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TiO2:Eu3+ nanoparticles with varying europium concentrations were successfully synthesized via a one-pot sol–gel approach using a molecular heterometallic single-source precursor (SSP) Eu-Ti. For comparison, nanomaterials with similar europium levels were also produced by impregnating europium salts onto the same TiO2 substrate. All the nanomaterials were thoroughly characterized using Eu elemental analysis, powder X-ray diffraction (XRD), scanning (SEM), transmission (TEM), scanning transmission electron microscopy (STEM), Brunauer–Emmett–Teller (BET) analysis, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and photoluminescence (PL). This low-temperature synthesis yielded crystalline powders, and calcination at 400 °C was performed to remove surface organic impurities, enabling a precise comparison of the final nanomaterials. While both preparation methods produced materials with similarly dispersed and localized dopants on the TiO2 surface, photoluminescence studies revealed that the SSP-derived nanomaterials exhibited significantly superior electro-optical properties. This enhanced efficiency is attributed to the co-hydrolysis of both reactants, which facilitates an optimized interface between the crystalline TiO2 core and the dopant-rich amorphous surface, thereby enabling far more effective charge transfer than that achieved by impregnation. [ABSTRACT FROM AUTHOR]

Dinuclear transition metal complexes with direct metal–metal interactions have the potential to generate unique reactivities and properties. Using asymmetric triazine ligands HN3tBuR (R = Et, iPr, nBu) featuring different alkyl substituents at 1,3-N centers, we report here the first rational synthesis of 'tetragonal lantern' type Fe(II) triazenides [Fe2(N3tBuR)4] [R = Et (1), iPr (2), nBu (3)] having an exceptionally short Fe–Fe distance (2.167–2.174 Å). Unlike the previously reported lantern structures with related amidinate or guanidinate ligands, highly air-sensitive 1–3 show a lower spin ground state, as indicated by Mössbauer, 1H NMR and DFT studies. [ABSTRACT FROM AUTHOR]

Efficient and selective extractions of precious and critical metal ions such as Au(III) and Pd(II) were investigated using zirconia nanoparticles surface modified with different organic mono- and di-carbamoyl phosphonic acid ligands. The modification is made on the surface of commercial ZrO2 that is dispersed in aqueous suspension and was achieved by optimizing the Bronsted acid–base reaction in ethanol/H2O solution (1:2), resulting in inorganic–organic systems of ZrO2-Ln (Ln: organic carbamoyl phosphonic acid ligand). The presence, binding, amount, and stability of the organic ligand on the surface of zirconia nanoparticles were confirmed by different characterizations such as TGA, BET, ATR-FTIR, and 31P-NMR. Characterizations showed that all the prepared modified zirconia had a similar specific surface area (50 m2.g−1) and the same amount of ligand on the zirconia surface in a 1:50 molar ratio. ATR-FTIR and 31P-NMR data were used to elucidate the most favorable binding mode. Batch adsorption results showed that (i) ZrO2 surface modified with di-carbamoyl phosphonic acid ligands had the highest adsorption efficiency to extract metals than mono-carbamoyl ligands, and (ii) higher hydrophobicity of the ligand led to better adsorption efficiency. The surface-modified ZrO2 with di-N,N-butyl carbamoyl pentyl phosphonic acid ligand (ZrO2-L6) showed promising stability, efficiency, and reusability in industrial applications for selective gold recovery. In terms of thermodynamic and kinetic adsorption data, ZrO2-L6 fits the Langmuir adsorption model and pseudo-second-order kinetic model for the adsorption of Au(III) with maximum experimental adsorption capacity qmax = 6.4 mg.g−1. [ABSTRACT FROM AUTHOR]

In aircraft and spacecraft, outside air is not directly fed to the passenger because it contains ozone at elevated altitudes. The decomposition of low concentration ozone in the air was carried out at 25 °C by catalytic oxidation on Pd-based catalysts supported on a high surface area hybrid TiO2. The use of these hybrid catalysts has shown a beneficial effect, both on the catalytic activity and on the catalyst stability. Kinetic studies showed that the most promising catalytic phase (Pd/TiO2_100) was the one obtained from the TiO2 support containing the lowest content of citrate ligands and leading to small Pd particles (around 4 nm). The effect of catalyst synthesis on the decomposition of O3 gas (15 ppm) in a dry and humid (HR = 10%) stream in a closed environment such as aircraft or spacecraft was also investigated in this study and further elucidated by detailed characterizations. It was shown that the system could be used as an effective treatment for air coming from outside. [ABSTRACT FROM AUTHOR]