐García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona c/Martí i Franquès 1‐11 Barcelona 08028 Spain
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13
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An unconstrained approach to systematic structural and energetic screening of materials interfaces. Nat Commun 2022; 13:6236. [PMID: 36266341 PMCID: PMC9585034 DOI: 10.1038/s41467-022-33414-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 09/15/2022] [Indexed: 11/08/2022] Open
Abstract
From grain boundaries and heterojunctions to manipulating 2D materials, solid-solid interfaces play a key role in many technological applications. Understanding and predicting properties of these complex systems present an ongoing and increasingly important challenge. Over the last few decades computer simulation of interfaces has become vastly more powerful and sophisticated. However, theoretical interface screening remains based on largely heuristic methods and is strongly biased to systems that are amenable to modelling within constrained periodic cell approaches. Here we present an unconstrained and generally applicable non-periodic screening approach for systematic exploration of material's interfaces based on extracting and aligning disks from periodic reference slabs. Our disk interface method directly and accurately describes how interface structure and energetic stability depends on arbitrary relative displacements and twist angles of two interacting surfaces. The resultant detailed and comprehensive energetic stability maps provide a global perspective for understanding and designing interfaces. We confirm the power and utility of our method with respect to the catalytically important TiO2 anatase (101)/(001) and TiO2 anatase (101)/rutile (110) interfaces.
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14
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Remesal ER, Morales-García Á. Carbon-doped anatase titania nanoparticles: similarities and differences with respect to bulk and extended surface models. Phys Chem Chem Phys 2022; 24:21381-21387. [PMID: 36047279 DOI: 10.1039/d2cp02455a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
C-Doping of titania nanoparticles is analyzed by using all-electron density functional theory-based calculations considering the (TiO2)84 nanoparticle as a realistic representative of nanoparticles in the scalable regime. Several sites are evaluated including substituting oxygen (CO) and titanium (CTi) sites as well as interstitial (Ci) situations. The formation energy of such a doped structure is studied as a function of the oxygen chemical potential (or oxygen partial pressure). Our calculations predict that low partial oxygen pressure favors the formation of C-doped (TiO2)84 NPs at oxygen and interstitial sites. For the former, the most stable situation is for O sites at the inner part of the nanoparticle. Interestingly, the substitution of O by C at facet sites requires formation energies as those reported in previous studies where the bulk anatase and surfaces models were considered. However, C-doping - at other low coordinated sites not presented in extended models - is even more favorable which shows the need to employ more realistic models for nanostructures involved in photocatalytic processes.
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Affiliation(s)
- Elena R Remesal
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
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15
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Samanta B, Morales-García Á, Illas F, Goga N, Anta JA, Calero S, Bieberle-Hütter A, Libisch F, Muñoz-García AB, Pavone M, Caspary Toroker M. Challenges of modeling nanostructured materials for photocatalytic water splitting. Chem Soc Rev 2022; 51:3794-3818. [PMID: 35439803 DOI: 10.1039/d1cs00648g] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Understanding the water splitting mechanism in photocatalysis is a rewarding goal as it will allow producing clean fuel for a sustainable life in the future. However, identifying the photocatalytic mechanisms by modeling photoactive nanoparticles requires sophisticated computational techniques based on multiscale modeling. In this review, we will survey the strengths and drawbacks of currently available theoretical methods at different length and accuracy scales. Understanding the surface-active site through Density Functional Theory (DFT) using new, more accurate exchange-correlation functionals plays a key role for surface engineering. Larger scale dynamics of the catalyst/electrolyte interface can be treated with Molecular Dynamics albeit there is a need for more generalizations of force fields. Monte Carlo and Continuum Modeling techniques are so far not the prominent path for modeling water splitting but interest is growing due to the lower computational cost and the feasibility to compare the modeling outcome directly to experimental data. The future challenges in modeling complex nano-photocatalysts involve combining different methods in a hierarchical way so that resources are spent wisely at each length scale, as well as accounting for excited states chemistry that is important for photocatalysis, a path that will bring devices closer to the theoretical limit of photocatalytic efficiency.
