Scientific Papers in SCI

In this study, we have advanced the plasma-flash sintering (PFS) technique by demonstrating the preparation of dense ZnO ceramics at room temperature using a moderate electric field of 250 V cm-1 under a low-pressure nitrogen atmosphere. This specific environment facilitates the sequential occurrence of plasma generation followed by the flash sintering event. Compared to traditional flash sintering technique, our approach significantly reduces both energy consumption and processing time, while eliminating the need for a furnace. Impedance spectroscopy confirms that ZnO ceramic produced via this method exhibits enhanced electrical conductivity. Hence, PFS is shown to be a potential tool for tuning the electrical properties of sintered materials at room temperature while boosting energy efficiency.

In this study, the potential of a bimetallic Metal-Organic Framework Zn-MIL53(Fe) for electro-Fenton catalysis was evaluated. After the material characterisation, its catalytic activity was validated in Fenton reaction to degrade a model organic pollutant: Rhodamine B. After that, the evaluation of Zn-MIL53(Fe) as electro-Fenton catalyst was performed and improved outcomes were reached by electro-Fenton regarding anodic oxidation. Then, electro-Fenton treatment optimisation was carried out using response surface methodology assays considering different catalyst dosages (7.2-43.2 mg), current intensities (5-45 mA) and treatment time (30-90 min) in a volume of 0.1 L. Under optimal conditions, a degradation rate over 90 % for Fluoxetine and Sulfamethoxazole in synthetic wastewater was achieved within 90 min, using graphite sheet as anode and nickel foam as cathode (25 mA), with a catalyst dosage of 43.2 mg in a volume of 0.1 L. Additionally, its application in the pathogen inactivation was evaluated using different gram-negative and gram-positive bacteria. Complete eliminations of both types of bacteria were reached in 5 min using the optimal conditions. In the end, Zn-MIL53(Fe) was proven as a reusable material, capable of performing 3 complete cycles of electro-Fenton treatment for both types of pollutants bacteria and pharmaceuticals, which makes it a promising candidate for more efficient wastewater treatment applications which involve the Fenton reaction.

Fogging, icing, or frosting on optical lenses, optics/photonics, windshields, vehicle/airplane windows, and solar panel surfaces have often shown serious safety concerns with hazardous conditions and impaired sight. Various active techniques, such as resistive heating, and passive techniques, such as icephobic treatments, are widely employed for their prevention and elimination. However, these methods are not always suitable, effective, or efficient. This review provides a comprehensive overview of the fundamentals and recent advances of transparent thin-film surface acoustic wave (SAW) technologies on glass substrates for monitoring and prevention/elimination of fogging, frosting, and icing. Key challenges related to fogging and icing on glass substrates are discussed, along with fundamental mechanisms that establish thin-film SAWs as optimal solution for these issues. Various types of thin-film acoustic wave technologies are discussed, including recent wearable and flexible SAW devices integrated onto glass substrates for expanding future applications. The focus of this review is on the principles and strategies for hybrid or integrated de-fogging/de-icing and sensing/monitoring functions. Finally, critical issues and future outlooks for thin-film-based SAW technology on glass substrates in industry applications are presented

The presence of contaminants of emerging concern and antibiotic-resistant bacteria in aquatic environments is a major global challenge. Heterogeneous photo-Fenton-type treatments have proven effective; however, affordable and sustainable catalysts are needed to address real-world water treatment challenges. For the first time, we report the efficacy of a heterogeneous bimetallic Fe-Cu clinoptilolite catalyst, which can remove up to 29 contaminants of emerging concern (pharmaceuticals, metabolites, industrial products, herbicides and insecticides) at concentrations ranging from 6.38 to 2358 ng/L, and inactivate naturally occurring bacteria (Escherichia coli and total coliforms) from Guadaira River water (Spain) to the detection limit of 1 CFU/100 mL. Heterogeneous photo-Fenton (1 g/L of NZ-Fe-Cu catalyst, 2.9 mM H2O2 and visible light: 410-710 nm / 9 W/m2) was the selected method for treating real river water. The successful synthesis of the material was demonstrated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM/ EDX). DR-UV-Vis measurements allowed the estimation of the optical band gap, which was used to evaluate the photocatalytic performance of the bimetallic zeolite. X-ray photoelectron spectroscopy (XPS) allowed the determination of the charge of iron and copper cations in the zeolite. The photocatalytic mechanism of this new material was investigated, including hydroxyl radical detection, reusability, and stability (Fe-and Cu-leaching tests). Complete inactivation of antibiotic-resistant bacteria Pseudomonas aeruginosa and Staphilococcus aureus (initial concentration approximate to 106 CFU/mL) without further regrowth for 24 h was achieved. These results highlight the potential of this new catalyst for the decontamination and disinfection of river water, supporting its suitability for reclaimed water in agricultural irrigation and its promising applicability in broader wastewater treatment applications.

