Scientific Papers in SCI

Poly(lactic acid) (PLA) is a bio-based polymer with high potential; however, its inherent brittleness restricts its practical applications. This work evaluates ethylene brassylate (EB), a macrocyclic diester of natural origin, as a plasticizer for PLA at 5–20 wt%. Thermal analysis confirmed a plasticizing effect, with the glass transition temperature decreasing from 59.9 °C in neat PLA to 38.0 °C in PLA-20 EB. Mechanical tests showed that 20 wt% EB increased elongation at break from 10 % (neat PLA) to over 460 % and improved impact resistance by ∼70 %. Furthermore, moisture resistance was preserved, and microscopy confirmed good miscibility with no phase separation. Under composting, degradation occurs more rapidly in proportion to EB content, reaching ∼90 % mass loss after four weeks. Migration tests revealed values below 40 mg kg⁻¹ for PLA-EB < 10 wt% EB, whereas PLA-15 EB reached the regulatory limit. EB is therefore an efficient bio-based plasticizer for PLA, offering enhanced ductility, toughness, and biodegradation, with promising applications in sustainable packaging, especially for refrigerated and cold-chain storage. © 2025 The Authors

Metal halide perovskite solar cells (MHPSCs) hold great promise due to their high efficiency and low fabrication costs, but their long-term stability under environmental conditions remains the main challenge. However, their long-term operational stability under environmental stress remains a critical limitation for commercialization. In this work, we explore a dual passivation strategy using ultrathin adamantane-based plasma polymer (ADA) films, deposited via remote plasma-assisted vacuum deposition (RPAVD), to enhance the environmental stability of MHPSCs. The ADA layers are introduced simultaneously at both the electron transport layer (ETL)/perovskite and perovskite/hole transport layer (HTL) interfaces, offering a conformal, transparent, and thermally stable coating compatible with delicate perovskite films. This approach enables interfacial defect passivation and acts as a protective barrier against moisture and UV-induced degradation. Devices incorporating ADA layers exhibit significantly improved stability under harsh conditions, retaining 80 % of their initial efficiency after 4000 min over extended exposure to humidity and continuous illumination. These results demonstrate the potential of multifunctional plasma-polymer coatings for the scalable and robust fabrication of perovskite solar cells with enhanced durability.

This research illustrates the efficacy of hydrothermal carbonization (HTC) as a pretreatment method to improve the pyrolytic performance of wood-derived lignin-rich lignocellulosic biomass (LB), supported by thorough characterization of its derived products such as syngas, tar, and biochar. A systematic comparison of non-HTC-treated LB and HTC-treated LB through their respective pyrolytic-derived biochar (NLB, HLB) obtained across temperatures (400-1000 degrees C) revealed their basic structural and reactivity variations. HTC resulted in a new carbonyl peak with a 28 % increase in CO concentration in derived biochar, with partial aromatization evidenced by CC bonds at 1509 cm(-)(1) . Spectroscopic analysis confirmed that HTC promoted a defective carbon structure in derived biochar while enhancing its crystallinity and maintaining its integrity even at higher temperatures. XPS analysis demonstrated that at 1000 degrees C, HLB-T-10 retained active oxygen functionalities, while its associated pyrolytic products H-2 and CO boosted from 22.45 % to 40.4 % and 32.3-33.4 %, respectively, with drastically lowered CO2 emissions from 39.95 % to 11.5 %. Regulated deoxygenation routes cause tar composition to shift toward desirable aromatic chemicals. This comprehensive strategy offers a sustainable valorization technique that increases syngas generation efficiency, lowers emissions, and optimizes biorefinery product selection.

