Covering TiO2 nanopowders with Co 2+ , Ni 2+ , Ag + nanoparticles and determination of their practical application in ecology and green energetics by EPR method

Author: Salome Gogichaishvili
Keywords: EPR, spin-traps, nanoparticles, ecology, energetics, nanopowders, photocatalysts
Annotation:

Water pollution is one of the biggest ecological problems nowadays. Photocatalytic nanopowders are substances that, in the result of light absorption, acquire oxidizing properties, which makes them able to break up environment molecules, for instance, decomposition of water into hydrogen and oxygen, destruction of bacteria and viruses, etc. They can also be used for air purification. Currently titanium dioxide TiO2 (anatase) is believed to be the most promising substance as the basis for efficient photocatalysis for this aim. Using spin traps one could capture extremely unstable radicals producing stable capture products which EPR spectra could give unequivocal information on nature and type of captured radical. By the spin trapping method it was shown that visual light influence produces hydroxyl radicals. It is considered the mechanisms of photochemical reactions. We can determine 1) whether our sample is electron donor or not, and 2) determine its efficiency by the intensity of EPR signal.