The exploration of novel entropy-stabilized oxides (ESOs), particularly those with fluorite or bixbyite structures, has recently attracted considerable attention due to their potential technological applications, including thermal barrier coatings and catalysts/photocatalysts. This study seeks to identify optimal synthesis pathways that lower kinetic barriers and expedite the formation of the entropy-stabilized single phase, thereby contributing to more efficient fabrication processes for these complex materials, which hold promise for a wide range of technological uses. In this context, two distinct rare-earth-based systems, i.e. (Ce0.2Zr0.2Yb0.2Er0.2La0.2)O1.7 and (Ce0.2Nd0.2Er0.2Yb0.2La0.2)O1.6, were synthesized via co-precipitation (using ammonia and ammonium carbonate as precipitating agents) and through the conventional solid-state method. A detailed structural analysis revealed that precursor reactivity strongly influences the transition to a single-phase fluorite-like or bixbyite-like highentropy oxide (HEO). Specifically, precursors derived from ammonium carbonate displayed higher reactivity, promoting phase formation at lower temperatures, while ammonia-based precursors required higher transition temperatures due to agglomeration effects. Conversely, the solid-state synthesis route exhibited reduced reactivity, thereby delaying (or even inhibiting) phase transitions in the more complex bixbyite-like system. Thus, our findings highlight the critical role of kinetic barriers in forming entropy-stabilized fluorite-like and/or bixbyitelike structures and underscore the importance of the chosen synthesis cycle in optimizing HEO fabrication for future technological applications.

The toxicity of lunar dust (LD), anecdotally reported by Apollo astronauts, raises concerns for future missions involving prolonged human presence on the Moon. LD toxicity is thought to involve oxidative stress driven by nanophase metallic iron (np-Fe0), a peculiar feature of LD. In life-supporting lunar habitat, np-Fe0 embedded in the amorphous phases of LD may react with O2 prior to accessing the lung, complicating toxicity assessments. Due to limited availability of real LD samples, toxicological evaluations rely on lunar dust simulants (LDS). A novel Simulant Moon Agglutinate (SMA), composed of a glassy matrix with np-Fe0, was produced and ball milled in an inert atmosphere to expose non-oxidized Fe0 surface centers and to obtain a dust with respirable particle size. Physicochemical properties, oxidative activity, and iron release in simulated body fluids were assessed on selected SMA samples. SMA were aged in air, and the kinetics of free radical generation revealed a strong redox activity that decreased with aging. After an oxidative ageing of 1 month, SMA was still active in generating free radicals, to a higher extent that other LD simulants like JSC-1A-vf, highlighting the key role of np-Fe0 in eliciting LD peculiar reactivity. In vitro tests showed that SMA caused no cell membrane damage, suggesting that LD toxicity mechanisms might involve free radicals and may differ from terrestrial toxic dust, such as quartz.

Ultrastable Y (USY) zeolites with different Si/Al ratios were used as a support for Fe0 and Fe3O4, loaded via vacuum impregnation of ferrous solutions followed by thermal treatment in a reducing atmosphere. The influence of Fe0/Fe3O4 ratios in the magnetically recoverable Fe0/Fe3O4/USY composite catalysts was explored in the solar-assisted photo-Fenton degradation of chloramphenicol (CAP), a recalcitrant antibiotic frequently detected in pharmaceutical wastewater. Under optimized conditions (pH = 4, H2O2dosage = 0.12 g L-1, catalyst loading = 1.5 g L-1), the Fe0(3.3 %)/Fe3O4(1.6 %)/USY catalyst achieved 98 % CAP degradation within 30 min in the dark and 52 % TOC removal after 120 min under simulated solar irradiation. Scavenger and band structure analyses revealed that hydroxyl radicals were the primary oxidative species responsible for CAP degradation. The catalyst exhibited excellent reusability and maintained high activity in the presence of common inorganic ions present in real water matrix, confirming its robustness under realistic water treatment conditions. A comparative energy consumption analysis demonstrated that the proposed system requires significantly lower energy input compared to similar photocatalytic and photo-Fenton processes reported in the literature. These findings highlight the potential of Fe0/Fe3O4/USY as a cost-effective and sustainable solution for the removal of emerging pharmaceutical contaminants from aqueous environments.

