Hydrogenation shrinks the colossal permittivity of Sb/Co co-doped TiO2 nanoparticles-structural and optical investigations

Abstract

Pristine and (Sb/Co)-codoped TiO2 anatase powders were synthesized by hydrothermal method and some of the samples were hydrogenated. The samples were characterized by the traditional techniques: X-rays, optical diffuse reflection spectroscopy (DRS), and ac-electrical measurements. It was observed that the (Sb/Co) codoping induces the growth of the anatase. The optical absorption investigation was clarified by the generation of an intermediate band in the bandgap of TiO2. The catalysis power of the Co2+ ions to the adsorbed H2-dissociation strongly supports the optical absorption strength. The Sb5+/Co2+ codoping could generate weak colossal permittivity, which was lowered by ∼50% with hydrogenation. Such important results was studied and explained.