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This work deals with the design of nanocomposite hydrogenation-dehydration bifunctional catalysts for the one-pot conversion of CO2 to dimethyl ether (DME), focusing on obtaining a high and homogeneous dispersion of a Cu-based CO2 hydrogenation phase into the pores of mesostructured supports. Particularly, three aluminosilicate mesostructured acid catalysts with catalytic activity towards methanol dehydration and featuring different porous structures (Al-MCM-41, Al-SBA-15, Al-SBA-16) were synthesized and used as supports to host a CuO/ZnO/ZrO2 (CZZ) CO2 hydrogenation catalyst for methanol synthesis. The use of a mesostructured support allows to maximize the exposed surface of the CO2 reduction function by nanostructuring it through its confinement within the mesochannels, thus obtaining nanocomposite bifunctional catalysts with an ultra-small hydrogenation nanophase. The nanocomposites were obtained using an impregnation strategy combined with a self-combustion reaction, allowing to incorporate the CO2 reduction phase inside the mesopores. In all cases, the characterization shows that the hydrogenation phase species are highly and homogeneously dispersed into the supports as either small nanoparticles or as a nanolayer. The as-obtained nanocomposites were tested for their catalytic activity and the results discussed taking into account the structural, textural, and acidic properties of the supports and nanocomposites., (© 2025 Wiley‐VCH GmbH.)

Spinel-structured transition metal (TM) oxides have shown great potential as a sustainable alternative to platinum group metal-based electrocatalysts. Among them, high-entropy oxides (HEOs) with multiple TM-cation sites are suitable for engineering octahedral redox-active centers to enhance the catalyst reactivity. This paper reports on the preparation of electrospun (Cr 1/5 Mn 1/5 Fe 1/5 Co 1/5 Ni 1/5 ) 3 O 4 nanofibers (NFs) and their evaluation as electrocatalysts. Its main aim is to unveil the nanostructural features that play a key role in the alkaline oxygen evolution reaction. Differing calcination temperature (300-800 °C) and duration (2 or 4 h) leads to different morphology of the NFs, crystallinity of the oxide, density of defects, and cation distribution in the lattice, which reflect in different electrocatalytic behaviors. The best performance (overpotential and Tafel slope at 10 mA cm -2 : 325 mV and 40 mV dec -1 , respectively) pertains to the NFs calcined at 400 °C for 2 h. To gain a deeper understanding of their electrocatalytic properties, the pristine NFs are investigated by a combination of analytical techniques. In particular, broadband electric spectroscopy reveals that the mobility of oxygen vacancies in the best electrocatalyst is associated to very fast local dielectric relaxations of metal coordination octahedral geometries and experimentally demonstrates the key role of O-deficient octahedra., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceous and various Penicillium species, which are known for contaminating agricultural products and posing significant health risks, which include immunotoxicity. This study aims to evaluate the potential of nanostructured lipid carriers (NLCs) loaded with a carotenoid-enriched extract from pumpkin peel ( Cucurbita maxima L.) in mitigating the toxic effects of OTA. To address the poor bioavailability and instability of carotenoids, nanoencapsulation techniques were employed to enhance their delivery and efficacy. NLCs were formulated using hydrogenated sunflower oil, pumpkin oil, and soy lecithin using hot high-pressure homogenization. The in vitro study involved co-digesting OTA-contaminated bread with an NLC formulation and assessing the impact of the encapsulated carotenoid on OTA bioaccessibility, bioavailability, and cellular toxicity using Caco-2 and Jurkat T cells. Even though no significant influence was observed on the bioaccessibility and bioavailability of OTA, carotenoid-loaded NLCs exhibited cytoprotective effects by improving cell viability and mitigating OTA-induced toxicity in both Caco-2 and Jurkat T cells. Particularly, the flow cytometry analysis highlighted the ability of carotenoids to mitigate OTA-induced cellular damage by decreasing ROS production and limiting mitochondrial mass changes. The study suggests that the encapsulation of carotenoids in NLCs represents a promising strategy to enhance their protective effects against OTA toxicity, potentially offering a novel approach to food safety and public health protection. The study underscores the potential of nanotechnology in improving the bioavailability and efficacy of natural antioxidants to mitigate mycotoxin-induced damage.

Plants, including pumpkins ( Cucurbita spp.), are an interesting source of nutrients and bioactives with various health benefits. In this research, carotenoid extracts obtained from the pulp of eight pumpkin varieties, belonging to the C. moschata and C. maxima species, were tested for cytotoxicity on SH-SY5Y neuroblastoma cells. The results showed that pumpkin bioactives exert a cytotoxic action against the tested cells, in particular Butternut extract at a 100 μM (53.69 μg/mL) concentration after 24 h of treatment and Mantovana extract at 50 μM (26.84 μg/mL) after 48 h. Moreover, the carotenoid extracts also showed interesting in vitro antioxidant activity, evaluated by ABTS and ORAC assays. To fully characterize the qualitative and quantitative profile of carotenoids in the tested extracts, a high-performance chromatographic technique was performed, revealing that pumpkin pulp carotenoids were mainly represented by β-carotene, mono- and di-esterified hydroxy- and epoxy-carotenoids. Moreover, the carotenoid dataset was also useful for discriminating samples from two different species. In conclusion, the results of the present study highlight the potential anti-cancer activity of pumpkin carotenoid extracts and the possibility of using them as chemotherapeutic adjuvants.

The side reactions and dendrite growth at the interface of Zn anodes greatly limit their practical applications in Zn metal batteries. Herein, we propose a hybrid molecular sieve-based interfacial layer (denoted as Z 7 M 3 ) with a hierarchical porous structure for Zn metal anodes, which contains 70 vol % microporous ZSM-5 molecular sieves and 30 vol % mesoporous MCM-41 molecular sieves. Through comprehensive molecular dynamics simulations, we demonstrate that the mesopores (∼2.5 nm) of MCM-41 can limit the disordered diffusion of free water molecules and increase the wettability of the interfacial layer toward aqueous electrolytes. In addition, the micropores (∼0.56 nm) of ZSM-5 can optimize the Zn 2+ solvation structures by reducing the bonded water molecules, which simultaneously decrease the constraint force of solvated water molecules to Zn 2+ ions, thus promoting the penetrability and diffusion kinetics of Zn 2+ ions in Z 7 M 3 . The synergetic effects from the hybrid molecular sieves maintain a constant Zn 2+ concentration on the surface of the Zn electrode during Zn deposition, contributing to dendrite-free Zn anodes. Consequently, Z 7 M 3 -coated Zn electrodes achieved excellent cycling stability in both half and full cells.

