Institute of Chemistry
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Item type:Publication, Stabilizing latent fingermarks developed with iodine fuming: A new method(Elsevier BV, 2025-05-17); Slobodan, Oklevski - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Elementary, my dear Watson! The making of a collection of the natural elements(Society of Chemists and Technologists of Macedonia, 2022-06-21); <jats:p>A unique collection of samples of the chemical elements has been created and displayed at our Institute of Chemistry. Although whole collections are now commercially available, we decided to use, as much as possible, samples from local resources. The general idea was for each item to have a story, making it more interesting for the students and visitors. We were able to acquire elemental samples mined in Macedonia. Other samples were from our student and research labs, as well as donations from colleagues, and the rest were obtained from commercial sources. A web page was created with all the information on each sample, some of them containing videos. Next to the noble gases, mini Tesla coils were mounted to light up the gases.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Elementary, my dear Watson! The making of a collection of the natural elements(Society of Chemists and Technologists of Macedonia, 2022-06-21); <jats:p>A unique collection of samples of the chemical elements has been created and displayed at our Institute of Chemistry. Although whole collections are now commercially available, we decided to use, as much as possible, samples from local resources. The general idea was for each item to have a story, making it more interesting for the students and visitors. We were able to acquire elemental samples mined in Macedonia. Other samples were from our student and research labs, as well as donations from colleagues, and the rest were obtained from commercial sources. A web page was created with all the information on each sample, some of them containing videos. Next to the noble gases, mini Tesla coils were mounted to light up the gases.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Facile Synthesis of Cu<sub>x</sub>S Electrocatalysts for CO<sub>2</sub> Conversion into Formate and Study of Relations Between Cu and S with the Selectivity(Wiley, 2024-10-25); Koleva, Violeta<jats:title>Abstract</jats:title><jats:p>The conversion of CO<jats:sub>2</jats:sub> into formate (HCOO<jats:sup>−</jats:sup>), a techno‐economically feasible product, can be achieved using earth‐abundant Cu<jats:sub>x</jats:sub>S electrocatalysts, but questions remain regarding how catalyst structure, composition, and reaction environment influence product selectivity. A novel synthesis method based on electrodeposition of Cu foam and its subsequent sulfidation via immersion in sulfur saturated toluene solution resulted in Cu<jats:sub>x</jats:sub>S foams. Catalytic activity studies found that HCOO<jats:sup>−</jats:sup> selectivity is dependent on electrochemical activation at higher overpotentials. To understand the effects of activation, determine the active forms of the catalysts, and identify the role of sulfur, the electrodes are carefully characterized as well as gaseous and sulfur dissolved in electrolyte. This included study of the effects of intentional addition of solution sulfur species, identification of the sulfur loss, determination of the electrode composition and relating sulfur speciation to observed product selectivity. It is found that residual sulfur stabilizes Cu<jats:sup>+</jats:sup> during electrolysis at potentials favoring HCOO<jats:sup>−</jats:sup> production, in contrast to pristine Cu that undergoes complete reduction and shows poor HCOO<jats:sup>−</jats:sup> selectivity. Sulfur in both the catalyst and dissolved in electrolyte are of dynamic nature, and surface residues of SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup> species are identified in all activated catalysts which correspond with enhanced HCOO<jats:sup>−</jats:sup> production.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Facile Synthesis of Cu<sub>x</sub>S Electrocatalysts for CO<sub>2</sub> Conversion into Formate and Study of Relations Between Cu and S with the Selectivity(Wiley, 2024-10-25); Koleva, Violeta<jats:title>Abstract</jats:title><jats:p>The conversion of CO<jats:sub>2</jats:sub> into formate (HCOO<jats:sup>−</jats:sup>), a techno‐economically feasible product, can be achieved using earth‐abundant Cu<jats:sub>x</jats:sub>S electrocatalysts, but questions remain regarding how catalyst structure, composition, and reaction environment influence product selectivity. A novel synthesis method based on electrodeposition of Cu foam and its subsequent sulfidation via immersion in sulfur saturated toluene solution resulted in Cu<jats:sub>x</jats:sub>S foams. Catalytic activity studies found that HCOO<jats:sup>−</jats:sup> selectivity is dependent on electrochemical activation at higher overpotentials. To understand the effects of activation, determine the active forms of the catalysts, and identify the role of sulfur, the electrodes are carefully characterized as well as gaseous and sulfur dissolved in electrolyte. This included study of the effects of intentional addition of solution sulfur species, identification of the sulfur loss, determination of the electrode composition and relating sulfur speciation to observed product selectivity. It is found that residual sulfur stabilizes Cu<jats:sup>+</jats:sup> during electrolysis at potentials favoring HCOO<jats:sup>−</jats:sup> production, in contrast to pristine Cu that undergoes complete reduction and shows poor HCOO<jats:sup>−</jats:sup> selectivity. Sulfur in both the catalyst and dissolved in electrolyte are of dynamic nature, and surface residues of SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup> species are identified in all activated catalysts which correspond with enhanced HCOO<jats:sup>−</jats:sup> production.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Upcycling of plastic waste into multi-walled carbon nanotubes as efficient organic dye adsorbent(Slovenian Chemical Society, 2025-03-03); ; Kovačič, SebastijanMulti-walled CNTs with an average diameter of about 80 nm, a length of several micrometers and surface area (SBET) of 100 m2 g-1 were obtained by pyrolysis of low-density polyethylene waste. The potential of the resulting MWCNTs material to purify water containing organic dyes was tested with Bezaktiv Blau HE-RM (BB) and Bezaktiv Rot S-3B (BR) reactive dyes. 200 mg L-1 MWCNT material was used to follow the adsorption of 30 mg L-1, 40 mg L-1, 50 mg L-1 and 60 mg L-1 BB and BR at pH 3 and a temperature of ~25 oC. The results have shown that this material has a high potential as a sorbent, and its adsorption capacity of 257 mg g-1 (for Bezaktiv Blau HE-RM) and 213 mg g-1 (for Bezaktiv Rot) is close to some commercial MWCNTs and functionalized MWCNT-based adsorbents. The adsorption process was very fast, reaching 80-90 % of the dye removal in 10-15 minutes, and the equilibrium time was reached in 40-60 minutes. The adsorption isotherm showed that the Langmuir model was more suitable than the Freundlich model for describing the adsorption properties of the pollutants. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal behavior of acid phosphate salts Ca2MH7(PO4)4⋅2H2O (M = K+, NH4 +) and CaK3H(PO4)2(Elsevier, 2023-06); New knowledge about various aspects of little-known acid salts is of great scientific and practical importance in view of their potential application in different areas such as proton conductors. For the first time, the thermal behavior of three acid phosphate salts, dicalcium potassium heptahydrogen tetrakis(phosphate) dihydrate (Ca2KH7(PO4)4⋅2H2O), dicalcium ammonium heptahydrogen tetrakis(phosphate) dihydrate (Ca2(NH4)H7(PO4)4⋅2H2O) and calcium tripotassium hydrogenbis(phosphate) (CaK3H(PO4)2), has been investigated. By means of simultaneous thermogravimetry, differential thermal and mass spectrometry analyses (TG/DTA/MS) he schemes of their thermal decomposition have been proposed. The two isostructural compounds Ca2KH7(PO4)4⋅2H2O and Ca2(NH4)H7(PO4)4⋅2H2O are stable up to 90 – 95 ◦C and then undergo multiple-steps thermal decomposition process owing to dehydration of the crystallization water and dehydration-condensation. The anhydrous salt CaK3H(PO4)2 exhibits very high thermal stability up to 530 ◦C. The products of the thermal decomposition have been identified.