Articles publicats en revistes (Ciència dels Materials i Química Física)

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2D MoS2/Cu2O on 3D mesoporous silica as visible-NIR nanophotocatalysts for environmental and biomedical applications
(Royal Society of Chemistry, 2025-07-28) Sepulveda, Borja; Esplandiu, María J.; Shahnazarova, Gubakhanim; Ramírez, Jessica C.; Al Bast, Nour A.H.; Fraxedas, Jordi; Lafuente, Aritz; Vaca, Cristina; Sledzinska, Marianna; Novikov, Valentin; Nogues, Carme; Nogues, Josep; Serrà i Ramos, Albert
Nanostructures based on transition metal dichalcogenides have attracted considerable attention due to their tunable optoelectronic properties and large surface areas, showing a great potential as photocatalysts. Here, a novel supported structure based on 2D-MoS2/Cu2O nanoflakes grown on 3D mesoporous silica templates fabricated by a combination of solvothermal synthesis and e-beam deposition methods is presented. The synthesized MoS2 nanoflakes exhibited a combination of trigonal-prismatic 2H and distorted-trigonal 1T′ phases, which contributed to a high density of active catalytic sites, facilitating efficient photogenerated charge transfer to analytes at the liquid interface. The deposition of Cu on the MoS2 nanoflakes enabled the formation of a semiconducting MoS2/Cu2O heterostructure with greatly enhanced photocatalytic activity. The supported MoS2/Cu2O nanoflakes showed excellent stability and an efficient generation of reactive oxygen species (ROS) with white and near infrared (NIR) light. The photocatalytic potential of the MoS2/Cu2O nanoflakes was established by the nearly complete degradation and mineralization of two organic pollutants (the antibiotic tetracycline and the biotoxin anatoxin-A) under low intensity white light, using ultralow catalyst concentration (ca. 4 μg mL−1). In addition, the use of MoS2/Cu2O nanostructures as photodynamic agents under low intensity NIR light was demonstrated. The NIR illuminated MoS2/Cu2O nanoflakes, placed at a distance of 120 μm from cultured cancer cells, enabled the complete elimination of cells via apoptosis, despite the large separation between them. These results underline the high photocatalytic activity of the supported MoS2/Cu2O nanoflakes to produce ROS with visible and NIR light, thus highlighting their suitability for environmental remediation and biomedical applications.
Removal of amoxicillin and ketorolac combining an IrO₂-Ta₂O₅|Ti anode with a carbon paper cathode
(Elsevier Ltd., 2025-10-13) Yáñez-Ángeles, M.J.; Sirés Sadornil, Ignacio; Bacame-Valenzuela, F.J.; Reyes-Vidal, Y.; Bustos, E.
Contaminants in water resources are known to cause serious environmental and health issues. Despite using different methods to eliminate such chemicals, emerging contaminants are usually persistent, especially in conventional water treatment technologies. Electro-oxidation (EO) is a straightforward technique that has been proven effective for degrading pharmaceuticals in water. In this work, the performance of EO has been investigated using an IrO2-Ta2O5|Ti anode containing 18.79 % Ti, 58.09 % O, 7.06 % Ir, and 2.36 % Ta, with a roughness of 252.6 μm, a surface area of 0.0667 cm2, and a roughness factor of 0.07575, in different setups by combining it with either a titanium mesh or carbon paper (CP) as a cathode, with or without a constant air flow rate. The accumulation of hydrogen peroxide (H2O2), hydroxyl radical (•OH), and active chlorine was monitored to evaluate the performance of each setup in two different media (0.1 M NaCl and 0.1 M Na2SO4). The EO process was conducted at a cell potential of 2.5 V for 120 min, and the removal of amoxicillin (AMX) and ketorolac (KET) was assessed by Ultraperformance Liquid Chromatography coupled to UV–Vis Spectrometry (UPLC-UV/Vis). In this sense, using the IrO2-Ta2O5|Ti||CP system, 10 mg l-1 AMX showed a removal efficiency of 100 % after 6 min in 0.1 M NaCl and after 30 min in 0.1 M Na2SO4. In comparison, 10 mg l-1 KET showed a removal efficiency of 100 % after 5 min in 0.1 M NaCl and 82.5 % after 120 min in 0.1 M Na2SO4, with a corresponding decrease in toxicity within <10 min. The mineralization of AMX and KET solutions was determined using total organic carbon (TOC) analysis. Our results showed that higher H2O2 and •OH radicals were produced in a 0.1 M Na2SO4 medium. Moreover, in aerated systems, the 2e- oxygen reduction reaction (ORR) at CP contributed to the faster degradation of the drugs. The chlorine production accelerated the disappearance of both drugs in the NaCl medium. Finally, reaction routes for the AMX degradation in Na2SO4 and KET degradation in NaCl are proposed, considering the interfacial oxidants generated (H2O2, •OH, Cl2/HClO) and the corresponding by-products identified by High Performance Liquid Chromatography coupled to tandem Mass Spectrometry (HPLC-MS/MS). The decrease in toxicity was observed within <10 min.