Leaching is a pretreatment that removes ionic species responsible for undesired reactions during biomass thermochemical transformation. Despite numerous reported leaching conditions, the impact of specific factors on ionic species removal remains insufficiently understood for widespread application. This study investigates the relationship between experimental factors and their optimal levels in aqueous medium, focusing on the effects of pH and acid type on rice husk and bio-silica's physicochemical and thermochemical properties. Optimal leaching conditions were identified as HCl at pH 1.5, 70 degrees C, 150 min, 1 g rice husk per 80 g H2O, and 30 rpm, yielding biosilica with 99.45 +/- 0.04 % purity, a surface area of 318 +/- 10 m2 g-1, and a pore volume of 0.46 +/- 0.01 cm3 g-1. Leaching enhances devolatilization during thermal decomposition but inhibits biochar oxidation. 29Si NMR analysis revealed 16.4 % Q3 and Q2 silanol groups in the bio-silica, while SEM-EDX confirmed its high purity and porosity. These results offer key insights into improving leaching methods, helping to produce better-quality biosilica, and supporting its use in eco-friendly industrial applications.

A novel and straightforward one-step method has been developed for the controlled deposition of gold nanoparticles (AuNPs) with uniform diameters onto the titanosilicate (TS-1) zeolitic surface via a direct anionic exchange (DAE) approach. This innovative process simultaneously introduces auxiliary mesoporosity into the zeolite framework, overcoming critical limitations associated with traditional microporous catalysts, including diffusion constraints and rapid deactivation. The resultant hierarchical Au/TS-1 catalyst demonstrates remarkable enhancements in catalytic performance for the liquid-phase propylene epoxidation with H2O2 coupled with outstanding stability, a challenge that has long hindered the application of such materials. With its exceptional catalytic properties and simplified preparation procedure, this system represents a significant advancement in catalyst design. The developed material shows great potential for industrial applications and paves the way for the creation of next-generation catalysts essential for sustainable development.

The utilization of nickel-ruthenium as bimetallic catalysts is widely recognized for its efficacy in enhancing the catalytic performance in the carbon dioxide methanation reaction. The present study focuses on the synergistic interplay between both active sites and their respective roles in the reaction mechanism through operando DRIFT-MS analysis. Findings reveal that the bimetallic catalyst is constituted by NiRu nanocrystallites with Ru atoms segregated at defect edge/corner sites, promoting the dissociation of carbon dioxide and the formation of CH x species. Furthermore, Ni atoms predominantly occupy facets or terrace sites, characterized by higher electron density conducive to carbon monoxide hydrogenation to methane. This research offers a comprehensive elucidation of the carbon dioxide methanation mechanism within a bimetallic system and underscores the efficacy of the operando methodology in advancing our fundamental understanding of heterogeneous catalysis.

The search for flexible piezoelectric materials to build adaptable sensors, electronics, and nanogenerators has become a key area of interest. The addition of piezoceramic particles to piezoelectric polymers, such as the copolymer poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE), is one of the strategies used to enhance the piezoelectric response. In this work, the effect of BaTiO3 content on the beta-phase formation, crystallization, and piezoelectric and dielectric properties of the polymer-based composites is investigated. High-energy ball milling was used as an effective, greener technique to achieve well-dispersed mixtures compared to those obtained using organic solvents. During the dispersion process, amorphization and reduction of the crystalline domain size occur. After compression molding and postprocessing, the crystallinity was recovered and was strongly dependent on the filler content. Although significant differences in the beta-phase fraction were not observed, conformational defects are induced with high BaTiO3 contents. The interlayer distances became smaller due to the presence of the ceramic particles after compression molding and remained almost unchanged after postprocessing. For the composites, the minimum voltage required to obtain a measurable piezoelectric coefficient (d 33 ) was significantly reduced compared to neat PVDF-TrFE, even for low contents, which is key for real applications. Three different piezoelectric behaviors were found depending on the BaTiO3 fraction. For composites with 40 vol %, where both matrix and filler contribute to the overall piezoelectric response, the use of a two-step poling method induced a synergistic effect with an increase in d 33 of similar to 180%. However, the relaxation of the ceramic contribution after 24 h returns the value of d 33 to that obtained by applying a one-step poling strategy.