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Affiliation(s)
- Bipasa Samanta
- Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3600003, Israel
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain.
| | - Nicolae Goga
- Faculty of Engineering in Foreign Languages, Universitatea Politehnica din Bucuresti, Bucuresti, Romania.
| | - Juan Antonio Anta
- Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, Crta. De Utrera km. 1, 41089 Sevilla, Spain.
| | - Sofia Calero
- Materials Simulation & Modeling, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Anja Bieberle-Hütter
- Electrochemical Materials and Interfaces, Dutch Institute for Fundamental Energy Research (DIFFER), 5600 HH Eindhoven, The Netherlands.
| | - Florian Libisch
- Institute for Theoretical Physics, TU Wien, 1040 Vienna, Austria.
| | - Ana B Muñoz-García
- Dipartimento di Fisica "Ettore Pancini", Università di Napoli Federico II, Via Cintia 21, Napoli 80126, Italy.
| | - Michele Pavone
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia 21, Napoli 80126, Italy.
| | - Maytal Caspary Toroker
- Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3600003, Israel.,The Nancy and Stephen Grand Technion Energy Program, Technion - Israel Institute of Technology, Haifa 3600003, Israel.
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16
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Wang P, Zhang L, Zhang Z, Wang S, Yao C. Influence of Parameters on Photodynamic Therapy of Au@TiO 2-HMME Core-Shell Nanostructures. NANOMATERIALS 2022; 12:nano12081358. [PMID: 35458066 PMCID: PMC9032932 DOI: 10.3390/nano12081358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 04/11/2022] [Accepted: 04/11/2022] [Indexed: 11/18/2022]
Abstract
Photodynamic therapy (PDT) is a promising tumor therapy and has been proven to be an effective, safe and minimally invasive technique. Hematoporphyrin monomethyl ether (HMME) mediated PDT has been used in clinical treatment of port wine stain (PWS) due to its single component, high yield of singlet oxygen and short light-sensitive period. However, as an amphiphilic photosensitizer, HMME is easy to aggregate due to the presence of a hydrophobic group, which undesirably reduced its generation of singlet oxygen and bioavailability. In this study, we synthesized the stable conjugate of Au@TiO2 core-shell nanostructure with HMME, and the influence of different factors on PTD efficiency were studied. The results showed that the nanostructure had higher PTD efficiency for KB cells than that of HMME. The irradiation wavelength, gold nanoparticle shape and the shell thickness are all important factors for KB cell PDT.
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17
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Pedrielli A, Trevisanutto PE, Monacelli L, Garberoglio G, Pugno NM, Taioli S. Understanding anharmonic effects on hydrogen desorption characteristics of Mg nH 2n nanoclusters by ab initio trained deep neural network. NANOSCALE 2022; 14:5589-5599. [PMID: 35344577 DOI: 10.1039/d1nr08359g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Magnesium hydride (MgH2) has been widely studied for effective hydrogen storage. However, its bulk desorption temperature (553 K) is deemed too high for practical applications. Besides doping, a strategy to decrease such reaction energy for releasing hydrogen is the use of MgH2-based nanoparticles (NPs). Here, we investigate first the thermodynamic properties of MgnH2n NPs (n < 10) from first-principles, in particular by assessing the anharmonic effects on the enthalpy, entropy and thermal expansion by means of the stochastic self consistent harmonic approximation (SSCHA). This method goes beyond previous approaches, typically based on molecular mechanics and the quasi-harmonic approximation, allowing the ab initio calculation of the fully-anharmonic free energy. We find an almost linear dependence on temperature of the interatomic bond lengths - with a relative variation of few percent over 300 K - alongside with a bond distance decrease of the Mg-H bonds. In order to increase the size of MgnH2n NPs toward experiments of hydrogen desorption we devise a computationally effective machine learning model trained to accurately determine the forces and total energies (i.e. the potential energy surfaces), integrating the latter with the SSCHA model to fully include the anharmonic effects. We find a significative decrease of the H-desorption temperature for sub-nanometric clusters MgnH2n with n ≤ 10, with a non-negligible, although little effect due to anharmonicities (up to 10%).