Lithium-ion batteries, essential for electronics and electric vehicles, predominantly use cathodes made from critical materials like cobalt. Sulfur-based cathodes, offering a high theoretical capacity of 1675 mAh g -1 and environmental advantages due to sulfur's abundance and lower toxicity, present a more sustainable alternative. However, state-of-the-art sulfur-based electrodes do not reach the theoretical capacities, mainly because conventional electrode production relies on mixing of components into weakly coordinated slurries. Consequently, sulfur's mobility leads to battery degradation-an effect known as the "sulfur-shuttle". This study introduces a solution by developing a microporous, covalently-bonded, imine-based polymer network grown in situ around sulfur particles on the current collector. The polymer network (i) enables selective transport of electrolyte and Li-ions through pores of defined size, and (ii) acts as a robust host to retain the active component of the electrode (sulfur species). The resulting cathode has superior rate performance from 0.1 C (1360 mAh g -1 ) to 3 C (807 mAh g -1 ). Demonstrating a high-performance, sustainable sulfur cathode produced via a simple one-pot process, our research underlines the potential of microporous polymers in addressing sulfur diffusion issues, paving the way for sulfur electrodes as viable alternatives to traditional metal-based cathodes., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Ultrasound-assisted extraction of (poly)phenols from pumpkin pulp was optimized using response surface methodology. Time, solvent-to-sample ratio and percentage of water in ethanol were considered and a full factorial design was applied. The optimized conditions (10 min; 30 mL/g; 50% water in ethanol) were used to isolate (poly)phenols from five pumpkin varieties (Hokkaido, Lunga di Napoli, Mantovana, Moscata di Provenza, Violina rugosa), collected for two successive years. Phenolic acids were the most abundant phenolic class (gallic acid up to 413.50 μg/g), even if differences were observed among varieties and harvesting years. Generally, Violina rugosa harvested in 2021 showed the highest total phenol content (7.59 mg gallic acid equivalents/g) and antioxidant properties (16.93 mg Trolox equivalents/g). All pumpkin variety exhibited antimicrobial activity within a concentration range of 1.95 to 250 μg/mL. In conclusion, the pumpkin pulp can be considered a promising natural source of (poly)phenols for the development of health-promoting products., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The Stöber method is a widely-used sol-gel route for synthesizing amorphous SiO 2 colloids and conformal coatings. However, the material systems compatible with this method are still limited. Herein, we have extended the approach to metal-organic frameworks (MOFs) and coordination polymers (CPs) by mimicking the Stöber method. We introduce a general synthesis route to amorphous MOFs or CPs by making use of a base-vapor diffusion method, which allows to precisely control the growth kinetics. Twenty-four different amorphous CPs colloids were successfully synthesized by selecting 12 metal ions and 17 organic ligands. Moreover, by introducing functional nanoparticles (NPs), a conformal amorphous MOFs coating with controllable thickness can be grown on NPs to form core-shell colloids. The versatility of this amorphous coating technology was demonstrated by synthesizing over 100 core-shell composites from 20 amorphous CPs shells and over 30 different NPs. Besides, various multifunctional nanostructures, such as conformal yolk-amorphous MOF shell, core@metal oxides, and core@carbon, can be obtained through one-step transformation of the core@amorphous MOFs. This work significantly enriches the Stöber method and introduces a platform, enabling the systematic design of colloids exhibiting different level of functionality and complexity., (© 2024. The Author(s).)

Metal Organic Frameworks (MOFs) are organic-inorganic hybrid materials with exceptionally customizable composition and properties. MOFs intrinsically possess open metal sites, tunable pore size/shape and an ultra-large specific surface area, and have obtained significant attention over the past 30 years. Furthermore, through the integration of functional moieties such as, molecules, functional groups, noble metal clusters and nanocrystals or nanoparticles into MOFs, the resulting composites have greatly enriched the physical and chemical properties of pure MOFs, enabling their application in a wider range of fields. Triethylamine (TEA) as an organic base has consistently played a fundamental role in the development of MOFs. In this Concept, the versatility of triethylamine when involved in the synthesis of MOFs is discussed. Four sections are used to elaborate on the role of TEA including: (1) Single crystal synthesis; (2) Size and morphology control; (3) Counterion of MOFs; (4) MOFs composites synthesis. In the last part, we highlight the potential of TEA for further developments., (© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

This study shows that the simple approach of keeping anodic TiO 2 nanotubes at 70 °C in ethanol for 1 h results in improved photoelectrochemical water splitting activity due to initiation of crystallization in the material amplified by the light-induced formation of a Ti 3+ -V o states under UV 365 nm illumination. For the first time, the light-induced Ti 3+ -V o states are generated when oxygen is present in the reaction solution and are stable when in contact with air (oxygen) for a long time (two months). We confirmed here that the amorphous or nearly amorphous structure of titania supports the survival of Ti 3+ species in contact with oxygen. It is also shown that the ethanol treatment substantially improves the morphology of the titania nanotube arrays, specifically, less surface cracking and surface purification from C- and F-based contamination from the electrolyte used for anodizing., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

The realization of large-scale industrial application of alkaline water electrolysis for hydrogen generation is severely hampered by the cost of electricity. Therefore, it is currently necessary to synthesize highly efficient electrocatalysts with excellent stability and low overpotential under an industrial-level current density. Herein, Ir-incorporated in partially oxidized Ru aerogel has been designed and synthesized via a simple in situ reduction strategy and subsequent oxidation process. The electrochemical measurements demonstrate that the optimized Ru 98 Ir 2 -350 electrocatalyst exhibits outstanding hydrogen evolution reaction (HER) performance in an alkaline environment (1 M KOH). Especially, at the large current density of 1000 mA cm -2 , the overpotential is as low as 121 mV, far exceeding the benchmark Pt/C catalyst. Moreover, the Ru 98 Ir 2 -350 catalyst also displays excellent stability over 1500 h at 1000 mA cm -2 , denoting its industrial applicability. This work provides an efficient route for developing highly active and ultra-stable electrocatalysts for hydrogen generation under industrial-level current density., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Dural arteriovenous fistulas (DAVFs) are intracranial vascular abnormalities in which one or more meningeal arteries shunt into a venous structure, either a cortical vein or a venous sinus, causing cerebral venous hypertension and risk of haemorrhage. Imaging diagnosis and characterisation are of paramount importance to grade the haemorrhagic risk and direct management. Non-invasive vascular neuroimaging might pose a diagnostic suspicion, but invasive catheter digital subtraction angiography (DSA) is usually required. We present the case of a patient with an atypical acute cerebral haemorrhage in which admission imaging with CT angiography (CTA) and MR angiography (MRA) was unremarkable, while advanced morphological MR with susceptibility-weighted imaging (SWI) revealed specific findings suggesting unilateral chronic venous hypertension. Successively, DSA detected a small DAVF that was treated with endovascular embolization. This case report raises awareness on subtle but important conventional imaging findings that suggest the presence of an AV shunt, to avoid misdiagnosis and delayed treatment., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

The integration of metal oxide nanomaterials with mesoporous silica is a promising approach to exploiting the advantages of both types of materials. Traditional synthesis methods typically require multiple steps. This work instead presents a fast, one-step, template-free method for the synthesis of metal oxides homogeneously dispersed within mesoporous silica, including oxides of W, Ti, Nb, Ta, Sn, and Mo. These composites have tunable metal oxide contents, large surface areas, and wide mesopores. The combination of Nb 2 O 5 nanoparticles (NPs) with SiO 2 results in an increased surface area and a larger number of acid sites compared to pure Nb 2 O 5 NPs. The surface texture and acidity of the silica-niobia composites can be tuned by adjusting the Nb/Si molar ratio. Moreover, the silica provides protection to the niobia NPs, preventing sintering during thermal treatment at 400 °C. The silica-niobia materials exhibit superior performance as catalysts in the aldol condensation of furfural (Fur) with acetone compared to pure niobia, leading to an up to 62% in product yield. Additionally, these catalysts show remarkable stability, retaining their performance over multiple runs. This work demonstrates the potential of the proposed synthesis approach for preparing more sustainable, high-performance, durable, and stable nanoscale metal oxide-based catalysts with a tunable composition, surface area, and active site density.