This study explores the influence of two different synthesis methods on the sintering behavior of three novel high-entropy oxides possibly suitable for thermal barrier applications: (Ce0.2Zr0.2Yb0.2Er0.2Nd0.2)O2-δ, (Ce0.2Zr0.2Yb0.2Er0.2La0.2)O2-δ, and (Ce0.2Nd0.2Yb0.2Er0.2La0.2)2O3+δ. Rare-Earth-based High-Entropy Oxides (RE-HEOs), recently known for their exceptional thermal stability and compositional flexibility, have gained increasing attention as potential candidates for many advanced technological applications. Thus, our current work focuses on the specific effects of synthesis techniques, namely co-precipitation and hydrothermal treatment, on the entropy-driven stabilization, microstructure, electrochemical properties, and sintering behavior of three novel RE-HEOs. The obtained results reveal significant differences in terms of densification yield and of the obtaining of the designed entropy-stabilized single phase depending on the adopted synthesis route, underscoring the critical role of synthesis in optimizing RE-HEOs for near-future technological applications.

This work presents the design and synthesis of novel high-entropy perovskite oxides (HEPOs) derived from BaCeO3, formulated using the cluster-plus-glue atom model. Particularly, through a carbonate-based co-precipitation technique, we synthesized three novel high-entropy perovskite oxides (HEPOs) derived from barium cerate by substituting cerium with different combinations of five different elements (Ce, Zr, Yb, Sm, La, Gd, Nd) in equal molar ratios, i.e., Ba(Ce0.2Zr0.2Yb0.2La0.2Sm0.2)O2.7, Ba(Ce0.2Sm0.2Yb0.2Nd0.2Gd0.2)O2.6, and Ba(Ce0.2Zr0.2Nd0.2La0.2Sm0.2)O2.7. Upon calcination of the as-synthesized samples at different temperatures and subsequent quenching, the formation of an entropy-stabilized single phase was analyzed and assessed. To rationalize the observed differences in phase evolution, a novel set of empirical descriptors, including configurational entropy, Goldschmidt tolerance factor, and B-site size mismatch, was proposed and discussed. With the aim of studying the sinterability of the single-phase samples, the calcination treatment was optimized by reducing its temperature and duration (i.e., 1300 °C for 6 h) so that subsequent densification higher than 95% was achieved by sintering at 1500 °C for 6 h.

A tailor-made design strategy was adopted for the synthesis of three zeolite-based magnetic nanocomposites (MNCs). In this view, ferrierite (Fe-FERR), L-type (Fe-L), and USY (Fe-USY) zeolites functionalized with FeSO4 and thermally treated were used for the simultaneous removal of pollutants with contrasting physicochemical properties. Sulfanilamide (SA) and methylene blue (MB) were selected as model pollutants as they offer contrasting physicochemical properties, which makes their adsorption potentially governed by both hydrophobic and polar interactions. To address this, we synthesized amphiphilic MNCs, to establish interactions of both types for simultaneous SA and MB adsorption. Preliminary magnetic functionalization ensured easier separation and multiple reuse of the adsorbents, as well as reduced generation of wastes. The structural (XRD, FTIR, SEM) and magnetic characterization confirmed their rapid separability under an external magnetic field. The amphiphilic MNCs exhibited efficient adsorption of SA (pH 5-6, mainly due to electrostatic interactions) and MB (pH 4.0-5.0, mainly attributed to the hydrophobic interaction). The adsorption kinetics of SA and MB could be described adopting the intraparticle diffusion and the pseudo-second order models, respectively. To enhance the comprehension of SA and MB adsorption, advanced adsorption models were adopted, rooted in statistical physics principles. The maximum values of the adsorption capacities (6.00 × 105 μmol/kg with sulfanilamide, and 120,000 mg/kg with Methylene Blue) were satisfactory if compared to conventional adsorbents. A pH-triggered regeneration procedure was developed, allowing an almost complete recycle and reuse of the magnetic adsorbents.