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Affiliation(s)
- Andrea Pedrielli
- European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-Fondazione Bruno Kessler), Trento, Italy.
- Laboratory for Bioinspired, Bionic, Nano, Meta Materials and Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Italy
| | - Paolo E Trevisanutto
- Dipartimento di Ingegneria, Unità di Ricerca di Fisica non lineare e Modelli matematici, Università Campus Bio-Medico, Via Alvaro del Portillo 21, Roma, 00154, Italy
| | | | - Giovanni Garberoglio
- European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-Fondazione Bruno Kessler), Trento, Italy.
- Trento Institute for Fundamental Physics and Applications (TIFPA-INFN), Italy
| | - Nicola M Pugno
- Laboratory for Bioinspired, Bionic, Nano, Meta Materials and Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Italy
- School of Engineering and Materials Science, Queen Mary University of London, UK
| | - Simone Taioli
- European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-Fondazione Bruno Kessler), Trento, Italy.
- Trento Institute for Fundamental Physics and Applications (TIFPA-INFN), Italy
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18
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Nunzi F, De Angelis F. Modeling titanium dioxide nanostructures for photocatalysis and photovoltaics. Chem Sci 2022; 13:9485-9497. [PMID: 36091912 PMCID: PMC9400622 DOI: 10.1039/d2sc02872g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/25/2022] [Indexed: 11/21/2022] Open
Abstract
Heterogenous photocatalysis is regarded as a holy grail in relation to the energy and environmental issues with which our society is currently struggling. In this context, the characterization of titanium dioxide nanostructures and the relationships between structural/electronic parameters and chemical/physical–chemical properties is a primary target, whose achievement is in high demand. Theoretical simulations can strongly support experiments to reach this goal. While the bulk and surface properties of TiO2 materials are quite well understood, the field of nanostructures still presents a few unexplored areas. Here we consider possible approaches for the modeling of reduced and extended TiO2 nanostructures, and we review the main outcomes of the investigation of the structural, electronic, and optical properties of TiO2 nanoparticles and their relationships with the size, morphology, and shape of the particles. Further investigations are highly desired to fill the gaps still remaining and to allow improvements in the efficiencies of these materials for photocatalytic and photovoltaic applications. The latest findings from theoretical investigations into TiO2 nanoparticles are reviewed, including both realistic models from a bottom-up approach (1–3 nm diameter) and cut from bulk models (>3 nm diameter) in a top-down approach.![]()
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Affiliation(s)
- Francesca Nunzi
- Department of Chemistry, Biology and Biotechnology, University of Perugia Via Elce di Sotto 8 06123 Perugia Italy
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche (SCITEC-CNR) Via Elce di Sotto 8 06123 Perugia Italy
| | - Filippo De Angelis
- Department of Chemistry, Biology and Biotechnology, University of Perugia Via Elce di Sotto 8 06123 Perugia Italy
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche (SCITEC-CNR) Via Elce di Sotto 8 06123 Perugia Italy
- Department of Natural Sciences and Mathematics, College of Sciences and Human Studies, Prince Mohammad Bin Fahd University Khobar Dhahran 34754 Saudi Arabia
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19
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Diez-Cabanes V, Morales-García Á, Illas F, Pastore M. Tuning the Interfacial Energetics in WO 3/WO 3 and WO 3/TiO 2 Heterojunctions by Nanostructure Morphological Engineering. J Phys Chem Lett 2021; 12:11528-11533. [PMID: 34797657 DOI: 10.1021/acs.jpclett.1c03227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nowadays, semiconducting heterojunction-based devices exhibit the best photocatalytic performance, with transition metal oxides such as tungsten (WO3) and titanium (TiO2) being the workhorse materials employed in these composites. Contrary to their bulk counterparts, WO3 and TiO2 nanostructures offer a huge versatility because their optoelectronic properties (i.e., energy levels) can be tuned by modifying their size, morphology, and composition, thus being, in principle, able to optimize the electron/hole injection barriers inside the device. However, this approach requires a deep fundamental knowledge of their structure-property relationships, which are extremely difficult to access from experiments. In this context, we employed state-of-the-art theoretical methods to determine the size and morphology dependency of the energetic alignment in WO3/WO3 and TiO2/WO3 nanostructure heterojunctions. Our results demonstrated that any type of alignment can be achieved by the proper choice of the nanostructures involved in the junction, while setting important rules for the design of efficient multicomponent devices.