Pumpkin ( Cucurbita sp.) represents an unquestionable source of valuable nutrients and bioactive compounds having a broad spectrum of health-promoting effects. The goal of this work was to characterize the byproducts (peels and filaments) of different pumpkin varieties belonging to C. moschata (Butternut, Lunga di Napoli, Moscata di Provenza, and Violina rugosa) and C. maxima (Delica, Delica vanity, Hokkaido, and Mantovana) species in terms of total carotenoid content, antioxidant activity, and carotenoid profiling. The research revealed that peels and filaments were a good source of β-carotene and other non-esterified carotenoids, as well as esterified carotenoids. Considering the growing market demand for safe and healthy food products, pumpkin byproducts, having also an interesting antioxidant bioactivity, could be useful in the development of novel functional products.

High-entropy oxides (HEOs) have emerged as promising anode materials for next-generation lithium-ion batteries (LIBs). Among them, spinel HEOs with vacant lattice sites allowing for lithium insertion and diffusion seem particularly attractive. In this work, electrospun oxygen-deficient (Mn,Fe,Co,Ni,Zn) HEO nanofibers are produced under environmentally friendly calcination conditions and evaluated as anode active material in LIBs. A thorough investigation of the material properties and Li + storage mechanism is carried out by several analytical techniques, including ex situ synchrotron X-ray absorption spectroscopy. The lithiation process is elucidated in terms of lithium insertion, cation migration, and metal-forming conversion reaction. The process is not fully reversible and the reduction of cations to the metallic form is not complete. In particular, iron, cobalt, and nickel, initially present mainly as Fe 3+ , Co 3+ /Co 2+ , and Ni 2+ , undergo reduction to Fe 0 , Co 0 , and Ni 0 to different extent (Fe < Co < Ni). Manganese undergoes partial reduction to Mn 3+ /Mn 2+ and, upon re-oxidation, does not revert to the pristine oxidation state (+4). Zn 2+ cations do not electrochemically participate in the conversion reaction, but migrating from tetrahedral to octahedral positions, they facilitate Li-ion transport within lattice channels opened by their migration. Partially reversible crystal phase transitions are observed., (© 2023 The Authors. Small published by Wiley-VCH GmbH.)

Herein, we report the study of atomically precise Au x Ag 25- x nanoclusters (NCs) toward photocatalytic hydrogen evolution. The incorporation of Au atoms into Ag 25 NCs not only narrowed the HOMO-LUMO gaps but also created an interstitial Au-Ag microenvironment, which promoted the photogenerated charge carrier utilization and optimized the reaction dynamics.

CuO-based nanostructures have been widely investigated in catalysis, sensing, and energy conversion and storage in recent years. The unique properties of these nanostructures are largely related to the morphology and crystallinity of CuO. The controlled deposition of conformal CuO thin films by atomic layer deposition (ALD) has remained challenging until now owing to the limited understanding of the nucleation behavior and growth process. Here, a novel ALD process for copper oxide was developed using copper(II) trifluoroacetylacetonate [Cu(tfacac) 2 ] as the metal precursor. The nucleation and initial growth of a CuO film are strongly dependent on the surface OH concentration. A continuous particulate-like CuO film was grown on OH-abundant pristine SiO 2 particles, whereas the surface of the annealed SiO 2 particles (presenting mostly isolated OH groups) remained uncoated under the same growth conditions. Moreover, a uniform and conformal CuO film was grown on covalently functionalized CNTs under identical conditions as pristine SiO 2 particles. This study provides a strategy for tailoring the structure and the properties of thin films via ALD, which is promising for designing well-tailored nanostructures for various applications.

Metal oxide semiconductor (MOS) thin films are of critical importance to both fundamental research and practical applications of gas sensors. Herein, a high-performance H 2 sensor based on palladium (Pd) and rhodium (Rh) co-functionalized Fe 2 O 3 films with an ultrathin thickness of 8.9 nm deposited by using atomic layer deposition is reported. The sensor delivers an exceptional response of 105.9 toward 10 ppm H 2 at 230 °C, as well as high selectivity, immunity to humidity, and low detection limit (43 ppb), which are superior to the reported MOS sensors. Importantly, the Fe 2 O 3 film sensor under dynamic H 2 detection is for the first time observed by operando transmission electron microscopy, which provides deterministic evidence for structure evolution of MOS during sensing reactions. To further reveal the sensing mechanism, density functional theory calculations are performed to elucidate the sensitization effect of PdRh catalysts. Mechanistic studies suggest that Pd promotes the adsorption and dissociation of H 2 to generate PdH x , while Rh promotes the dissociation of oxygen adsorbed on the surface, thereby jointly promoting the redox reactions on the films. A wireless H 2 detection system is also successfully demonstrated using the thin film sensors, certifying a great potential of the strategy to practical sensors., (© 2023 Wiley-VCH GmbH.)