Halide perovskite solar cells (PSCs) offer high efficiency at low production costs, making them a promising solution for future photovoltaic technologies. Optimizing charge transport layers is crucial, with porous TiO2 widely used as electron transport layers (ETLs) due to their suitable energy band alignment, transparency, and abundance. However, their performance depends strongly on crystallinity, requiring high-temperature processing (>450 degrees C), which increases costs and limits their applicability on flexible substrates. Low-temperature wet-chemical methods face scalability issues due to material waste and hazardous solvents. Therefore, plasma-based technologies provide a scalable, eco-friendly alternative for fabricating oxide-based ETLs. This study presents a plasma-based synthesis of TiO2 layers using remote plasma-assisted vacuum deposition (RPAVD) and soft plasma etching (SPE) at temperatures below 200 degrees C, enabling precise control over microstructure and porosity. The resulting nanocolumnar and aerogel-like TiO2 films are antireflective and enhance optical and electronic properties, leading to improved PSC efficiency (champion PCE = 14.6%) comparable to high-temperature processed devices. The devices are based on a 3D organometal perovskite with mixed cations (MA, FA, Cs, Rb) and halides (I, Br), with a nominal composition of (Rb(0.03)Cs(0.03)FA(0.69)MA(0.25))(PbI3)(0.83)(PbBr3)(0.17). Our results highlight the potential of RPAVD+SPE for producing low-temperature ETLs, offering a feasible, industrially scalable solution for flexible, high-performance photovoltaics.

Natural zeolites can be used to obtain effective catalysts for heterogeneous photocatalytic reactions due to their low cost and favorable physicochemical properties for water treatment. In this work, a natural clinoptilolite is modified by incorporating iron (NZ-Fe) and copper (NZ-Cu) as compensation cations through ion exchange processes. Metals incorporation and structural stability are demonstrated through X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. DR-UV-Vis measurements are used to estimate the bandgap and predict the photocatalytic performance of both materials. Their effectiviness in heterogeneous photocatalytic systems is confirmed by evaluating the inactivation of E. coli as a model pathogen in water. The bacterial detection limit (initial approximate to 106 CFU/mL) is reached using 1 gL-1 of both catalysts, 100 ppm of H2O2 under visible light (410-710 nm) and near neutral pH in 2 h, with no post-treatment regrowth observed. Experimental data are analyzed according to the Chick-Watson, Weibull, and Hom disinfection kinetic models. Although more hydroxyl radicals are generated (trapping tests) and less iron leachate is observed for NZ-Fe, good reusability is attained for three disinfection cycles when NZ-Cu is used. This makes copper-exchanged clinoptilolite a suitable and low-cost photocatalyst for water disinfection through heterogeneous photo-Fenton-type processes.

The pressing demand for sustainable alternatives to fossil fuels coupled with environmental risks associated with inappropriate sewage sludge (SS) disposal calls for innovative valorization strategies that transform waste into value-added products. This study introduces a novel approach by directly incorporating zeolite catalysts (HZSM-5 and USY) into the hydrothermal carbonization (HTC) of SS, followed by pyrolysis (Py) of the derived hydrochar (HC). Insights into derived HC are explored through comprehensive characterization, such as morphology, crystallinity, functionality, and thermal analysis. HZSM-5 significantly reduced the activation energy of HC from 27 to 5.5 kJ mol-1, while increasing the structural disorder (ID/IG0.73). The selective production of CO and H2 was achieved through temperature-dependent pyrolysis between 500 and 900 degrees C. HZSM-5 facilitated an increase in CO production to 54.18%, whereas USY boosted CO yield up to 35.6%. The optimal product distribution was achieved by strategically incorporating zeolite catalysts, allowing for precise control of N and O functionality and promoting selective syngas and chemical precursors yield. This innovative catalyst-mediated HTC-Py cascade offers unique control over pyrolytic products by introducing an efficient pathway for transforming problematic SS into green energy carriers, thus bridging the gap between environmental sustainability and feasible industrial utilization.

The integration of biochars into photocatalytic systems to increase their efficiency in the degradation of different pollutants in water has gained attention in recent years. However, systematic studies on optimizing biochar properties for photocatalysis remain limited. This work explores the incorporation of biochar from olive pruning (BCO), produced via CO₂ pyrolysis at 800 °C, into WO₃/AgBr photocatalysts for Rhodamine B degradation used as a model pollutant. Characterization of BCO reveals a hydrophilic, porous material (487 m²/g surface area) rich in mineral content (notably CaCO₃). The study evaluates the effects of incorporation method (mechanical vs. in situ) and biochar content (1 and 10 wt. %) on photocatalytic performance. Comprehensive characterization of BCO and the resulting composites supports the observed activity trends. The findings highlight the potential of agricultural waste valorization for environmental remediation and offer insights into designing efficient biochar-based photocatalytic systems.