This study proposes a fast and simple method for the in situ growth of metal-organic frameworks (MOFs) on metal oxide substrates as an alternative to the traditional approaches of using gold substrates and self-assembled monolayers (SAMs). As a case study, zeolitic imidazolate framework 8 (ZIF-8) crystals were grown in micro columnar TiO2 films through simple alternate and successive immersions of the TiO2 films into solutions containing the MOFs precursors. The growth process of the MOF crystals in the interstitial spaces between the TiO2 columns was investigated by varying the metal-to-ligand ratio (1:2, 1:4, and 1:8) and by employing modulating agents such as triethylamine. It was found that the optimal deposition of ZIF-8 occurred when using a higher excess of ligand and the addition of triethylamine after a controlled number of immersion cycles. These results were obtained by using glancing angle X-ray diffraction (GAXRD) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS) as characterization techniques. Additionally, a density functional theory (DFT) study as well as Fourier-transform infrared spectroscopy (FTIR) and GAXRD experiments were conducted to elucidate the nucleation process. It was concluded that the starting point is the formation of a covalent bond between the Zn cations and the TiO2 on the metal oxide surface after immersion of the film into a Zinc (II) nitrate solution, allowing for the formation of MOF nuclei once the film is subsequently immersed in the 2-methylimidazole solution. The results demonstrate the feasibility of in situ growth of MOF crystals onto metal oxide structures by a layer-by-layer strategy, offering a promising alternative to conventional methods.

In recent years, coffee waste by-products have been incorporated into polymer blends to reduce environmental pollution. In this study, coffee parchment (CP) was incorporated into biodegradable polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) polymer blends to prepare ribbons through the extrusion process. Extracted green coffee bean oil (CO) was used as a plasticizer, and CP was used as a filler with and without functionalization. A solution of chitosan nanoparticles (ChNp) as a coating was applied to the ribbons. For the raw material, proximal analysis of the CP showed cellulose and lignin contents of 53.09 +/- 3.42% and 23.60 +/- 1.74%, respectively. The morphology of the blends was observed via scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) showed an increase in the ribbons' thermal stability with the functionalization. The results of differential scanning calorimetry (DSC) revealed better miscibility for the functionalized samples. The mechanical properties showed that with CP incorporation into the blends and with the ChNp coating, the Young's modulus and the tensile strength decreased with no significant changes in the elongation at break. This work highlights the potential of reusing different by-products from the coffee industry, such as coffee oil from green beans and coffee parchment as a filler, and incorporating them into PLA PBAT biodegradable polymer blend ribbons with a nanostructured antimicrobial coating based on chitosan for future applications in food packaging.

Metal-organic frameworks (MOFs) have recently been proposed as a plausible solution to the pressing issue of water scarcity and as a means of remediating contaminated water bodies. In light-assisted water treatment, they have so far only been exploited via the hydroxyl radical route, through Fenton-like processes. A new avenue is introduced here by the biomimetic conceptual design of MOF bearing hypervalent metal atoms for photocatalytic water treatment. We report a zeolitic imidazole framework (ZIF) material doped with iron (Fe-ZIF-7-III; UPO-4) synthesized via a novel mild treatment to stabilize photoactive hypervalent ferryl ions for the first time in a MOF for water treatment. The successful synthesis of the 2D material and the adequate incorporation of iron into the structure were demonstrated using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). A simulation study analyzed the structure and stability of the Fe-ZIF-7-III material as well as the involvement of ferryl ions in the photo-Fenton-type process. Furthermore, the calculated band gap of this material shows its viability for use in photocatalysis using sunlight. This was confirmed by evaluating the photodegradation of caffeine, a model pollutant in water, without the assistance of hydroxyl radicals as indicated by a scavenger test. The recyclability test revealed that Fe-ZIF-7-III could be used continuously with effective catalytic activity, thus opening the door to the field of studying hypervalent metal MOFs not yet explored in water treatment.

Interface engineering using self-assembled 2D perovskite interfaces is a consolidated route to efficient and durable perovskite solar cells. Whether the 2D perovskite forms a homogeneous conformal layer or is heterogeneously distributed on the surface, interface defects are passivated, leading to a general improvement in the device's open circuit voltage (VOC) and stability. Here, an innovative strategy is developed for manipulating the composition of the 2D/3D perovskite interface that results in the formation of a gradient halide distribution, which extends from the surface to the bulk. The use of a bromide-based 2D perovskite triggers a progressive Br/I exchange, affecting not only the surface but also the perovskite underneath. As a result, not only the device VOC improve, as expected, but also the photogenerated current is boosted, leading to a device efficiency of up to 24.4%. Such mixed halide gradient effectively passivates surface and bulk defects making the perovskite active layer more efficient and robust, as demonstrated by the superior device stability showing zero losses in performances upon 36 days (more than 800 h) test in outdoor conditions, those ones relevant for a marketable product.