H2O2 electrosynthesis in a reactor without forced aeration for the complete degradation of antibiotics by photoelectro-Fenton-like process at neutral pH
(Elsevier B.V., 2025-10-15) Cornejo, Oscar M.; Ornelas Dávila, O.; Dávila-Jiménez, Martín M.; Sirés Sadornil, Ignacio
Innovative systems for H2O2-based advanced wastewater treatment avoiding the need of external aeration are pursued with great interest, since they allow decreasing the capital expenses significantly. This work shows the good performance of a rotating cylinder electrode (RCE) reactor for continuous H2O2 electrosynthesis sustained by anodic oxygen, and its use in the degradation of the antibiotic enrofloxacin (ENR) by photoelectro-Fenton (PEF) process at pH 7 using Fe(III)-ethylenediamine-N,N´-disuccinic (EDDS) acid complex as catalyst. For H2O2 accumulation in different aqueous matrices, each peripheral velocity (U) was linked to a specific limiting current (IL) using a mass transport correlation. H2O2 concentrations in the range of 2.4–3.7 mM were attained after 60 min of electrolysis at U = 198.9 cm s−1 (1000 rpm, IL = 0.31 A). At that rotation rate, the elimination of 5 mg L−1 ENR was 100 % after 30 min in a 50 mM Na2SO4 + 0.1 mM Fe(III)-EDDS. Moreover, ENR removal over 95 % was reached at 60 min in actual urban wastewater. The main by-products were oxalic and oxamic acid, accompanied by nitrate, ammonium, and fluoride ions. The superiority of PEF process as decontamination process was verified from the lower toxicity of the treated ENR solutions.
Unlocking flooded domains in air-breathing cathodes with edge-located asymmetric CoN2O2 sites for robust H2O2 electrosynthesis
(Elsevier B.V., 2025-10-19) Xia, Pan; He, Tianwei; Xu, Tong; Zhu, Zhong-Shuai; Sun, Yu; Duan, Xiaoguang; Wang, Chao; He, Qiang; Sirés Sadornil, Ignacio; Ye, Zhihong
Air-breathing gas-diffusion electrodes (GDEs) eliminating energy-intensive aeration hold great promise for industrial-scale hydrogen peroxide electrosynthesis. However, this configuration suffers from limited O2 mass transport and easy flooding. Herein, the active region of GDEs was extended beyond the three-phase boundary into the flooded domain by designing an alveolate carbon-supported Co single-atom electrocatalyst featuring abundant edge-located asymmetric CoN2O2 sites (eCoN2O2) to modulate the catalytic layer. The porous framework facilitates O2 mass transport, while the eCoN2O2 sites enable efficient O2 activation, sustaining fast ORR thanks to rational electrode design across the scales. Moreover, the superior O2 enrichment capability of eCoN2O2 allows efficient utilization of dissolved O2. Notably, the eCoN2O2-based GDE delivers a high H2O2 yield of 738.5 mg L−1 after 6 h at 25 mA cm−2, showing a 3.8-fold increase over basal-plane CoN4 moiety and even outperforming many aeration-driven systems. This work paves the way for integrated design of electrocatalysts and GDE architectures.
