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${\mathrm{\text{TiO}}}_2$ nanomaterials with different content of ${\mathrm{\text{Ce}}}^{4+}$ ion were synthesized by the chemical method from solutions and demonstrated improved photocatalytic and optical properties with significant redshift compared to pristine ${\mathrm{\text{TiO}}}_2$. According to X-ray phase analysis and transmission electron microscopy, all synthesized materials are characterized by anatase modification, which holds up to $800^{\circ }$C, the particle size for all materials is 12–21 nm. X-ray diffraction spectra revealed that the anatase to rutile phase transition for materials doped with ${\mathrm{\text{Ce}}}^{4+}$ ions begins at a higher temperature of $800^{\circ }$C compared to pristine ${\mathrm{\text{TiO}}}_2$. The influence of synthesis conditions and ${\mathrm{\text{Ce}}}^{4+}$ content (0.1–2 mol.%) on characteristics and photocatalytic activity were investigated. The Ce-doped ${\mathrm{\text{TiO}}}_2$ nanomaterial, containing 0.1% ${\mathrm{\text{Ce}}}^{4+}$ provides an extremely high degree of methylene blue decomposition by 93% within visible light irradiation for 3 h. The stability of the catalyst over four cycles has been shown, which makes it possible to use it in the purification of water resources from dyes or other pollutants.

Three types of hexagonal wurtzite ZnO nanostructures namely nanorods, nanodisks and nanoflowers were prepared in three different pH value solutions. The results indicated that the concentration of H⁺ ions in the solution would greatly affect the growth behaviors of ZnO crystal. In addition to a broad ultraviolet emission found on the photoluminescence spectra, two weaker peaks corresponding to the blue emission of ZnO were observed at 2.75 and 2.68 eV, which probably originate from the electron transition from the shallow donor level of interstitial Zn to the valence band of ZnO.

Present work points out the differences between possible tubular carbon structures: nanotubes and nanofibers, as well as describes ways of their modification for utilization for new materials design. For material characterization, XRD, XPS, Raman spectroscopy, thermal analysis, HRTEM and SEM, pore size distribution, EELS, elemental analysis and adiabatic bomb calorimetry were used. Heats of formation for nanotubes and nanofibers and their dependence on carboxylation extent as well as properties of the modified materials are also discussed. The perspectives of applications of modified carbon nanotubes in catalysis and polymers chemistry are given.

Well-defined flowerlike Bi₂O₂CO₃ nanostructures were fabricated by a simple one-pot solvothermal method with high yield. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy, transmission electron microscopy, nitrogen sorption, photoluminescence spectra and UV–visible diffuse reflectance spectroscopy. The photocatalytic properties of the as-prepared samples were further investigated by photocatalytic decomposition of Rhodamine B (RhB) dye, and it was found that the Bi₂O₂CO₃ nanoflowers showed a good photocatalytic activity under UV light. The excellent photocatalytic performance of Bi₂O₂CO₃ flowerlike nanostructures is related to its special nanostructure and morphology, indicates its potential application in photocatalysis and nanosensors.