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Lead is one of the key metals of the all-inorganic lead halide perovskites. This work tailors novel architectures of lead's coordination sphere using a β-diketone (H-hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione) and a glyme (monoglyme, diglyme, triglyme, or tetraglyme) ligand. The coordination chemistry and thermal behaviour of these "Pb(hfa)2·glyme" adducts have been analysed through FT-IR spectroscopy, 1H and 13C NMR analyses, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Single-crystal X-ray diffraction studies provide evidence of the formation of a monomeric Pb(hfa)2·monoglyme structure. In order to validate the potentiality of these "Pb(hfa)2·glyme" precursors for the fabrication of Pb-based halide perovskites, a facile, one-step and low-temperature solution approach has been applied to prepare CsPbBr3 microcrystals with a process carried out in air under atmospheric pressure. Pure stoichiometric CsPbBr3 powders, obtained using Cs(hfa) and Br2 as cesium and bromide sources, respectively, show excellent stability under atmospheric conditions. Better results are obtained in terms of yield and stability from the diglyme and tetraglyme lead adducts. Field emission scanning electron microscopy (FE-SEM) indicates a good uniform morphology of cubic grains, while the structure and the 1 : 1 : 3 stoichiometry of Cs : Pb : Br are confirmed by X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX), respectively. Tauc plots derived from absorption spectroscopy point to optical energy band-gaps (Eg) in the 2.21–2.27 eV range, in agreement with literature data. The present research elucidates the potential of these novel "Pb(hfa)2·glyme" adducts as promising lead precursors for CsPbBr3 perovskite synthesis, paving the way for their implementation in various technological applications. [ABSTRACT FROM AUTHOR]

Lithium niobate is a lead-free material which has attracted considerable attention due to its excellent optical, piezoelectric, and ferroelectric properties. This research is devoted to the synthesis through an innovative sol–gel/spin-coating approach of polycrystalline LiNbO3 films on Si substrates. A novel single-source hetero-bimetallic precursor containing lithium and niobium was synthesized and applied to the sol–gel synthesis. The structural, compositional, and thermal characteristics of the precursor have been tested through attenuated total reflection, X-ray photoelectron spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The LiNbO3 films have been characterized from a structural point of view with combined X-ray diffraction and Raman spectroscopy. Field-emission scanning electron microscopy, energy dispersive X-ray analysis, and X-ray photoelectron spectroscopy have been used to study the morphological and compositional properties of the deposited films. [ABSTRACT FROM AUTHOR]

In the present work, an in-depth study on the sol-gel process for the fabrication of Eu-doped CaF2 materials in the form of thin films has been addressed for the production of down-shifting layers. Fine-tuning of the operative parameters, such as the annealing temperature, substrate nature and doping ion percentage, has been finalized in order to obtain Eu(III)-doped CaF2 thin films via a reproducible and selective solution process for down-shifting applications. An accurate balance of such parameters allows for obtaining films with high uniformity in terms of both their structural and compositional features. The starting point of the synthesis is the use of a mixture of Ca(hfa)2•diglyme•H2O and Eu(hfa)3•diglyme adducts, with a suited ratio to produce 5%, 10% and 15% Eu-doped CaF2 films, in a water/ethanol solution. A full investigation of the structural, morphological and compositional features of the films, inspected using X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDX), respectively, has stated a correlation between the annealing temperature and the structural characteristics and morphology of the CaF2 thin films. Interestingly, crystalline CaF2 films are obtained at quite low temperatures of 350–400 °C. The down-shifting properties, validated by taking luminescence measurements under UV excitation, have allowed us to correlate the local environment in terms of the degree of symmetry around the europium ions with the relative doping ion percentages. [ABSTRACT FROM AUTHOR]

The monoclinic structures of vanadium dioxide are widely studied as appealing systems due to a plethora of functional properties in several technological fields. In particular, the possibility to obtain the VO2 material in the form of thin film with a high control of structure and morphology represents a key issue for their use in THz devices and sensors. Herein, a fine control of the crystal habit has been addressed through an in-depth study of the metal organic chemical vapor deposition (MOCVD) synthetic approach. The focus is devoted to the key operative parameters such as deposition temperature inside the reactor in order to stabilize the P21/c or the C2/m monoclinic VO2 structures. Furthermore, the compositional purity, the morphology and the thickness of the VO2 films have been assessed through energy dispersive X-ray (EDX) analyses and field-emission scanning electron microscopy (FE-SEM), respectively. THz time domain spectroscopy is used to validate at very high frequency the functional properties of the as-prepared VO2 films. [ABSTRACT FROM AUTHOR]

