Publications

This study synthesized a solid-solution series of KCo1-x Ni x Cr2(PO4)3 phosphates with the alpha-CrPO4-type three-dimensional framework, in which edge-sharing CrO6 octahedra and PO4 tetrahedra create tunnels hosting K+ cations. Systematic Ni2+/Co2+ substitution was used to tune dielectric and charge-transport properties. All compounds showed stable paraelectric behavior; increasing Co content enhanced polarizability and dielectric permittivity while maintaining low dielectric loss. When used as electrode materials in graphite-based supercapacitors, higher Co content led to improved electrochemical performance, with the Co1Ni0 composition delivering a specific capacitance of 447 F/g, an energy density of 48.18 Wh/kg, and a power density of 1752 W/kg. The results demonstrate that Ni2+/Co2+ substitution is an effective strategy for designing advanced supercapacitor electrodes that combine high charge-storage capacity (due to increased permittivity) with improved power capability (due to higher conductivity).

beta-SiC nanostructures were synthesized and incorporated into polypropylene (PP) to obtain SiC/PP nanocomposites (1-10 wt%). Scanning Electron Microscopy (SEM) revealed mixed morphologies of SiC with relatively uniform distribution, but progressive agglomeration at higher loadings. Debye-Scherrer calculations indicated that the SiC crystallite size in the composites evolves non-monotonically from 2.01 to 51.32 nm as a function of filler concentration, reflecting a competition between heterogeneous nucleation, particle aggregation, and interfacial confinement. Ultraviolet-Visible (UV-Vis) spectroscopy demonstrated deep-UV absorption below similar to 230 nm and slight shifts of the direct band gap, with Eg varying in a narrow range between 5.82 and 5.98 eV across the SiC/PP nanocomposite materials (Eg(PP) = 5.88 eV, Eg(SiC) = 5.79 eV). Fourier Transform Infrared (FTIR) and Raman spectroscopy revealed the gradual reduction of PP-characteristic bands and the growth of Si-C vibrational signatures, accompanied by an increase in the PP beta-phase fraction, indicating effective interfacial interactions and beta-nucleation by beta-SiC. Dielectric spectroscopy revealed Maxwell-Wagner-Sillars relaxation and a loading-dependent decrease of the permittivity at 80 degrees C and log omega approximate to 5.75 from epsilon ' approximate to 8.12 (PP) to approximate to 5.3-4.9 for composites. similar to 3 wt% SiC/PP provides an optimal compromise between dispersion, crystallinity, optical, and dielectric properties, making these nanocomposites promising for deep-UV-active insulating films and lightweight dielectric components.

This study explores how catalysts containing a low palladium loading (0.5 wt%) contribute to the selective hydrogenation of cinnamaldehyde. High specific surface area (SSA) mesoporous (2 wt%) TiO2 - SiO2 (UVM-7) materials were prepared by two different approaches: a one-step procedure, in which titania and silica precursors were added from the beginning to generate Ti2@UVM-7 support, and a two-step procedure, where TiO2 was deposited onto the UVM-7 silica surface via wet impregnation technique (Ti2/UVM-7). Both types of supports were decorated with Pd nanoparticles (NPs) through the deposition-precipitation technique. The obtained catalysts were thoroughly characterized by using different techniques, including XRD, N2 adsorption-desorption isotherms at liquid N2 temperature, ATR-FTIR, TEM-EDX, SEM-EDX, and XPS. Characterization data revealed that one-step procedure largely preserves the textural and structural properties of the support following the deposition-precipitation of the noble metal, whereas the two-step procedure slightly alters the UVM-7 morphology. Moreover, the preparation method of the supports impacts the Pd particle sizes and the metal-support interaction (MSI). The one-step procedure tends to promote the growth of larger Pd NPs, likely due to the TiO2 species being well embedded within the SiO2 matrix. In contrast, the two-step procedure yields well-dispersed Pd NPs smaller than 2 nm, due to the confinement of TiO2 nanodomains within the UVM-7 cavities, which enhances the MSI. Consequently, enhanced catalytic performance and stability were achieved with 0.5Pd/Ti2/UVM-7 (similar to 99% hydrocinnamaldehyde yield, TOF 4.81 s-1), due to the formation of very small Pd nanoparticles on the support that promote the MSI.

