Glasses with the compositions in mol % of 50ZnO:(50 − x)B₂O₃:0.5Eu₂O₃:xWO₃, x = 0, 1, 3, 5 and 10 were obtained by applying the melt-quenching method and investigated by Raman spectroscopy, DSC analysis and photoluminescence (PL) spectroscopy. Raman spectra revealed that tungstate ions incorporate into the base zinc borate glass as tetrahedral [WO₄]²⁻ groups, and octahedral [WØ₄O₂]²⁻ species with four bridging and two non-bridging oxygen atoms. There are also metaborate, [BØ₂O]⁻ and pyroborate units, [B₂O₅]⁴⁻, in the glass networks. The glasses are characterized by good transmission in the visible region, at about 80%. Photoluminescence (PL) spectra evidenced that WO₃ is an appropriate constituent for the modification of zinc borate glass structure and for enhancing the Eu³⁺ luminescent intensity. The most intense luminescence peak observed, at 612 nm, suggests that the glasses are potential materials for red emission.

The effect of the addition of Nb₂O₅ (up to 5 mol%) on the structure and luminescent properties of ZnO-B₂O₃ glass doped with 0.5 mol% (1.32 × 10²²) Eu₂O₃ was investigated by applying infrared (IR), Raman and photoluminescence (PL) spectroscopy. Through differential thermal analysis and density measurements, various physical properties such as molar volume, oxygen packing density and glass transition temperature were determined. IR and Raman spectra revealed that niobium ions enter into the base zinc borate glass structure as NbO₄ tetrahedra and NbO₆ octahedra. A strong red emission from the ⁵D₀ level of Eu³⁺ ions was registered under near UV (392 nm) excitation using the ⁷F₀ → ⁵L₆ transition of Eu³⁺. The integrated fluorescence intensity ratio R (⁵D₀ → ⁷F₂/⁵D₀ → ⁷F₁) was calculated to estimate the degree of asymmetry around the active ion, suggesting a location of Eu³⁺ in non-centrosymmetric sites. The higher Eu³⁺ luminescence emission observed in zinc borate glasses containing 1–5 mol% Nb₂O₅ compared to the Nb₂O₅-free zinc borate glass evidences that Nb₂O₅ is an appropriate component for modifying the host glass structure and improving the emission intensity.

TiO₂/TeO₂ powders were obtained by an aqueous sol-gel method. Telluric acid (H₆TeO₆) and titanium butoxide were used as precursors. The as-prepared gel was step-wisely heated in the temperature range 200–700 °C and subsequently characterized by XRD, IR, and UV-Vis analysis and SEM. Mixtures containing TiO₂ (anatase), α-TeO₂ (paratellurite), and TiTe₃O₈ were established by XRD as final products, depending on heating temperature. The thermal stability of the obtained gels in the temperature range 100–400 °C was investigated. It was found by IR spectroscopy that the samples heated up to 300–400 °C consist mainly of an organic–inorganic amorphous phase which is transformed into an inorganic one above these temperatures. The microstructure of the gels was verified by scanning electron microscopy (SEM). The photocatalytic degradation of the synthesized nanopowders toward Malachite green organic dye (MG) was examined in order to evaluate the potential applications for environmental remediation. The prepared TiO₂/TeO₂ samples showed up to 60% decoloration efficiency after 120 min exposure to UV-light. The composition exhibited good antimicrobial activity against E. coli K12. The properties of the obtained material were investigated by the reactions of complete catalytic oxidation of different alkanes and toluene, and it could be suggested that TiO₂/TeO₂ powders are promising material for use as an active phase in environmental catalysts.

BaMoO₄ was obtained via facile mechanochemical synthesis at room temperature and a solid-state reaction. An evaluation of the phase composition and structural and optical properties of BaMoO₄ was conducted. The influence of different milling speeds on the preparation of BaMoO₄ was explored. A shorter reaction time for the phase formation of BaMoO₄ was achieved using a milling speed of 850 rpm. A milling speed of 500 rpm led to partial amorphization of the initial reagents and to prolongation of the synthesis time of up to 3 h of milling time. Solid-state synthesis was performed via heat treatment at 900 °C for 15 h. X-ray diffraction analysis (XRD), infrared (IR) and UV diffuse reflectance (UV-Vis) and photoluminescence (PL) spectroscopy were carried out to characterize the samples. Independently of the method of preparation, the obtained samples had tetragonal symmetry. The average crystallite sizes of all samples, calculated using Scherrer’s formula, were in the range of 240 to 1540 Å. IR spectroscopy showed that more distorted structural MoO₄ units were formed when the compound was synthesized via a solid-state reaction. The optical band gap energy of the obtained materials was found to decrease from 4.50 to 4.30 eV with increasing crystallite sizes. Green- and blue-light emissions were observed for BaMoO₄ phases under excitation wavelengths of 330 and 488 nm. It was established that the intensity of the PL peaks depends on two factors: the symmetry of MoO₄ units and the crystallite sizes.