Development of ternary blended cements (LC3) to be applied as thermal energy storage material in concentrated solar power plants
(Elsevier, 2025-08-15) Betancor-Cazorla, L.; Vielma Leal, Carlos A.; Mañosa Bover, Jofre; Dosta Parras, Sergi; Chimenos Ribera, Josep Ma.; Barreneche, Camila
Currently, there is great awareness of the increase in energy consumption, dependence on fossil fuels, and greenhouse gas emissions, particularly CO2. One of the largest sources of carbon dioxide emissions is the cement and concrete industry, which has been growing in recent years. Therefore, it is necessary to implement measures to limit the global pollution caused by this sector. Furthermore, with the development of renewable energies, there is a growing need to develop batteries and materials that allow to store this energy for later use. Therefore, the main objective of this study is the development of ternary blended cements (LC3), in which clinker is partially replaced by thermally and mechanically activated kaolinitic clay, to be implemented as a thermal storage material in CSP plants. The development of the alternative cements was carried out in the laboratory and a full characterization was performed to evaluate their physical, mechanical, and thermal properties. In addition, a comparison of these properties with Portland cements was performed, to evaluate whether the characteristics presented met the required needs. Therefore, LC3 cements have affordable energy storage capacity to be implemented as TES media. In addition, LC3 cements have the same storage capacity as OPC, and it is maintained after aging test. Finally, an LCA was performed to quantify and evaluate the reductions provided by LC3 in terms sustainability reduction impact in the environment to be using this alternative cement in comparison with the common one. The results showed that both the mechanical and thermal properties of the cements are in line with the expected values and allow their use as TES materials regarding the energy storage capacity, energy density and energy performance by achieving and environmental impact reduction up to 22,6 %. Therefore, this study confirms that LC3 cement is more sustainable cements that significantly reduce CO2 eq. emissions (up to 24 % reduction).
Synergistic enhancement of Raney-Ni catalyst for methane dry reforming viaelectrochemically e ngineered CoNi co-catalyst
(Elsevier B.V., 2025-09-29) Lloreda Rodes, Judit; Serrano, Isabel; Llorca, Jordi, 1966-; Abad, Vanessa; Gómez, Elvira; Serrà i Ramos, Albert
Dry reforming of methane (DRM) offers a promising route to convert biogas into syngas while capturing CO₂.However, the harsh reaction conditions (≥700 ◦C) lead to rapid deactivation of conventional Ni-based catalystsdue to carbon deposition and sintering. In this work, we explore the catalytic behavior of commercial Raney-Nifor DRM and introduce electrochemically synthesized CoNi microparticles as co-catalysts to enhance stabilityand performance. Catalyst screening was performed in a fixed-bed reactor using a CH₄:CO₂:N₂ = 3:2:10 feedmixture under atmospheric pressure. Raney-Ni showed high activity (CH₄ conversion >92 % at 700 ◦C), butsuffered from coke accumulation and deactivation after 5 h of continuous operation. CoNi–Raney-Ni compositeswere prepared via physical blending of CoNi and Raney-Ni powders, and tested at various compositions. Thebest-performing among the tested compositions (25 wt% CoNi) maintained high conversion (>90 %) and stablesyngas production (H₂/CO ≈ 1.0) over extended periods. Post-reaction analysis revealed extensive filamentouscarbon on pure Raney-Ni, while CoNi-containing catalysts exhibited smoother surfaces and suppressed graphiticcarbon, as confirmed by FE-SEM and Raman spectroscopy. Notably, CoNi alone showed minimal CH₄ activationbut enhanced CO₂ dissociation and limited carbon formation. These results demonstrate a synergistic effect,where CoNi promotes carbon gasification while Raney-Ni provides high CH₄ reactivity. This composite approachenables scalable, low-cost catalysts with improved coke tolerance for biogas reforming applications.
Insights into mechanothermal activation of kaolinite: A novel multistep process for cement precursors
(Elsevier, 2025-07-28) Alvarez-Coscojuela, Adrian; Mañosa Bover, Jofre; Marco-Gibert, Josep; Córdoba, Javier C.; Chimenos Ribera, Josep Ma.
This study introduces a novel method for activating kaolinitic clays through mechanothermal activation (MTA), combining mechanical activation (MA) and thermal treatment to enhance kaolin’s pozzolanic reactivity at lower temperatures than traditional thermal activation (TA). MA effectively lowers kaolin’s dehydroxylation temperature, releasing significant hydroxyl groups at just 300 ◦C. Thermogravimetric analysis data confirms that implementing MTA unlocks the kaolinite dehydroxylation at 300 ◦C and 400 ◦C to a great extent and allows almost complete dehydroxylation at 500 ◦C. X-ray diffraction, surface area analysis, and particle size measurements revealed kaolin’s structural changes under MA, TA, and MTA treatments. The pozzolanic values achieved through MTA are significantly higher than those obtained with MA and TA at 300 ◦C, 400 ◦C, and 500 ◦C, as evidenced by reactivity tests. By enabling kaolinite activation at lower temperatures, MTA fosters a promising approach for developing sustainable building materials with a reduced carbon footprint.
