High Photocatalytic Activity Nanomaterials Based on Titanium Dioxide

Abstract

Abstract—X-ray diffraction, optical spectroscopy, and electron paramagnetic resonance (EPR) have been used to study microspheres and nanoheterostructures based on titanium dioxide synthesized by aerosol pyrolysis and sol–gel methods. All test samples are characterized by a large specific surface area (about 100 m²/g of substance). It was established that the main type of radicals in the resulting structures are N^•, NO^•, as well as Ti³⁺, Mo⁵⁺, V⁴⁺, and W⁵⁺ centers. Microspheres and nanoheterostructures consisting of several metal oxides have high photocatalytic activity in the visible spectrum and the ability to accumulate photogenerated charge carriers. As a result, catalytic reactions in the samples continue even after illumination is turned off. A correlation was found between the rate of photocatalysis and the radical concentration in the studied structures. The results can be used to develop new-generation energy-efficient catalytic devices based on nanocrystalline titanium oxide, which operate in the visible range and do not require continuous illumination.