Research

12 pages, 1678 KiB

Open AccessArticle

Flexible and Transparent Luminescent Cellulose-Transition Metal Cluster Composites

by Maria Amela-Cortes, Noée Dumait, Franck Artzner, Stéphane Cordier and Yann Molard

Nanomaterials 2023, 13(3), 580; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13030580 - 31 Jan 2023

Cited by 2 | Viewed by 1090

Red-NIR luminescent polymers are principally obtained from petroleum-based derivatives in which emitters, usually a critical raw material such as rare-earth or platinum group metal ions, are embedded. Considering the strong ecological impact of their synthesis and the major risk of fossil fuel energy [...] Read more.

Red-NIR luminescent polymers are principally obtained from petroleum-based derivatives in which emitters, usually a critical raw material such as rare-earth or platinum group metal ions, are embedded. Considering the strong ecological impact of their synthesis and the major risk of fossil fuel energy shortage, there is an urgent need to find alternatives. We describe a luminescent nanocomposite based on red-NIR phosphorescent molybdenum nanoclusters, namely Cs₂Mo₆I₈(OCOC₂F₅)₆, embedded in an eco-friendly cellulose biopolymer matrix that is obtained by a simple solvent casting technique. While homogeneity is kept up to 20 wt% of cluster complex doping, annealing hybrids leads to a large increase of their emission efficiency, as demonstrated by quantum yield measurements. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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18 pages, 9314 KiB

Open AccessArticle

Enhanced NH₃ Sensing Performance of Mo Cluster-MoS₂ Nanocomposite Thin Films via the Sulfurization of Mo₆ Cluster Iodides Precursor

by Meiqi Zhang, Fabien Grasset, Yuji Masubuchi, Toshihiro Shimada, Thi Kim Ngan Nguyen, Noée Dumait, Adèle Renaud, Stéphane Cordier, David Berthebaud, Jean-François Halet and Tetsuo Uchikoshi

Nanomaterials 2023, 13(3), 478; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13030478 - 24 Jan 2023

Cited by 2 | Viewed by 1684

Abstract

The high-performance defect-rich MoS₂ dominated by sulfur vacancies as well as Mo-rich environments have been extensively studied in many fields, such as nitrogen reduction reactions, hydrogen evolution reactions, as well as sensing devices for NH₃, which are attributed to the [...] Read more.

The high-performance defect-rich MoS₂ dominated by sulfur vacancies as well as Mo-rich environments have been extensively studied in many fields, such as nitrogen reduction reactions, hydrogen evolution reactions, as well as sensing devices for NH₃, which are attributed to the under-coordinated Mo atoms playing a significant role as catalytic sites in the defect area. In this study, the Mo cluster-MoS₂ composite was creatively synthesized through a one-step sulfurization process via H₂/H₂S gas flow. The Mo₆ cluster iodides (MIs) coated on the fluorine-doped tin oxide (FTO) glass substrate via the electrophoretic deposition method (i.e., MI@FTO) were used as a precursor to form a thin-film nanocomposite. Investigations into the structure, reaction mechanism, and NH₃ gas sensing performance were carried out in detail. The results indicated that during the gas flowing, the decomposed Mo₆ cluster iodides played the role of template and precursor, forming complicated Mo cluster compounds and eventually producing MoS₂. These Mo cluster-MoS₂ thin-film nanocomposites were fabricated and applied as gas sensors for the first time. It turns out that after the sulfurization process, the response of MI@FTO for NH₃ gas increased three times while showing conversion from p-type to n-type semiconductor, which enhances their possibilities for future device applications. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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16 pages, 6975 KiB

Open AccessArticle

Nano TiO₂ and Molybdenum/Tungsten Iodide Octahedral Clusters: Synergism in UV/Visible-Light Driven Degradation of Organic Pollutants

by Margarita V. Marchuk, Igor P. Asanov, Maxim A. Panafidin, Yuri A. Vorotnikov and Michael A. Shestopalov

Nanomaterials 2022, 12(23), 4282; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12234282 - 01 Dec 2022

Cited by 6 | Viewed by 1174

Abstract

Emissions of various organic pollutants in the environment becomes a more and more acute problem in the modern world as they can lead to an ecological disaster in foreseeable future. The current situation forces scientists to develop numerous methods for the treatment of [...] Read more.