Development of Alternative Porous Magnesium Potassium Phosphate Cements as Thermal Insulating Materials
(MDPI, 2025-08-22) Giró Paloma, Jessica; Mañosa Bover, Jofre; Maldonado-Alameda, Alex; Alfocea Roig, Anna; Huete-Hernández, Sergio; Chimenos Ribera, Josep Ma.; Formosa Mitjans, Joan
Magnesium potassium phosphate cement (MKPC), a type of chemically bonded phosphate ceramic (CBPC), presents a promising alternative to ordinary Portland cement (OPC). This study focuses on developing sustainable MKPC (sust-MKPC) as a thermally passive material for building applications. A low-grade magnesium oxide (LG-MgO) industrial by-product was utilized to formulate sust-MKPC, with hydrogen peroxide employed as an air-entraining agent (AEA) to induce high porosity and enhance thermal insulation while supporting sustainability goals by reducing energy consumption in climate control systems. Seven formulations incorporating varying hydrogen peroxide contents (0, 1, 2, 3, 5, 7.5, and 10 wt.%) were prepared to evaluate the impact of AEA on the thermal and physicomechanical properties. Comprehensive characterization, including porosity and thermal conductivity measurements, revealed that increasing the AEA content significantly improved thermal inertia and lowered thermal conductivity due to porosity. However, this enhancement was accompanied by a marked reduction in mechanical strength and density, highlighting the trade-off between thermal performance and structural integrity in porous sust-MKPC formulations.
Unlocking Alternative Cement Solutions: Utilizing Wastes and By-Products for Magnesium Phosphate Cement Development
(MDPI, 2025-09-03) Alfocea Roig, Anna; Giró Paloma, Jessica; Huete Hernández, Sergio; Formosa Mitjans, Joan
Concrete is the most used material worldwide, with cement as its essential component. Cement production, however, has a considerable environmental footprint contributing nearly 8% of global CO2 emissions, largely from clinker calcination. This review aims to examine strategies for reducing these emissions, with a particular focus on alternative materials for producing magnesium phosphate cements (MPCs). Specifically, the objectives are first to summarize mitigation pathways, such as CO2 capture, energy efficiency, and alternative raw materials, and second evaluate the feasibility of using industrial wastes and by-products, including low-grade MgO, tundish deskulling waste (TUN), boron-MgO (B-MgO), and magnesia refractory brick waste (MRB), as MgO sources for MPC. The review highlights that these materials represent a promising route to reduce the environmental impact of cement production and support the transition toward carbon neutrality by 2050.
Corrigendum to “Degradation of antibiotics and profiling of transformation products upon peracetic acid–mediated treatment of electrochlorinated groundwater in a flow–through reactor” [Water Research 284 (2025) 124013]
(Elsevier Ltd., 2025-07-07) Lu, Wang; Chen, Nan; Feng, Chuanping; Zhang, Gong; Sirés Sadornil, Ignacio
The authors regret that the horizonal axis of Fig. 1c, d was missing. The corrigendum figure is presented as follows:
A Human-Scale Clinically-Ready Electromagnetic Navigation System for Magnetically-Responsive Biomaterials and Medical Devices
(Wiley-VCH, 2024-04-11) Gervasoni, Simone; Pedrini, Norman; Rifai, Tarik; Fischer, Cedric; Landers, Fabian C.; Mattmann, Michael; Dreyfus, Roland; Viviani, Silvia; Veciana, Andrea; Masina, Enea; Aktas, Buse; Puigmartí-Luis, Josep; Chautems, Christophe; Pané, Salvador; Boehler, Quentin; Gruber, Philip; Nelson, Bradley J.
Magnetic navigation systems are used to precisely manipulate magnetically responsive materials enabling the realization of new minimally invasive procedures using magnetic medical devices. Their widespread applicability has been constrained by high infrastructure demands and costs. The study reports on a portable electromagnetic navigation system, the Navion, which is capable of generating a large magnetic field over a large workspace. The system is easy to install in hospital operating rooms and transportable through health care facilities, aiding in the widespread adoption of magnetically responsive medical devices. First, the design and implementation approach for the system are introduced and its performance is characterized. Next, in vitro navigation of different microrobot structures is demonstrated using magnetic field gradients and rotating magnetic fields. Spherical permanent magnets, electroplated cylindrical microrobots, microparticle swarms, and magnetic composite bacteria-inspired helical structures are investigated. The navigation of magnetic catheters is also demonstrated in two challenging endovascular tasks: 1) an angiography procedure and 2) deep navigation within the circle of Willis. Catheter navigation is demonstrated in a porcine model in vivo to perform an angiography under magnetic guidance.
