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Carbon nanomaterials doped with heteroatoms, in particular, nitrogen atoms, are of great interest for electrochemical power engineering as nonmetallic catalysts or carriers of catalytically active metal nanoparticles. A nanostructured, reduced graphene oxide modified with nitrogen in a gas discharge plasma in a vacuum chamber of a magnetron-ion sputtering facility is considered. It is shown that plasma treatment of reduced graphene oxide does not cause undesirable morphological changes in the structure of carbon nanomaterial, but it leads to the incorporation of nitrogen atoms into the structure of reduced graphene oxide with the formation of pyridine-, pyrrole-, and graphite-like configurations. The application of pulsed negative bias voltages of various magnitudes to the substrate with the sample increases the concentration of nitrogen atoms to 2.6 at % and also promotes an increase in the proportion of nitrogen atoms in the pyridine form and a slight decrease in the proportion of atoms in the pyrrole form. The results allow for considering the obtained carbon nanomaterials for use as components of electrochemical devices, for example, fuel cells, in the future.

The anatase nanoparticles are stabilized with titanium tetraisopropoxide Ti[OCH(CH3)2]4 and isopropyl alcohol without surfactants suitable for biological studies. We showed that the hydrodynamic radii in suspensions depend on temperature and the duration of hydrolysis, whereas the composition (a mixture of anatase with brookite, anatase, brookite, and rutile) and the sizes of crystallites (X-ray), nanoparticles, and aggregates (SEM) in the dried state are mainly dependent on the pH of the environment. The nonphase of the samples stems from coherent intergrowth of unit cells of anatase and brookite via geometric and structural complementarity. We found that photocatalytic activity (PCA; Rhodamine 6G model dye under UV radiation) depends on OH/H2O ratio (adsorbed), whereas antimicrobial activity (AMA) in the dark depends on an amount of free water on the surface of nanoparticles according to X-ray photoelectron spectroscopy (XPS). We revealed that samples with the smallest sizes of nanoparticles of all levels possess the highest PCA and AMA relative to Staphylococcus aureus and Escherichia coli.