BiOX (X = Cl, Br, I) photocatalysts with dominant (110) facets were synthesized via a mannitol-assisted solvothermal method. This is the first report on the exposed (110) facets-, size-, and defects-controlled synthesis of BiOX achieved by solvothermal synthesis with mannitol. This polyol alcohol acted simultaneously as a solvent, capping agent, and/or soft template. The mannitol concentration on the new photocatalysts morphology and surface properties was investigated in detail. At the lowest concentration tested, mannitol acted as a structure-directing agent, causing unification of nanoparticles, while at higher concentrations, it functioned as a solvent and soft template. The effect of exposed (110) facet and surface defects (Bi^(3−x)+, Bi⁴⁺, Bi⁵⁺) of BiOX on the photocatalytic activity of nanomaterials under the UV–Vis irradiation were evaluated by oxidation of Rhodamine B (RhB) and 5-fluorouracil (5-FU), an anticancer drug, and by reduction of Cr(VI). Additionally, the influence of crucial factors on the formation of BiOX in the synthesis with mannitol was discussed extensively, and the mechanism of BiOX formation was proposed. These studies presented a new simple method for synthesizing BiOX without any additional surfactants or shape control agents with good photocatalytic activity. The study also provided a better understanding of the effects of solvothermal conditions on the BiOX crystal growth.

The benefits of silver nanoparticles (AgNPs) have been known in many fields from catalysis through optics to medicine due to their unique size-dependent properties. Recently, there is also a growing interest in novel skincare formulations containing AgNPs. In this work, AgNPs were successfully synthesised and were characterised by UV-Vis spectroscopy and Transmission Electron Microscopy (TEM). In addition, an analysis of particle size distribution (measured by Dynamic Light Scattering – DLS) and zeta potential (using the method Electrophoretic Light Scattering – ELS) were made. The obtained AgNPs were in two sizes: small (20 nm ± 5 nm) and large (100 nm ± 5 nm). The assessment of the cytotoxic effect on human skin cells was done. Smaller AgNPs showed less cytotoxicity and thus greater safety for skin, so they were introduced into new skincare formulations such as oil/water (O/W) emulsion, water/oil (W/O) emulsion and hydrogel. Moreover, the study of release AgNPs from emulsions and hydrogel using Franz diffusion chamber with pig skin as a membrane has been conducted. The receptor fluid measurements were performed by Atomic Absorption Spectroscopy (AAS). The last point of the research was the performance of microbiological tests to determine the antibacterial effect of the smaller AgNPs in both solution and cosmetic. Graphical abstract

Novel carbon dots (CDs) synthetized from microalga Chlorella pyrenoidosa were used to produce CDs-ZnO nanoparticles to enhance the photocatalytic performance of carbamazepine removal.