Chiral inorganic superstructures have received considerable interest due to the chiral communication between inorganic compounds and chiral organic additives. However, the demanding fabrication and complex multilevel structure seriously hinder the understanding of chiral transfer and self-assembly mechanisms. Herein, we use chiral CuO superstructures as a model system to study the formation process of hierarchical chiral structures. Based on a simple and mild synthesis route, the time-resolved morphology and the in situ chirality evolution could be easily followed. The morphology evolution of the chiral superstructure involves hierarchical assembly, including primary nanoparticles, intermediate bundles, and superstructure at different growth stages. Successive redshifts and enhancements of the CD signal support chiral transfer from the surface penicillamine to the inorganic superstructure. Full-field electro-dynamical simulations reproduced the structural chirality and allowed us to predict its modulation. This work opens the door to a large family of chiral inorganic materials where chiral molecule-guided self-assembly can be specifically designed to follow a bottom-up chiral transfer pathway., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Metal-organic frameworks (MOFs) with encapsulated nanoparticles (NPs) enjoy a vastly expanded application potential in catalysis, filtration, and sensing. The selection of particular modified core-NPs has yielded partial successes in overcoming lattice mismatch. However, restrictions on the choice of NPs not only limit the diversity, but also affect the properties of the hybrid materials. Here, we show a versatile synthesis strategy using a representative set of seven MOF-shells and six NP-cores that are fine-tuned to incorporate from single to hundreds of cores in mono-, bi-, tri- and quaternary composites. This method does not require the presence of any specific surface structures or functionalities on the pre-formed cores. Our key point is to regulate the diffusion rate of alkaline vapors that deprotonate organic linkers and trigger the controlled MOF-growth and encapsulation of NPs. This strategy is expected to pave the way for the exploration of more sophisticated MOF-nanohybrids., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Background: Pancreatic lipase (PL) is a key lipolytic enzyme in humans for the digestion and absorption of dietary fats. Thereby, PL is a well-recognized target in the management of obesity and its inhibition attracts the interest of researchers globally. The screening of new natural PL inhibitors as alternative strategy to the synthesis of chemical ones represents nowadays a hot topic in research. The main challenge in this matter is the lack of a universal analytical method allowing the monitoring of PL activity and the reliable quantification of lipid digestion products., Results: The (normal phase)-high-performance liquid chromatography-evaporative light scattering detector [(NP)-HPLC-ELSD] method proposed in this work represents a direct and rapid strategy to simultaneously quantify the products obtained from in vitro PL digestion. As one of the main novelties, the triacylglycerol (TAG) fraction from extra-virgin olive oil was selected as natural substrate. The PL activity was measured by monitoring the levels of remaining TAGs and formed free fatty acids (FFAs), using Orlistat as known inhibitor. The method validation confirmed the adequacy of the analytical method for quantitative purposes, showing high recovery percentage values (between 99% and 103%) and low relative standard deviation (RSD%) values (between 2% and 7%) for triolein and oleic acid standard solutions, as well as appreciably low limit of detection (LOD) and limit of quantification (LOQ) values (respectively 58 and 177 ng mL -1 for triolein; 198 and 602 ng mL -1 for oleic acid). Finally, the developed HPLC-ELSD method was successfully applied to evaluate the inhibitory effect of a polyphenolic extract obtained from apple pomace. The results showed a comparable inhibition degree between a 4.0 mg mL -1 apple pomace solution and a 1.0 μg mL -1 Orlistat solution., Conclusion: The proposed innovative method reveals highly sensitive and simple to follow the fate of PL digestion, thus opening the way to further investigations in the research of new potentially anti-obesity compounds. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Changes in electronic and compositional structures of Pt-Ni electrocatalysts with 44% of Ni fraction with repeated chemical dealloying have been studied. By comparing the Pt-enriched surfaces formed using hydroquinone and sulfuric acid as a leaching agent, we found that hydroquinone generated Pt-enriched surfaces exhibit the highest oxygen reduction reaction (ORR) activity after repeating the treatment twice. In particular, it was found that while sulfuric acid causes an uncontrollable dissolution of Ni clusters, the unique selectivity of hydroquinone allows the preferential dissolution of Ni atoms alloyed with Pt. Despite its wide usage in the field, the results show that traditional acid leaching is unsuitable for Pt-Ni alloys with a high Ni content and an incomplete alloying level. We finally proved that the unique and lasting selectivity of hydroquinone enables an incompletely alloyed Pt-Ni catalyst to obtain a highly ORR active Pt shell region without an extensive loss of Ni.

High-entropy oxide nanofibers, based on equimolar (Cr,Mn,Fe,Co,Ni), (Cr,Mn,Fe,Co,Zn) and (Cr,Mn,Fe,Ni,Zn) combinations, were prepared by electrospinning followed by calcination. The obtained hollow nanofibers exhibited a porous structure consisting of interconnected nearly strain-free (Cr 1/5 Mn 1/5 Fe 1/5 Co 1/5 Ni 1/5 ) 3 O 4 , (Cr 1/5 Mn 1/5 Fe 1/5 Co 1/5 Zn 1/5 ) 3 O 4 and (Cr 1/5 Mn 1/5 Fe 1/5 Ni 1/5 Zn 1/5 ) 3 O 4 single crystals with a pure Fd 3̄ m spinel structure. Oxidation state of the cations at the nanofiber surface was assessed by X-ray photoelectron spectroscopy and cation distributions were proposed satisfying electroneutrality and optimizing octahedral stabilization. The magnetic data are consistent with a distribution of cations that satisfies the energetic preferences for octahedral vs. tetrahedral sites and is random only within the octahedral and tetrahedral sublattices. The nanofibers are ferrimagnets with relatively low critical temperature more similar to cubic chromites and manganites than to ferrites. Replacing the magnetic cations Co or Ni with non-magnetic Zn lowers the critical temperature from 374 K (Cr,Mn,Fe,Co,Ni) to 233 and 105 K for (Cr,Mn,Fe,Ni,Zn) and (Cr,Mn,Fe,Co,Zn), respectively. The latter nanofibers additionally have a low temperature transition to a reentrant spin-glass-like state.

Niobium pentoxides have received considerable attention and are promising anode materials for lithium-ion batteries (LIBs), due to their fast Li storage kinetics and high capacity. However, their cycling stability and rate performance are still limited owing to their intrinsic insulating properties and structural degradation during charging and discharging. Herein, a series of mesoporous Nb 2 O 5 @TiO 2 core-shell spherical heterostructures have been prepared for the first time by a sol-gel method and investigated as anode materials in LIBs. Mesoporosity can provide numerous open and short pathways for Li + diffusion; meanwhile, heterostructures can simultaneously enhance the electronic conductivity and thus improve the rate capability. The TiO 2 coating layer shows robust crystalline skeletons during repeated lithium insertion and extraction processes, retaining high structural integrity and, thereby, enhancing cycling stability. The electrochemical behavior is strongly dependent on the thickness of the TiO 2 layer. After optimization, a mesoporous Nb 2 O 5 @TiO 2 core-shell structure with a ∼13 nm thick TiO 2 layer delivers a high specific capacity of 136 mA h g -1 at 5 A g -1 and exceptional cycling stability (88.3% retention over 1000 cycles at 0.5 A g -1 ). This work provides a facile strategy to obtain mesoporous Nb 2 O 5 @TiO 2 core-shell spherical structures and underlines the importance of structural engineering for improving the performance of battery materials.

Pumpkin is considered a functional food with beneficial effects on human health due to the presence of interesting bioactives. In this research, the impact of unconventional ultrasound-assisted extraction (UAE) and microwave-assisted extraction techniques on the recovery of total non-polar carotenoids from Cucurbita moschata pulp was investigated. A binary (hexane:isopropanol, 60:40 v/v ) and a ternary (hexane:acetone:ethanol, 50:25:25 v/v/v ) mixture were tested. The extracts were characterized for their antioxidant properties by in vitro assays, while the carotenoid profiling was determined by high-performance liquid chromatography coupled with a diode array detector. UAE with the binary mixture (30 min, 45 °C) was the most successful extracting technique, taking into consideration all analytical data and their correlations. In parallel, solid lipid nanoparticles (SLN) were optimized for the encapsulation of the extract, using β-carotene as a reference compound. SLN, loaded with up to 1% β-carotene, had dimensions (~350 nm) compatible with increased intestinal absorption. Additionally, the ABTS ((2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay showed that the technological process did not change the antioxidant capacity of β-carotene. These SLN will be used to load an even higher percentage of the extract without affecting their dimensions due to its liquid nature and higher miscibility with the lipid with respect to the solid β-carotene.

