Miloš Marinković

In this study, a modified sol–gel method was used to synthesize pure TiO2 and TiO2/CeO2-based materials, followed by the loading of 3 wt.% silver ions onto the catalyst surfaces using a wet-impregnation method. All synthesized and modified catalysts were characterized using Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques to analyze their textural, morphological, and structural properties. The photocatalytic activity of these materials was evaluated for the degradation/decolorization of crystal violet (CV) dye under ultraviolet (UV) irradiation. Moreover, the effects of various process parameters, including initial dye concentration, catalyst amount, and UV wavelength, on photocatalytic efficiency were analyzed. The results indicated that the addition of CeO2 and Ag into the TiO2 catalyst significantly enhanced the photocatalytic activity compared with pure TiO2 under identical experimental conditions. Further analysis of the photocatalytic process demonstrated that the TiO2/CeO2 binary oxide catalyst, as well as Ag-doped samples (TiO2/Ag and TiO2/CeO2/Ag), exhibited improved photocatalytic performance relative to pure TiO2.

This study explores the antioxidant potential and delivery performance of five structurally distinct cannabinoids, with a particular focus on cannabinol (CBN). Comprehensive structural characterization using mass spectrometry (MS) and nuclear magnetic resonance (NMR) revealed key molecular features relevant to antioxidant function. Among the tested compounds, CBN exhibited the most potent and balanced radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals. Based on these findings, CBN was selected for formulation into soy lecithin liposomes. The resulting CBN-loaded liposomes displayed favorable colloidal properties, with an average size of approximately 122.9 ± 0.4 nm. Results indicating increased membrane order upon CBN incorporation suggest enhanced stability of the liposomal bilayer. Antioxidant activity assays showed that CBN-loaded liposomes retain significant radical scavenging capacity, though with a moderate reduction compared to free CBN. EPR imaging further demonstrated superior diffusion of liposomal CBN through a gelatin-based semi-solid model compared to the control solution. While the current model does not replicate skin architecture, it provides a cost-effective and reproducible platform for early-stage screening of formulation mobility. These results position CBN-loaded liposomes as a promising candidate for dermal antioxidant applications, combining favorable physicochemical properties with enhanced diffusion behavior.

In this study, TiO2-based catalysts were synthesized using a modified sol-gel method. The catalysts were prepared at two different pH values (10 and 13) and were subsequently doped with zirconia to improve their photocatalytic performance. The physico-chemical properties of the catalysts, including structural, textural, morphological, and thermal properties, were studied using XRD, BET, SEM, and TG/DTA methods, respectively. The photocatalytic activity of the synthesized catalysts was tested in the degradation/decolorization reaction of methylene blue dye. The results indicated that the synthesis parameters and zirconia doping had a significant impact on the catalysts' physico-chemical characteristics and, therefore, their activity. It can be pointed out that catalysts with improved properties and enhanced photocatalytic activity can be obtained by carefully selecting and optimizing synthesis conditions, as well as by modifying or doping them with a suitable dopant.

The aim of this study was preparation of one low cost and environmentally friendly material for wastewater treatment toward both inorganic and organic pollutants, based on natural zeolite from one of the largest zeolite deposits in Serbia (Zlatokop, Vranjska Banja). The idea was to integrate zero-valent bimetallic FeNi particles onto zeolite, based on liquid-phase reduction method. Obtained material zvFeNi@zVB showed good sorption properties with high removal efficiency under the investigated conditions toward inorganic (M(II) heavy metal ions Cu, Cd, Pb, Zn) and organic (dyes Reactive Blue 19 and Methylene Blue) pollutants. Compared with pure FeNi material, modified zeolite (zvFeNi@zVB) showed better sorption properties and “faster clean” water from evaluated pollutants.

In this study, raw and chemically activated natural zeolite from Zlatokop deposit (Serbia) were investigated by FTIR, XRD, SEM-EDX, TGA and BET in order to define their properties as further potential sorption materials. Obtained results indicate porous (meso-pore range) and defined crystal alumino-silicate structure of these materials, with Na+, K+, such as Ca2+ and Mg2+ as dominating exchangeable cations. Content of clinoptilolite (ca. 90%) indicates the high quality of the zeolite samples. Preliminary sorption analyses of these materials toward copper(II) ion from aqueous solution showed good removal efficiency for base activated zeolite (zVBB) compared to raw natural (zVBN) and acid activated (zVBA) zeolite. Since these were preliminary sorption tests, the investigated zeolites will be further examined under different experimental conditions.

Heterogeneous catalysis is in recent focus of research for biodiesel production from vegetable oils because of advantages such as easy separation and reuse of catalysts, although homogeneous catalysis is most commonly used method. The aim of this study was preparation of ?-Al2O3 support by modified sol-gel procedure, synthesis of the KI/Al2O3 catalyst and testing its activity in the transesterification of sunflower oil with methanol. Influences of different process parameters on conversion of sunflower oil to methyl esters were examined. The gained results implicate that the potassium iodide incorporation into/onto the structure of ?-Al2O3 significantly influences textural and structural properties of the catalyst. Additionally, the catalyst basic strength is increased and all together those properties are positively affecting the activity of the catalyst in the reaction of transesterification of sunflower oil with methanol. The impregnation of alumina with potassium iodide resulted in the additional formation of basic catalytically active sites. The surface properties of the catalyst have an essential impact on its catalytic performance. Under relatively mild process conditions and relatively short reaction time, the usage of the KI/Al2O3 catalyst resulted in very high conversion to fatty acids methyl esters (i.e. 99.99 %).