ICN2 Publications

2020

  • A copper(II) zig-zag metal–organic coordination polymer: synthesis, crystal structure, topology study, hirshfeld surface analysis and survey different conditions on morphology of a novel nano structure [Cu(L)(SCN)(H2O)2]n.2H2O

    Souri B., Hayati P., Rezvani A.R., Mendoza-Meroño R., Janczak J. Inorganic and Nano-Metal Chemistry; 50 (2): 80 - 93. 2020. 10.1080/24701556.2019.1662040. IF: 0.685

    Nanostructured Functional Materials

    One copper(II) coordination polymer compound [Cu(L)(SCN)(H2O)2]n.2H2O (1) where L stand for 2-pyridinecarboxylic acid, was synthesized following two different experimental methods, branch tube and sonochemical irradiation nano methods. Independently of the methodology used, the same crystalline phase is obtained for each compound. Single crystal X-ray analyses on compound 1 showed that Cu2+ ions are 6-coordinated. Additionally, H-bonds incorporate the zig-zag chains in 1 into 2D (along (1,1,0) direction) frameworks. Topological analysis shows that the compound 1 is 2C1 net. Hirshfeld surface analysis of compound 1 was studied. Also, theoretical and experimental morphology were studied. The thermal stability of compound 1 was studied by thermal gravimetric. Finally, the role of reaction time and temperature on growth and final morphology of the structures obtained by sonochemical irradiation are investigated. The results indicated that particle size was reduced with increasing sonication power, temperature, sonication time and decreasing concentration of reactant. © 2019, © 2019 Taylor & Francis Group, LLC.


  • A First Evaluation of Thick Oxide 3C-SiC MOS Capacitors Reliability

    Li F., Mawby P., Song Q., Perez-Tomas A., Shah V., Sharma Y., Hamilton D., Fisher C., Gammon P., Jennings M. IEEE Transactions on Electron Devices; 67 (1, 8935512): 237 - 242. 2020. 10.1109/TED.2019.2954911. IF: 2.704

    Advanced Electronic Materials and Devices

    Despite the recent advances in 3C-SiC technology, there is a lack of statistical analysis on the reliability of SiO2 layers on 3C-SiC, which is crucial in power MOS device developments. This article presents a comprehensive study of the medium-and long-term time-dependent dielectric breakdowns (TDDBs) of 65-nm-thick SiO2 layers thermally grown on a state-of-the-art 3C-SiC/Si wafer. Fowler-Nordheim (F-N) tunneling is observed above 7 MV/cm and an effective barrier height of 3.7 eV is obtained, which is the highest known for native SiO2 layers grown on the semiconductor substrate. The observed dependence of the oxide reliability on the gate active area suggests that the oxide quality has not reached the intrinsic level. Three failure mechanisms were identified and confirmed by both medium-and long-term results. Although two of them are likely due to extrinsic defects from material quality and fabrication steps, the one dominating the high field (>8.5 MV/cm) should be attributed to the electron impact ionization within SiO2. At room temperature, the field acceleration factor is found to be ≈0.906 dec/(MV/cm) for high fields, and the projected lifetime exceeds 10 years at 4.5 MV/cm. © 1963-2012 IEEE.


  • Cooling and self-oscillation in a nanotube electromechanical resonator

    Urgell C., Yang W., De Bonis S.L., Samanta C., Esplandiu M.J., Dong Q., Jin Y., Bachtold A. Nature Physics; 16 (1): 32 - 37. 2020. 10.1038/s41567-019-0682-6. IF: 20.113

    Magnetic Nanostructures

    Nanomechanical resonators are used with great success to couple mechanical motion to other degrees of freedom, such as photons, spins and electrons1,2. The motion of a mechanical eigenmode can be efficiently cooled into the quantum regime using photons2–4, but not other degrees of freedom. Here, we demonstrate a simple yet powerful method for cooling, amplification and self-oscillation using electrons. This is achieved by applying a constant (d.c.) current of electrons through a suspended nanotube in a dilution refrigerator. We demonstrate cooling to 4.6 ± 2.0 quanta of vibrations. We also observe self-oscillation, which can lead to prominent instabilities in the electron transport through the nanotube. We attribute the origin of the observed cooling and self-oscillation to an electrothermal effect. This work shows that electrons may become a useful resource for cooling the mechanical vibrations of nanoscale systems into the quantum regime. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.