We introduce for the first time a core-shell structure composed of nanostructured self-standing titania nanotubes (TNT, light absorber) filled with Au nanowire (AuNW) array (electrons collector) applied to the photoelectrocatalytic water splitting. Its activity is four times higher than that of reference TNT-Ti obtained with the same anodizing conditions. The composite photoanode brings a distinct photocurrent generation (8 mA cm -2 at 1.65 V vs. RHE), and a high incident photon to current efficiency of 35% obtained under UV light illumination. Moreover, the full system concept of selected constitutional materials, based on Au noble metal and the very stable semiconductor TiO 2 , ensures a stable performance over a long-time range with no photocurrent loss during 100 on-off cycles of light illumination, after 12 h constant illumination and after one-month storage in air. We provide experimental evidence by photoelectron spectroscopy measurements, confirming that the electronic structure of TNT-AuNW is rectifying for electrons and ohmic for holes, while the electrochemical characterization confirms that the specific architecture of the photoanode supports electron separation due to the presence of a Schottky type contact and fast electron transport through the Au nanowires. Although the composite material shows an unchanged electrochemical band gap, typical for plain TiO 2 , we find this material to be an innovative platform for efficient photoelectrochemical water splitting under UV light illumination, with significant potential for further modifications, for example extension into the visible light regime.

Atomic layer deposition (ALD) is a deposition technique well-suited to produce high-quality thin film materials at the nanoscale for applications in transistors. This review comprehensively describes the latest developments in ALD of metal oxides (MOs) and chalcogenides with tunable bandgaps, compositions, and nanostructures for the fabrication of high-performance field-effect transistors. By ALD various n-type and p-type MOs, including binary and multinary semiconductors, can be deposited and applied as channel materials, transparent electrodes, or electrode interlayers for improving charge-transport and switching properties of transistors. On the other hand, MO insulators by ALD are applied as dielectrics or protecting/encapsulating layers for enhancing device performance and stability. Metal chalcogenide semiconductors and their heterostructures made by ALD have shown great promise as novel building blocks to fabricate single channel or heterojunction materials in transistors. By correlating the device performance to the structural and chemical properties of the ALD materials, clear structure-property relations can be proposed, which can help to design better-performing transistors. Finally, a brief concluding remark on these ALD materials and devices is presented, with insights into upcoming opportunities and challenges for future electronics and integrated applications., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Heterostructures made from metal oxide semiconductors (MOS) are fundamental for the development of high-performance gas sensors. Since their importance in real applications, a thorough understanding of the transduction mechanism is vital, whether it is related to a heterojunction or simply to the shell and core materials. A better understanding of the sensing response of heterostructured nanomaterials requires the engineering of heterojunctions with well-defined core and shell layers. Here, we introduce a series of prototypes CNT- n MOS, CNT- p MOS, CNT- p MOS- n MOS, and CNT- n MOS- p MOS hierarchical core-shell heterostructures (CSHS) permitting us to directly relate the sensing response to the MOS shell or to the p-n heterojunction. The carbon nanotubes are here used as highly conductive substrates permitting operation of the devices at relatively low temperature and are not involved in the sensing response. NiO and SnO 2 are selected as representative p- and n-type MOS, respectively, and the response of a set of samples is studied toward hydrogen considered as model analyte. The CNT- n,p MOS CSHS exhibit response related to the n,p MOS-shell layer. On the other hand, the CNT- p MOS- n MOS and CNT- n MOS- p MOS CSHS show sensing responses, which in certain cases are governed by the heterojunctions between n MOS and p MOS and strongly depends on the thickness of the MOS layers. Due to the fundamental nature of this study, these findings are important for the development of next generation gas sensing devices.

Metal carbides are promising materials for electrocatalytic reactions such as water electrolysis. However, for application in catalysis for the oxygen evolution reaction (OER), protection against oxidative corrosion, a high surface area with facile electrolyte access, and control over the exposed active surface sites are highly desirable. This study concerns a new method for the synthesis of porous tungsten carbide films with template-controlled porosity that are surface-modified with thin layers of nickel oxide (NiO) to obtain active and stable OER catalysts. The method relies on the synthesis of soft-templated mesoporous tungsten oxide (mp. WO x ) films, a pseudomorphic transformation into mesoporous tungsten carbide (mp. WC x ), and a subsequent shape-conformal deposition of finely dispersed NiO species by atomic layer deposition (ALD). As theoretically predicted by density functional theory (DFT) calculations, the highly conductive carbide support promotes the conversion of Ni 2+ into Ni 3+ , leading to remarkably improved utilization of OER-active sites in alkaline medium. The obtained Ni mass-specific activity is about 280 times that of mesoporous NiO x (mp. NiO x ) films. The NiO-coated WC x catalyst achieves an outstanding mass-specific activity of 1989 A g Ni -1 in a rotating-disc electrode (RDE) setup at 25 °C using 0.1 m KOH as the electrolyte., (© 2021 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Fresh olive mill wastewaters phenolic extracts are of great interest as preservatives or fortifying ingredients but are characterized by limited stability. The purpose of this study was to use mesoporous silica to enhance their stability and preserve their antioxidant properties. The phenolic extracts were characterized for their composition by HPLC-DAD and included in a mesoporous matrix with or without a lipid coating. The inclusion complexes were characterized in terms of total phenolic content, radical scavenging capacity and in vitro antioxidative activity and cell compatibility. Besides, inclusion complex stability under different storage conditions (22 and 37 °C, 75% relative humidity, 1 month) was evaluated. The inclusion process was nearly quantitative and modified neither the total phenolic content nor the total antioxidant capacity. None of the inclusion complex concentrations assayed on the HT29 cell line showed toxicity. Moreover, HT29 cells treated with the inclusion complex exhibited a significant antioxidant effect, while the lipid coating impaired the antioxidant activity. The complexes without lipid were stable under all the investigated conditions, while the lipid-coated products were less stable under the more drastic conditions. Overall, inclusion complexes in mesoporous silica have suitable characteristics to be used for different applications, including food supplementation.

Taxifolin, also known as dihydroquercetin, possesses several interesting biological properties. The purpose of the study was to identify polymorphs of taxifolin prepared using crystallization in different solvents. Data from X-ray powder diffraction, differential scanning calorimetry, and thermogravimetry enabled us to detect six different crystalline phases for taxifolin. Besides the already known fully hydrated phase, one partially hydrated phase, one monohydrated phase, two anhydrous polymorphs, and one probably solvated phase were obtained. The unit cell parameters were defined for three of them, while one anhydrous polymorph was fully structurally characterized by X-ray powder diffraction data. Scanning electron microscopy and hot stage microscopy were also employed to characterize the crystallized taxifolin powders. The hydrate and anhydrous forms showed remarkable stability in drastic storage conditions, and their solubility was deeply evaluated. The anhydrous form converted into the hydrate form during the equilibrium solubility study and taxifolin equilibrium solubility was about 1.2 mg/mL. The hydrate taxifolin intrinsic dissolution rate was 56.4 μg cm -2 min -1 . Using Wood's apparatus, it was not possible to determine the intrinsic dissolution rate of anhydrous taxifolin that is expected to solubilize more rapidly than the hydrate form. In view of its high stability, its use can be hypothesized.

