High Photocatalytic Activity Nanomaterials Based on Titanium Dioxide

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 m(2)/g of substance). It was established that the main type of radicals in the resulting structures are N-center dot, NO center dot, 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.