Magnetometry and optical spectroscopy study of the photocatalytic activity of TiO2 nanopowders coated by NiB nanoclusters using the electroless technology

T.A. Gavasheli, T.O. Gegechkori, G.I. Mamniashvili, M.M. Nadareishvili, T.I. Zedginidze, T.G. Petriashvili, A.D. Shengelaya ,D.M. Daraselia and D.L. Japaridze
Ivane javakhishvili Tbilisi State University,
Georgia

Keywords: photocatalysis, magnetometry, optical spectrometry, titanium dioxide, NiB nanoclasters

Summary:

The possibilities for changing the absorption spectra of the anatase modification of the photocatalytic TiO2 nanopowder were studied with the aim to use more efficiently the energy of UV solar radiation for photocatalysis and to involve the visible light energy absorption into this process for enhancing the efficiency of the photocatalytic reaction. For this aim TiO2 nanopowders coated by NiB nanoclasters have been prepared by original electroless deposition method. The presence of NiB nanoclasters at the surface of TiO2 grains was confirmed by measuring the temperature dependence of magnetization. It was found by optical spectroscopy method that the deposition of Ni-B clusters on the TiO2 powder increases significantly the light absorption in the UV region. It was also revealed that, after the deposition of the Ni-B nanoclusters on the TiO2 nanopowder, in the result of heat treatment in vacuum, the absorption spectra of the TiO2 nanopowder was shifted to longer wavelength, and the absorption in the visible part of light spectrum increased. From the experiments carried out, it follows that the absorption in the visible part of light can be increased as well by selecting the sizes of nanopowder particles coated with Ni-B clusters. The performed investigations showed that it is possible to enhance significantly the visible light absorption and the efficiency of the photocatalytic reaction. Acknowledgments.This work is supported by the Shota Rustaveli National Science Foundation (SRNSF) Basic research FR/41/3-250/14 grant.