Ligands in ligand-protected metal clusters play a crucial role, not only because of their interaction with the metal core, but also because of the functionality they provide to the cluster. Here, we report the utilization of secondary phosphine oxide (SPO), as a new family of functional ligands, for the preparation of an undecagold cluster Au11-SPO . Different from the commonly used phosphine ligand (i.e., triphenylphosphine, TPP), the SPOs in Au11-SPO work as electron-withdrawing anionic ligands. While coordinating to gold via the phosphorus atom, the SPO ligand keeps its O atom available to act as a nucleophile. Upon photoexcitation, the clusters are found to inject holes into p-type semiconductors (here, bismuth oxide is used as a model), sensitizing the p-type semiconductor in a different way compared to the photosensitization of a n-type semiconductor. Furthermore, the Au11-SPO /Bi 2 O 3 photocathode exhibits a much higher activity toward the hydrogenation of benzaldehyde than a TPP-protected Au 11 -sensitized Bi 2 O 3 photocathode. Control experiments and density functional theory studies point to the crucial role of the cooperation between gold and the SPO ligands on the selectivity toward the hydrogenation of the C═O group in benzaldehyde.

We report CNT/Al2O3 core-shell nanostructures for the electrochemical detection of dihydroxybenzene (DHB) isomers. Amorphous films of Al2O3 (1.2-15.4 nm in thickness) are uniformly deposited onto the inner and outer walls of CNTs by atomic layer deposition. The effect of the Al2O3 shell thickness on the electrochemical detection of dihydroxybenzene isomers was explored using cyclic and square-wave voltammetry. The best sensing properties are found at a shell thickness of approx. 2.4 nm (CNT/Al2O3(9) sensor), where the oxidation peak currents (sensor-signal) increased ca. 10 times as compared to a sensor fabricated with non-coated CNTs. All of the three DHB isomers (hydroquinone, catechol and resorcinol) are independently detected in the concentration ranges of 2-1000 μmol L-1, 0.5-700 μmol L-1 and 3.5-500 μmol L-1, respectively. The sensors show reliable repeatability, reproducibility, long-term stability, and applicability in the analysis of real samples. Based on these findings, a plausible mechanism is proposed highlighting the role of the Al2O3-shell.

We report on a Cu(ii) catalyzed process for the production of cysteine based chiral carbon dots; the process does not require any thermal treatment and the carbon dot formation is driven by the production of reactive radical species that are generated in the reaction media by the catalytic role played by the multivalent transition metal. The nanomaterial presents a well-defined chirality and the enantioselectivity of the synthesis is proved by the isolation of both the carbon dot enantiomers. We focused our attention on the processes that take place during the carbon dot formation and the relationship with the structure of the organic starting material. Thanks to the comparison of reactions conducted with different organic substrates whose thiyl radical chemistry is known, we recognized a non-trivial role of the radical hydrogen abstraction reactions in the carbon dot formation process. The reported process allows access to a large variety of analyses to monitor the reaction mixtures during the reaction course. Finally, we report a detailed analysis on the evolution of optical chirality during the synthesis and related this feature with the formation mechanism of the nanomaterial revealing significant evidence on the chirality origin and structure of chiral carbon dots.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) hold great promise for room temperature (RT) NO 2 sensors. However, the exposure of the edges of TMDs with high adsorption capability and electronic activity remains a great obstacle to achieve high sensor sensitivity. Herein, we demonstrate a high-performance RT NO 2 gas sensor based on WS 2 nanosheets/carbon nanofibers (CNFs) composite with abundant intentionally exposed WS 2 edges. Few-layer WS 2 nanosheets are anchored on CNFs through a hydrothermal process. The approach permits to achieve a coating presenting an optimized active surface area and accessibility of the sensing layers. The exposure of WS 2 edges remarkably improves the sensing properties. Consequently, the WS 2 @CNFs composite exhibits excellent selectivity to NO 2 at RT with improved response and much lower detection limit in comparison to the WS 2 and CNFs counterparts. Density functional theory (DFT) calculations verify a surprisingly strong NO 2 adsorption on WS 2 edge sites (adsorption energy 3.40 eV) with a partial charge transfer of 0.394e, while a week adsorption on the basal surface of WS 2 (adsorption energy 0.25 eV) with a partial charge transfer of 0.171e. The strategy proposed herein will be instructive to the design of efficient material structures for low-power NO 2 sensors with optimized performances., (Copyright © 2021. Published by Elsevier B.V.)

One-dimensional (1D) electrospun nanomaterials have attracted significant attention due to their unique structures and outstanding chemical and physical properties such as large specific surface area, distinct electronic and mass transport, and mechanical flexibility. Over the past years, the integration of metal sulfides with electrospun nanomaterials has emerged as an exciting research topic owing to the synergistic effects between the two components, leading to novel and interesting properties in energy, optics and catalysis research fields for example. In this review, we focus on the recent development of the preparation of electrospun nanomaterials integrated with functional metal sulfides with distinct nanostructures. These functional materials have been prepared via two efficient strategies, namely direct electrospinning and post-synthesis modification of electrospun nanomaterials. In this review, we systematically present the chemical and physical properties of the electrospun nanomaterials integrated with metal sulfides and their application in electronic and optoelectronic devices, sensing, catalysis, energy conversion and storage, thermal shielding, adsorption and separation, and biomedical technology. Additionally, challenges and further research opportunities in the preparation and application of these novel functional materials are also discussed.

Hydrogen is a fuel with a potentially zero-carbon footprint viewed as a viable alternative to fossil fuels. It can be produced in a large scale via electrochemical water splitting using electricity derived from renewable sources, but this would require highly active, inexpensive, and stable hydrogen evolution reaction (HER) catalysts to replace the Pt benchmark. Transition-metal phosphides (TMPs) are potential Pt replacements owing to their generally high activity as well as versatility as HER catalysts for different pH media. This review summarizes the recent progress in the development of TMP HER electrocatalysts, focusing on the strategies that have been recently explored to tune the activity in acidic, neutral, and basic media. These strategies are the doping of TMPs with metal and nonmetal elements, fabrication of multimetallic phosphide phases, and construction of multicomponent heterostructures comprising TMPs and another component such as a different TMP or a metal oxide/hydroxide. The synthetic methods utilized to design the catalysts are also presented. Finally, the challenges still remaining and future research directions are discussed.

Purpose: Cerebrovascular disease (CVD) is considered a major risk factor for fatal outcome in COVID-19. We aimed to evaluate the possible association between computed tomography (CT) signs of chronic CVD and mortality in infected patients., Materials and Methods: We performed a double-blind retrospective evaluation of the cerebral CT scans of 83 COVID-19 patients looking for CT signs of chronic CVD. We developed a rapid visual score, named CVD-CT, which summarized the possible presence of parietal calcifications and dolichosis, with or without ectasia, of intracranial arteries, areas of chronic infarction and leukoaraiosis. Statistical analysis was carried out with weighted Cohen's K test for inter-reader agreement and logistic regression to evaluate the association of in-hospital mortality with CVD-CT, chest X-ray (CXR) severity score (Radiographic Assessment of Lung Edema-RALE) for radiological assessment of pulmonary disease, sex and age., Results: CVD-CT (odds ratio 1.6, 95% C.I. 1.2-2.1, p = 0.001) was associated with increased risk of mortality. RALE showed an almost significant association (odds ratio 1.05, 95% C.I. 1-1.1, p 0.06), whereas age and sex did not., Conclusion: CVD-CT is associated with risk of mortality in COVID-19 patients. The presence of CT signs of chronic CVD may be correlated to a condition of fragility of the circulatory system, which constitutes a key risk factor for death in infected patients.