In the last years gallic acid (GA) has been used in a growing number of industrial applications, thanks to its interesting properties. Unfortunately, the consequent presence of GA in wastewaters raises significant environmental problems. In this view, two tailor-made magnetic metal-ceramic nanocomposites, obtained from zeolite A, were developed for the adsorptive separation of GA from wastewaters. Optimized configurations of the nanocomposites, to increase their adsorption capacity and stability, were obtained by suitable modification of a patented process. The adsorption process was characterized as regards the role played by the most relevant parameters (kinetics, pH, GA concentration). The GA removal was strongly affected by pH. The experimental results suggested the interactions between GA and the nanocomposites to be based on two different mecha-nisms. The adsorption kinetics were in all cases described by the pseudo second-order model. The adsorption isotherms data were satisfactorily described by the Sips model, a combination of the Langmuir and Freundlich isotherm type models. Suitable conditions were found to achieve the GA desorption, as well as the recycle of the magnetic adsorbents. In this view, a procedure for the thermal regeneration of the exhausted adsorbent was devel-oped on the basis of the TG and DTA analyses. In order to offer a more environmentally friendly approach, as well as to achieve a full recovery of the economically valuable GA, a procedure for the alkaline desorp-tion was successfully developed. A detailed cost analysis was also carried out, showing that the specific cost for GA unit volume removal is comparable with those pertaining to alternative methods. (c) 2022 Published by Elsevier B.V.

Highly efficient, separable, and stable magnetic iron-based-photocatalysts produced from ultra-stable Y (USY) zeolite were applied, for the first time, to the photo-Fenton removal of phenol under solar light. USY Zeolite with a Si/Al molar ratio of 385 was impregnated under vacuum with an aqueous solution of Fe2+ ions and thermally treated (500–750 °C) in a reducing atmosphere. Three catalysts, Fe-USY500°C-2h, Fe-USY600°C-2h and Fe-USY750°C-2h, containing different amounts of reduced iron species entrapped in the zeolitic matrix, were obtained. The catalysts were thoroughly characterized by absorption spectrometry, X-ray powder diffraction with synchrotron source, followed by Rietveld analysis, X-ray photoelectron spectroscopy, N2 adsorption/desorption at −196 °C, high-resolution transmission electron microscopy and magnetic measurements at room temperature.

Magnetic zeolites with a Ni content of 4.80 and 6.20 wt%, were prepared by Ni-exchanging zeolites 4 A and 13x, respectively, and thermally treating the Ni-exchanged zeolites at 735-750 degrees C, under a reducing atmosphere. This thermal treatment gave rise to the formation of Ni0 nanoparticles dispersed in a ceramic matrix, which partially retained the zeolitic structure (about 50%). The obtained nanocomposites were fully characterized using atomic absorption spectrometry, X-rays powder diffraction (with synchrotron source) followed by Rietveld analysis, High-Resolution Transmission Electron Microscopy, N2 adsorption/desorption at-196 degrees C and magnetic measurements at both room temperature and low temperature. To highlight the effect of nickel content on the final properties of the nanocomposites, the features of the samples produced in this work were compared with the features of the nanocomposites obtained, in previous works, from the same zeolites loaded with a low (approx. 1%) and a high (approx. 15 wt%) Ni content.The most important result obtained here is that only by entering the intermediate Ni content of this work (4.80-6.20 wt%) it was possible to obtain real magnetic zeolites as the final product of the process. The low Ni content gave rise to a poor magnetic response, whereas the high Ni content resulted in the almost total destruction of the zeolite framework.

Three tailor-made magnetic metal-ceramic nanocomposites, obtained from zeolite A (ZA1 and ZA2) and a natural clinoptilolite (LB1), have been used as adsorbents to remove sulfanilamide (SA), a sulfonamide antibiotic of common use, from water. A patented process for the synthesis of nanocomposites has been suitably modified to maximize the efficiency of the SA removal, as well as to extend the applicability of the materials. The role played by the main process parameters (kinetic, pH, initial concentration of SA) has been characterized. The significant effect of the pH on the SA removal has been explained identifying two possibly coexisting mechanisms of SA adsorption, based on polar and hydrophobic interactions, respectively. The adsorption kinetics have been in all cases described by the pseudo second-order model. The adsorption isotherms obtained with ZA1 have been satisfactorily described by the Langmuir model, suggesting a monolayer adsorption of SA on the magnetic nanocomposites resulting from a uniform surface energy. The isotherms obtained with LB1 could be described by a more complex approach, deriving by the additive superposition of Langmuir and Sips models. In order to ensure an effective removal of the antibiotic and a proper recycle of the magnetic adsorbents, a sustainable regeneration procedure of the exhausted adsorbent has been developed, based on the treatment with a dilute solution of NaOH.