  • Differential properties and effects of fluorescent carbon nanoparticles towards intestinal theranostics

    Vallan L., Hernández-Ferrer J., Grasa L., González-Domínguez J.M., Martínez M.T., Ballesteros B., Urriolabeitia E.P., Ansón-Casaos A., Benito A.M., Maser W.K. Colloids and Surfaces B: Biointerfaces; 185 (110612) 2020. 10.1016/j.colsurfb.2019.110612. IF: 3.973

    Electron Microscopy Unit

    Given the potential applications of fluorescent carbon nanoparticles in biomedicine, the relationship between their chemical structure, optical properties and biocompatibility has to be investigated in detail. In this work, different types of fluorescent carbon nanoparticles are synthesized by acid treatment, sonochemical treatment, electrochemical cleavage and polycondensation. The particle size ranges from 1 to 6 nm, depending on the synthesis method. Nanoparticles that were prepared by acid or sonochemical treatments from graphite keep a crystalline core and can be classified as graphene quantum dots. The electrochemically produced nanoparticles do not clearly show the graphene core, but it is made of heterogeneous aromatic structures with limited size. The polycondensation nanoparticles do not have C[dbnd]C double bonds. The type of functional groups on the carbon backbone and the optical properties, both absorbance and photoluminescence, strongly depend on the nanoparticle origin. The selected types of nanoparticles are compatible with human intestinal cells, while three of them also show activity against colon cancer cells. The widely different properties of the nanoparticle types need to be considered for their use as diagnosis markers and therapeutic vehicles, specifically in the digestive system. © 2019 Elsevier B.V.


  • Editorial note - Professor Turner's retirement

    Gu M.B., Li C., Merkoçi A., the new editorial team of Biosensors and Bioelectronics, Co-Editors in chief Biosensors and Bioelectronics; 150 (111913) 2020. 10.1016/j.bios.2019.111913. IF: 9.518

    Nanobioelectronics and Biosensors

    [No abstract available]


  • Engineering grain boundaries at the 2D limit for the hydrogen evolution reaction

    He Y., Tang P., Hu Z., He Q., Zhu C., Wang L., Zeng Q., Golani P., Gao G., Fu W., Huang Z., Gao C., Xia J., Wang X., Wang X., Zhu C., Ramasse Q.M., Zhang A., An B., Zhang Y., Martí-Sánchez S., Morante J.R., Wang L., Tay B.K., Yakobson B.I., Trampert A., Zhang H., Wu M., Wang Q.J., Arbiol J., Liu Z. Nature Communications; 11 (1, 57) 2020. 10.1038/s41467-019-13631-2. IF: 11.878

    Magnetic Nanostructures | Advanced Electron Nanoscopy

    Atom-thin transition metal dichalcogenides (TMDs) have emerged as fascinating materials and key structures for electrocatalysis. So far, their edges, dopant heteroatoms and defects have been intensively explored as active sites for the hydrogen evolution reaction (HER) to split water. However, grain boundaries (GBs), a key type of defects in TMDs, have been overlooked due to their low density and large structural variations. Here, we demonstrate the synthesis of wafer-size atom-thin TMD films with an ultra-high-density of GBs, up to ~1012 cm−2. We propose a climb and drive 0D/2D interaction to explain the underlying growth mechanism. The electrocatalytic activity of the nanograin film is comprehensively examined by micro-electrochemical measurements, showing an excellent hydrogen-evolution performance (onset potential: −25 mV and Tafel slope: 54 mV dec−1), thus indicating an intrinsically high activation of the TMD GBs. © 2020, The Author(s).