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Affiliation(s)
- Valentin Diez-Cabanes
- Université de Lorraine & CNRS, Laboratoire de Physique et Chimie Théoriques (LPCT), UMR 7019, F-54000 Nancy, France
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franqués 1-11, 08028 Barcelona, Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franqués 1-11, 08028 Barcelona, Spain
| | - Mariachiara Pastore
- Université de Lorraine & CNRS, Laboratoire de Physique et Chimie Théoriques (LPCT), UMR 7019, F-54000 Nancy, France
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20
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Abstract
Ag–TiO2 nanostructures were prepared by electrospinning, followed by calcination at 400 °C, and their photocatalytic and antibacterial actions were studied. Morphological characterization revealed the presence of one-dimensional uniform Ag–TiO2 nanostructured nanofibers, with a diameter from 65 to 100 nm, depending on the Ag loading, composed of small crystals interconnected with each other. Structural characterization indicated that Ag was successfully integrated as small nanocrystals without affecting much of the TiO2 crystal lattice. Moreover, the presence of nano Ag was found to contribute to reducing the band gap energy, which enables the activation by the absorption of visible light, while, at the same time, it delays the electron–hole recombination. Tests of their photocatalytic activity in methylene blue, amaranth, Congo red and orange II degradation revealed an increase by more than 20% in color removal efficiency at an almost double rate for the case of 0.1% Ag–TiO2 nanofibers with respect to pure TiO2. Moreover, the minimum inhibitory concentration was found as low as 2.5 mg/mL for E. coli and 5 mg/mL against S. aureus for the 5% Ag–TiO2 nanofibers. In general, the Ag–TiO2 nanostructured nanofibers were found to exhibit excellent structure and physical properties and to be suitable for efficient photocatalytic and antibacterial uses. Therefore, these can be suitable for further integration in various important applications.
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21
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Di Liberto G, Cipriano LA, Tosoni S, Pacchioni G. Rational Design of Semiconductor Heterojunctions for Photocatalysis. Chemistry 2021; 27:13306-13317. [PMID: 34264526 PMCID: PMC8518984 DOI: 10.1002/chem.202101764] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Indexed: 11/06/2022]
Abstract
Electronic structure calculations provide a useful complement to experimental characterization tools in the atomic-scale design of semiconductor heterojunctions for photocatalysis. The band alignment of the heterojunction is of fundamental importance to achieve an efficient charge carrier separation, so as to reduce electron/hole recombination and improve photoactivity. The accurate prediction of the offsets of valence and conduction bands in the constituent units is thus of key importance but poses several methodological and practical problems. In this Minireview we address some of these problems by considering selected examples of binary and ternary semiconductor heterojunctions and how these are determined at the level of density functional theory (DFT). The atomically precise description of the interface, the consequent charge polarization, the role of quantum confinement, the possibility to use facet engineering to determine a specific band alignment, are among the effects discussed, with particular attention to pros and cons of each one of these aspects. This analysis shows the increasingly important role of accurate electronic structure calculations to drive the design and the preparation of new interfaces with desired properties.