We report a microwave assisted synthesis of NaNbO3 perovskite mesocrystals with a hierarchical morphology formed by the self-assembly of nanoparticles in particle clusters. The synthesis method combines non-aqueous sol-gel synthesis and microwave heating in a single step process that allows us to isolate crystalline single phase NaNbO3 in few minutes. A detailed investigation of the effect of the reaction temperature on the crystallinity and morphology of the product was conducted. The synthesis stabilizes the unusual orthorhombic phase Pmma, a property that can be ascribed to the crystal size (24 nm). TEM and SAED analyses show that the hierarchical polycrystalline particles behave as single crystals, a feature related to a non-classical crystallization mechanism. Moreover, the optical bandgap of this NaNbO3 phase was estimated for the first time. The results suggest the potential of this synthetic procedure for the fast production of high quality tertiary oxide nanocrystals.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) such as MoS2 are materials for multifarious applications such as sensing, catalysis, and energy storage. Due to their peculiar charge-transport properties, it is always desired to control their morphologies from vertical nanostructures to horizontal basal-plane oriented smooth layers. In this work, we established a low-temperature ALD process for MoS2 deposition using bis(t-butylimino)bis(dimethylamino)molybdenum(vi) and H2S precursors. The ALD reaction parameters, including reaction temperature and precursor pulse times, are systematically investigated and optimized. Polycrystalline MoS2 is conformally deposited on carbon nanotubes, Si-wafers, and glass substrates. Moreover, the morphologies of the deposited MoS2 films are tuned from smooth film to vertically grown flakes, and to nano-dots, by controlling the reaction parameters/conditions. It is noticed that our MoS2 nanostructures showed morphology-dependent optical and electrocatalytic properties, allowing us to choose the required morphology for a targeted application.

The deposition of an atomically precise nanocluster, for example, Ag 44 (SR) 30 , onto a large-band-gap semiconductor such as TiO 2 allows a clear interface to be obtained to study charge transfer at the interface. Changing the light source from visible light to simulated sunlight led to a three orders of magnitude enhancement in the photocatalytic H 2 generation, with the H 2 production rate reaching 7.4 mmol h -1  g catalyst -1 . This is five times higher than that of TiO 2 modified with Ag nanoparticles and even comparable to that of TiO 2 modified with Pt nanoparticles under similar conditions. Energy band alignment and transient absorption spectroscopy reveal that the role of the metal clusters is different from that of both organometallic complexes and plasmonic nanoparticles: A type II heterojunction charge-transfer route is achieved under UV/Vis irradiation, with the cluster serving as a small-band-gap semiconductor. This results in the clusters acting as co-catalysts rather than merely photosensitizers., (© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

In the last years, hematite has been utilized in a plethora of applications. High aspect-ratio nanohematite and hematite/silica core-shell nanostructures are arousing growing interest for applications exploiting their magnetic properties. Atomic layer deposition (ALD) is utilized here to produce SiO 2 -coated α-Fe 2 O 3 nanofibers (NFs) through two synthetic routes, viz. electrospinning/calcination/ALD or electrospinning/ALD/calcination. The number of ALD cycles (10-100) modulates the coating thickness, while the chosen route controls the final nanostructure. Porous and partially hollow NFs are produced. Their hierarchical structure and the nature and density of the lattice defects and strain are characterized by combining electron microscopy, diffraction, and spectroscopy techniques. The uncoated hematite NFs mostly have surface-related strain, which is attributed to oxygen vacancies/Fe 2+ sites. ALD coating causes microstrain release and decrease of surface states. NFs calcined after ALD have extensive bulk strain, which is ascribed to the presence of dislocations throughout the volume of the NF grains. Bulk strain determines the remanent magnetization, whereas both surface and bulk strain influence the coercive field and the thermal behavior across the Morin temperature, including the magnetic memory effect. To the best of the authors' knowledge, the correlation between lattice defects/strain and magnetic properties of SiO 2 -coated α-Fe 2 O 3 NFs has never been reported before.

The gas-sensing properties and mechanism and the role of the shell thickness of structurally well-defined SnO 2 /NiO heterostructures are studied. One-dimensional (1D) SnO 2 /NiO core-shell nanowires (CSNWs) were produced by a two-step process; single-crystalline SnO 2 -core nanowires (NWs) were synthesized by vapor-liquid-solid (VLS) deposition and then decorated with a polycrystalline NiO-shell layer by atomic layer deposition (ALD). The thickness of the NiO-shell layer was precisely controlled between 2 and 8.2 nm. The electrical conductance of the sensors was decreased many orders of magnitude with the NiO coating, suggesting that the conductivity of the sensors is dominated by Schottky barrier junctions across the n (core)- p (shell) interfaces. The gas-sensing response of pristine SnO 2 NWs and SnO 2 /NiO CSNWs sensors with various thicknesses of the NiO-shell layers was investigated toward hydrogen at various temperatures. The response of the SnO 2 /NiO- X ( X is the number of ALD cycles) CSNWs significantly depends on the thickness of the NiO-shell layer. The SnO 2 /NiO-100 sensor showed the best performance (NiO-shell thickness ca. 4.1 nm), where the radial modulation of the space-charge region is maximized. The sensing response of the SnO 2 /NiO-100 sensor was 114 for 500 ppm of hydrogen at 500 °C, which was about four times higher than the response of pristine SnO 2 NWs. The sensing mechanism is mainly based on the formation of a p-n junction at the p- NiO-shell and the n- SnO 2 -core interface and the modulation of the hole-accumulation region in the NiO-shell layer. The remarkable performance of the SnO 2 /NiO CSNWs sensors toward hydrogen is attributed to the high surface to volume ratio of the 1D SnO 2 core-NWs, the conformal NiO shell layer, and the optimized shell layer thickness radially modulating the space-charge regions.

The search for new cathode materials is primordial for alkali-ion battery systems, which are facing a constantly growing demand for high energy density storage devices. In quest of more performing active compounds on the positive side, anhydrous iron(III) fluoride demonstrated to be a good compromise in terms of high capacity, operating voltage, and low cost. However, its reaction toward lithium leads to complicated insertion/conversion reactions, which hinder its performances in Li-ion cells. Cycling this material against larger ions such as sodium and potassium is hard or simply impossible due to the size of the channels of the FeF 3 framework impeding ions diffusion. Herein, we propose a strategy based on the use of cubic perovskite AFeF 3 (A = K + , NH 4 + ) as starting materials, allowing the straightforward insertion (after a first disinsertion of the alkali and/or NH 4 + ion) of lithium within the structure and enabling the cycling toward larger alkali ions such as sodium and potassium. For example, a cubic KFeF 3 perovskite, produced by a facile synthesis method, shows superior rate capability toward lithium retaining a capacity of up to 132 mA·h·g -1 at 5 C or of 120 mA·h·g -1 at 5 C toward sodium and enabling cycling toward potassium. Moreover, cubic NH 4 FeF 3 perovskite is discussed for the first time as the suitable cathode material for alkali-ion batteries.