Divalent Nickel cations were incorporated in two commercial zeolites (Na-A zeolite and Na-X zeolite) by a process of ionic exchange marginally affecting structure, morphology and porosity of the host materials, as verified by XRD, HRTEM and physisorption measurements. Comparable amounts of magnetic ions were introduced (4.80 wt% in Na-A zeolite and 6.20 wt% in Na-X zeolite), as checked by AAS and TGA. Magnetic measurements were done between 2 and 300 K using a SQUID magnetometer up to 70 kOe. The initial susceptibility follows the Curie-Weiss law with Curie temperatures theta of 10.3 and 11.5 K. The effective magnetic moments on Ni2+ ions suggest almost complete quenching of the angular momentum. No long-range magnetic order is found below theta; however, FC/ZFC magnetization curves indicate the formation of superparamagnetic clusters of magnetic ions with blocking temperature of about 6.5 K in both zeolites. Cluster size, average number of clustered ions, effective anisotropy of clusters are evaluated. A comprehensive picture of all magnetic effects taking place over the whole temperature range is drawn by combining magnetic, structural and morphological data.

In this work, four zeolite-bearing materials (three naturally occurring and one of synthetic origin) were considered for thermal energy capture and storage. Such materials can store thermal energy as heat of desorption of the water present therein, heat that is given back when water vapor is allowed to be re-adsorbed by zeolites. This study was carried out by determining the loss of water after different activation thermal treatments, the water adsorption kinetics and isotherm after an activation step of the zeolites, the intergranular and intragranular porosity, and the thermal conductivity of the zeolite-bearing materials. Moreover, the thermal stability of the framework of the zeolites of the four materials tested was investigated over a large number of thermal cycles. The results indicate that zeolite 13X was the most suitable material for thermal energy storage and suggest its use in the capture and storage of thermal energy that derives from thermal energy waste.

Two natural zeolite-bearing rocks (one containing clinoptilolite and the other chabazite, phillipsite, and analcime) were Fe-exchanged and thermally treated in a reducing atmosphere at 750 degrees C for 2 h. Two nanocomposites, formed by the dispersion of Fe nanoparticles in a ceramic matrix, were obtained. The prepared lunar dust simulants also contain Na+, K+, Ca2+, and Mg2+ and other mineral phases originally present in the starting materials. The samples were fully characterized by different techniques such as atomic absorption spectrometry, X-ray powder diffraction, followed by Rietveld analysis, transmission electron microscopy, N-2 adsorption/desorption analysis at 77 K, measurements of grain size distribution, magnetic property measurements, broad-band dielectric spectroscopy, and DC conductivity measurements. The results of this characterization showed that the obtained metal-ceramic nanocomposites exhibit a chemical and mineralogical composition and electrical and magnetic properties similar to real moon dust and, thus, appear valid moon dust simulants.

Beaked corn represents one of the most characteristics and neglected group of Italian maize landraces. These genotypes, classified in the “Rostrata” group, were mostly grown in northern Italy, on the left bank of the Pò river, until the end of the Second World War and then subjected to strong genetic erosion because of the subsequent introduction of improved genotypes and hybrids of US origin. These materials are experiencing a revival period for cultivation, commercial exploitation and an increased number of farmers is seeking particular genotypes for the production of niche products. In Valchiavenna (Sondrio, Lombardia, Italy) maize cultivation has historical importance for polenta preparation and is characterized by the presence of at least three accessions of “Mais Rostrato Val Chiavenna”, one conserved since 1982 in germplasm bank ( here named as R17_BG) and two in situ (here named as R17_M; R17_T), with distinctive morphological traits at both ear and plant level. In the present study, these accessions have been characterized at the morphological and genetic level with 10 SSR markers and compared to other landraces of the Rostrata group. SSR analysis revealed from 3 to 11 alleles per locus evidencing a good level of heterosis and absence of allele fixation for landraces. Both phylogenetic and STRUCTURE analysis evidence that the three “Mais Rostrato Val Chiavenna” are different entities with a distinct genetic origin. Historical investigation revealed that the morphology most close to the “original” Mais Rostrato di Val Chiavenna is that of R17_T, dating back to the XIX century. These observations, coupled with morphological and genetic results may corroborate that R17_T corresponds to the original “Mais Rostrato Val Chiavenna”.

