Publications by authors named "Victor Sans"

Cost-effective and efficient photoelectrochemical (PEC) water splitting stands out as one of the most promising strategies to address sustainable energy supply in the form of green H. Large-area photoelectrodes featuring precise chemical and morphological control are key components for a practical solar-to-hydrogen conversion. Herein, we report the continuous flow synthesis of BiVO nanoparticles (NPs) by using a simple microreactor configuration.

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The generation of stable white light emission using lead-free perovskites remains a huge challenge in the development of future display and lighting technologies, due to fast material deterioration and the decrease of the color quality. In this work, we report a combination of diverse types of 2D ASnX (A = bulky cation, X = Br, I) perovskites exhibiting self-trapped exciton (STE) emission and blue luminescent carbon quantum dots (CQDs), with the purpose of generating ASnX/CQD inks with a broadband emission in the visible region and a tunable white light color. By varying the concentration of the 2D perovskite, the white emission of the mixtures is modulated to cool, neutral, and warm tonalities, with a PL quantum yield up to 45%.

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Direct air capture and integrated conversion is a very attractive strategy to reduce CO concentration in the atmosphere. However, the existing capturing processes are technologically challenging due to the costs of the processes and the low concentration of CO. The efficient valorization of the CO captured could help overcome many techno-economic limitations.

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Halide perovskite nanocrystals (PNCs) have emerged as potential visible-light photocatalysts because of their outstanding intrinsic properties, including high absorption coefficient and tolerance to defects, which reduces non-radiative recombination, and high oxidizing/reducing power coming from their tuneable band structure. Nevertheless, their sensitivity to humidity, light, heat and water represents a great challenge that limits their applications in solar driven photocatalytic applications. Herein, we demonstrate the synergistic potential of embedding PNCs into polymeric ionic liquids () to fabricate suitable composites for photodegradation of organic dyes.

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Innovation in materials specially formulated for additive manufacturing is of great interest and can generate new opportunities for designing cost-effective smart materials for next-generation devices and engineering applications. Nevertheless, advanced molecular and nanostructured systems are frequently not possible to integrate into 3D printable materials, thus limiting their technological transferability. In some cases, this challenge can be overcome using polymeric macromolecules of ionic nature, such as polymeric ionic liquids (PILs).

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Electrochemical continuous-flow reactors offer a great opportunity for enhanced and sustainable chemical syntheses. Here, we present a novel application of electrochemical continuous-flow oscillatory baffled reactors (ECOBRs) that combines advanced mixing features with electrochemical transformations to enable efficient electrochemical oxidations under continuous flow at a millimeter distance between electrodes. Different additive manufacturing techniques have been employed to rapidly fabricate reactors.

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3D printable materials based on polymeric ionic liquids (PILs) capable of controlling the synthesis and stabilisation of silver nanoparticles (AgNPs) and their synergistic antimicrobial activity are reported. The interaction of the ionic liquid moieties with the silver precursor enabled the controlled in situ formation and stabilisation of AgNPs via extended UV photoreduction after the printing process, thus demonstrating an effective decoupling of the device manufacturing from the on-demand generation of nanomaterials, which avoids the potential aging of the nanomaterials through oxidation. The printed devices showed a multi-functional and tuneable microbicidal activity against Gram positive (B.

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The efficient transformation of CO into chemicals and fuels is a key challenge for the decarbonisation of the synthetic production chain. Formic acid (FA) represents the first product of CO hydrogenation and can be a precursor of higher added value products or employed as a hydrogen storage vector. Bases are typically required to overcome thermodynamic barriers in the synthesis of FA, generating waste and requiring post-processing of the formate salts.

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We report the design and preparation of multifunctional hybrid nanomaterials through the stabilization of gold nanoparticles with thiol-functionalised hybrid organic-inorganic polyoxometalates (POMs). The covalent attachment of the hybrid POM forms new nanocomposites that are stable at temperatures and pH values which destroy analogous electrostatically functionalised nanocomposites. Photoelectrochemical analysis revealed the unique photochemical and redox properties of these systems.

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An oxalate-bridged binuclear iron(III) ionic liquid combined with an imidazolium based cation, (dimim) [Fe Cl (μ-ox)], was synthesized and characterized by a wide range of techniques. This halometallate ionic liquid was active in catalyzing the depolymerization of polyethylene terephthalate (PET) by glycolysis, under conventional and microwave-assisted heating conditions. Both methodologies were very selective towards the production of bis(2-hydroxyethyl)terephthalate (BHET).

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The formulation of advanced molecular materials with bespoke polymeric ionic-liquid matrices that stabilize and solubilize hybrid organic-inorganic polyoxometalates and allow their processing by additive manufacturing, is effectively demonstrated. The unique photo and redox properties of nanostructured polyoxometalates are translated across the scales (from molecular design to functional materials) to yield macroscopic functional devices with reversible photochromism. These properties open a range of potential applications including reversible information storage based on controlled topological and temporal reduction/oxidation of pre-formed printed devices.

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This study explores a new method to maximize the visible-light-driven photocatalytic performance of organic-inorganic hybrid polyoxometalates (POMs). Experimental and theoretical investigations of a family of phosphonate-substituted POMs show that modification of grafted organic moieties can be used to tune the electronic structure and photoactivity of the metal oxide component. Unlike fully inorganic polyoxotungstates, these organic-inorganic hybrid species are responsive to visible light and function as photocatalysts (λ > 420 nm) in the decomposition of a model environmental pollutant.