Emissions of various organic pollutants in the environment becomes a more and more acute problem in the modern world as they can lead to an ecological disaster in foreseeable future. The current situation forces scientists to develop numerous methods for the treatment of polluted water. Among these methods, advanced photocatalytic oxidation is a promising approach for removing organic pollutants from wastewater. In this work, one of the most common photocatalysts—titanium dioxide—was obtained by direct aqueous hydrolysis of titanium (IV) isopropoxide and impregnated with aqueous solutions of octahedral cluster complexes [{M₆I₈}(DMSO)₆](NO₃)₄ (M = Mo, W) to overcome visible light absorption issues and increase overall photocatalytic activity. XRPD analysis showed that the titania is formed as anatase-brookite mixed-phase nanoparticles and cluster impregnation does not affect the morphology of the particles. Complex deposition resulted in the expansion of the absorption up to ~500 nm and in the appearance of an additional cluster-related band gap value of 1.8 eV. Both types of materials showed high activity in the photocatalytic decomposition of RhB under UV- and sunlight irradiation with effective rate constants 4–5 times higher than those of pure TiO₂. The stability of the catalysts is preserved for up to 5 cycles of photodegradation. Scavengers’ experiments revealed high impact of all of the active species in photocatalytic process indicating the formation of an S-scheme heterojunction photocatalyst. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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17 pages, 2919 KiB

Open AccessArticle

Nanostructured Hybrids Based on Tantalum Bromide Octahedral Clusters and Graphene Oxide for Photocatalytic Hydrogen Evolution

by Jhon Sebastián Hernández, Maxim Shamshurin, Marta Puche, Maxim N. Sokolov and Marta Feliz

Nanomaterials 2022, 12(20), 3647; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12203647 - 18 Oct 2022

Cited by 4 | Viewed by 1288

Abstract

The generation of hydrogen (H₂) using sunlight has become an essential energy alternative for decarbonization. The need for functional nanohybrid materials based on photo- and electroactive materials and accessible raw materials is high in the field of solar fuels. To reach [...] Read more.

The generation of hydrogen (H₂) using sunlight has become an essential energy alternative for decarbonization. The need for functional nanohybrid materials based on photo- and electroactive materials and accessible raw materials is high in the field of solar fuels. To reach this goal, single-step synthesis of {Ta₆Brⁱ₁₂}@GO (GO = graphene oxide) nanohybrids was developed by immobilization of [{Ta₆Brⁱ₁₂}Br^a₂(H₂O)^a₄]·4H₂O (i = inner and a = apical positions of the Ta₆ octahedron) on GO nanosheets by taking the advantage of the easy ligand exchange of the apical cluster ligands with the oxygen functionalities of GO. The nanohybrids were characterized by spectroscopic, analytical, and morphological techniques. The hybrid formation enhances the yield of photocatalytic H₂ from water with respect to their precursors and this is without the presence of precious metals. This enhancement is attributed to the optimal cluster loading onto the GO support and the crucial role of GO in the electron transfer from Ta₆ clusters into GO sheets, thus suppressing the charge recombination. In view of the simplicity and versatility of the designed photocatalytic system, octahedral tantalum clusters are promising candidates to develop new and environmentally friendly photocatalysts for H₂ evolution. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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14 pages, 3209 KiB

Open AccessArticle

Oxygen-Sensitive Photo- and Radioluminescent Polyurethane Nanoparticles Modified with Octahedral Iodide Tungsten Clusters

by Vyacheslav A. Bardin, Yuri A. Vorotnikov, Dmitri V. Stass, Natalya A. Vorotnikova and Michael A. Shestopalov

Nanomaterials 2022, 12(20), 3580; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12203580 - 12 Oct 2022

Cited by 6 | Viewed by 1304

Abstract

The development of cancer treatment techniques able to cure tumors located deep in the body is an urgent task for scientists and physicians. One of the most promising methods is X-ray-induced photodynamic therapy (X-PDT), since X-rays have unlimited penetration through tissues. In this [...] Read more.