Atomic hydrogen interaction with transition metal surfaces: A high-throughput computational study
(American Chemical Society, 2024-11-16) Allés, Miquel; Meng, Ling; Beltrán, Ismael; Fernández, Ferran; Viñes Solana, Francesc
Hydrogen adatoms are involved in many reactions catalyzed by Transition Metal (TM) surfaces, such as the Haber–Bosch process or the reverse water gas shift reaction, key to our modern society. Any rational improvement on such a catalyst requires an atomistic knowledge of the metal↔hydrogen interaction, only attainable from first-principles calculations on suited, realistic models. The present thorough density functional theory study evaluates such H interaction at a low coverage on most stable surfaces of bcc, fcc, and hcp TMs. These are (001), (011), and (111) for bcc and fcc TMs and (0001), (101̅0), and (112̅0) for hcp, covering 27 TMs and 81 different TM surfaces in total. In general terms, the results validate, while expanding, previous assessments, revealing that TM surfaces can be divided into two main groups, one in the majority where H2 would be thermodynamically driven to dissociate into H adatoms, located at heights of ∼0.5 or ∼1.0 Å, and another for late TMs, generally with a d10 electronic configuration, where H2 adsorption with no dissociation would be preferred. No trends in H adsorption energies are found down the groups, but yes along the d series, with a best linear adjustment found for the d-band center descriptor, especially suited for close-packed fcc and hcp TMs surfaces, with a mean absolute error of 0.15 eV. Gibbs free adsorption energies reveal a theoretical volcano plot where fcc TMs are best suited, but with peak Pt performance displaced due to dispersive force inclusion in the method. Still, the volcano plot with respect to the experimental logarithm of the exchanged current density polycrystalline data is far from being valid for a quantitative assessment, although useful for a qualitative screening and to confirm the trends computationally observed.
Atomic layer deposition of SnO2 and TiO2 on electrodeposited BiOI thin films for efficient light-driven peroxymonosulfate activationited BiOI thin films for efficient light-driven peroxymonosulfate activation
(Elsevier, 2025-09) Huidobro, Laura; Abid, Mahmoud; Maslouh, Haitham; Demore, Arnaud; Bechelany, Mikhael; Gómez, Elvira; Serrà i Ramos, Albert
Light-driven peroxymonosulfate (PMS) activation is gaining traction as a green advanced oxidation strategy for degrading recalcitrant water pollutants; however, catalyst instability and sluggish charge separation still hinder its practical application. Here, we report for the first time the fabrication of ALD-engineered BiOI thin-film heterojunctions, coated with nanometric SnO2 or TiO2 layers (∼5 nm) and decorated with Pd nanoparticles (∼2 nm), which simultaneously enhance catalytic activity and stability. The BiOI/SnO2 and BiOI/TiO2 systems exhibit well-defined type-II band alignments, facilitating efficient interfacial charge transfer, while Pd nanoparticles form Schottky junctions that extract photogenerated electrons and mitigate BiOI photocorrosion. Using 20 ppm tetracycline (TC) at pH 7 as a model contaminant, TiO2-BiOI achieved 92.7 % TC removal and 84.8 % total organic carbon (TOC) mineralization within 90 min under UV-A light (365 nm) with 2.5 mM PMS. In contrast, SnO2-BiOI showed superior performance under simulated sunlight (λ > 400 nm), attaining 80.8 % degradation and 76.5 % mineralization. Radical scavenging assays revealed a threefold increase in sulfate and hydroxyl radical production compared to pristine BiOI. Pd modification reduced Bi and I leaching by more than 80 % after 360 min of continuous irradiation and preserved over 95 % of the photocatalytic activity across ten successive reuse cycles. This work establishes a modular ALD-based strategy to design stable semiconductor/oxide/metal nanointerfaces for wavelength-tunable PMS activation. The resulting thin-film catalysts, fabricated on FTO substrates with sub-nanometer precision, offer a scalable platform for solar-driven water purification and expand the material design space for sulfate-radical-based advanced oxidation processes.
