Supramolecular Anchoring of Octahedral Molybdenum Clusters onto Graphene and Their Synergies in Photocatalytic Water Reduction

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.inorgchem.9b02529"[EN] Dihydrogen (H-2) production from sunlight should become one of the most important energy production means in the future. To reach this goal, low-cost and efficient photocatalysts still need to be discovered. Here we show that red near-IR luminescent metal cluster anions, once combined with pyrene-containing cations, are able to photocatalytically produce molecular hydrogen from water. The pyrene moieties act simultaneously as energy transmitters and as supramolecular linkers between the cluster anions and graphene. This association results in a hybrid material combining the emission abilities of pyrene and cluster moieties with the electronic conduction efficiency of graphene. Hydrogen evolution reaction (HER) studies show that this association induces a significant increase of H 2 production compared to that produced separately by clusters or graphene. Considering the versatility of the strategy described to design this photocatalytic hybrid material, transition-metal clusters are promising candidates to develop new, environmentally friendly, and low-cost photocatalysts for HER.The Severo Ochoa Program (SEV-2016-0683), Ministerio de Ciencia, Innovation y Universidades (PGC2018-099744), Consejo Superior de Investigaciones Cientificas (I-Link1063), and University of Rennes are thanked for financial support. We thank Dr. Marta Puche for her technical assistance with the preparation of dispersed graphene solutions at the ITQ.Feliz Rodriguez, M.; Atienzar Corvillo, PE.; Amela-Cortes, M.; Dumait, N.; Lemoine, P.; Molard, Y.; Cordier, S. (2019). Supramolecular Anchoring of Octahedral Molybdenum Clusters onto Graphene and Their Synergies in Photocatalytic Water Reduction. Inorganic Chemistry. 58(22):15443-15454. https://doi.org/10.1021/acs.inorgchem.9b02529S1544315454582

Examples of Studies on Electrophoretic Deposition Process of Functional Thin Films

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SYNTHESIS AND CHARACTERIZATION OF NANOCOMPOSITES COATING BASED ON INORGANIC OCTAHEDRAL CLUSTER UNITS FABRICATED BY ELECTROPHORETIC DEPOSITION PROCESS

Composite nanoarchitectures represent a new class of nanostructured entities that integrate various dissimilar nanoscale building blocks including clusters, particles, wires and films [1]. The heterogeneous composite nanostructured materials are composed by definition of multi-(nano)components, each tailored to address different requirements. As one of the nanocomponents, nanometer sized transition metal clusters (\u3c2 nm), which consist of less than a few dozens of metal atoms, could be defined as a link between atom and nanoparticle [2-7]. In this presentation, the first preparation of functional thin films based on octahedral molybdenum metal clusters deposited on ITO glass substrate by EPD will be discussed in detail [8]. More generally, we will focus on our recent results on thin films for optical and energy applications [9-10]. References [1] R. Liu et al., Chem. Commun., 2011, 47, 1384 [2] F. A. Cotton, Inorg. Chem., 1964, 3, 1217 [3] A. Perrin et al., C. R. Chimie, 2012, 15, 815 [4] Y. Luab et al., Chem. Soc. Rev., 2012, 41, 3594 [5] V. Fedorov, J. Clust. Sci., 2015, 26, 3 [6] S. Cordier et al., J. Inorg. Organomet. Polym., 2015, 25 189 [7] F. Grasset et al., Adv. Mater., 2008, 20, 1710 [8] T.K.N Nguyen et al., ECS J. Solid State Sci. Technol., 2016, (10) R178-R186 [9] T. G. Truong et al., Sci. Technol. Adv. Mat., 2016, 17(1), 443 [10] A. Renaud et al., ChemistrySelect, 2016, 1, 228

Flexible and Transparent Luminescent Cellulose-Transition Metal Cluster Composites

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

Expanding the Toolbox of Octahedral Molybdenum Clusters and Nanocomposites Made Thereof: Evidence of Two-Photon Absorption Induced NIR Emission and Singlet Oxygen Production

