Chiral nanostructures exhibiting different absorption of right- and left-handed circularly polarized light are of rapidly growing interest due to their potential applications in various fields. Here, we have studied the induction of chirality in atomically thin (0.6–1.2 nm thick) ZnSe and CdSe nanoplatelets grown by a colloidal method and coated with L-cysteine and N-acetyl-L-cysteine ligands. We conducted an analysis of the optical and chiroptical properties of atomically thin ZnSe and CdSe nanoplatelets, which was supplemented by a detailed analysis of the composition and coordination of ligands. Different signs of circular dichroism were shown for L-cysteine and N-acetyl-L-cysteine ligands, confirmed by different coordination of these ligands on the basal planes of nanoplatelets. A maximum value of the dissymmetry factor of (2–3) × 10⁻³ was found for N-acetyl-L-cysteine ligand in the case of the thinnest nanoplatelets.

Nanocrystalline ZnO, ZnO(Ga), and ZnO(Ga, In) samples with different indium contents were prepared by wet-chemical method and characterized in detail by ICP-MS and XRD methods. Gas sensing properties toward NO₂ were studied at 150–450 °C by DC conductance measurements. The optimal temperature for gas sensing experiments was determined. The dependence of the ZnO(Ga, In) sensor signal to NO₂ at 250 °C correlates with the change of conductivity of the samples. The introduction of indium into the system leads to an increase in the values of the sensor signal in the temperature range T < 250 °C. The investigation of the local sample conductivity by scanning spreading resistance microscopy demonstrates that, at high indium content, the sensor properties are determined by the In–Ga–Zn–O layer that forms on the ZnO surface.

Nanosized titanium dioxide (TiO₂) is currently being actively studied by the global scientific community, since it has a number of properties that are important from a practical point of view. One of these properties is a large specific surface, which makes this material promising for use in photocatalysts, sensors, solar cells, etc. In this work, we prepared photocatalysts based on TiO₂ nanotubes for converting carbon dioxide (CO₂) into energy-intensive hydrocarbon compounds. Efficient gas-phase CO₂ conversion in the prepared single-walled TiO₂ nanotube-Cu_xO composites was investigated. Parameters of defects (radicals) in composites were studied. Methanol and methane were detected during the CO₂ photoreduction process. In single-walled TiO₂ nanotubes, only Ti³⁺/oxygen vacancy defects were detected. The Cu²⁺ centers and O₂⁻ radicals were found in TiO₂ nanotube-Cu_xO composites using the EPR technique. It has been established that copper oxide nanoparticles are present in the TiO₂ nanotube-Cu_xO composites in the form of the CuO phase. A phase transformation of CuO to Cu₂O takes place during illumination, as has been shown by EPR spectroscopy. It is shown that defects accumulate photoinduced charge carriers. The mechanism of methane and methanol formation is discussed. The results obtained are completely original and show high promise for the use of TiO₂-Cu_xO nanotube composites as photocatalysts for CO₂ conversion into hydrocarbon fuel precursors.