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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]

For the first time, the simultaneous synthesis and deposition of heterometallic porphyrin conjugated polymer thin films from a simple and scalable gas‐phase approach are reported. The oxidative chemical vapor deposition (oCVD) reaction of 5,15‐(diaryl) porphyrins chelated with different metal cations (M = Co(II), Ni(II), Zn(II), Cu(II), Pd(II)) readily yields the formation of new hetero‐metalated fused porphyrin tapes, such as evidenced by in‐depth high‐resolution mass spectrometry studies. The impact of the coreactants on the regioselectivity of the intermolecular dehydrogenative coupling reaction and the formation of double or triple bonds between the porphyrin units is demonstrated. The oCVD reaction of multiple porphyrins brings the possibility to easily engineer the chemical features and the electronic and optoelectronic properties of these highly conjugated porphyrin polymers. Particularly, it is demonstrated that porphyrin conjugated polymers having different chelated metal cations can achieve higher electrical conductivities and promote narrower bandgaps. The gas‐phase approach presented herein overcomes the main limitations of the conventional solution‐based approaches and opens the path to the engineering of a novel class donor–acceptor heterometallic polymers with high interest in several fields including multimetallic electrocatalysis, photocatalysis, sensing, and nonlinear optics applications. [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 development of highly active, low-cost, and robust electrocatalysts for the oxygen evolution reaction (OER) is a crucial endeavor for the clean and economically viable production of hydrogen via electrochemical water splitting. Herein, cuprous oxide (Cu 2 O) thin films are deposited on silver nanowire (AgNW) networks by atmospheric-pressure spatial atomic layer deposition (AP-SALD). AgNW@Cu 2 O nanocomposites supported on conductive copper electrodes exhibited superior OER activity as compared to bare copper substrate and bare AgNWs. Moreover, a relationship between Cu 2 O thickness and OER activity was established. Notably, the most effective catalyst (AgNW@50nm-thick Cu 2 O) demonstrated very high OER activity with a low overpotential of 409 mV to deliver a current density of 10 mA cm -2 ( η 10 ), a Tafel slope of 47 mV dec -1 , a turnover frequency (TOF) of 4.2 s -1 at 350 mV, and good durability in alkaline media (1 M KOH). This highlights the potential of AgNWs as a powerful platform for the formation of highly efficient copper oxide catalysts towards OER. This work provides a foundation for the development of nanostructured Cu-based electrocatalysts for future clean energy conversion and storage systems., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)