The development of cancer treatment techniques able to cure tumors located deep in the body is an urgent task for scientists and physicians. One of the most promising methods is X-ray-induced photodynamic therapy (X-PDT), since X-rays have unlimited penetration through tissues. In this work, octahedral iodide tungsten clusters, combining the properties of a scintillator and photosensitizer, are considered as a key component of nanosized polyurethane (pU) particles in the production of materials promising for X-PDT. Cluster-containing pU nanoparticles obtained here demonstrate bright photo- and X-ray-induced emission in both solid and water dispersion, great efficiency in the generation of singlet oxygen, and high sensitivity regarding photoluminescence intensity in relation to oxygen concentration. Additionally, incorporation of the cluster complex into the pU matrix greatly increases its stability against hydrolysis in water and under X-rays. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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16 pages, 2009 KiB

Open AccessArticle

Octahedral Molybdenum Cluster-Based Nanomaterials for Potential Photodynamic Therapy

by Marina Rodrigues Tavares, Kaplan Kirakci, Nikolay Kotov, Michal Pechar, Kamil Lang, Robert Pola and Tomáš Etrych

Nanomaterials 2022, 12(19), 3350; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12193350 - 26 Sep 2022

Cited by 4 | Viewed by 1614

Abstract

Photo/radiosensitizers, such as octahedral molybdenum clusters (Mo₆), have been intensively studied for photodynamic applications to treat various diseases. However, their delivery to the desired target can be hampered by its limited solubility, low stability in physiological conditions, and inappropriate biodistribution, thus [...] Read more.

Photo/radiosensitizers, such as octahedral molybdenum clusters (Mo₆), have been intensively studied for photodynamic applications to treat various diseases. However, their delivery to the desired target can be hampered by its limited solubility, low stability in physiological conditions, and inappropriate biodistribution, thus limiting the therapeutic effect and increasing the side effects of the therapy. To overcome such obstacles and to prepare photofunctional nanomaterials, we employed biocompatible and water-soluble copolymers based on N-(2-hydroxypropyl)methacrylamide (pHPMA) as carriers of Mo₆ clusters. Several strategies based on electrostatic, hydrophobic, or covalent interactions were employed for the formation of polymer-cluster constructs. Importantly, the luminescent properties of the Mo₆ clusters were preserved upon association with the polymers: all polymer-cluster constructs exhibited an effective quenching of their excited states, suggesting a production of singlet oxygen (O₂(¹Δ_g)) species which is a major factor for a successful photodynamic treatment. Even though the colloidal stability of all polymer-cluster constructs was satisfactory in deionized water, the complexes prepared by electrostatic and hydrophobic interactions underwent severe aggregation in phosphate buffer saline (PBS) accompanied by the disruption of the cohesive forces between the cluster and polymer molecules. On the contrary, the conjugates prepared by covalent interactions notably displayed colloidal stability in PBS in addition to high luminescence quantum yields, suggesting that pHPMA is a suitable nanocarrier for molybdenum cluster-based photosensitizers intended for photodynamic applications. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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16 pages, 2481 KiB

Open AccessArticle

pH-Driven Intracellular Nano-to-Molecular Disassembly of Heterometallic [Au₂L₂]{Re₆Q₈} Colloids (L = PNNP Ligand; Q = S²⁻ or Se²⁻)

by Bulat Faizullin, Irina Dayanova, Igor Strelnik, Kirill Kholin, Irek Nizameev, Aidar Gubaidullin, Alexandra Voloshina, Tatiana Gerasimova, Ilya Kashnik, Konstantin Brylev, Guzel Sibgatullina, Dmitry Samigullin, Konstantin Petrov, Elvira Musina, Andrey Karasik and Asiya Mustafina

Nanomaterials 2022, 12(18), 3229; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12183229 - 17 Sep 2022

Cited by 5 | Viewed by 1394

Abstract

The present work introduces a simple, electrostatically driven approach to engineered nanomaterial built from the highly cytotoxic [Au₂L₂]²⁺ complex (Au₂, L = 1,5-bis(p-tolyl)−3,7-bis(pyridine-2-yl)−1,5-diaza-3,7-diphosphacyclooctane (PNNP) ligand) and the pH-sensitive red-emitting [{Re₆Q₈}(OH)₆] [...] Read more.

