фотокаталіз

Titanium dioxide is the most widely used semiconductor substance as a photocatalytic material in self-cleaning surfaces, air and water purification systems, sterilization, hydrogen evolution, and photoelectrochemical conversion. In this work, we propose a photocatalysis effect-based optical information recording on the titanium dioxide nanoparticles and luminescent dye-doped polymer nanocomposite for the first time. The optical information was recorded as holographic gratings.

The current state of research on photocatalytic systems based on crystalline graphitic carbon nitride (CCN) for H₂ evolution from aqueous solutions of electron-donating substrates is considered. Methods of CCN synthesis and photocatalytic properties of different samples of CCN-undoped with a controlled defect structure and doped with metals and non-metals are discussed. Possible directions for further research of such CCN-based photocatalytic systems are outlined.

Boron-doped bulk samples of graphitic carbon nitride (B-g-C₃N₄) were synthesized by pyrolysis of melamine-boric acid mixtures, followed by their subsequent annealing in a eutectic melt of potassium and lithium chlorides, resulting in the formation of crystalline g-C₃N₄ (B-CGCN). The obtained materials demonstrate significantly higher activity in hydrogen evolution from aqueous-ethanolic solutions under visible light irradiation compared to undoped g-C₃N₄ and CGCN.

The article considers the influence of precursor type and sol-gel synthesis conditions of TiO₂ on its properties. The obtained TiO₂ samples were characterized by X-ray diffraction methods, electron microscopy, as a result of which it was found that all the obtained TiO₂ powders have the crystallite size in a nanorange of 2.5–17 nm. It was shown that sorption-photocatalytic properties of TiO₂ significantly depend on a phase composition, surface acidity, specific surface area and porosity.