Crystallochemical design of metal–organic polymer CuBTC and activated carbon composite

Metal–organic polymer CuBTC and composite with CuBTC and activated carbon (CuBTC/C) were prepared by hydrothermal method (BTC3− is a linker 1,3,5-benzenetricarboxylate ion, hydrolysis temperature 130 °C, ethanol + H2O in equal proportion as a solvent) and detailed characterized by a set of methods (X-ray diffraction—XRD, X-ray absorption spectroscopy—XAS, differential scanning calorimetry—DSC, scanning electron microscopy—SEM, low-temperature sorption capacity of samples to nitrogen—BET, X-ray photoelectron spectroscopy—XPS, FTIR-spectroscopy). According to XRD and XAS data, it was found that the composition of main phase CuBTC is [Cu3BTC2(H2O)3] × (nH2O + mC2H5OH) in both samples. The catalytic properties of CuBTC and CuBTC/C samples in the reaction of ethanol dehydrogenation were studied for the first time and the selectivity to acetaldehyde (AcH) was 100% in both cases. It was shown that on the CuBTC/C catalysis, the AcH yield is two times higher than on the CuBTC sample in the reaction of ethanol (Lewis base) dehydrogenation to acetaldehyde. This fact can be explained by the higher content of main phase CuBTC in composite CuBTC/C (~ 97.5 wt%) and the Cu2+ ions (Lewis acid sites) in bulk, the higher water and Cu2+ ions content on the particle surface in CuBTC/C (DSC, FTIR, XPS), the larger pore radii in CuBTC framework of the composite CuBTC/C (according to crystallochemical calculations) and the larger hydrogenation degree of CuBTC/C (XRD, DSC, FTIR) and the smaller specific surface area of CuBTC/C (SBET = 44.4 m2/g for CuBTC/C sample and SBET = 551.3 m2/g for CuBTC). It was found that in the reaction of propane conversion to ethylene C2H4 and methane CH4, the conversion degree on the samples CuBTC and CuBTC/C was the same from 100 °C up to 340 °C, which is caused by the absence of the Bronsted acid sites on the samples with CuBTC. Graphical abstract: [Figure not available: see fulltext.]. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature

Bactericidal properties of nanoscale zinc(II) and titanium (IV) oxides of different nature and their nanocomposites with polystyrene

The samples with nano-titanium dioxide (X-ray amorphous, η-modification, Degussa P25 mixture of rutile and anatase, Hombifine N, and Hombikat UV100 with anatase) and hexagonal nano-ZnO both in pure form and as a part of polystyrene (PS) nanocomposites were studied for antibacterial activity in the dark against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Bacillus antracoides, and Candida albicans microorganisms by the Kirby-Bauer disk diffusion method. Among the starting samples, ZnO exhibits ABA against all bacterial cultures in use; the sample with the η-phase exhibits ABA against Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus antracoides; the X-ray amorphous TiO2 exhibits ABA against Staphylococcus aureus and Candida albicans; and the remaining samples have no ABA. The diameters of the microbial growth retardation zone for the η-phase/PS, X-ray amorphous TiO2/PS, and ZnO/PS nanocomposites were found to be less than those for the starting oxides; the range of microbes inhibited by ZnO/PS was smaller since it exhibited no ABA against Candida albicans, while such activity remained in the X-ray amorphous TiO2/PS nanocomposite. © 2016, Pleiades Publishing, Ltd

Bactericidal properties of nanoscale zinc(II) and titanium (IV) oxides of different nature and their nanocomposites with polystyrene

The samples with nano-titanium dioxide (X-ray amorphous, η-modification, Degussa P25 mixture of rutile and anatase, Hombifine N, and Hombikat UV100 with anatase) and hexagonal nano-ZnO both in pure form and as a part of polystyrene (PS) nanocomposites were studied for antibacterial activity in the dark against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Bacillus antracoides, and Candida albicans microorganisms by the Kirby-Bauer disk diffusion method. Among the starting samples, ZnO exhibits ABA against all bacterial cultures in use; the sample with the η-phase exhibits ABA against Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus antracoides; the X-ray amorphous TiO2 exhibits ABA against Staphylococcus aureus and Candida albicans; and the remaining samples have no ABA. The diameters of the microbial growth retardation zone for the η-phase/PS, X-ray amorphous TiO2/PS, and ZnO/PS nanocomposites were found to be less than those for the starting oxides; the range of microbes inhibited by ZnO/PS was smaller since it exhibited no ABA against Candida albicans, while such activity remained in the X-ray amorphous TiO2/PS nanocomposite. © 2016, Pleiades Publishing, Ltd

New composites based on zeolites (H-Beta, H-ZSM-5) and nanosized titanium(iv) oxide (anatase and η-phase) doped by Ni, Ag, V with photocatalytic, adsorption and bactericidal properties

New NT:M/zeolite composites with functional nanoparticles of titanium(iv) oxides NT (η-phase and anatase) have been prepared by introducing nitrates with dopant metals (M = Ag, Ni, and V) and zeolites (H-Beta and H-ZSM-5) within the process of NT synthesis during the hydrolysis of TiOSO4·nH2O. The prepared composites have been characterized by X-ray diffraction, XAS-method, XPS-spectroscopy, UV-Vis diffuse reflectance spectroscopy, and Brunauer-Emmett-Teller and chemoluminescence methods. The greatest photodegradation rate constants (visible light radiation) were achieved in the reaction of thiamethoxam pesticide and difenoconazole fungicide oxidation in the presence of NE:Ni/H-Beta (NE - η-phase with composition TiO2−x·nH2O),i.e. k= 0.0270 min−1andk= 0.0147 min−1respectively, that is 2.5 times higher than thekvalue obtained for the commercial anatase Hombifine N (UV-irradiation). A relationship between the photocatalytic activity (PCA) and the NT:zeolite ratio, the type and concentration of M, the type of NT and zeolite, the content of OH groups and the reactive oxygen species (radical anions ˙OH, ˙O2−and H2O2) on the surface, and the composition and structure of the decomposed pollutant has been found. The decisive role of the composition of the volume and surface of nanocomposites in the realization of PCA has been noted. The adsorption (removal of P(v), As(v), Se(vi) ions from aqueous solutions) and antimicrobial activities (against bacteriaStaphylococcus epidermidis,Bacillus antracoides,Escherichia coli) of the NT:M/zeolite composites, in the absence of light emission, have been studied for the first time and their high performance has been demonstrated: the removal degrees of P(v), As(v), and Se(vi) ions from aqueous solutions in the presence of all composites were more than 99% and the inhibition growth zone of composites NA:Ag/zeolite was >13 mm. New composites could be recommended for preparing wound dressings, antiseptic ointments for external use and water filters. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021