International audienceBright NIR phosphorescence from octahedral molybdenum clusters has been known since the 1980s. However, their behavior toward NIR excitation has never been investigated. Here we report their abilities to emit NIR light and produce singlet oxygen upon two-photon absorption. This behavior is observed in solution, in the solid state, and when clusters are embedded homogeneously in a poly(dimethylsiloxane) matrix. Such discoveries open new perspectives in several fields like optoelectronics, photodynamic therapy, or bioimaging

Effect of Sulfurization Process on Octahedral Molybdenum Cluster from Mo₆ Cluster to MoS₂ Nanosheet

International audienceThe Mo 6 cluster which has the great optical properties and chemical activity because of their unique electronic structure have been attracted attention in many fields such as phosphor and photocatalyst. However, the Mo 6 cluster it’s hard to recycling which limited its industry application because of its such small nanoscale. Immobilizing the Mo 6 cluster on 2-D material has a great value to challenge it. In this research, we study on the sulfurization process of Mo 6 Br 12 cluster to investigate the more possibility of the immobilization of Mo 6 cluster

Tunable photo-induced electronic property of octahedral metal clusters

International audienceThe tunable photo-induced electronic property of the Cs2[{Mo6Bri8}Bra6] and Br2[{Ta6Bri12}(H2O)a6] octahedral metal cluster-based compounds was characterized by the zeta potential measurement upon irradiation by ultraviolet–visible (UV–Vis) light. The enhancement of the electronic charge on the surface of the [{Mo6Bri8}Bra6]2- cluster-based anion caused by the irradiation increased the negative zeta potential. Both compounds showed the dependence of the zeta potential as a function of the light excitation. This will be a promising property for sensor applications based on the reversibility of the photo-electrochemical properties of the functional cluster

Switchable Two-Dimensional Waveguiding Abilities of Luminescent Hybrid Nanocomposites for Active Solar Concentrators

International audiencePassing from fossil energy sources to renewable ones, meanwhile answering the increasing world energy demand, will require innovative and low-cost technologies. Smart photovoltaic windows could fulfill our needs in this matter. Their transparency can be controlled to manage solar energy and regulate interior temperature and illumination. Here, we present the one-pot synthesis of polymer-dispersed liquid crystals (PDLCs), in which highly red-NIR phosphorescent transition metal clusters are selectively embedded, either in the polymer, in the liquid crystal, or in both phases. The PDLC matrix is used as a tunable waveguide to transfer the emitted light from nanoclusters to the edge of the device, where solar cells could be placed to convert it into electricity. Edge emission is obtained in both "off" and "on" states, with a maximum intensity for the scattering "off" one. These doped PDLCs showing photo-activity features and high stability under voltage represent key stepping stones for integration in buildings, displays, and many other technologies

Light Emissive Nanocomposites Containing a Blue Fluorescent Dicationic Tetraphenylethene and a Red Phosphorescent [Mo6I8(OCOC2F5)2)6]2- Octahedral Cluster for Optical Writing

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A review on functional nanoarchitectonics nanocomposites based on octahedral metal atom clusters (Nb-6, Mo-6, Ta-6, W-6, Re-6): inorganic 0D and 2D powders and films

International audienceThis review is dedicated to various functional nanoarchitectonic nanocomposites based on molecular octahedral metal atom clusters (Nb-6, Mo-6, Ta-6, W-6, Re-6). Powder and film nanocomposites with two-dimensional, one-dimensional and zero-dimensional morphologies are presented, as well as film matrices from organic polymers to inorganic layered oxides. The high potential and synergetic effects of these nanocomposites for biotechnology applications, photovoltaic, solar control, catalytic, photonic and sensor applications are demonstrated. This review also provides a basic level of understanding how nanocomposites are characterized and processed using different techniques and methods. The main objective of this review would be to provide guiding significance for the design of new high-performance nanocomposites based on transition metal atom clusters