  • GaAs nanoscale membranes: Prospects for seamless integration of III-Vs on silicon

    Raya A.M., Friedl M., Martí-Sánchez S., Dubrovskii V.G., Francaviglia L., Alén B., Morgan N., Tütüncüoglu G., Ramasse Q.M., Fuster D., Llorens J.M., Arbiol J., Fontcuberta I Morral A. Nanoscale; 12 (2): 815 - 824. 2020. 10.1039/c9nr08453c. IF: 6.970

    Advanced Electron Nanoscopy

    The growth of compound semiconductors on silicon has been widely sought after for decades, but reliable methods for defect-free combination of these materials have remained elusive. Recently, interconnected GaAs nanoscale membranes have been used as templates for the scalable integration of nanowire networks on III-V substrates. Here, we demonstrate how GaAs nanoscale membranes can be seamlessly integrated on silicon by controlling the density of nuclei in the initial stages of growth. We also correlate the absence or presence of defects with the existence of a single or multiple nucleation regime for the single membranes. Certain defects exhibit well-differentiated spectroscopic features that we identify with cathodoluminescence and micro-photoluminescence techniques. Overall, this work presents a new approach for the seamless integration of compound semiconductors on silicon. © 2019 The Royal Society of Chemistry.


  • Graphene triggered enhancement in visible-light active photocatalysis as well as in energy storage capacity of (CFO)1-x(GNPs)x nanocomposites

    Israr M., Iqbal J., Arshad A., Rani M., Gómez‐Romero P., Benages R. Ceramics International; 46 (3): 2630 - 2639. 2020. 10.1016/j.ceramint.2019.09.232. IF: 3.450

    Novel Energy-Oriented Materials

    Cobalt ferrite-graphene nanoplatelets ((CFO)1-x(GNPs)x) nanocomposites are promising for efficient photocatalysis and high-performance supercapacitors. Multifunctional (CFO)1-x(GNPs)x nanocomposites prepared via facile chemical method have been investigated for their physio-chemical characteristics like crystal structure, morphology, chemical composition, optical properties, infrared vibrational modes, photocatalytic and supercapacitor applications. Interestingly, the photocatalytic activity of CFO nanostructures has been improved significantly from 38.3% to 98.7% with the addition of graphene which can be attributed to control over recombination of charge carriers. It is also found that the specific capacitance of the prepared (CFO)1-x(GNPs)x nanocomposite electrode at 0.5 Ag-1 is three times higher than that of only CFO based electrode which could be due to the conducting nature of graphene nanoplatelets (GNPs). The enhanced photocatalytic and improved electrochemical characteristics suggest the effective use of prepared nanocomposites in water purification and supercapacitor nanodevices. © 2019 Elsevier Ltd and Techna Group S.r.l.


  • Highly reduced ecotoxicity of ZnO-based micro/nanostructures on aquatic biota: Influence of architecture, chemical composition, fixation, and photocatalytic efficiency

    Serrà A., Zhang Y., Sepúlveda B., Gómez E., Nogués J., Michler J., Philippe L. Water Research; 169 (115210) 2020. 10.1016/j.watres.2019.115210. IF: 7.913