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The exploration of chemical space for new reactivity, reactions and molecules is limited by the need for separate work-up-separation steps searching for molecules rather than reactivity. Herein we present a system that can autonomously evaluate chemical reactivity within a network of 64 possible reaction combinations and aims for new reactivity, rather than a predefined set of targets. The robotic system combines chemical handling, in-line spectroscopy and real-time feedback and analysis with an algorithm that is able to distinguish and select the most reactive pathways, generating a reaction selection index (RSI) without need for separate work-up or purification steps.

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Chemical transformations are normally conducted in batch or flow mode, thereby allowing the chemistry to be temporally or spatially controlled, but these approaches are not normally combined dynamically. However, the investigation of the underlying chemistry masked by the self-assembly processes that often occur in one-pot reactions and exploitation of the potential of complex chemical systems requires control in both time and space. Additionally, maintaining the intermediate constituents of a self-assembled system "off equilibrium" and utilizing them dynamically at specific time intervals provide access to building blocks that cannot coexist under one-pot conditions and ultimately to the formation of new clusters.

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Tungsten-based polyoxometalates (POMs) have been employed as UV-driven photo-catalysts for a range of organic transformations. Their photoactivity is dependent on electronic transitions between frontier orbitals and thus manipulation of orbital energy levels provides a promising means of extending their utility into the visible regime. Herein, an organic-inorganic hybrid polyoxometalate, K [P W O (PO H C ) ]⋅6 C H NO, was found to exhibit enhanced redox behaviour and photochemistry compared to its purely inorganic counterparts.

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The employment of continuous-flow platforms for synthetic chemistry is becoming increasingly popular in research and industrial environments. Integrating analytics in-line enables obtaining a large amount of information in real-time about the reaction progress, catalytic activity and stability, etc. Furthermore, it is possible to influence the reaction progress and selectivity via manual or automated feedback optimisation, thus constituting a dial-a-molecule approach employing digital synthesis.

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A configurable platform for synthetic chemistry incorporating an in-line benchtop NMR that is capable of monitoring and controlling organic reactions in real-time is presented. The platform is controlled a modular LabView software control system for the hardware, NMR, data analysis and feedback optimization. Using this platform we report the real-time advanced structural characterization of reaction mixtures, including F, C, DEPT, 2D NMR spectroscopy (COSY, HSQC and F-COSY) for the first time.

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Herein, we present an approach for the rapid, straightforward and economical preparation of a tailored reactor device using three-dimensional (3D) printing, which can be directly linked to a high-resolution electrospray ionisation mass spectrometer (ESI-MS) for real-time, in-line observations. To highlight the potential of the setup, supramolecular coordination chemistry was carried out in the device, with the product of the reactions being recorded continuously and in parallel by ESI-MS. Utilising in-house-programmed computer control, the reactant flow rates and order were carefully controlled and varied, with the changes in the pump inlets being mirrored by the recorded ESI-MS spectra.

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We present a study in which the versatility of 3D-printing is combined with the processing advantages of flow chemistry for the synthesis of organic compounds. Robust and inexpensive 3D-printed reactionware devices are easily connected using standard fittings resulting in complex, custom-made flow systems, including multiple reactors in a series with in-line, real-time analysis using an ATR-IR flow cell. As a proof of concept, we utilized two types of organic reactions, imine syntheses and imine reductions, to show how different reactor configurations and substrates give different products.

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The batch synthesis of inorganic clusters can be both time consuming and limited by a lack of reproducibility. Flow-system approaches, now common in organic synthesis, have not been utilized widely for the synthesis of clusters. Herein we combine an automated flow process with multiple batch crystallizations for the screening and scale up of syntheses of polyoxometalates and manganese-based single-molecule magnets.

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We utilise 3D design and 3D printing techniques to fabricate a number of miniaturised fluidic 'reactionware' devices for chemical syntheses in just a few hours, using inexpensive materials producing reliable and robust reactors. Both two and three inlet reactors could be assembled, as well as one-inlet devices with reactant 'silos' allowing the introduction of reactants during the fabrication process of the device. To demonstrate the utility and versatility of these devices organic (reductive amination and alkylation reactions), inorganic (large polyoxometalate synthesis) and materials (gold nanoparticle synthesis) processes were efficiently carried out in the printed devices.

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Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.

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A novel laser electrodispersion (LE) technique was employed to deposit gold nanoparticles onto Si and SiO(x) surfaces. The LE technique combines laser ablation with cascade fission of liquid metal micro-drops, which results in the formation of nanoparticles upon rapid cooling. The shape and the size distribution of the Au nanoparticles prepared by LE depend on the nature of the support.

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The physico-chemical properties of polymers with ionic-liquid-like moieties covalently bound to their surfaces (SILLPs) have been studied by thermal and spectroscopic techniques, as well as by direct impedance and dielectric measurements, and compared to those of the corresponding bulk ionic liquids. The effective transfer of properties from ionic liquids in solution to the supported species has thereby been demonstrated. The effects of the chemical nature of these tunable "solid solvents" on their macroscopic swelling and microwave heating, as well as the stabilities and activities of different catalytic moieties immobilized on the SILLPs, have been studied.

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