SrVO3 has long been considered a prototype for studying electronic correlations due to its simple electronic structure and coherent t2g quasiparticle band. However, the origin of the incoherent satellite at 1.5 eV binding energy seen in photoemission remains enigmatic, having been attributed to Hubbard physics, oxygen vacancies, or plasmonic coupling. Here, we investigate the t2g band and satellite feature in epitaxially strained thin films of SrVO3 using angle-resolved photoemission spectroscopy. We observe an increase in the quasiparticle effective mass due to tensile strain as a result of the narrowing of the corresponding bandwidth. While a low-energy kink at 60 meV indicates additional electron-phonon interactions, no strain-dependent behavior is detected. The increased effective mass coincides with a decrease in the plasma frequency from reported ellipsometry measurements and theoretical calculations. From this, we associate the plasma frequency with the quasiparticle-satellite energy separation that follows the same strain-induced changes. This consistency affirms the identification of the satellite feature as a replica band due to coherent coupling between quasiparticles and low-energy plasmons and emphasizes the role of dynamical screening as a key organizing principle in the electronic structure of correlated oxides.

Rapidly solidified Fe-Pd-Ga ferromagnetic shape memory ribbons, containing 1 and 3 at. % Ga, were obtained, and annealed at 950 degrees C for 15 and 30 min. Gallium substitution destabilizes the cubic lattice but preserves ferromagnetic order; thereby, it modifies phase stability and magnetic sensitivity. The combined effects of composition and heat treatment on microstructure, martensitic transformation temperatures, transformation heat, kinetics, and magnetic-field-induced transformation shift are presented. Magnetic sensitivity is evaluated using thermomagnetic and magneto-elastic measurements, being further validated through Clausius-Clapeyron analysis. Short-time heat treatment enhances structural relaxation and significantly increases the transformation heat, whereas prolonged annealing promotes grain growth and precipitate formation without suppressing thermoelastic behavior. Increasing Ga content results in a pronounced linear increase of the martensitic transformation temperature with magnetic field, from approximately 0.6 K T-1 for 1 at. % Ga to about 1.45 K T-1 for 3 at. % Ga. The good agreement between thermomagnetic measurements and Clausius-Clapeyron analysis confirms that the transformation shift is primarily governed by intrinsic thermodynamic parameters. The smaller magneto-elastic response indicates that microstructure limits strain expression. Therefore, functional control requires tuning the balance between intrinsic thermodynamic driving forces and microstructure-dependent magneto-elastic effects through composition and heat treatment. This enables the design of thermally adaptive and magnetically programmable materials, where 3 at. % Ga composition is suitable for active magnetic control and that of 1 at. % Ga is optimized for enhanced thermal stability and precision sensing.

Tungsten (W) is the preferred plasma-facing material (PFM) for European demonstration fusion power plant (EU-DEMO) divertor target. At plasma operative conditions, such as high temperatures, high heat fluxes (HHFs), particle fluxes, and neutron irradiation, W is subject to recrystallization and to embrittlement. A proper doping of W with Potassium (K) can help improve the PFM properties. Nano K-bubbles dispersed at the grain boundaries of W can increase mechanical resistance by hindering grain growth, ultimately leading to the suppression of recrystallization. Newly developed K-doped W laminates (KdWLs) materials were produced by the National Institute of Materials Physics (NIMPs) by means of the field-assisted sintering technique (FAST). At the Special Technologies Laboratories of ENEA Frascati (ENEA-TES), water-cooled ITER-like divertor target mock-ups equipped with KdWL monoblocks were fabricated. The KdWL monoblocks were joined to CuCrZr International Thermonuclear Experimental Reactor (ITER) grade (CuCrZr-IG) cooling pipes by hot radial pressing (HRP) with an oxygen-free copper (OFC, Cu) interlayer manufactured by casting. Nondestructive examination (NDE) by ultrasonic inspection has been performed to assess the quality of the fabrication process and to analyze the structural integrity of the KdWL mock-up after HHF tests. The recent research activity is evaluating whether KdWL can represent a potential candidate armor material for a future water-cooled EU-DEMO divertor target. A dedicated qualification activity of the KdWL divertor target design is currently ongoing, and a mock-up has been produced to withstand cyclic loading up to 2000 cycles at 20 MW/m(2). In this work, new KdWL monoblocks were obtained following the optimization of the fabrication process. These monoblocks have been used to fabricate two new divertor target mock-ups to be tested, respectively, at thermal fatigue and overload.

In this study, the effect of urea and asparagine as potential N-doping precursors was compared in both one-step (activation) and two-step processes (hydrothermal carbonization + activation) using natural fibers (Kapok) as a precursor. The resulting activated carbons (ACs) were characterized for surface functional groups (FTIR and XPS), specific surface area (SSA, m2/g) and surface morphology. A comprehensive analytical approach was used to assess the surface chemistry, nitrogen speciation, and porosity development of the materials. Respect to dopant selection, urea doped materials led to a better N incorporation and higher specific surface area than those with asparagine. AC-HTC-600-U exhibited higher SSA (approximately 350 m2/g) and N-pyridine and N-pyrrolic species compared to AC-HTC-800-U (approximately 150 m2/g), while AC-HTC-800 showed higher N-graphitic species. Discrepancies between XPS and elemental analysis suggested a heterogeneous N distribution, associated to the dopant decomposition mechanism. Furthermore, SSA decay between 600 degrees C and 800 degrees C may support the microstructure collapse, highlighting the importance of a deep DFT analysis of the pore structure. These findings underscore the importance of dopant selection and temperature control in tailoring nitrogen retention and pore development in biomass-derived carbons and provide process-carbon structure pathway for designing sustainable N-doped porous carbons for supercapacitor electrodes and related energy-storage applications.