    Magnetic Nanostructures

    Developing efficient sunlight photocatalysts with enhanced photocorrosion resistance and minimal ecotoxicological effects on aquatic biota is critical to combat water contamination. Here, the role of chemical composition, architecture, and fixation on the ecotoxicological effects on microalgae of different ZnO and ZnO@ZnS based water decontamination photocatalysts was analyzed in depth. In particular, the ecotoxicological effects of films, nanoparticles and biomimetic micro/nano-ferns were carefully assessed by correlating the algae's viability to the Zn(II) release, the photocatalyst–microalgae interaction, and the production of reactive oxygen species (ROS). The results showed a drastic improvement in algal viability for supported ZnO@ZnS core@shell micro/nanoferns, as their ecotoxicity after 96 h light exposure was significantly lower (3.7–10.0% viability loss) compared to the ZnO films (18.4–35.5% loss), ZnO micro/nanoferns (28.5–53.5% loss), ZnO nanoparticles (48.3–91.7% loss) or ZnO@ZnS nanoparticles (8.6–19.2% loss) for catalysts concentrations ranging from 25 mg L−1 to 400 mg L−1. In particular, the ZnO@ZnS micro/nanoferns with a concentration of 400 mg L−1 exhibited excellent photocatalytic efficiency to mineralize a multi-pollutant solution (81.4 ± 0.3% mineralization efficiency after 210 min under UV-filtered visible light irradiation) and minimal photocorrosion (<5% of photocatalyst dissolution after 96 h of UV-filtered visible light irradiation). Remarkably, the ZnO@ZnS micro/nanoferns showed lower loss of algal viability (9.8 ± 1.1%) after 96 h of light exposure, with minimal reduction in microalgal biomass (9.1 ± 1.0%), as well as in the quantity of chlorophyll-a (9.5 ± 1.0%), carotenoids (8.6 ± 0.9%) and phycocyanin (5.6 ± 0.6%). Altogether, the optimized ZnO@ZnS core@shell micro/nanoferns represent excellent ecofriendly photocatalysts for water remediation in complex media, as they combine enhanced sunlight remediation efficiency, minimal adverse effects on biological microorganisms, high reusability and easy recyclability. © 2019 Elsevier Ltd


  • Investigation of The Cellular Response to Bone Fractures: Evidence for Flexoelectricity

    Núñez-Toldrà R., Vasquez-Sancho F., Barroca N., Catalan G. Scientific reports; 10 (1): 254. 2020. 10.1038/s41598-019-57121-3. IF: 4.011

    Oxide Nanophysics

    The recent discovery of bone flexoelectricity (strain-gradient-induced electrical polarization) suggests that flexoelectricity could have physiological effects in bones, and specifically near bone fractures, where flexoelectricity is theoretically highest. Here, we report a cytological study of the interaction between crack stress and bone cells. We have cultured MC3T3-E1 mouse osteoblastic cells in biomimetic microcracked hydroxyapatite substrates, differentiated into osteocytes and applied a strain gradient to the samples. The results show a strong apoptotic cellular response, whereby mechanical stimulation causes those cells near the crack to die, as indicated by live-dead and caspase staining. In addition, analysis two weeks post-stimulation shows increased cell attachment and mineralization around microcracks and a higher expression of osteocalcin -an osteogenic protein known to be promoted by physical exercise. The results are consistent with flexoelectricity playing at least two different roles in bone remodelling: apoptotic trigger of the repair protocol, and electro-stimulant of the bone-building activity of osteoblasts.


  • Ion bombardment induced formation of self-organized wafer-scale GaInP nanopillar assemblies

    Visser D., Jaramillo-Fernandez J., Haddad G., Sotomayor Torres C.M., Anand S. Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics; 38 (1, 012801) 2020. 10.1116/1.5127265. IF: 1.351

    Phononic and Photonic Nanostructures

    Ion sputtering assisted formation of nanopillars is demonstrated as a wafer-scale, lithography-free fabrication method to obtain high optical quality gallium indium phosphide (GaInP) nanopillars. Compared to binary materials, little has been reported on the formation of self-organized ternary nanostructures. Epitaxial (100) Ga0.51In0.49P layers lattice matched to GaAs were sputtered by nitrogen (N2) ions with relatively low ion beam energies (∼400 eV) to reduce ion bombardment induced damage. The influence of process parameters such as temperature, sputter duration, ion beam energy, and ion beam incidence angle on the pillar formation is investigated. The fabricated GaInP nanopillars have average diameters of ∼75-100 nm, height of ∼220 nm, and average density of ∼2-4 × 108 pillars/cm2. The authors show that the ion beam incidence angle plays an important role in pillar formation and can be used to tune the pillar shape, diameter, and spatial density. Specifically, tapered to near cylindrical pillar profiles together with a reduction in their average diameters are obtained by varying the ion beam incidence angle from 0° to 20°. A tentative model for the GaInP nanopillar formation is proposed based on transmission electron microscopy and chemical mapping analysis. μ-Photoluminescence and μ-Raman measurements indicate a high optical quality of the c-GaInP nanopillars. © 2019 Author(s).