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Affiliation(s)
- Giovanni Di Liberto
- Dipartimento di Scienza dei MaterialiUniversità di Milano – BicoccaVia R. Cozzi 5520125MilanoItaly
| | - Luis A. Cipriano
- Dipartimento di Scienza dei MaterialiUniversità di Milano – BicoccaVia R. Cozzi 5520125MilanoItaly
| | - Sergio Tosoni
- Dipartimento di Scienza dei MaterialiUniversità di Milano – BicoccaVia R. Cozzi 5520125MilanoItaly
| | - Gianfranco Pacchioni
- Dipartimento di Scienza dei MaterialiUniversità di Milano – BicoccaVia R. Cozzi 5520125MilanoItaly
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22
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Onur Şahin E, Dai Y, Chan CK, Tüysüz H, Schmidt W, Lim J, Zhang S, Scheu C, Weidenthaler C. Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase. Chemistry 2021; 27:11600-11608. [PMID: 34060158 PMCID: PMC8456846 DOI: 10.1002/chem.202101117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Indexed: 11/07/2022]
Abstract
Amorphous Tix Oy with high surface area has attracted significant interest as photocatalyst with higher activity in ultraviolet (UV) light-induced water splitting applications compared to commercial nanocrystalline TiO2 . Under photocatalytic operation conditions, the structure of the molecular titanium alkoxide precursor rearranges upon hydrolysis and leads to higher connectivity of the structure-building units. Structurally ordered domains with sizes smaller than 7 Å form larger aggregates. The experimental scattering data can be explained best with a structure model consisting of an anatase-like core and a distorted shell. Upon exposure to UV light, the white Tix Oy suspension turns dark corresponding to the reduction of Ti4+ to Ti3+ as confirmed by electron energy loss spectroscopy (EELS). Heat-induced crystallisation was followed by in situ temperature-dependent total scattering experiments. First, ordering in the Ti-O environment takes place upon to 350 °C. Above this temperature, the distorted anatase core starts to grow but the structure obtained at 400 °C is still not fully ordered.
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Affiliation(s)
- Ezgi Onur Şahin
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Yitao Dai
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Candace K. Chan
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
- Materials Science and EngineeringSchool for Engineering of MatterTransport and Energy (SEMTE)Arizona State UniversityAZ 85287-8706TempeUSA
| | - Harun Tüysüz
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Wolfgang Schmidt
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
| | - Joohyun Lim
- Nanoanalytics and InterfacesMax-Planck-Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
- Department of ChemistryKangwon National University24341ChuncheonRepublic of Korea
| | - Siyuan Zhang
- Nanoanalytics and InterfacesMax-Planck-Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | - Christina Scheu
- Nanoanalytics and InterfacesMax-Planck-Institut für Eisenforschung GmbHMax-Planck-Straße 140237DüsseldorfGermany
| | - Claudia Weidenthaler
- Heterogeneous CatalysisMax-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
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23
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Zhao W, Li Y, Shen W. Tuning the shape and crystal phase of TiO 2 nanoparticles for catalysis. Chem Commun (Camb) 2021; 57:6838-6850. [PMID: 34137748 DOI: 10.1039/d1cc01523k] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Synthesis of TiO2 nanoparticles with tunable shape and crystal phase has attracted considerable attention for the design of highly efficient heterogeneous catalysts. Tailoring the shape of TiO2, in the crystal phases of anatase, rutile, brookite and TiO2(B), allows tuning of the atomic configurations on the dominantly exposed facets for maximizing the active sites and regulating the reaction route towards a specific channel for achieving high selectivity. Moreover, the shape and crystal phase of TiO2 nanoparticles alter their interactions with metal species, which are commonly termed as strong metal-support interactions involving interfacial strain and charge transfer. On the other hand, metal particles, clusters and single atoms interact differently with TiO2, because of the variation of the electronic structure, while the surface of TiO2 determines the interfacial bonding via a geometric effect. The dynamic behavior of the metal-titania interfaces, driven by the chemisorption of the reactive molecules at elevated temperatures, also plays a decisive role in elaborating the structure-reactivity relationship.