The synthesis of carbodiimides via nitrene transfer to isocyanides has garnered significant attention in recent years. However, this reaction predominantly relies on homogeneous catalytic systems with high catalyst loadings. In this study, we employed ZIF-67 MOF as a heterogeneous catalyst for carbodiimide synthesis and conducted an in-depth analysis of its stability. Our findings reveal the non-innocent role of catalyst leaching, demonstrating that even as little as 0.04 mol% of leached cobalt species is sufficient to catalyze this reaction. This result is in contrast with previous reports, where 5-10 mol% of homogeneous cobalt-loading is required. Furthermore, this study highlights that lower catalyst loadings are more efficient, particularly in cases where isocyanides exhibit limited stability.

He-3 targets are a valuable tool in nuclear physics, particularly for studying nuclear structure and dynamics via direct reactions in inverse kinematics. However, they are often prone to degradation under intense beam irradiation and have insufficient He-3 content for use with lowintensity exotic beams. In a recent AGATA experiment at LNL, designed to study the astrophysically relevant lifetime of a O-15 excited state, two types of He-3 targets were tested. One was produced using ion implantation and the other with a novel magnetron sputtering technique, in both cases on Au substrates. Following irradiation with a stable O-16 beam, they were characterized using Nuclear Reaction Analysis (NRA) and Elastic Recoil Detection Analysis (ERDA). Results demonstrated that, under the here used fabrication conditions, sputtered targets present a higher He-3 content, while implanted ones exhibit thinner profiles. This highlights the possibilities and complementarity of these targets, suggesting their tailored use for future experimental campaigns.

Rice husk ash (RHA) was employed as a silica source to produce an alternative sodium silicate solution through the dissolution of varying quantities of RHA in an 8 M NaOH solution. The solution was employed in the production of alkali-activated cements based on electric arc furnace slag (EAFS). Solutions were prepared with varying activator modules (Ms, molar ratio SiO2/Na2O) of 0.60, 0.85, 1.00, and 1.15. As control samples, slags were activated with 8 M NaOH (Ms = 0.0) and with 8 M NaOH in conjunction with commercial sodium silicate (Ms = 1.0). Mechanical, physical, mineralogical (XRD, FTIR), and microstructural (SEM/EDS) tests were conducted to characterize the obtained pastes. The results of the FTIR and SEM analyses indicated that the SiO2/Na2O ratio exerts a significant influence on the reaction products formed. At Ms values higher than 0.85, the predominant reaction product was observed to be a more cross-linked hybrid gel (N,C)-A-S-H. Lower modules resulted in the predominant formation of C-A-S-H gel and a more porous structure with lower mechanical properties. Pastes activated with the alternative RHA solution and Ms = 1.0 exhibited a composition, microstructure, and strength that was similar to or superior to those prepared with conventional commercial activators.

Access to clean water is crucial for human health, yet microbial contamination poses significant challenges. This study investigates the effectiveness of novel photocatalytic catalysts: heterostructured TiO₂/AgBr and faceted titanium dioxide, for microbial inactivation under ultraviolet and visible light. Both catalysts were synthesized and characterized. Performance was evaluated using real wastewater samples and saline solutions, targeting gram-positive and gram-negative bacteria. The experimental approach included testing the photocatalysts with and without the addition of peroxydisulfate to assess its impact on inactivation effectiveness. Results indicated that the TiO₂/AgBr catalyst outperformed the faceted titanium dioxide one due to its superior visible light absorption and enhanced charge separation, achieving complete inactivation of environmental strains of Escherichia coli and significant inactivation for Enterococcus faecalis in real wastewater. The inclusion of peroxodisulfate with TiO₂/AgBr significantly improved inactivation rates, demonstrating a synergistic effect. Regarding wastewater composition, the treatment achieves a significant COD removal while the rest of studied parameters remain stable. Both catalysts effectively prevented bacterial regrowth for up to 48 hours, underscoring its long-term efficacy. Overall, these findings highlight the potential application of TiO₂/AgBr combined with peroxodisulfate as an effective strategy for microbial inactivation, contributing to the advancement in water treatment technologies across real environmental contexts.