The present work introduces a simple, electrostatically driven approach to engineered nanomaterial built from the highly cytotoxic [Au₂L₂]²⁺ complex (Au₂, L = 1,5-bis(p-tolyl)−3,7-bis(pyridine-2-yl)−1,5-diaza-3,7-diphosphacyclooctane (PNNP) ligand) and the pH-sensitive red-emitting [{Re₆Q₈}(OH)₆]⁴⁻ (Re₆-Q, Q = S²⁻ or Se²⁻) cluster units. The protonation/deprotonation of the Re₆-Q unit is a prerequisite for the pH-triggered assembly of Au₂ and Re₆-Q into Au₂Re₆-Q colloids, exhibiting disassembly in acidic (pH = 4.5) conditions modeling a lysosomal environment. The counter-ion effect of polyethylenimine causes the release of Re₆-Q units from the colloids, while the binding with lysozyme restricts their protonation in acidified conditions. The enhanced luminescence response of Re₆-S on the disassembly of Au₂Re₆-S colloids in the lysosomal environment allows us to determine their high lysosomal localization extent through the colocalization assay, while the low luminescence of Re₆-Se units in the same conditions allows us to reveal the rapture of the lysosomal membrane through the use of the Acridine Orange assay. The lysosomal pathway of the colloids, followed by their endo/lysosomal escape, correlates with their cytotoxicity being on the same level as that of Au₂ complexes, but the contribution of the apoptotic pathway differentiates the cytotoxic effect of the colloids from that of the Au₂ complex arisen from the necrotic processes. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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20 pages, 5665 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Controlling the Deposition Process of Nanoarchitectonic Nanocomposites Based on {Nb_6−xTa_xXⁱ₁₂}ⁿ⁺ Octahedral Cluster-Based Building Blocks (Xⁱ = Cl, Br; 0 ≤ x ≤ 6, n = 2, 3, 4) for UV-NIR Blockers Coating Applications

by Clément Lebastard, Maxence Wilmet, Stéphane Cordier, Clothilde Comby-Zerbino, Luke MacAleese, Philippe Dugourd, Toru Hara, Naoki Ohashi, Tetsuo Uchikoshi and Fabien Grasset

Nanomaterials 2022, 12(12), 2052; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12122052 - 15 Jun 2022

Cited by 3 | Viewed by 1949

Abstract

The antagonism between global energy needs and the obligation to slow global warming is a current challenge. In order to ensure sufficient thermal comfort, the automotive, housing and agricultural building sectors are major energy consumers. Solar control materials and more particularly, selective glazing [...] Read more.

The antagonism between global energy needs and the obligation to slow global warming is a current challenge. In order to ensure sufficient thermal comfort, the automotive, housing and agricultural building sectors are major energy consumers. Solar control materials and more particularly, selective glazing are part of the solutions proposed to reduce global energy consumption and tackle global warming. In this context, these works are focused on developing new highly ultraviolet (UV) and near-infrared (NIR) absorbent nanocomposite coatings based on K₄[{Nb_6-xTa_xXⁱ₁₂}X^a₆]. (X = Cl, Br, 0 ≤ x ≤ 6) transition metal cluster compounds. These compounds contain cluster-based active species that are characterized by their strong absorption of UV and NIR radiations as well as their good transparency in the visible range, which makes them particularly attractive for window applications. Their integration, by solution processes, into a silica-polyethylene glycol or polyvinylpyrrolidone matrices is discussed. Of particular interest is the control and the tuning of their optical properties during the integration and shaping processes. The properties of the solutions and films were investigated by complementary techniques (UV-Vis-NIR spectrometry, ESI-MS, SEM, HRTEM, etc.). Results of these works have led to the development of versatile solar control coatings whose optical properties are competitive with commercialized material. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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