  • Multi-approach analysis to assess the chromium(III) immobilization by Ochrobactrum anthropi DE2010

    Villagrasa E., Ballesteros B., Obiol A., Millach L., Esteve I., Solé A. Chemosphere; 238 (124663) 2020. 10.1016/j.chemosphere.2019.124663. IF: 5.108

    Electron Microscopy Unit

    Ochrobactrum anthropi DE2010 is a microorganism isolated from Ebro Delta microbial mats and able to resist high doses of chromium(III) due to its capacity to tolerate, absorb and accumulate this metal. The effect of this pollutant on O. anthropi DE2010 has been studied assessing changes in viability and biomass, sorption yields and removal efficiencies. Furthermore, and for the first time, its capacity for immobilizing Cr(III) from culture media was tested by a combination of High Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM) imaging coupled to Energy Dispersive X-ray spectroscopy (EDX). The results showed that O. anthropi DE2010 was grown optimally at 0–2 mM Cr(III). On the other hand, from 2 to 10 mM Cr(III) microbial plate counts, growth rates, cell viability, and biomass decreased while extracellular polymeric substances (EPS) production increases. Furthermore, this bacterium had a great ability to remove Cr(III) at 10 mM (q = 950.00 mg g−1) immobilizing it mostly in bright polyphosphate inclusions and secondarily on the cellular surface at the EPS level. Based on these results, O. anthropi DE2010 could be considered as a potential agent for bioremediation in Cr(III) contaminated environments. © 2019 Elsevier Ltd


  • Nano-lantern on paper for smartphone-based ATP detection

    Calabretta M.M., Álvarez-Diduk R., Michelini E., Roda A., Merkoçi A. Biosensors and Bioelectronics; 150 (111902) 2020. 10.1016/j.bios.2019.111902. IF: 9.518

    Nanobioelectronics and Biosensors

    ATP-driven bioluminescence relying on the D-luciferin-luciferase reaction is widely employed for several biosensing applications where bacterial ATP detection allows to verify microbial contamination for hygiene monitoring in hospitals, food processing and in general for cell viability studies. Several ATP kit assays are already commercially available but an user-friendly ATP biosensor characterized by low-cost, portability, and adequate sensitivity would be highly valuable for rapid and facile on site screening. Thanks to an innovative freeze-drying procedure, we developed a user-friendly, ready-to-use and stable ATP sensing paper biosensor that can be combined with smartphone detection. The ATP sensing paper includes a lyophilized “nano-lantern” with reaction components being rapidly reconstituted by 10 μL sample addition, enabling detection of 10−14 mol of ATP within 10 min. We analysed urinary microbial ATP as a biomarker of urinary tract infection (UTI), confirming the capability of the ATP sensing paper to detect the threshold for positivity corresponding to 105 colony-forming units of bacteria per mL of urine. © 2019 Elsevier B.V.


  • Preclinical evaluation of antigen-specific nanotherapy based on phosphatidylserine-liposomes for type 1 diabetes

    Villalba A., Rodriguez-Fernandez S., Ampudia R.-M., Cano-Sarabia M., Perna-Barrull D., Bertran-Cobo C., Ehrenberg C., Maspoch D., Vives-Pi M. Artificial Cells, Nanomedicine and Biotechnology; 48 (1): 77 - 83. 2020. 10.1080/21691401.2019.1699812. IF: 4.462