Maize is mainly affected by two fungal pathogens,Fusarium verticillioides andAspergillus flavus, causingFusarium ear rot (FER) andAspergillus ear rot (AER), respectively. Both fungi are of concern to stakeholders as they affect crop yield and quality, contaminating maize grains with the mycotoxins fumonisins and aflatoxins. The easiest strategy to prevent pre-harvest contamination byF. verticillioides andA. flavus is to develop maize hybrids resistant to FER and AER, as well as to their associated mycotoxins. The objective of this investigation was to test 46 F1 hybrids, originated from different Italian, US and Canadian breeding groups, for these important traits and their agronomic performances. All hybrids were planted and artificially inoculated with toxigenic strains ofF. verticillioides andA. flavus at two locations in 2017, and the best performing 17 out of 46 were also tested in 2018. Ear rots were present in all hybrids in 2017 and 2018, with percentages ranging from 6.50 to 49.50%, and 5.50 to 45.53%, for FER and AER, respectively. Seven hybrids (PC8, PC15, PC9, PC11, PC14, PC34 and PC17) presented the lowest levels of both diseases considering the overall locations and growing seasons, and three of these (PC8, PC11 and PC14) were also amongst the least mycotoxin contaminated hybrids in 2017. The inbred lines used in hybrid production may provide additional sources of resistance suitable in breeding programs targeting multiple pathogens and their mycotoxins.

In this work, three novel magnetic metal–ceramic nanocomposites were obtained by thermally treating Fe-exchanged zeolites (either A or X) under reducing atmosphere at relatively mild temperatures (750–800 °C). The so-obtained materials were thoroughly characterized from the point of view of their physico-chemical properties and, then, used as magnetic adsorbents in the separation of the target gene factors V and RNASE and of the Staphylococcus aureus bacteria DNA from human blood. Such results were compared with those obtained by using a top ranking commercial separation system (namely, SiMAG-N-DNA by Chemicell). The results obtained by using the novel magnetic adsorbents were similar to (or even better than) those obtained by using the commercial system, both during manual and automated separations, provided that a proper protocol was adopted. Particularly, the novel magnetic adsorbents showed high sensitivity during tests performed with small volumes of blood. Finally, the feasible production of such magnetic adsorbents by an industrial process was envisaged as well.

The use of humic-like substances, zeolites, various porous oxides (i.e., Al, Fe, or Si oxides), and magnetic nanocomposites in the adsorption of agrochemicals from water was critically reviewed. Firstly, the adsorbents were characterized from the structural, textural, and physico-chemical points of view. Secondly, the fundamental aspects of the adsorption of various agrochemicals on the solids (dependence on pH, kinetics, and isotherm of adsorption) were studied and interpreted on the basis of the adsorbent features. Thirdly, iterative processes of agrochemical removal from water by adsorption on the reported solids were described. In particular, in some cases the residual concentration of agrochemicals in water was lower than the maximum concentration of agrochemicals that the Italian regulations allow to be released in wastewater, surface waters, or sink water.

Magnetic nanocomposites with low Ni content (nominal 1 wt%) were produced by a process involving thermal treatments of Ni-exchanged zeolite precursors of different type and investigated by XRPD, TEM and dc magnetic techniques. Ni-rich nanoparticles of size in the 10-80 nm range (depending on parent zeolite and thermal treatment) are observed at zeolite grain boundaries and/or surfaces, while a fraction f o of Ni2+ ions are present inside the grains. The blocking temperature of nanoparticles is above room temperature. At high temperatures (75 K <= T <= 300 K) the sample magnetization is dominated by nanoparticles; below, the paramagnetic signal of Ni(2+ )ions begins to be observed. A new procedure of magnetic data analysis is proposed and applied to find the residual ionic fraction f(0) in the two limit cases of full/no quenching of the orbital momentum on Ni2+ ions; f(0) turns out to be in the range 1.5-14.5%, depending on type of parent zeolite and thermal treatment. The temperature behavior of the high-field magnetization in the 2-300 K range and the variation of room-temperature magnetization are both explained taking into account the ionic and nanoparticle fractions estimated using the proposed method. Clustering of weakly interacting Ni2+ ions appears at low temperature in the sample with the highest ionic concentration. (C) 2019 Elsevier B.V. All rights reserved.