Liquid-phase exfoliation (LPE) is a versatile and scalable method for producing high-quality two-dimensional materials (2DMs). However, commonly used solvents such as dimethylformamide (DMF) or N-methyl-2-pyrrolidone (NMP) are highly toxic, limiting their potential for large-scale industrial applications. In this study, we address this challenge using Cyrene (dihydrolevoglucosenone), a nontoxic and biodegradable solvent, for the exfoliation of several materials, including graphene, MoS₂, WS₂, MoO₃, V₂O₅, and hBN (hexagonal boron nitride). Exfoliation was carried out using low-powered bath sonication, a cost effective and energy efficient method and optimization was conducted to maximize the final concentration of exfoliated material. To assess the potential of Cyrene for LPE, extensive characterization and comparison of the produced 2DMs with their precursors was performed. The highest ink concentrations were observed for MoS₂ (2.6 mg mL⁻¹), followed by hBN (2.3 mg mL⁻¹) and V₂O₅ (1.9 mg mL⁻¹), demonstrating the ability of Cyrene to effectively stabilize a variety of 2D materials in dispersion. Structural and morphological properties of the exfoliated materials were characterized using X-ray diffraction (XRD), Raman spectroscopy, UV-vis spectroscopy, scanning electron microscopy (SEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). XRD patterns mainly showed only one reflection revealing the oriented nature of the materials, with significant broadening of the full width at half maximum (FWHM) compared to the original materials. Also, Raman spectroscopy spectra for graphene showed ratios characteristic of multi-layered structures and SEM imaging revealed a broad distribution of flake sizes. This work highlights the potential of Cyrene as a sustainable and efficient solvent for LPE of diverse 2D materials. The systematic optimization method presented here achieves high dispersion concentrations in a repeatable manner using low-power and ecofriendly means. These findings establish a foundation for the scalable production of 2D inks, enabling their use in advanced applications such as electrode, dielectric and semiconductor layers of electronic devices.

Magnetic resonance imaging (MRI) is one of the most commonly used imaging techniques for diagnosis in clinics. Often, magnetically-active substances, called contrast agents (CAs), have to be used, which increase contrast by shortening the longitudinal (T1) (resulting in signal enhancement in T1-weighted images) and/or transverse (T2) (resulting in signal decay in T2-weighted images) relaxation times of the water protons present in biological tissues. A further strategy to improve diagnostic accuracy is recording both kinds of images (T1-weighted and T2-weighted) using dual T1-T2 CAs, which facilitates the exclusion of false positives. The traditional T1 or T2 contrast agents are not suitable for such a purpose. This paper deals with the development of double sodium lanthanide tungstate-based nanoparticles containing Gd3+ and Dy3+ cations, which are dispersible in physiological media, do not show appreciable in vitro (for human fibroblast cells) and in vivo (for C. elegans) toxicity and present appropriate relaxivity values for their use as a dual T1-T2 contrast agent for magnetic resonance imaging. In addition, they show an excellent X-ray attenuation capacity, thanks mainly to their tungsten content, which makes them also useful for X-ray computed tomography. Hence, the developed nanoparticles are ideal multimodal probes to be used as a dual T1-T2 contrast agent for magnetic resonance imaging and as a contrast agent for X-ray computed tomography.

Heavy metal contamination is a critical environmental issue, often involving complex multicomponent systems. Swelling brittle micas, a family of designer sorbents, have demonstrated exceptional heavy metal removal capabilities, yet their behabior in competitive adsorption systems remains largely unexplored. This study systematically investigates the simultaneous uptake of Pb2*, Cd2*, and Hg2* on both as-synthesized brittle mica and its thiol-functionalized counterpart. Using X-ray diffraction (XRD) and nuclear magnetic resonance (NMR), we reveal critical structural transformations occurring at both short-and long-range scales during adsorption. Our findings demonstrate that competitive adsorption governs metal uptake, leading to a reduction in total adsorption capacity compared to single-metal systems. However, selectivity toward specific metal cations remains unchanged, irrespective of competing species or surface functionalization. Overall, this study not only improves our understanding of heavy metal adsorption but also paves the way for more effective and sustainable sorbent design in environmental remediation.