Water electrolysis for green hydrogen production is gaining tremendous attention in the quest towards sustainable energy sources. At the heart of water splitting technology are the electrocatalysts, which facilitate the two half-cell reactions, i.e., the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with the latter being the most thermodynamically uphill. Herein, we managed to fabricate Ni 1-x Fe x O microflowers (μFs) with varying % of Fe doping (0 < x < 0.36) via an easy chemical bath deposition (CBD) method. The as-synthesized μFs drop-casted on graphene paper (GP) are then applied as electrocatalysts for OER. Compared to contrast catalysts, the electrocatalyst with x Fe = 0.1 exhibits a lower overpotential of 297 mV at a current density of 10 mA cm−2, Tafel slope of 44 mV dec−1 and unprecedented turnover frequency of 4.6 s−1 at 300 mV. It is believed that this remarkable electrochemical performance mainly stems from the synergistic effects of Ni and Fe species, working in harmony to enhance charge transfer kinetics and intrinsic activity of the catalyst. This work provides a promising avenue for developing cost-effective and highly active electrocatalysts as advanced electrodes for energy related applications. [Display omitted] • Highly active NiFe-based electrocatalysts synthesized by a simple chemical route. • Effect of Fe doping concentration on oxygen evolution reaction of NiO. • Exceptional turnover frequency of Fe-doped NiO electrodes in alkaline conditions. [ABSTRACT FROM AUTHOR]

Industrial development and urbanization have increased the emission of Volatile Organic Compounds (VOCs) into the atmosphere, causing environmental and health risks. Several approaches are used for their abatement, including chemical, thermo‐ and photo‐catalytic oxidations, but they are not fully satisfactory. In this work, a thermoplastic TiO2‐based photo‐catalyst was used as a coating layer of a glass‐reactor. Solar‐triggered photocatalytic degradation of ethanol, toluene, and acetone (used as model VOCs) highlights the better performance of the coated photoreactor than that of TiO2 nanopowder. The influence of the pollutant flow rate on the photodegradation performance of the system was also investigated, revealing an inverse relationship between degradation and flow rates. The experimental data suggest that our approach provides a cost‐effective and efficient way to boost the abatement of VOCs, useful for further industrial‐scale applications. The morphology and the compositional homogeneity of the nanocomposite coating were addressed through Field Emission Scanning Electron Microscopy coupled with Energy Dispersive X‐ray Analysis. [ABSTRACT FROM AUTHOR]

Great scientific effort has strived to develop a low-cost and sustainable electrocatalyst with high electrocatalytic activity and long-term stability in the field of water splitting. In this work non-noble metal based NiCoP alloys are burgeoned from catalytic Ni substrates via a facile and eco-friendly electroless deposition method under mild conditions. By appropriately tuning the cobalt content in the chemical bath, we realize NiCoP coatings with tailored Co concentration. The electrochemical investigations of coatings deposited on flat Ni indicate an optimal Co content of 17 at % (Ni 0.83 Co 0.17 P) to maximize OER performance. Impressively, the Ni 0.83 Co 0.17 P coating deposited on nickel foam exhibits remarkable OER catalytic activity (η = 295 mV at 10 mA cm−2), noteworthy catalytic kinetics (Tafel slope as small as 45 mV dec−1) and high rate of oxygen production for each active site (turnover frequency of 0.16 s−1 at 300 mV) in 1 M KOH. Importantly, the Ni 0.83 Co 0.17 P/NF demonstrates excellent long-term stability as inferred by continuous test for 25 h. Furthermore, a full alkaline electrolyzer is designed using Ni 0.83 Co 0.17 P/NF as the anode and Pt decorated Ni−P/NF as the cathode, which can drive overall water splitting with a potential as low as 1.60 V at 10 mA cm−2, and also shows outstanding long-term durability. The cheapness of the present preparation method as well as its suitability for large-scale production without the need of expensive raw materials and energy-consuming processes paves the way towards commercial production of transition metal phosphide-based electrocatalysts. [Display omitted] • NiCoP alloys were fabricated via a facile and cheap electroless deposition method. • NiCoP coatings with optimized composition showed high OER performance. • The intrinsic catalytic activity was assessed by evaluation of turnover frequency. • An efficient alkaline electrolyzer based on metal phosphides was constructed. [ABSTRACT FROM AUTHOR]