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Affiliation(s)
- Wenning Zhao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Wenjie Shen
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
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24
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Diez-Cabanes V, Morales-García Á, Illas F, Pastore M. Understanding the Structural and Electronic Properties of Photoactive Tungsten Oxide Nanoparticles from Density Functional Theory and GW Approaches. J Chem Theory Comput 2021; 17:3462-3470. [PMID: 33966374 DOI: 10.1021/acs.jctc.1c00293] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tungsten trioxide (WO3)-derived nanostructures have emerged recently as feasible semiconductors for photocatalytic purposes due to their visible-light harvesting that overcomes the drawbacks presented by TiO2-derived nanoparticles (NPs). However, applications are still limited by the lack of fundamental knowledge at the nanoscale due to poor understanding of the physical processes that affect their photoactivity. To fill this gap, we report here a detailed computational study using a combined density functional theory (DFT)-GW scheme to investigate the electronic structure of realistic WO3 NPs containing up to 1680 atoms. Different phases and morphologies are considered to provide reliable structure-property relationships. Upon proper benchmark of our DFT-GW methodology, we use this highly accurate approach to establish relevant rules for the design of photoactive WO3 nanostructures by pointing out the most stable morphologies at the nanoscale and the appropriate size regime at which the photoactive efficiency is enhanced.
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Affiliation(s)
- Valentin Diez-Cabanes
- Laboratoire de Physique et Chimie Théoriques (LPCT), Université de Lorraine & CNRS, UMR 7019, F-54000 Nancy, France
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franqués 1-11, 08028 Barcelona, Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franqués 1-11, 08028 Barcelona, Spain
| | - Mariachiara Pastore
- Laboratoire de Physique et Chimie Théoriques (LPCT), Université de Lorraine & CNRS, UMR 7019, F-54000 Nancy, France
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25
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Mino L, Morales-García Á, Bromley ST, Illas F. Understanding the nature and location of hydroxyl groups on hydrated titania nanoparticles. NANOSCALE 2021; 13:6577-6585. [PMID: 33885537 DOI: 10.1039/d1nr00610j] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
TiO2 nanoparticles (NPs) are intensively studied and widely used due to their huge potential in numerous applications involving their interaction with ultraviolet light (e.g., photocatalysis and sunscreens). Typically, these NPs are in water-containing environments and thus tend to be hydrated. As such, there is a growing need to better understand the physicochemical properties of hydrated TiO2 NPs in order to improve their performance in photochemical applications (e.g., photocatalytic water splitting) and to minimise their environmental impact (e.g., potential biotoxicity). To help address the need for reliable and detailed data on how nano-titania interacts with water, we present a systematic experimental and theoretical study of surface hydroxyl (OH) groups on photoactive anatase TiO2 NPs. Employing well-defined experimentally synthesised NPs and detailed realistic NP models, we obtain the measured and computed infrared spectra of the surface hydroxyls, respectively. By comparing the experimental and theoretical spectra we are able to identify the type and location of different OH groups in these NP systems. Specifically, our study allows us to provide unprecedented and detailed information about the coverage-dependent distribution of hydroxyl groups on the surface of experimental titania NPs, the degree of their H-bonding interactions and their associated assigned vibrational modes. Our work promises to lead to new routes for developing new and safe nanotechnologies based on hydrated TiO2 NPs.
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Affiliation(s)
- Lorenzo Mino
- Department of Chemistry and NIS Centre, University of Torino, via Giuria 7, 10125 Torino, Italy.