A well-structured anode nanomaterial, which can ensure electron and ion transport and avoid excessive pulverization, is of crucial importance to achieve high capacity with superior cycling stability for both sodium- and lithium-ion batteries (SIBs and LIBs). For the purpose of a superior rate performance, this work here has designed and successfully synthesized a new Na + /Li + storage nanomaterial of SCS/Sn 2 Fe@GO through loading of a Sn 2 Fe nanoalloy on sea-sponge-like carbon spheres (SCSs), followed by a graphene oxide (GO) wrapping process. In such a designed composite, the SCS skeleton ensures electronic conductivity and shorts Na + and Li + diffusion pathways, while the Sn 2 Fe nanoalloy delivers a high capacity and prevents excessive pulverization. The GO shell around SCS/Sn 2 Fe greatly enhances the cyclability. Used as an anode, the SCS/Sn 2 Fe@GO nanocomposite enables a high capacity up to 660 mAh g -1 at 50 mA g -1 , which is maintained without decay up to 800 cycles in SIBs, and up to 850 mAh g -1 at 500 mA g -1 after 3500 cycles in LIBs, proving its applicability in new-generation SIBs and LIBs.

Fluorine-containing polyanionic compounds have attracted much attention in the last few years as potential positive electrode materials for rechargeable batteries. With their formula A a M b X c O 4 Y d (A=Li, Na…; M=Ti, V, Mn, Fe, Co, Ni…; X=P or S, and Y=F, OH, O), they offer a very rich chemistry and their electrochemical properties can be tuned by carefully choosing the different constituting elements. However, synthesis approaches that allow these materials to be obtained at low temperature are almost nonexistent. In this paper, the use of a nonaqueous fluorolytic sol-gel approach is reported to synthesize a tavorite-type LiFePO 4 F material and its electrochemical characterization was performed. The obtained material displays an electrochemical performance that positively compares with the literature with an excellent cycling stability (115 mA h -1  g -1 after 100 cycles at C/2 rate). A slight change in the synthesis parameters allowed Li 2 CoPO 4 F to be successfully obtained, demonstrating the versatility of the reported route, which can be adapted to synthesize other fluorine-containing polyanionic compounds, which are of great interest for energy storage applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The atomically precise bimetallic nanocluster (NC), Au 24 Ag 20 (PhCC) 20 (SPy) 4 Cl 2 (1) (Py=pyridine), was employed for the first time as a stable photosensitizer for photoelectrochemical applications. The sensitization of TiO 2 nanotube arrays (TNA) with 1 greatly enhances the light-harvesting ability of the composite because 1 shows a high molar extinction coefficient (ϵ) in the UV/Vis region. Compared to a more standard Au 25 (SG) 18 -TNA (2-TNA; SG=glutathione) composite, 1-TNA shows a much better stability under illumination in both neutral and basic conditions. The precise composition of the photosensitizers enables a direct comparison of the sensitization ability between 1 and 2. With the same cluster loading, the photocurrent produced by 1-TNA is 15 times larger than that of 2-TNA. The superior performance of 1-TNA over 2-TNA is attributed not only to the higher light absorption ability of 1 but also to the higher charge-separation efficiency. Besides, a ligand effect on the stability of the photoelectrode and charge-transfer between the NCs and the semiconductor is revealed. This work paves the way to study the role of metal nanoclusters as photosensitizers at the atomic level, which is essential for the design of better material for light energy conversion., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

MoS 2 , a typical layered transition-metal dichalcogenide, is promising as an electrode material in supercapacitors. However, its low electrical conductivity could lead to limited capacitance if applied in electrochemical devices. Herein, a new nanostructure composed of hollow carbon-MoS 2 -carbon was successfully synthesized through an l-cysteine-assisted hydrothermal method by using gibbsite as a template and polydopamine as a carbon precursor. After calcination and etching of the gibbsite template, uniform hollow platelets, which were made of a sandwich-like assembly of partial graphitic carbon and two-dimensional layered MoS 2 flakes, were obtained. The platelets showed excellent dispersibility and stability in water, and good electrical conductivity due to carbon provided by the calcination of polydopamine coatings. The hollow nanoplate morphology of the material provided a high specific surface area of 543 m 2  g -1 , a total pore volume of 0.677 cm 3  g -1 , and fairly small mesopores (≈5.3 nm). The material was applied in a symmetric supercapacitor and exhibited a specific capacitance of 248 F g -1 (0.12 F cm -2 ) at a constant current density of 0.1 A g -1 ; thus suggesting that hollow carbon-MoS 2 -carbon nanoplates are promising candidate materials for supercapacitors., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

To meet the demands of long cycle life under high rate for lithium-ion batteries, the advancement of anode materials with stable structural properties is necessarily demanded. Such promotion needs to design reasonable structure to facilitate the transportation of electron and lithium ions (Li + ). Herein, a novel C/Fe 3 O 4 sea-sponge-like structure was synthesized by ultrasonic spray pyrolysis following thermal decomposition process. On the basis of sea-sponge carbon (SSC) excellences in electronic conductivity and short Li + diffusion pathway, nano-Fe 3 O 4 anchored on stable SSC skeleton can deliver high electrochemical performance with long cycle life under high rate. During electrochemical cycling, well-dispersed nano-Fe 3 O 4 in ∼6 nm not only averts excessive pulverization and is enveloped by solid electrolyte interphase film, but also increases Li + diffusion efficiency. The much improved electrochemical properties showed a capacity of around 460 mAh g -1 at a high rate of 1.5C with a retention rate of 93%, which is maintained without degradation up to 1000 cycles (1C = 1000 mA g -1 ).

Anhydrous nanoscopic CuF 2 is synthesized from alkoxides Cu(OR) 2 (R=Me, tBu) by their reaction either in pure liquid HF at -70 °C, or under solvothermal conditions at 150 °C using excess HF and THF as solvent. Depending on the synthesis method, nanoparticles of sizes between 10 and 100 nm are obtained. The compound is highly hygroscopic and forms different hydrolysis products under moist air, namely CuF 2 ⋅2 H 2 O, Cu 2 (OH)F 3 , and Cu(OH)F, of which only the latter is stable at room temperature. CuF 2 exhibits an electrochemical plateau at a potential of ≈2.7 V when cycled versus Li in half cell Li-ion batteries, which is attributed to a non-reversible conversion mechanism. The cell capacity in the first cycle depends on the particle size, being 468 mAh g -1 for ≈8 nm crystallite diameter, and 353 mAh g -1 for ≈12 nm crystallite diameter, referred to CuF 2 . However, such a high capacity cannot be sustained for several cycles and the capacity rapidly fades out. The cell voltage decreases to ≈2.0 V for CuF 2 ⋅2 H 2 O, Cu 2 (OH)F 3 , and Cu(OH)F. As all the compounds studied in this work show irreversible conversion reactions, it can be concluded that copper-based fluorides are unsuitable for Li-ion battery applications., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)