Polylactide-based materials represent a promising bio-based alternative to traditional food packaging polymers. However, their widespread use is still limited due to significant drawbacks, such as brittleness, high gas permeability, and biodegradability only under specific conditions. This work introduces fully bio-based Triphenyl Acetic Glyceroate (TPAG), synthesized through a solvent-free and mild conditions valorization of glycerol and phenylacetic acid, as a polylactide (PLA) plasticizer and multiple property-enhancer for extending foodstuff shelf-life. After optimizing TPAG synthesis and confirming its structure through FT-IR and NMR, PLA-based films are prepared at different TPAG contents (0, 5, 10, and 20 phr). Detailed investigations of the films' thermal, mechanical, optical, hydrodynamic, barrier, antioxidant, antibacterial, migration, and biodegradation characteristics are carried out. TPAG shows a significant plasticizing effect while maintaining high transparency and improving PLA's antioxidant, antibacterial and UV-blocking activities. Moreover, a notable lowering in oxygen and water vapor transmission rate is detected, revealing water vapor barrier properties closer to LDPE. Migration tests verify the material's compliance with European regulations up to 10 phr, and BOD assessments in seawater indicate improved biodegradability. Fresh food preservation is evaluated on pear slices, showing limited variation of color, acidity, antioxidant power, and weight loss comparable to LDPE-based commercial packaging.

Gel polymer electrolytes (GPEs) are regarded as a promising alternative to conventional electrolytes, combining the advantages of solid and liquid electrolytes. Leveraging the abundance and eco-friendliness of cellulose-based materials, GPEs were produced using methyl cellulose and incorporating various doping agents, either an ionic liquid (1-Butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [Pyr14][TFSI]), its polymeric ionic liquid analogue (Poly(diallyldimethylammonium bis(trifluoromethylsulfonyl)imide) [PDADMA][TFSI]), or an anionically charged backbone polymeric ionic liquid (lithium poly[(4-styrenesulfonyl)(trifluoromethyl(S-trifluoromethylsulfonylimino) sulfonyl) imide] LiP[STFSI]). The ion dynamics and molecular interactions within the GPEs were thoroughly analyzed using Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), Heteronuclear Overhauser Enhancement Spectroscopy (HOESY), and Pulsed-Field Gradient Nuclear Magnetic Resonance Diffusion (PFG-NMR). Li+ transference numbers (tLi+) were successfully calculated. Our study found that by combining slow-diffusing polymeric ionic liquids (PILs) with fast-diffusing lithium salt, we were able to achieve transference numbers comparable to those of liquid electrolytes, especially with the anionic PIL, LiP[STFSI]. This research highlights the influence of the polymer ' s nature on lithium-ion transport within GPEs. Additionally, micro supercapacitor (MSC) devices assembled with these GPEs exhibited capacitive behavior. These findings suggest that further optimization of GPE composition could significantly improve their performance, thereby positioning them for application in sustainable and efficient energy storage systems.

The influence of the characteristic features and firing temperature on the ceramic properties of raw kaolin samples were examined studying a wide range of firing temperatures (1000–1500 ºC). The techniques of investigation have been particle size analysis, Transmission Electron Microscopy (TEM), X-ray powder Diffraction (XRD), X-ray Fluorescence analysis (XRF), and Thermal Analysis using Termodilatometry (TD), Thermalgravimetric analysis (TGA) and Differential Thermal Analysis (DTA). Uniaxial pressed cylindric bodies were obtained and fired from 1000 to 1500 °C/2 h. TEM allowed investigate morphological differences and identification of kaolinite and halloysite. The mineralogical analysis indicated that the kaolinite content is high (80–90 wt%). The contents of oxide impurities are relatively low although in a sample is 7.6 wt% on a calcined basis. The characteristic sharp DTA exothermic effect of kaolinite was observed in the range 900–1000 °C. The ceramic properties of the group of kaolin samples has been determined: linear firing shrinkage, water absorption capacity, apparent density and open porosity. Sintering diagrams allowed investigate the progressive decrease of water absorption and the increase of firing shrinkage. In some kaolin samples the water absorption reached zero at 1450–1500 ^ᵒC. High sintering temperatures have been observed when kaolinite is present in high contents and the fluxes content is low. The maximum values of apparent density were determined, with a sample with the highest value (2.75 ± 0.10 g/cm³). The open porosity changes from ∼ 34–38 % at 1000 ᵒC up to zero or minimum values (< 3 %) at 1500 ^ᵒC. This behaviour is associated to the progressive sintering of the particles and filling of pores by glassy phase originated by the presence of fluxes and the influence of a low particle size. The formation of mullite and cristobalite by firing have been studied by XRD. Mullite has been detected from 1000 to 1100 ᵒC and the crystals developed as increasing firing temperatures. Cristobalite (α-cristobalite) has been identified at 1200–1300 ºC. The presence of an alkaline melt could impede the crystallization of cristobalite. This study presents a comparative research because all these commercial kaolin samples have been examined under the same experimental conditions. Consequently, the results have allowed to provide new data about raw kaolin powders with high kaolinite content in the range 80–90 wt%.