Corrigendum to “Mechanical activation of muscovite-rich clay: A novel approach for ternary blended cement” [Constr. Build. Mater., 489 (2025) 142182] (Construction and Building Materials (2025) 489, (S0950061825023335), (10.1016/j.conbuildmat.2025.142182))
(Elsevier, 2025-12-01) Mañosa Bover, Jofre; Maldonado Alameda, Alex; Chimenos Ribera, Josep Ma.
Corrigendum to “Mechanical activation of muscovite-rich clay: A novel approach for ternary blended cement” [Constr. Build. Mater., 489 (2025) 142182]
Single-Molecule Electrical Conductance in Z-form DNA:RNA
(Wiley-VCH, 2024-12-18) Aguilar, Mauricio R.; Jover Modrego, Jesús; Ruiz Sabín, Eliseo; Aragonès, Albert C.; Artés, Juan M.
Nucleic acids have emerged as new materials with promising applications in nanotechnology, molecular electronics, and biosensing, but their electronic properties, especially at the single-molecule level, are largely underexplored. The Z-form is an exotic left-handed helical oligonucleotide conformation that may be involved in critical biological processes such as the regulation of gene expression and epigenetic processes. In this work, the electrical conductance of individual Guanine Cytosine (GC)-rich DNA:RNA molecules is measured in physiological buffer and 2,2,2-Trifluoroethanol (TFE) solvent, corresponding to the natural (right-handed helix) A-form typical in DNA:RNA hybrids and the (left-handed) Z-form conformations, respectively. Single-molecule conductance measurements are performed using the Scanning Tunneling Microscopy (STM)-assisted break-junction method in the so-called “blinking” approach, recording the spontaneous formation of single-biomolecule junctions and performing statistical analysis of the signals. Circular Dichroism (CD) experiments and ab initio calculations are also done to rationalize the measured molecular conductivity with a simple structural and electronic model. These results show that the electrical conductivity of the Z-form is one order of magnitude lower than that of the more compact A-form. The longer molecular length and higher energy for the Highest Occupied Molecular Orbital (HOMO) of the Z-form account for the differences in single-molecule conductance observed experimentally.
Computationally screening non-precious single atom catalysts for oxygen reduction in alkaline media
(Elsevier B.V., 2024-04-01) Shaldehi, Tahereh Jangjooye; Meng, Ling; Rowshanzamir, Soosan; Parnian, Mohammad Javad; Exner, Kai; Viñes Solana, Francesc; Illas i Riera, Francesc
he performance of single-atom catalysts (SACs) containing Sc, Ti, V, Mn, Fe, Ni, Cu, and Pt on N-doped carbon (NC) as possible cathodes in advanced chlor-alkali electrolysis has been investigated by means of density functional theory (DFT) with the aim of finding candidates to improve the sluggish kinetics of the oxygen reduction reaction (ORR). A plausible mechanism is proposed for the ORR that allows making use of the computational hydrogen electrode (CHE) approach in this environment, and suitable models have been used to estimate the free-energy changes corresponding to the elementary reaction steps. The performance of the different catalysts has been analyzed in terms of the electrochemical-step symmetry index (ESSI) and Gmax descriptors. From these descriptors, the Cu-containing SAC is predicted to exhibit the highest catalytic activity which is consistent with a theoretical overpotential of 0.71 V, indicating that this type of catalysts in oxygen depolarized cathodes (ODCs) may overcome the limitations of the high cost and low abundance of Pt and other precious metals.
Ferrofluid-based bioink for 3d printed skeletal muscle tissues with enhanced force and magnetic response
(John Wiley & Sons, 2025-06-25) Fuentes Llanos, Judith; Guix Noguera, Maria; Cenev, Zoran M.; Bakenecker, Anna; Ruiz González, Noelia; Beaune, Grégory; Timonen, Jaakko V. I.; Sánchez Ordóñez, Samuel; Magdanz, Veronika
3D printing has emerged as a transformative technology in several manufacturing processes, being of particular interest in biomedical research for allowing the creation of 3D structures that mimic native tissues. The process of tissue 3D printing entails the construction of functional, 3D tissue structures. In this article, the integration of ferrofluid consisting of iron oxide nanoparticles into muscle cell-laden bioink is presented to obtain a 3D printed magnetically responsive muscle tissue, i.e., the ferromuscle. Using extrusion-based methods, the seamless integration of biocompatible ferrofluids are achieved to cell-laden hydrogels. The resulting ferromuscle tissue exhibits improved tissue differentiation demonstrated by the increased force output upon electrical stimulation compared to muscle tissue prepared without ferrofluid. Moreover, the magnetic component originating from the iron oxide nanoparticles allows magnetic guidance, as well as good cytocompatibility and biodegradability in cell culture. These findings offer a new versatile fabrication approach to integrate magnetic components into living constructs, with potential applications as bioactuators and for future integration in smart, functional muscle implants.