Substitution of the diglyme ligand of [Eu(hfa)3(diglyme)] (where hfa is hexafluoroacetylacetonate) with a simple 1,10-phenanthroline leads to a six-fold increase of the product μβEFISH, as measured by the Electric-Field-Induced Second Harmonic generation (EFISH) technique. Similarly, [Eu(tta)3(1,10-phenanthroline)] (where Htta is 2-thenoyltrifluoroacetone) is characterized by a large second-order NLO response. Both 1,10-phenanthroline europium complexes have great potential as multifunctional materials for photonics. [ABSTRACT FROM AUTHOR]

Nanocomposites obtained by the decoration of graphene-based materials with silver nanoparticles (AgNPs) have received increasing attention owing to their antimicrobial activity. However, the complex synthetic methods for their preparation have limited practical applications. This study aims to synthesize novel NanoHybrid Systems based on graphene, polymer, and AgNPs (namely, NanoHy-GPS) through an easy microwave irradiation approach free of reductants and surfactants. The polymer plays a crucial role, as it assures the coating layer/substrate compatibility making the platform easily adaptable for a specific substrate. AgNPs' loading (from 5% to 87%) can be tuned by the amount of Silver salt used during the microwave-assisted reaction, obtaining spherical AgNPs with average sizes of 5–12 nm homogeneously distributed on a polymer-graphene nanosystem. Interestingly, microwave irradiation partially restored the graphene sp2 network without damage of ester bonds. The structure, morphology, and chemical composition of NanoHy-GPS and its subunits were characterized by means of UV-vis spectroscopy, thermal analysis, differential light scattering (DLS), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray analysis (EDX), Atomic Force Microscopy (AFM), and High-Resolution Transmission Electron Microscopy (HRTEM) techniques. A preliminary qualitative empirical assay against the typical bacterial load on common hand-contacted surfaces has been performed to assess the antibacterial properties of NanoHy-GPS, evidencing a significative reduction of bacterial colonies spreading. [ABSTRACT FROM AUTHOR]

Increasing awareness of environmental concerns has strongly pushed the scientific community towards the search for new solutions for efficient removal of oils and organic solvents from water. Here, we report the preparation of multifunctional TiO2-coated melamine-formaldehyde (MF) sponges as absorbent material for oils and organic solvents in water. TiO2-coated MF sponges were fabricated through an environmentally friendly approach, consisting in a simple immersion of the sponge into an oleic acid-capped TiO2 nanoparticles dispersion. The adhesion of TiOle coating to the sponge was then improved by the deposition of a low surface energy diamond-like carbon (DLC) thin layer. Our results highlighted that the modified MF sponges possess superhydrophobic and oleophilic behaviour, inertness to corrosive environment, good durability and reusability. Furthermore, the superhydrophobic DLC/TiO2@sponges showed (1) novel self-cleaning properties towards an absorbed commercial organic dye (IR-270BKA, chosen as representative) under visible light irradiation and (2) enhanced flame-retardant behaviour respect to the pristine MF sponge. These findings point out an important added value of DLC/TiOle@sponges making them promising candidates for wastewater treatments. [ABSTRACT FROM AUTHOR]

The low efficiency of water electrolysis mostly arises from the thermodynamic uphill oxygen evolution reaction. The efficiency can be greatly improved by rationally designing low-cost and efficient oxygen evolution anode materials. Herein, we report the synthesis of Ni–P alloys adopting a facile electroless plating method under mild conditions on nickel substrates. The relationship between the Ni–P properties and catalytic activity allowed us to define the best conditions for the electroless synthesis of highperformance Ni–P catalysts. Indeed, the electrochemical investigations indicated an increased catalytic response by reducing the thickness and Ni/P ratio in the alloy. Furthermore, the Ni–P catalysts with optimized size and composition deposited on Ni foam exposed more active sites for the oxygen evolution reaction, yielding a current density of 10 mA cm−2 at an overpotential as low as 335 mV, exhibiting charge transfer resistances of only a few ohms and a remarkable turnover frequency (TOF) value of 0.62 s−1 at 350 mV. The present study provides an advancement in the control of the electroless synthetic approach for the design and large-scale application of high-performance metal phosphide catalysts for electrochemical water splitting. [ABSTRACT FROM AUTHOR]