    Supramolecular NanoChemistry and Materials

    Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of insulin-producing cells. Due to the ability of apoptotic cells clearance to induce tolerance, we previously generated liposomes rich in phophatidylserine (PS) –a feature of apoptotic cells– loaded with insulin peptides to mimic apoptotic beta-cells. PS-liposomes arrested autoimmunity in experimental T1D through the induction of tolerance. The aim of this study was to investigate the potential of several peptides from different T1D autoantigens encapsulated in (PS)-liposomes for T1D prevention and to assess its safety. T1D autoantigens (Insulin, C-peptide, GAD65 and IA2) were encapsulated in PS-liposomes. Liposomes were administered to the 'gold-standard' model for the study of autoimmune T1D, the Non-Obese Diabetic mouse, that spontaneously develop the disease. Safety and toxicity of liposomes were also determined. Only PS-liposomes encapsulating insulin peptides decrease T1D incidence in the Non-Obese Diabetic mouse model. Disease prevention correlates with a decrease in the severity of the autoimmune islet destruction driven by leukocytes. PS-liposomes neither showed toxic effect nor secondary complications. Among the here referred autoantigens, insulin peptides are the best candidates to be encapsulated in liposomes, like an artificial apoptotic cell, for the arrest of autoimmunity in T1D in a safe manner. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.


  • Supramolecular Fullerene Sponges as Catalytic Masks for Regioselective Functionalization of C60

    Fuertes-Espinosa C., García-Simón C., Pujals M., Garcia-Borràs M., Gómez L., Parella T., Juanhuix J., Imaz I., Maspoch D., Costas M., Ribas X. Chem; 6 (1): 169 - 186. 2020. 10.1016/j.chempr.2019.10.010. IF: 18.205

    Supramolecular NanoChemistry and Materials

    Isomer-pure poly-functionalized fullerenes are required to boost the development of fullerene chemistry in all fields. On a general basis, multi-adduct mixtures with uncontrolled regioselectivity are obtained, and the use of chromatographic purification is prohibitively costly and time consuming, especially in the production of solar cells. Single-isomer poly-functionalized fullerenes are only accessible via stoichiometric, multistep paths entailing protecting-unprotecting sequences. Herein, a nanocapsule is used as a supramolecular tetragonal prismatic mask to exert full control on the reactivity and the equatorial regioselectivity of Bingel-Hirsch cyclopropanation reactions of a confined C60 guest. Thus, equatorial bis-, tris-, and tetrakis-C60 homo-adducts are exclusively obtained in a stepwise manner. Furthermore, isomer-pure equatorial hetero-tetrakis-adducts or hetero-Th-hexakis-adducts are synthesized at will in one-pot synthesis for the first time. This work provides a synthetically valuable path to produce a plethora of new pure-isomer poly-functionalized C60-based compounds as candidates for testing in solar cell devices and biomedical applications. Video Abstract: The supramolecular mask protocol is a significant step forward for the regioselective functionalization of fullerenes. The exquisite ability to form pure-isomer poly-functionalized C60 adducts, overcoming tedious and non-practical chromatographic separations, allows for their direct testing in solar cell prototypes. Furthermore, the supramolecular mask strategy can be applied to C70 or higher fullerenes, opening a plethora of poly-functionalized fullerene derivatives to be synthesized and tested. Moreover, apart from the nucleophilic cyclopropanations reported herein, the protocol is currently being expanded to Diels-Alder (DA), 1,3-dipolar cycloadditions and PC60BM-type cyclopropanations, thus enabling a variety of regioselective functionalization reactions. This supramolecular mask strategy can help the discovery of the next generation of improved solar cells (organic or perovskite based) or new drug candidates. An unprecedented and straightforward supramolecular mask strategy to prepare exclusively equatorial bis-, tris-, and tetrakis-cyclopropanated-C60 Bingel-Hirsch derivatives is reported. By taking advantage of the high affinity for fullerene of tetragonal prismatic supramolecular cages, a highly stable C60⊂1a·(BArF)8 host-guest complex is submitted to Bingel-Hirsch cyclopropanation reaction conditions. Regioselectivity is strictly dictated by the four cross-shaped apertures of the nanocapsule in a controlled fashion. Moreover, stepwise-cyclopropanated adducts up to tetrakis additions are obtained in excellent yields and purities. © 2019 Elsevier Inc.