Nanofiber mats were fabricated by combining cellulose, xylan, and organosolv lignin. The biopolymers, and a small amount (15 wt. %) of polyethylene oxide, were dissolved in a mixture of trifluoroacetic acid and trifluoroacetic anhydride, then blended in various ratios (keeping cellulose as the main component and changing the proportions of lignin and hemicellulose) and processed via electrospinning. The resulting nanofiber mats were systematically characterized for their CIELAB color parameters, morphology, chemical composition, mechanical strength, thermal stability, hydrodynamic behavior, antioxidant capacity, and wettability. The incorporation of organosolv lignin significantly altered the color of the nanofiber mats, making them more brownish, with luminosity values from 90 for L-0 to 58 for L-50. It also disrupted the hydrogen bonding network, as evidenced by the chemical shift of the ATR-FTIR spectra. Additionally, organosolv lignin affected key mechanical properties with mechanical values similar to other polymer nanofibers, while thermogravimetric analysis revealed an enhancement of about 10 degrees C in the heat resistant index, thereby broadening the potential applications of the nanofiber mats. Finally, the presence of organosolv lignin improved antioxidant capacity to values of 100 % of RSA, reduced water uptake, and increased water contact angle to values of 110 degrees for L-50.

Herein we report a green mechanochemical synthesis with low energy input of dual-function materials for integrated CO₂ capture and dry reforming of methane. The materials produced syngas during the CH₄ step (up to 0.6 mmol g⁻¹ CO and 7.7 mmol g⁻¹ H₂) and CO during the CO₂ step (up to 3.1 mmol g⁻¹) via the reverse Boudouard reaction due to the carbon produced from CH₄ cracking.

Cardiovascular mortality remains a major health challenge. Cardiomyocyte (CM)-based tissue engineering (TE) offers promising alternatives for developing therapies via in vitro models. However, the immature phenotype of CM in engineered tissues hampers progress. Recent studies introduce conductive materials like graphene to enhance CM maturation, but conventional graphene synthesis suffers from complexity, toxicity, and low yield. Laser-induced graphene (LIG) provides a sustainable, cost-effective, eco-friendly solution with efficient conductivity and biocompatibility. A LIG-based substrate is bioengineered in this study, hypothesizing that its conductive, anisotropic properties promote CM maturation and mimic the native cardiac niche. LIG is fabricated using a CO2 laser with Parylene-C as a precursor. Stem cells (SCs) and SC-derived embryoid bodies (EBs) are cultured on LIG substrates, and their viability, metabolic activity, morphology, and protein expression are evaluated through immunofluorescence and electron microscopy. Both SCs and EBs maintain viability and activity throughout the culture. Moreover, EB-derived CM exhibit spontaneous contraction and express cardiac-specific proteins, confirming functional differentiation on LIG matrices. This first report demonstrates that LIG substrates support SC culture and differentiation, highlighting their potential in developing refined in vitro cardiac models and advancing regenerative therapeutic strategies. The findings support LIG as a transformative advancement in TE.

Lead-free piezoelectric ceramics (Ba1-xCax) (Ti1-yHfy)O-3 with stoichiometries close to the morphotropic phase boundary (MPB) were synthesized by high-energy ball milling. The influence of Hf and Ca contents and the sintering method (conventional and hot-press) on the piezoelectric, dielectric, and ferroelectric response was investigated. It was confirmed that the different phases stabilized at room temperature and the structural distortion are strongly dependent on the stoichiometry. The coexistence of tetragonal, orthorhombic and rhombohedral phases was observed in samples with the lowest Ca and Hf contents. These samples, which are in the MPB region, also showed the greatest structural distortion, resulting in higher values of d(33). Samples with lower Hf content exhibited a higher coercive field, remnant polarization, and temperature in the ferroelectric to paraelectric transition. Despite the high sintering temperature leading to high densification, grain growth during sintering was limited because of the use of mechanochemically synthesized powders. Although Ba0.85Ca0.15Hf0.10Ti0.90O3 stoichiometry has been reported in the literature as the best for piezoelectric properties, in this work, BCHT solid solution with the lowest dopant content studied (Ba0.90Ca0.10Hf0.05Ti0.95O3) showed the best combination of functional properties. Ceramics of this composition with grain size <2 mu m exhibited a d(33) > 250 pC/N, with almost no relaxation after 24 h, and the highest permittivity. In the field of piezoelectric materials, there is considerable interest in reducing grain size while maintaining high piezoelectric performance, as this can lead to improvements in mechanical properties.