Stability descriptors for the formation of solid solutions can be divided into two categories: inspired by Hume–Rothery rules (HRR) and derived from thermodynamic approaches. Herein, HRRs are extended from binary to high-entropy alloys (HEAs) focusing on compositions prepared by ball milling. Parameters describing stability criteria are interrelated and implicitly account for the microstrains’ storage energy, more determinant than entropy increase in stabilization of HEAs and more effective in bcc structures than close-packed ones (fcc and hcp). An effective temperature, T_eff, is defined as the ratio between increase in metallic bonding energy of solid solutions with respect to segregated pure constituents and configurational entropy. This versatile parameter is used as a threshold for stabilization of HEAs at equilibrium and out of equilibrium. When T_eff is below room temperature, HEA would be stable at equilibrium. When T_eff is below melting temperature, HEA would be obtained by rapid quenching. Limitations related to electronegativity differences remain valid in mechanically alloyed solid solutions. However, ball milling broadens the allowed differences in atomic size to form HEA. Moreover, thermodynamic criteria can be surpassed in these systems, allowing the formation of single-phase solid solutions beyond the compositional range predicted by those criteria.

Direct upgrading of biogas by CO2 methanation aims to produce a gas to be injected into the grid. Operating at moderate pressures favors thermodynamics, but catalyst surface and reaction mechanism under realistic conditions are not well investigated. We study the role of basic and metallic sites on performance and mechanism of clean biogas methanation (CO2/CH4=1/1 v/v) at 1, 5 and 7 bar. Ni/Mg/La/Al hydrotalcite-derived catalysts, with different Ni and La contents, are investigated combining tests and physico-chemical characterization, including quasi-in situ XPS at 7 bar, with CO2-adsorption and methanation DRIFTS at 1 and 7 bar, respectively. An optimized catalyst (6.5 wt% La, 35 wt% Ni) with 3-4 nm Ni0 and balanced basicity, achieves 96 LCH4*gcat- 1* h- 1 (300 degrees C, 7 bar). DRIFTS confirm catalysts activity experimental trend. Optimizing Ni and La results in higher consumption rates of formate intermediate and sufficient Ni0 sites for CO formation. Increasing pressure to 7 bar promotes CO and m-HCOO reactivity.

Globalisation has brought numerous benefits regarding the cost-effective transportation of goods. Still, the shipping industry faces challenges such as corrosion, biofouling, and restrictions on heavy pollutant products used in paintings. This study proposes a solution using a multifunctional coating based on zirconium nitride and copper nano-structured coating, applying high-power impulse and direct current magnetron sputtering processes (i.e., HiPIMS and DCMS, respectively). The coating's morphological, structural, and chemical features were analysed using advanced characterisation techniques (SEM, EDX, STEM, SAED and EELS). Potentiodynamic polarisation (PP) and Electrochemical Impedance Spectroscopy (EIS - up to 30 days) were employed to study the corrosion resistance in saline solution (3.5 wt. % NaCl). Besides, activated ZrN-Cu exhibited a corrosion rate decrease from similar to 354 x 10(-4) to 52 x 10(-4) mm/yr when compared to its inactivated counterpart. Besides, a similar to 3.5-fold impedance increasing was exhibited by activated ZrN-Cu after 30 days of exposure to saline solution, meaning an increase in corrosion resistance compared to the non-activated ZrN-Cu. SEM micrographs revealed that the copper diffusion in ZrN-Cu can be provoked by a strong oxidising agent (NaOCl) or by an electrical potential. Based on the chartered evidence, a diffusion mechanism is proposed for the biocidal release (Cu) in the obtained ZrN-Cu films. The present study depicts a solution that offers a controlled biocide release and corrosion resistance, opening the possibility of its application in the maritime industry.

CO₂ hydrogenation with green hydrogen is a practical approach for the reduction of CO₂ emissions and the generation of high-value-added chemicals. Generally, product selectivity is affected by the associated reaction mechanisms, internal catalyst identity and structure, and external reaction conditions. Here we examine typical CO₂ hydrogenation reaction pathways, which can provide insight useful for the atomic-level design of catalysts. We discuss how catalyst chemical states, particle sizes, crystal facets, synergistic effects and unique structures can tune product selectivity. Different catalysts, such as Fe-, Co-, Ni-, Cu-, Ru-, Rh-, Pd-based and bifunctional structured catalysts, and their influence on CO₂ hydrogenation products (such as CO, methane, methanol, ethanol and light olefins) are discussed. Beyond catalyst design, emerging catalytic reaction engineering methods for assisting the tuning of product selectivity are also discussed. Future challenges and perspectives in this field are explored to inspire the design of next-generation selective CO₂ hydrogenation processes to facilitate the transition towards carbon neutrality.