Nowadays, paraprobiotics are considered a promising evolution of probiotics, due to their capacity to preserve or sometimes to enhance the functional properties of their counterpart probiotic viable cells. The present study investigates the production of heat-treated paraprobiotics derived from the selected probiotic Lacticaseibacillus rhamnosus MIUG BL38 strain. The paraprobiotics obtained after treatments at 82 degrees C for 5 min exhibited higher ABTS free radical scavenging activity (15.34 f 1.34%) compared to the untreated cells (10.62 f 3.18%). SEM analysis confirmed that L. rhamnosus MIUG BL38 cellular morphology was largely preserved at 74 degrees C treatment, while the temperature increase led to enhanced cell wall alterations. FT-IR results indicated the presence of specific functional groups of lipids, proteins, or carbohydrates, suggesting that structural modifications of these molecules may appear as a consequence of the cells exposure to increased temperature of 82 degrees C. Although the heat-treated paraprobiotics were characterized by changes within the cell wall molecules, their cell surface proteins (CSPs) maintained antimicrobial activity against potentially pathogenic E. coli and P. aeruginosa strains, highlighting that this property was preserved from the L. rhamnosus MIUG BL 38 strain. Further, the molecular modelling investigations focused on the SpaC pilus model of L. rhamnosus GG revealed that the thermal treatment at 82 degrees C resulted in vWFA domain loosening and important rearrangements of the arm-like structure, therefore suggesting the potential interference with mucin proteins recognition and binding. The obtained results revealed the suitability of the L. rhamnosus MIUG BL 38 strain to be used for obtaining paraprobiotics through heattreatment, with promising properties.

Capacitive energy storage is part of a promising energy harvesting and storage solution to power Internet of Things (IoT) sensors, overcoming the critical limitations of conventional supercapacitors and micro-batteries. Moreover, achieving high recoverable energy storage density (ESD) and high efficiency (eta) simultaneously is a key goal in energy storage, often requiring hybrid systems (e.g., combining batteries and supercapacitors) to balance the trade-offs. Here, we demonstrate a ultra-thin film capacitor with unprecedented high ESD that can be efficiently released at low operating voltage. This is achieved by using a novel heterostructure design combining ferroelectric La-doped HfO2 and a ferroelectric perovskite that is a relaxor induced by polar nanoregions, which enables a low hysteresis loss in the capacitor, thereby leading to an improved eta. Additionally, the relaxor ferroelectric layer thickness was optimized to give an optimum voltage drop to allow high maximum polarization and low remnant polarization, the former to allow an ESD of over 50 J/cm3, and the latter to allow & eng; to be maximized at similar to 95%. Therefore, our fluorite/perovskite heterostructure design and unique materials strategy have together provided a novel way to achieve unprecedented dielectric energy storage properties, proving a new route to electrostatic energy storage for autonomous IoT sensors.

Increasing environmental pollution has intensified the focus on sustainability, encouraging the development of eco-friendly materials. This study reports the synthesis of binary (ZnO-TiO2) and ternary (SnO2-ZnO-TiO2) compounds and their loading with Au/Ag/Pt/P noble metals (NMs) to enhance photodegradation efficiency under visible light compared to pristine TiO2. The compounds were synthesized in a single step via laser pyrolysis, and then noble metal deposition through chemical impregnation and reduction was performed. Structural and morphological analyses revealed TiO2-based nanoparticles with varied morphologies decorated with noble metal nanoparticles with sizes between 2 and 6 nm (for Pt and Pd). Photocatalytic tests demonstrated a significant improvement in Methyl Orange (MO) degradation under visible light, especially for Ag-loaded samples. The degradation rate increased from 1.03 & times; 10(-3) min(-1) (TZ) to 22.65 & times; 10(-3) min(-1) (TZS_Ag), while it was 0.09 & times; 10(-3) min(-1) for the commercial P25 sample. Biocompatibility assays indicated lower cytotoxicity than Degussa P25, with Au- and Pd-loaded samples showing improved compatibility with HaCaT and HEK293 cells. Overall, these findings demonstrate that the developed TiO2-based nanocomposites, designed through a novel and sustainable strategy combining binary/ternary heterostructures with noble metal loading, are promising candidates for efficient visible light-driven photocatalytic environmental decontamination with enhanced biological compatibility.