Carbon materials are essential for emerging energy applications and there is a pressing need to be able to produce carbons with controlled properties from sustainable precursors. Iron-catalysed graphitization of biomass is an attractive approach, where simple iron salts are used to convert organic matter to graphitic carbons at relatively low temperature. The choice of iron salt can have a significant impact on the chemical and structural properties of carbons derived from biomass. In this paper, we report a detailed mechanistic investigation of iron catalysed graphitization of cellulose by Fe(NO3)3 and FeCl3. In situ small and wide angle X-ray scattering and electron microscopy show that the evolution of catalyst particles from the two salts follows very different pathways. Remarkably, graphitization by FeCl3 is an order of magnitude faster than by Fe(NO3)3.

This study investigates the high-temperature stability and phase composition of two high-entropy oxides (HEOs), (Mn0.2Co0.2Ni0.2Cu0.2Fe0.2)Fe2O4 and (Mn0.2Co0.2Ni0.2Cu0.2Mg0.2)Fe2O4, prepared as single-phase samples using the reactive flash sintering technique. Results show that the annealing temperature in a nitrogen atmosphere has a significant impact on the stability of the compounds. The destabilization of the spinel structure occurs in a twostep process: spinel HEO -> spinel HEO + Fe2O3 -> spinel HEO + Cu based-oxide. This sequence is inferred from in-situ XRD experiments and calorimetric analysis, and confirmed by TEM observations. Impedance spectroscopy analysis revealed a complex, thermally activated electrical response comprising bulk and grain boundary contributions. AC conductivity follows Jonscher's universal power law, with a temperature dependence of the S parameter consistent with overlapping large polaron tunneling. These findings provide insight into charge transport and relaxation processes in the prepared HEOs, improving their understanding for potential electrical applications.

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

Graphene and its composites have attracted much attention for applications in energy storage systems. However, the toxic solvents required for the exfoliation process have hampered the exploitation of its properties. In this work, graphene dispersions are obtained via liquid phase exfoliation (LPE) of graphite in cyrene, an environmentally friendly solvent with solubility parameters like those of N-methyl-2-pirrolidone. The obtained dispersions with a concentration of 0.2 mg ml-1 comprised multilayered graphene sheets with lateral sizes in the hundreds of nanometers, as confirmed by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. Mixing the obtained dispersions with ethanol made it possible to collect the graphene, which was redispersed in 2-Propanol. This active material was used to fabricate supercapacitor electrodes using a scalable spray deposition method on carbon nanotube (CNT) current collectors with the aid of vinyl masks. The device, tested with a PVA/LiCl gel electrolyte, achieved a specific capacitance of 3.4 mF cm(-2) (0.015 mA cm(-2)). In addition, the devices show excellent cycling stability (>10 000 cycles at 0.5 mA cm(-2)) and good mechanical properties, losing less than 10% of initial capacitance after 1000 bending cycles. This work demonstrates the adaptability of liquid-phase exfoliation to produce graphene sustainably, providing the proof-of-concept for further 2D materials processing and green microsupercapacitor (MSC) fabrication.

Single-atom catalysts (SACs) have emerged as a promising class of materials, leveraging the benefits of both homogeneous and heterogeneous catalysis to enhance efficiency and selectivity. In this work we have investigated the catalytic performance of SACs supported on graphitic carbon nitride (g-C3N4) for hydroformylation reactions. A systematic evaluation of nine transition metal SACs (Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, and Pt) anchored on g-C3N4 was conducted using a combination of Density Functional Theory (DFT) calculations and experimental validation. Computational results indicate that at higher metal loadings, most metal atoms tend to migrate into the interlayers of g-C3N4, reducing their accessibility to reactant species and limiting their involvement in the catalytic process. However, Ru, Os, Ir, and Co single atoms remain stabilized on the heptazine rings, residing on the outermost layer and preserving active sites, albeit with lower predicted catalytic activity compared to Rh, while Fe, Ni, Pd, and Pt preferentially localize within the interlayers. Ru, Rh, and Co SACs anchored on g-C3N4 were experimentally synthesized and characterized using Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), along with catalytic testing, confirming the single-atom nature of the catalysts and corroborating the theoretical findings.

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.

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.