Size-Dependent Ab Initio Atomistic Thermodynamics from Cluster to Bulk: Application to Hydration of Titania Nanoparticles
(American Chemical Society, 2024-08-06) Recio-Poo, Miguel; Morales García, Ángel; Illas i Riera, Francesc; Bromley, Stefan Thomas
Ab initio atomistic thermodynamics (AIAT) has become an indispensable tool to estimate Gibbs free energy changes for solid surfaces interacting with gaseous species relative to pressure (p) and temperature (T). For such systems, AIAT assumes that solid vibrational contributions to Gibbs free energy differences cancel out. However, the validity of this assumption is unclear for nanoscale systems. Using hydrated titania nanoparticles (NPs) as an example, we estimate the vibrational contributions to the Gibbs free energy of hydration (ΔGhyd(T,p)) for arbitrary NP size and degree of hydration. Comparing ΔGhyd(T,p) phase diagrams for NPs when considering these contributions (AIATnano) relative to a standard AIAT approach reveals significant qualitative and quantitative differences, which only become negligible for large systems. By constructing a size-dependent ΔGhyd(T,p) phase diagram, we illustrate how our approach can provide deeper insights into how nanosytems interact with their environments, with many potential applications (e.g., catalytic nanoparticles, biological colloids, nanoparticulate pollutants).
Comprehensive Density Functional and Kinetic Monte Carlo Study of CO2 Hydrogenation on a Well-Defined Ni/CeO2 Model Catalyst: Role of Eley-Rideal Reactions
(American Chemical Society, 2024-02-16) Lozano-Reis, Pablo; Gamallo Belmonte, Pablo; Sayós Ortega, Ramón; Illas i Riera, Francesc
A detailed multiscale study of the mechanism of CO2 hydrogenation on a well-defined Ni/CeO2 model catalyst is reported that couples periodic density functional theory (DFT) calculations with kinetic Monte Carlo (kMC) simulations. The study includes an analysis of the role of Eley–Rideal elementary steps for the water formation step, which are usually neglected on the overall picture of the mechanism, catalytic activity, and selectivity. The DFT calculations for the chosen model consisting of a Ni4 cluster supported on CeO2 (111) show large enough adsorption energies along with low energy barriers that suggest this catalyst to be a good option for high selective CO2 methanation. The kMC simulations results show a synergic effect between the two 3-fold hollow sites of the supported Ni4 cluster with some elementary reactions dominant in one site, while other reactions prefer the another, nearly equivalent site. This effect is even more evident for the simulations explicitly including Eley–Rideal steps. The kMC simulations reveal that CO is formed via the dissociative pathway of the reverse water–gas shift reaction, while methane is formed via a CO2 → CO → HCO → CH → CH2 → CH3 → CH4 mechanism. Overall, our results show the importance of including the Eley–Rideal reactions and point to small Ni clusters supported on the CeO2 (111) surface as potential good catalysts for high selective CO2 methanation under mild conditions, while very active and selective toward CO formation at higher temperatures.
Theoretical Prediction of Core-Level Binding Energies: Analysis of Unexpected Errors
(American Chemical Society, 2024-02-08) Sousa Romero, Carmen; Bagus, Paul S.; Illas i Riera, Francesc
The analysis of the C(1s) and O(1s) core-level binding energies (CLBEs) of selected molecules computed by means of total energy Hartree–Fock (ΔSCF-HF) differences shows that in some cases, the calculated values for the C(1s) are larger than the experiment, which is unexpected. The origin of these unexpected errors of the Hartree–Fock ΔSCF BEs is shown to arise from static, nondynamical, electron correlation effects which are larger for the ion than for the neutral system. Once these static correlation effects are included by using complete active space self-consistent field (CASSCF) wave functions that include internal correlation terms, the resulting ΔSCF BEs are, as expected, smaller than measured values.

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