The aim of the present paper is to study the antimicrobial effects of Nb₂O₅-containing nanosized powders. A combination of inorganic [telluric acid (H₆TeO₆)] and organic [Ti(IV) n-butoxide, Nb(V) ethoxide (C₁₀H₂₅NbO₅)] precursors was used to prepare gels. To allow for further hydrolysis, the gels were aged in air for a few days. The gels were amorphous, but at 600 °C the amorphous phase was absent, and only TiO₂ (anatase) crystals were detected. The average crystallite size of TiO₂ (anatase) was about 10 nm. The UV-Vis spectrum of the as-prepared gel showed red shifting in the cut-off region. The obtained nanopowders were evaluated for antimicrobial properties against E. coli ATCC 25922, P. aeruginosa ATCC 27853, S. aureus ATCC 25923, and C. albicans 18804. Among these, only E. coli was examined in combination with the antibiotic ciprofloxacin to assess whether there was a potential synergistic effect. The results showed that the material exhibited antibacterial activity against the abovementioned bacterial strains but not against C. albicans. In the case of E. coli combined with ciprofloxacin, a concentration-dependent enhancement in antibacterial activity was observed. The obtained samples can be considered as prospective materials for use as environmental catalysts. The newly synthesized nanocomposite showed a balancing, modulating, and neutralizing effect on the generation of ROS. The inhibitory effect was preserved in all tested model chemical systems at pH 7.4 (physiological), indicating potential biological applications in inflammatory and oxidation processes in vivo.

The present paper deals with the synthesis, characterization, and properties of sol-gel-derived TiO₂/TeO₂/Nb₂O₅ nanopowders. The gels were prepared using a combination of organic [Ti (IV) n-butoxide, Nb (V) ethoxide (C₁₀H₂₅NbO₅)] and inorganic [telluric acid (H₆TeO₆)] precursors. The aging of gels was performed in air for several days in order to enable further hydrolysis. The phase formation of the gels was investigated by XRD upon heating in the temperature range of 200–700 °C. It was established that the gels heat-treated up to 300 °C exhibited a predominantly amorphous phase in all binary and ternary compositions. The amount of amorphous phase gradually decreased with increasing temperature, and the first TiO₂ (anatase) crystals were detected at about 400–500 °C. The average crystallite size of TiO₂ (anatase) in the powdered samples heat-treated at 400 °C was about 10 nm. By DTA, it was established that the decomposition of organics is accompanied by strong weight loss occurring in the temperature range of 200–300 °C. The completeness of the hydrolysis-condensation reactions was verified by IR and UV–Vis analyses. The UV–Vis spectra of the as-prepared gels exhibited red shifting of the cut-off. Photoluminescence spectra exhibited a change in intensity with varying temperature and composition. The performed photocatalytic tests showed that all powders possess photocatalytic activity toward Malachite green organic dye. The obtained nanopowders exhibited good antibacterial properties against E. coli ATCC 25922. The obtained samples can be considered as prospective materials for use as environmental catalysts.

In this study, Fe-doped SrTiO₃ powders have been synthesized using the sol-gel approach. The effect of the Fe³⁺ doping on the degradation efficiency of SrTiO₃ toward specific pollutants was studied. The obtained samples were characterized using the following techniques: XRD, SEM-EDS, FTIR, UV-Vis, and BET. Subsequently, the samples were tested for degradation of two organic pollutants—tetracycline hydrochloride and Malachite green in distilled water under different light sources—UV light and visible light. The investigated powders exhibited good photocatalytic degradation efficiency against both pollutants. A comparison of the photocatalytic abilities of the samples under different lights has been made, which emphasizes the paper’s novelty. Undoped SrTiO₃ exhibited better photocatalytic activity for TCH both under UV and visible light irradiation in comparison to the Fe-doped. The SrTi_0.15Fe_0.85O₃ shows superior photocatalytic activity under visible light irradiation for the degradation of MG dye. The antibacterial activity has been tested against two bacterial strains, E. coli ATCC 25922 and P. aeruginosa ATCC 27853. It has been found that the antibacterial efficiency of the Fe-doped sample is greater than compared of the undoped one.

In this study, sol–gel-synthesized nanoparticles were characterized by various physicochemical techniques, including scanning electron microscopy (SEM), X-ray powder diffraction (XRD), UV-Vis spectrophotometry, and thermogravimetric analysis (DTA/TG). The as-obtained powders were tested for their antimicrobial activity against the Gram-positive bacteria Staphylococcus aureus and Enterococcus faecalis, as well as the fungal strains Candida albicans and Saccharomyces cerevisiae. Additionally, the photocatalytic performance of the samples was evaluated under simulated solar light. The results are promising for possible environmental applications. The antimicrobial assessment also revealed notable effects, with varying degrees of growth inhibition observed across the tested microorganisms. The main approach in this study consists of the combination of physicochemical characterization with antibacterial and photocatalytic evaluations, resulting in promising multifunctional materials.

This study investigates the synthesis, characterization, antimicrobial performance, and redox activity of sol–gel–derived TiO₂/TeO₂/CuO powders. The as-prepared gel with the nominal composition 80TiO₂/10TeO₂/10CuO was subjected to thermal treatment at 400 °C and 600 °C for 2 h, resulting in the formation of composite materials at both temperatures. By UV-Vis spectroscopy, it has been found that CuO is responsible for the red shifting of the absorption edge. The SEM-EDS analysis verified the elemental composition of the synthesized powders. The antimicrobial activity of the heat-treated powders was proved against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, representative Gram-negative and Gram-positive bacteria frequently associated with hospital-acquired infections and antibiotic resistance. At physiological pH, the 600 °C-treated sample exhibited strong prooxidant properties, supporting antimicrobial activity. At alkaline conditions, the nanomaterials were effective against superoxide radicals. The variation in oxidation with changes in pH is indicative of the potential for controlled application. Antimicrobial activity was assessed through minimum inhibitory concentration (MIC) assays and spot and luminescent tests, providing both quantitative and qualitative evaluations.