In this paper, we investigate the Casimir-Lifshitz free energy mechanism that governs both ice growth and melting near metal surfaces, with a particular focus on the role of oxidation. Our study reveals that metals such as gold, iron, and aluminum induce incomplete premelting, resulting in micron-sized liquid water layers when in contact with ice. These layers could have significant implications for the defrosting of metallic surfaces. When exposed to water vapor at the triple point, aluminum and other metals can induce the formation of notably thick layers of either liquid water or ice, which can theoretically become infinitely thick if other interactions are disregarded. However, when aluminum undergoes oxidation to form alumina, its behavior changes dramatically. Alumina surfaces cause complete melting when in direct contact with bulk ice and result in only micron-sized layers of water or ice in vapor conditions. In contrast, magnetite, the oxidized form of iron, retains metalliclike behavior due to its high dielectric constant, similar to other metals, and continues to support thick layers of water or ice. This distinction highlights the significant influence of oxidation on the dynamics of ice growth and melting near different metal surfaces.

Plasma treatment of seeds is an efficient procedure to accelerate germination, to improve initial stages of plant growth, and for protection against pathogen infection. Most studies relate these beneficial effects with biochemical modifications affecting the metabolism and genetic growth factors of seeds and young plants. Using barley seeds, in this work, we investigate the redistribution of ions in the seed surface upon their treatment with cold air plasmas. In addition, we investigate the effect of plasma in the lixiviation of ions through the seeds' hull when they are immersed in water. Ion redistribution in the outer layers of air plasma-treated seeds has been experimentally determined through X-ray photoelectron spectroscopy analysis in combination with in-depth chemical profiling with gas cluster ion beams. The results show that in the shallowest layers of the seed hull (at least up to a depth of similar to 100 nm) there is an enrichment of K+ and Ca2+ ions, in addition to changes in the O/C and N/C atomic ratios. These data have been confirmed by the electron microscopy/fluorescence analysis of seed cuts. Observations have been accounted for by a Monte Carlo model, simulating the electrostatic interactions that develop between the negative charge accumulated at the seed surface due to the interaction with the plasma sheath and the positive ions existing in the interior. Furthermore, it is shown that upon water immersion of plasma-treated seeds mobilized ions tend to lixiviate more efficiently than in pristine seeds. The detection of a significant concentration of NO3 - anions in the water has been attributed to a secondary reaction of nitrogen species incorporated into the seeds during plasma exposure with reactive oxygen species formed on their surface during this treatment. The implications of these findings for the improvement of the germination capacity of seeds are discussed.

One of the biggest players in the world economy is the naval industry, which mainly controls the merchandise transportation sector. Any issue with ships could represent millions of USD of loss and increases in the cost of goods for the population worldwide. Two main problems which this industry has fought are corrosion and biofouling. Lastly, the pollution of the sea has gained importance, and more strict policies have been applied regarding the use of certain products by this industry. One of these is paintings, which represented this industry's definitive solution to avoid the mentioned problems for a long time. This situation allowed to explore other solutions like PVD coatings through multifunctional coatings. Zirconium nitride has been demonstrated to be useful in resisting corrosion with reliable mechanical properties. However, this material does not possess antimicrobial action. The present study presents a nanostructured coating combining ZrN with Cu, which works as a biocide, contributing to the desired multifunctionality. The developed coating was obtained using a hybrid magnetron co-sputtering employing High-power impulse (HiPIMS) and direct current (DCMS) power sources under a reactive atmosphere. SEM, EDX, XRD and Raman spectroscopy were used to assess the physico-chemical properties of the coatings. Besides, depth-sensing nano-indentation explored the mechanical properties. The tribological performance was tested by a reciprocating tribometer under dry and wet (with 3.5 % w/w NaCl solution) contact conditions and employing a soda lime glass ball as a counterbody. The results showed that adding Cu to ZrN through this technology resulted in a limited hardness reduction from 19 (pure ZrN) to 14 GPa. Also, the chemical activation with NaOCl solution softens the obtained coating and, together with the saline solution, influences the wear resistance. However, the nanostructured coating has been demonstrated to be suitable for use under real conditions, without loss of its protection over the used substrate. It opens a new possibility of a solution for the naval industry.