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26
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Morales‐García Á, Viñes F, Gomes JRB, Illas F. Concepts, models, and methods in computational heterogeneous catalysis illustrated through
CO
2
conversion. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1530] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ángel Morales‐García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona Barcelona Spain
| | - Francesc Viñes
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona Barcelona Spain
| | - José R. B. Gomes
- CICECO—Aveiro Institute of Materials, Department of Chemistry University of Aveiro Aveiro Portugal
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB) Universitat de Barcelona Barcelona Spain
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TiO2-Graphene Quantum Dots Nanocomposites for Photocatalysis in Energy and Biomedical Applications. Catalysts 2021. [DOI: 10.3390/catal11030319] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The focus of current research in material science has shifted from “less efficient” single-component nanomaterials to the superior-performance, next-generation, multifunctional nanocomposites. TiO2 is a widely used benchmark photocatalyst with unique physicochemical properties. However, the large bandgap and massive recombination of photogenerated charge carriers limit its overall photocatalytic efficiency. When TiO2 nanoparticles are modified with graphene quantum dots (GQDs), some significant improvements can be achieved in terms of (i) broadening the light absorption wavelengths, (ii) design of active reaction sites, and (iii) control of the electron-hole (e−-h+) recombination. Accordingly, TiO2-GQDs nanocomposites exhibit promising multifunctionalities in a wide range of fields including, but not limited to, energy, biomedical aids, electronics, and flexible wearable sensors. This review presents some important aspects of TiO2-GQDs nanocomposites as photocatalysts in energy and biomedical applications. These include: (1) structural formulations and synthesis methods of TiO2-GQDs nanocomposites; (2) discourse about the mechanism behind the overall higher photoactivities of these nanocomposites; (3) various characterization techniques which can be used to judge the photocatalytic performance of these nanocomposites, and (4) the application of these nanocomposites in biomedical and energy conversion devices. Although some objectives have been achieved, new challenges still exist and hinder the widespread application of these nanocomposites. These challenges are briefly discussed in the Future Scope section of this review.
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Di Liberto G, Tosoni S, Pacchioni G. Role of surface termination in forming type-II photocatalyst heterojunctions: the case of TiO 2/BiVO 4. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:075001. [PMID: 33086209 DOI: 10.1088/1361-648x/abc357] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this work we investigate TiO2 and BiVO4 nanostructures by means of density functional theory (DFT) calculations, to provide an estimate of the band alignment in TiO2/BiVO4 interfaces, highly active in photo-electrochemistry and photocatalytic water splitting. Calculations were carried out with both DFT range separated and self-consistent dielectric dependent hybrid functionals (HSE06 and PBE0DD). The impact of systems' size has been investigated. The converged electronic levels of TiO2 and BiVO4 surfaces have been used to predict the band alignment in TiO2/BiVO4 heterostructures. Results indicated that when TiO2 (101) surface is matched with BiVO4 (110), a type-II alignment is obtained, where the band edges of BiVO4 are higher in energy that those of TiO2. This picture is favorable for charge-carriers separation upon photoexcitation, where electrons move toward TiO2 and holes toward BiVO4. On the contrary, if TiO2 (101) is interfaced to BiVO4 (010) the offset between the band edges is negligible, thus reducing the driving force toward separation of charge carriers. These results rationalize the dependence on the facet's exposure of the observed photocatalytic performances of TiO2/BiVO4 composites, where the TiO2 (101)/BiVO4 (110) interface outperforms the TiO2 (101)/BiVO4 (010) one.
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Affiliation(s)
- Giovanni Di Liberto
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R Cozzi 55, 20125 Milano, Italy
| | - Sergio Tosoni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R Cozzi 55, 20125 Milano, Italy
| | - Gianfranco Pacchioni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R Cozzi 55, 20125 Milano, Italy
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29
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Amodeo J, Pietrucci F, Lam J. Out-of-Equilibrium Polymorph Selection in Nanoparticle Freezing. J Phys Chem Lett 2020; 11:8060-8066. [PMID: 32880462 DOI: 10.1021/acs.jpclett.0c02129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The ability to design synthesis processes that are out of equilibrium has opened the possibility of creating nanomaterials with remarkable physicochemical properties, choosing from a much richer palette of possible atomic architectures compared to equilibrium processes in extended systems. In this work, we employ atomistic simulations to demonstrate how to control polymorph selection via the cooling rate during nanoparticle freezing in the case of Ni3Al, a material with a rich structural landscape. State-of-the-art free-energy calculations allow us to rationalize the complex nucleation process, discovering a switch between two kinetic pathways, yielding the equilibrium structure at room temperature and an alternative metastable one at higher temperature. Our findings address the key challenge in the synthesis of nanoalloys for technological applications, i.e., rationally exploiting the competition between kinetics and thermodynamics by designing a treatment history that forces the system into desirable metastable states.