  • Tunable room-temperature spin galvanic and spin Hall effects in van der Waals heterostructures

    Benítez L.A., Savero Torres W., Sierra J.F., Timmermans M., Garcia J.H., Roche S., Costache M.V., Valenzuela S.O. Nature Materials; 2020. 10.1038/s41563-019-0575-1. IF: 38.887

    Theoretical and Computational Nanoscience | Physics and Engineering of Nanodevices

    Spin–orbit coupling stands as a powerful tool to interconvert charge and spin currents and to manipulate the magnetization of magnetic materials through spin-torque phenomena. However, despite the diversity of existing bulk materials and the recent advent of interfacial and low-dimensional effects, control of this interconversion at room temperature remains elusive. Here, we demonstrate strongly enhanced room-temperature spin-to-charge interconversion in graphene driven by the proximity of WS2. By performing spin precession experiments in appropriately designed Hall bars, we separate the contributions of the spin Hall and the spin galvanic effects. Remarkably, their corresponding conversion efficiencies can be tailored by electrostatic gating in magnitude and sign, peaking near the charge neutrality point with an equivalent magnitude that is comparable to the largest efficiencies reported to date. Such electric-field tunability provides a building block for spin generation free from magnetic materials and for ultra-compact magnetic memory technologies. © 2020, The Author(s), under exclusive licence to Springer Nature Limited.


  • Ultrathin Films of Porous Metal–Organic Polyhedra for Gas Separation

    Andrés M.A., Carné-Sánchez A., Sánchez-Laínez J., Roubeau O., Coronas J., Maspoch D., Gascón I. Chemistry - A European Journal; 26 (1): 143 - 147. 2020. 10.1002/chem.201904141.

    Supramolecular NanoChemistry and Materials

    Ultrathin films of a robust RhII-based porous metal–organic polyhedra (MOP) have been obtained. Homogeneous and compact monolayer films (ca. 2.5 nm thick) were first formed at the air–water interface, deposited onto different substrates and characterized using spectroscopic methods, scanning transmission electron microscopy and atomic force microscopy. As a proof of concept, the gas separation performance of MOP-supported membranes has also been evaluated. Selective MOP ultrathin films (thickness ca. 60 nm) exhibit remarkable CO2 permeance and CO2/N2 selectivity, demonstrating the great combined potential of MOP and Langmuir-based techniques in separation technologies. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Understanding galvanic replacement reactions: the case of Pt and Ag

    Merkoçi F., Patarroyo J., Russo L., Piella J., Genç A., Arbiol J., Bastús N.G., Puntes V. Materials Today Advances; 5 (100037) 2020. 10.1016/j.mtadv.2019.100037.

    Inorganic Nanoparticles | Advanced Electron Nanoscopy

    Synthesis of nanocrystals (NCs), where material science elements are addressed with organic chemistry precision techniques, is especially challenging and difficult to control. This difficulty arises from the increased complexity of the mineralization processes and the generation of a liquid-solid interface. These aspects, along with a strong susceptibility to reaction kinetics, ultimately translate into serious challenges for reproducibility and morphological control. By systematically varying the different parameters used to control the morphology of NCs, including complexing agents, coreducers, and cooxidants, the general reaction landscape can be mapped and the most stable and reproducible recipes can be identified. We apply this concept to the model transmetallation reaction between immiscible Pt and Ag forming hollow Pt NCs by galvanic replacement reactions. In this work, 648 synthetic recipes were performed and characterized per duplicate, from which a subset of 307 recipes leading to the controlled formation of hollow NCs were further analyzed to correlate reaction conditions with the final obtained structure and stability (reproducibility). As a result, we present robust general synthetic protocols leading to the ad hoc production of Pt-based hollow NCs with independent control of shell thickness, void size, surface roughness, and degree of porosity. © 2019 The Authors


  • Unfolding method for periodic twisted systems with commensurate Moiré patterns

    Sánchez-Ochoa F., Hidalgo F., Pruneda M., Noguez C. Journal of Physics Condensed Matter; 32 (2, 025501) 2020. 10.1088/1361-648X/ab44f0.

