Rutile TiO₂ with highly active facets has attracted much attention owing to its enhanced activity during the photocatalytic degradation of pollutants such as pharmaceuticals in wastewater. However, it is difficult to obtain by controlling the synthetic conditions. This paper reports a simple hydrothermal synthesis of rutile TiO₂ nanorods with highly exposed {110} facets. The obtained rutile was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and Raman spectroscopy. The main contribution to the photocatalytic activity comes from rutile nanorods with highly dominant active {110} facets, which were studied in the photodegradation of reactive cinnamic acid and more recalcitrant ibuprofen. The contribution of active species was also investigated. The present work further confirmed the hydrothermal synthesis route for controlling the preparation of highly crystalline and active rutile nanocrystals.

A highly efficient and stable photocatalyst, Ag₃PO₄, was prepared using a simple co-precipitation method at room temperature. The precursors used in this process were AgNO₃ and K₂HPO₄. The resulting Ag₃PO₄ photocatalyst forms irregularly-shaped spheres with diameters ranging from 300 to 1 μm. The shape of the Ag₃PO₄ photocatalyst slightly changes when different surfactants (PVA, PVP, PEG) are used. The powdered Ag₃PO₄ photocatalyst exhibits excellent visible light-driven photocatalytic performance. It is capable of decomposing rhodamine B (RhB) as a model pollutant in just 5 min under visible light irradiation. This performance is quite remarkable. Interestingly, Ag₃PO₄ floating composite sheets have been achieved using polystyrene (PS) and fumed silica Aerosil 200. After three cycles, the decolorization of RhB dyes remains at 87% with the 30% Ag₃PO₄@PS/Aerosil 200 sheet. This indicates that the Ag₃PO₄@PS/Aerosil 200 photocatalyst is highly reusable and stable.

We present a systematic study of the fundamental optical properties of indium selenide (InSe) single crystals over a temperature range of 17 K to 300 K. The high structural quality of the β-polytype crystals was confirmed through X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy, demonstrating excellent crystallinity and a nearly stoichiometric In:Se ratio. The temperature-dependent absorption and photoluminescence (PL) spectra are characterized by a prominent free exciton (FX) resonance. At 17 K, the photoluminescence spectrum exhibits a distinct fine-structure splitting of the Wannier–Mott exciton, yielding a triplet state at 1.333 eV and a singlet state at 1.336 eV. Additionally, a biexciton (XX) is localized at an energy of 1.322 eV as confirmed by the nonlinear dependence of intensity on excitation power density. At low temperatures, the absorption spectrum exhibits the free exciton ground state (n = 1) at 1.338 eV together with the first excited state (n = 2) at 1.350 eV. We systematically tracked and analyzed the temperature evolution of these quasiparticle energies. These findings enhance our understanding of the intrinsic many-body interactions in high-quality InSe, providing essential parameters for advancing its applications in innovative optoelectronic and quantum light-emitting devices.