An array of highly oriented anatase nanoparticles was successfully prepared from NH₄TiOF₃ with the assistance of polyetheleneglycol-400 at 450 °C. The study showed the stability of obtained layered TiO₂-anatase close to 1200 °C. This research confirmed for the first time that the transition of mesocrystalline anatase to the rutile phase occurs between 1000 °C and 1200 °C, which is more than 400 °C higher than the transition of bulk TiO₂ due to the used precursor. A small quantity of K-phase nanowhiskers, which issued after 800 °C in the composite based on TiO₂, stimulated a fourfold increase in photocatalytic performance. This study offers a new approach to the construction and preparation of effective nanocrystalline photocatalyst.

This work reports the effect of tin (Sn) doping on the infrared (IR) and terahertz (THz) properties of vanadium dioxide (VO${}_2$) films. The films were grown by hydrothermal synthesis with a post-annealing process and then fully characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and temperature-controlled electrical resistivity as well as IR and THz spectroscopy techniques. Utilizing (NH${}_4$)${}_2$SnF${}_6$ as a Sn precursor allows the preparation of homogeneous Sn-doped VO${}_2$ films. Doping of VO${}_2$ films with Sn led to an increase in the thermal hysteresis width while conserving the high modulation depth in the mid-IR regime, which would be beneficial for the applications of VO${}_2$ films in IR memory devices. A further analysis shows that Sn doping of VO${}_2$ films significantly affects the temperature-dependent THz optical properties, in particular leading to the suppression of the temperature-driven THz transmission modulation. These results indicate Sn-doped VO${}_2$ films as a promising material for the development of switchable IR/THz dichroic components.