Calcium Looping has recently attracted attention as a high temperature thermochemical energy storage system. However, significant sintering due to the high temperatures hampers the recyclability of CaO. Hydration and hydroxylation has been explored as a method to regenerate the spent CaO. This study investigates a novel synergistic integration of carbonation (CaCO3/CaO) and hydroxylation (CaO/Ca(OH)2) reactions. Calcination was conducted in N2 and N2/H2O mixtures with 29 % steam content. Carbonation was conducted in CO2/H2O mixture with similar steam concentrations. Results show that steam plays a dual role: during calcination, it promotes the formation of large pores on the CaO surface, and during carbonation, it enhances mineralization, resulting in larger CaCO3 grains. Also, steam promotes CO2 diffusion through the CaCO3 layer and, at the same time, significantly mitigates the deactivation of CaO along the cycles. Specifically, sequential calcination/ carbonation cycles without steam yield a residual conversion value of 0.14. Steam injection improved residual conversion to 0.27. Alternatively, the interleaving of hydroxylation/dehydroxylation cycles in the sequence further increased this value to 0.64 without steam and up to 0.76 with steam injection. Hydroxylation/dehydroxylation cycles alone demonstrated high stability, with a residual conversion of 0.98 when interleaved with calcination/carbonation cycles under 29 % steam conditions. Additionally, frequent hydroxylation/dehydroxylation cycles improve overall conversion stability, highlighting their synergistic benefits within the integrated process. This work underscores the potential of integrating Calcium Looping with Calcium Hydroxide for improved multicycle performance and opens pathways for scaling experiments to pilot systems, alongside assessing the efficiency and economic viability of this integrated approach.

This work presents the surface modification of commercially pure Ti specimens (c.p.-Ti) prepared by conventional powder metallurgy by depositing a thin film of a ß-Ti alloy (Ti-35Nb-7Zr-5Ta, wt. %, TNZT). Two types of pulsed technologies: conventional (p-DC) and high-power impulse magnetron sputtering (HiPIMS), with and without bias assistance (−60 V) under similar power conditions (250 W) were applied on titanium specimens and silicon substrates leading to different film morphologies and functional properties. Microstructural, X-ray diffraction, nanoindentation, surface wetting, XPS and electrochemical impedance measurements were done to characterize their functionality. All the coatings presented a reduced Young's Modulus (E ≤ 80GPa) compared to the bulk Ti, representing a reduction of more than 30 %. This decrease can significantly contribute to the reduction of the stress-shielding effect, mitigating the risk of implant loosening and failure. The hardness values of TNZT coatings, slightly lower than c.p.-Ti substrate, range from 4.1 to 4.7 GPa. XPS analysis shows a passivation layer of TiO₂, Nb₂O₅, and ZrO₂, which offers high impedance and excellent corrosion resistance. The best compromise between mechanical and corrosion properties is achieved with the HiPIMS technology, thanks to its compact film microstructure with high electrical resistance, despite its limited thickness of about 1 μm. 

In contemporary catalytic interface exploration, experimental studies often take a backseat to theoretical simulations, hindering the development of pristine catalytic interfaces. This research leverages monolayer dispersion theory to design an efficient CO oxidation catalyst through precise manipulation of non-precious metal NiO-CeO2 interfaces. Employing the pioneering XRD extrapolation method, we fabricated monolayer dispersed Ni-O-Ce and Ce-O-Ni interfaces, unlocking insights into their impact on the CO oxidation mechanism. The method accurately quantified monolayer dispersion capacities: 0.526 mmol NiO/(100 m2 CeO2) for NiO/CeO2 and 0.0638 mmol CeO2/(100 m2 NiO) for CeO2/NiO, revealing intricate interactions between active components and supports. Utilizing numerical values derived from monolayer dispersion theory, we constructed CeO2-sup- ported NiO (Ni-O-Ce) and NiO-supported CeO2 (Ce-O-Ni) catalysts in a monolayer dispersed state. The Ni-O-Ce interface, generating abundant oxygen vacancies, significantly enhanced CO adsorption and facilitated surface reactive oxygen species production, leading to a remarkable 14-fold increase in intrinsic CO oxidation activity and a notable 4.2-fold improvement in water resistance. Integrating XRD extrapolation, H2-TPR, O2-TPD, COTPD, XPS, Raman, and in situ IR techniques, our study demonstrates the feasibility of crafting efficient catalysts with monolayer dispersed atomic-scale catalytic interfaces to elucidate the mechanisms underlying catalytic interface effects on CO oxidation.