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Affiliation(s)
- Jonathan Amodeo
- Université de Lyon, INSA-Lyon, MATEIS, UMR 5510 CNRS, 69621 Villeurbanne, France
| | - Fabio Pietrucci
- Sorbonne Université, CNRS UMR 7590, IMPMC, 75005 Paris, France
| | - Julien Lam
- Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Code Postal 231, Boulevard du Triomphe, 1050 Brussels, Belgium
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30
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Morales-García Á, Rhatigan S, Nolan M, Illas F. On the use of DFT+U to describe the electronic structure of TiO 2 nanoparticles: (TiO 2) 35 as a case study. J Chem Phys 2020; 152:244107. [PMID: 32610938 DOI: 10.1063/5.0012271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
One of the main drawbacks in the density functional theory (DFT) formalism is the underestimation of the energy gaps in semiconducting materials. The combination of DFT with an explicit treatment of the electronic correlation with a Hubbard-like model, known as the DFT+U method, has been extensively applied to open up the energy gap in materials. Here, we introduce a systematic study where the selection of the U parameter is analyzed considering two different basis sets: plane-waves and numerical atomic orbitals (NAOs), together with different implementations for including U, to investigate the structural and electronic properties of a well-defined bipyramidal (TiO2)35 nanoparticle. This study reveals, as expected, that a certain U value can reproduce the experimental value for the energy gap. However, there is a high dependence on the choice of basis set and on the U parameter employed. The present study shows that the linear combination of the NAO basis functions, as implemented in Fritz Haber Institute ab initio molecular simulation (FHI-aims), requires, requires a lower U value than the simplified rotationally invariant approach, as implemented in the Vienna ab initio simulation package (VASP). Therefore, the transfer of U values between codes is unfeasible and not recommended, demanding initial benchmark studies for the property of interest as a reference to determine the appropriate value of U.
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Affiliation(s)
- Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Stephen Rhatigan
- Tyndall National Institute, University College Cork, Lee Maltings, Cork T12 R5CP, Ireland
| | - Michael Nolan
- Tyndall National Institute, University College Cork, Lee Maltings, Cork T12 R5CP, Ireland
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
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31
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Di Liberto G, Tosoni S, Illas F, Pacchioni G. Nature of SrTiO3/TiO2 (anatase) heterostructure from hybrid density functional theory calculations. J Chem Phys 2020; 152:184704. [DOI: 10.1063/5.0007138] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Giovanni Di Liberto
- Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Roberto Cozzi 55, 20125 Milano, Italy
| | - Sergio Tosoni
- Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Roberto Cozzi 55, 20125 Milano, Italy
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Gianfranco Pacchioni
- Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Roberto Cozzi 55, 20125 Milano, Italy
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32
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Valero R, Morales-García Á, Illas F. Investigating the character of excited states in TiO2 nanoparticles from topological descriptors: implications for photocatalysis. Phys Chem Chem Phys 2020; 22:3017-3029. [DOI: 10.1039/c9cp05526f] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Excited state topological descriptors based on the attachment/detachment one-electron charge density are used to investigate the centroids of photoactive TiO2 nanoclusters and nanoparticles.
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Affiliation(s)
- Rosendo Valero
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
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33
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Macià Escatllar A, Morales-García Á, Illas F, Bromley ST. Efficient preparation of TiO2 nanoparticle models using interatomic potentials. J Chem Phys 2019; 150:214305. [DOI: 10.1063/1.5095071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Antoni Macià Escatllar
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computatcional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computatcional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computatcional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Stefan T. Bromley
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computatcional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1-11, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
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