    Theory and Simulation

    We present a general unfolding method for the electronic bands of systems with double-periodicity. Within density functional theory with atomic orbitals as basis-set, our method takes into account two symmetry operations of the primitive cell: a standard expansion and a single rotation, letting to elucidate the physical effects associated to the mutual interactions between systems with more than one periodicity. As a result, our unfolding method allows studying the electronic properties of vertically stacked two-dimensional homo-or heterostructures. We apply our method to study 3 × 3single-layer graphene, √13×√ twisted single-layer graphene, and 2√3×2√3 graphene-√7×√7 tungsten disulfide heterostructure with an interlayer angle of 10.9°. Our unfolding method allows observing typical mini gaps reported in heterostructures, as well as other electronic deviations from pristine structures, impossible to distinguish without an unfolding method. We anticipate that this unfolding method can be useful to compare with experiments to elucidate the electronic properties of two-dimensional homo-or heterostructures, where the interlayer angle can be considered as an additional parameter. © 2019 IOP Publishing Ltd.


  • Water/methanol solutions characterized by liquid μ-jet XPS and DFT—The methanol hydration case

    Pellegrin E., Perez-Dieste V., Escudero C., Rejmak P., Gonzalez N., Fontsere A., Prat J., Fraxedas J., Ferrer S. Journal of Molecular Liquids; 300 (112258) 2020. 10.1016/j.molliq.2019.112258. IF: 4.561

    Force Probe Microscopy and Surface Nanoengineering

    The advent of liquid μ-jet setups as proposed by Faubel and Winter – in conjunction with X-ray Photoemission Spectroscopy (XPS) – has opened up a large variety of experimental possibilities in the field of atomic and molecular physics. In this study, we present first results from a synchrotron-based XPS core level and valence band electron spectroscopy study on water (10-4 M aqueous NaCl solution) as well as a water/methanol mixture using the newly commissioned ALBA liquid μ-jet setup. The experimental results are compared with simulations from density functional theory (DFT) regarding the electronic structure of single molecules, pure molecular clusters, and mixed clusters configurations as well as previous experimental studies. We give a detailed interpretation of the core level and valence band spectra for the vapour and liquid phases of both sample systems. The resulting overall picture gives insight into the water/methanol concentrations of the vapour and liquid phases as well as into the local electronic structure of the pertinent molecular clusters under consideration, with a special emphasis on methanol as the simplest amphiphilic molecule capable of creating hydrogen bonds. © 2019 Elsevier B.V.


  • Writing chemical patterns using electrospun fibers as nanoscale inkpots for directed assembly of colloidal nanocrystals

    Kiremitler N.B., Torun I., Altintas Y., Patarroyo J., Demir H.V., Puntes V.F., Mutlugun E., Onses M.S. Nanoscale; 12 (2): 895 - 903. 2020. 10.1039/c9nr08056b. IF: 6.970

    Inorganic Nanoparticles

    Applications that range from electronics to biotechnology will greatly benefit from low-cost, scalable and multiplex fabrication of spatially defined arrays of colloidal inorganic nanocrystals. In this work, we present a novel additive patterning approach based on the use of electrospun nanofibers (NFs) as inkpots for end-functional polymers. The localized grafting of end-functional polymers from spatially defined nanofibers results in covalently bound chemical patterns. The main factors that determine the width of the nanopatterns are the diameter of the NF and the extent of spreading during the thermal annealing process. Lowering the surface energy of the substrates via silanization and a proper choice of the grafting conditions enable the fabrication of nanoscale patterns over centimeter length scales. The fabricated patterns of end-grafted polymers serve as the templates for spatially defined assembly of colloidal metal and metal oxide nanocrystals of varying sizes (15 to 100 nm), shapes (spherical, cube, rod), and compositions (Au, Ag, Pt, TiO2), as well as semiconductor quantum dots, including the assembly of semiconductor nanoplatelets. © 2019 The Royal Society of Chemistry.